Vm-dev August 2015

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37 participants
78 discussions

VM Maker: VMMaker.oscog-eem.1434.mcz
by commits＠source.squeak.org 18 Aug '15

18 Aug '15

Eliot Miranda uploaded a new version of VMMaker to project VM Maker: http://source.squeak.org/VMMaker/VMMaker.oscog-eem.1434.mcz ==================== Summary ==================== Name: VMMaker.oscog-eem.1434 Author: eem Time: 17 August 2015, 4:55:04.843 pm UUID: 34b0a129-6a56-4023-94d1-50a55188b497 Ancestors: VMMaker.oscog-eem.1433 Fix negative 64-bit shift in the 64-bit Spur interpreter. =============== Diff against VMMaker.oscog-eem.1433 =============== Item was changed: ----- Method: InterpreterPrimitives>>primitiveBitShift (in category 'arithmetic integer primitives') ----- primitiveBitShift | integerReceiver integerArgument shifted | <var: #integerReceiver type: #sqInt> integerArgument := self stackTop. (objectMemory isIntegerObject: integerArgument) ifFalse: [^self primitiveFail]. integerReceiver := self stackValue: 1. objectMemory wordSize = 4 ifTrue: [integerReceiver := self positive32BitValueOf: integerReceiver] ifFalse: [integerReceiver := self signed64BitValueOf: integerReceiver]. self successful ifTrue: [(integerArgument := objectMemory integerValueOf: integerArgument) >= 0 ifTrue: "Left shift -- must fail bits would be lost" [integerArgument <= objectMemory numSmallIntegerBits ifFalse: [^self primitiveFail]. shifted := integerReceiver << integerArgument. integerReceiver = (objectMemory wordSize = 4 ifTrue: [shifted >> integerArgument] + ifFalse: [shifted >>> integerArgument]) ifFalse: - ifFalse: [shifted >>> integerArgument]) ifFalse: [^self primitiveFail]] ifFalse: "Right shift -- OK to lose bits" [integerArgument >= objectMemory numSmallIntegerBits negated ifFalse: [^self primitiveFail]. + shifted := integerReceiver >>> (0 - integerArgument)]. - shifted := integerReceiver >> (0 - integerArgument)]. shifted := objectMemory wordSize = 4 ifTrue: [self positive32BitIntegerFor: shifted] ifFalse: [(objectMemory isIntegerValue: shifted) ifTrue: [objectMemory integerObjectOf: shifted] ifFalse: [self signed64BitIntegerFor: shifted]]. self pop: 2 thenPush: shifted]!

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Recent Cog crashes with AndreasSystemProfiler
by J. Vuletich (mail lists) 17 Aug '15

17 Aug '15

Hi Eliot, Folks, I found that recent Cog VMs crash when using AndreasSystemProfiler. I'm using Cuis https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev , but could reproduce the problem in Squeak4.6-15078 and AndreasSystemProfiler from http://ss3.gemstone.com/ss/AndreasSystemProfiler.html . I tried on Windows 7 and Linux Debian Jessie and saw similar behavior. I could try on a Mac if helpful. To reproduce the problem, evaluate this, several times. Usually crashes after 4 or 5 tries: AndreasSystemProfiler spyOn:[10000 timesRepeat: [3.14159 printString]] This does _not_ crash in coglinux-15.22.3370 or cogwin-15.22.3370 (from June 4th). With this VM I can evaluate the expression over 40 times and never saw a crash. It does crash on the newer release: cogwin-15.24.3386 and coglinux-15.24.3386. It also crashes on the very latest cogwin-15.28.3410 and coglinux-15.28.3410. I tried on one machine with Win7 and Linux and on another PC with Win7. Results were consistent. All the crash dumps are at https://www.dropbox.com/sh/juewbluobhciejh/AABjvOKULw9mZNvlVg3t8Dyga?dl=0 .. The Linux crash files include these lines at the end: stack page bytes 4096 available headroom 2788 minimum unused headroom 3004 (Segmentation fault) The Windows crash files include a "Stack backtrace" and a "Smalltalk stack dump". Thanks in advance for your help. Regards, Juan Vuletich

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VM Maker: VMMaker.oscog-eem.1433.mcz
by commits＠source.squeak.org 15 Aug '15

15 Aug '15

Eliot Miranda uploaded a new version of VMMaker to project VM Maker: http://source.squeak.org/VMMaker/VMMaker.oscog-eem.1433.mcz ==================== Summary ==================== Name: VMMaker.oscog-eem.1433 Author: eem Time: 15 August 2015, 1:19:34.476 am UUID: 9ad71bda-65b6-4a4b-a0a1-97c45ec115cd Ancestors: VMMaker.oscog-eem.1432 Good to know the max number of live pages on map as well and this makeds for cleaner counting code. =============== Diff against VMMaker.oscog-eem.1432 =============== Item was changed: ----- Method: CoInterpreter>>mapStackPages (in category 'object memory support') ----- mapStackPages <inline: #never> <var: #thePage type: #'StackPage *'> <var: #theSP type: #'char *'> <var: #theFP type: #'char *'> <var: #frameRcvrOffset type: #'char *'> <var: #callerFP type: #'char *'> <var: #theIPPtr type: #'char *'> + | numLivePages | + numLivePages := 0. - stackPages countStackPagesMap. 0 to: numStackPages - 1 do: [:i| | thePage theSP theFP frameRcvrOffset callerFP theIPPtr theIP oop | thePage := stackPages stackPageAt: i. thePage isFree ifFalse: [self assert: (self ifCurrentStackPageHasValidHeadPointers: thePage). + numLivePages := numLivePages + 1. - stackPages countLivePageWhenMapping. theSP := thePage headSP. theFP := thePage headFP. "Skip the instruction pointer on top of stack of inactive pages." thePage = stackPage ifTrue: [theIPPtr := ((self isMachineCodeFrame: theFP) or: [(self iframeSavedIP: theFP) = 0]) ifTrue: [0] ifFalse: [theFP + FoxIFSavedIP]] ifFalse: [theIPPtr := theSP. theSP := theSP + objectMemory wordSize]. [self assert: (thePage addressIsInPage: theFP). self assert: (thePage addressIsInPage: theSP). self assert: (theIPPtr = 0 or: [thePage addressIsInPage: theIPPtr]). frameRcvrOffset := self frameReceiverLocation: theFP. [theSP <= frameRcvrOffset] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. theSP := theSP + objectMemory wordSize]. (self frameHasContext: theFP) ifTrue: [(objectMemory shouldRemapObj: (self frameContext: theFP)) ifTrue: [stackPages longAt: theFP + FoxThisContext put: (objectMemory remapObj: (self frameContext: theFP))]. "forwarding scheme in SqueakV3 obj rep makes this hard to check." objectMemory hasSpurMemoryManagerAPI ifTrue: [self assert: ((self isMarriedOrWidowedContext: (self frameContext: theFP)) and: [(self frameOfMarriedContext: (self frameContext: theFP)) = theFP])]]. (self isMachineCodeFrame: theFP) ifFalse: [(objectMemory shouldRemapObj: (self iframeMethod: theFP)) ifTrue: [theIPPtr ~= 0 ifTrue: [theIP := stackPages longAt: theIPPtr. theIP = cogit ceReturnToInterpreterPC ifTrue: [self assert: (self iframeSavedIP: theFP) > (self iframeMethod: theFP). theIPPtr := theFP + FoxIFSavedIP. theIP := stackPages longAt: theIPPtr] ifFalse: [self assert: theIP > (self iframeMethod: theFP)]. theIP := theIP - (self iframeMethod: theFP)]. stackPages longAt: theFP + FoxMethod put: (objectMemory remapObj: (self iframeMethod: theFP)). theIPPtr ~= 0 ifTrue: [stackPages longAt: theIPPtr put: theIP + (self iframeMethod: theFP)]]]. (callerFP := self frameCallerFP: theFP) ~= 0] whileTrue: [theSP := (theIPPtr := theFP + FoxCallerSavedIP) + objectMemory wordSize. theFP := callerFP]. theSP := theFP + FoxCallerSavedIP + objectMemory wordSize. [theSP <= thePage baseAddress] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. + theSP := theSP + objectMemory wordSize]]]. + stackPages recordLivePagesOnMapping: numLivePages! - theSP := theSP + objectMemory wordSize]]]! Item was changed: CogClass subclass: #CogStackPages + instanceVariableNames: 'coInterpreter objectMemory pages mostRecentlyUsedPage overflowLimit bytesPerPage statNumMaps statPageCountWhenMappingSum statMaxPageCountWhenMapping' - instanceVariableNames: 'coInterpreter objectMemory pages mostRecentlyUsedPage overflowLimit bytesPerPage statNumMaps statPageCountWhenMappingSum' classVariableNames: '' poolDictionaries: 'VMBasicConstants' category: 'VMMaker-Interpreter'! !CogStackPages commentStamp: 'eem 8/14/2015 16:43' prior: 0! I am a class that helps organize the StackInterpreter's collection of stack pages. I hold the set of stack pages represented by InterpreterStackPage instances/StackPage structs. The pages are held in a doubly-linked list that notionally has two heads: mostRecentlyUsedPage-->used page<->used page<->used page<->used page<--leastRecentlyUsedPage ^ <-next-prev-> ^ | | v <-prev-next-> v free page<->free page<->free page<->free page In fact we don't need the least-recently-used page, and so it is only present conceptually. The point is that there is a possibly empty but contiguous sequence of free pages starting at mostRecentlyUsedPage nextPage. New pages are allocated preferentially from the free page next to the MRUP. If there are no free pages then (effectively) the LRUP's frames are flushed to contexts and it is used instead. I have two concrete classes, one for the StackInterpreter and one for the CoInterpreter. Instance Variables bytesPerPage: <Integer> coInterpreter: <StackInterpreter> mostRecentlyUsedPage: <CogStackPage> objectMemory: <ObjectMemory|SpurMemoryManager> overflowLimit: <Integer> pages: <Array of: CogStackPage> statNumMaps: <Integer> statPageCountWhenMappingSum: <Integer> bytesPerPage - the size of a page in bytes coInterpreter - the interpreter the receiver is holding pages for mostRecentlyUsedPage - the most recently used stack page objectMemory - the objectMemory of the interpreter overflowLimit - the length in bytes of the portion of teh stack that can be used for frames before the page is judged to have overflowed pages - the collection of stack pages the receiver is managing statNumMaps - the number of mapStackPages calls statPageCountWhenMappingSum: - the sum of the number of in use pages at each mapStackPages, used to estimate the average number of in use pages at scavenge, which heavily influences scavenger performance ! Item was removed: - ----- Method: CogStackPages>>countLivePageWhenMapping (in category 'accessing') ----- - countLivePageWhenMapping - <inline: true> - statPageCountWhenMappingSum := statPageCountWhenMappingSum + 1! Item was removed: - ----- Method: CogStackPages>>countStackPagesMap (in category 'accessing') ----- - countStackPagesMap - <inline: true> - statNumMaps := statNumMaps + 1! Item was changed: ----- Method: CogStackPages>>initialize (in category 'initialization') ----- initialize "Here we can initialize the variables C initializes to zero. #initialize methods do /not/ get translated." + statNumMaps := statPageCountWhenMappingSum := statMaxPageCountWhenMapping := 0! - statNumMaps := statPageCountWhenMappingSum := 0! Item was added: + ----- Method: CogStackPages>>recordLivePagesOnMapping: (in category 'statistics') ----- + recordLivePagesOnMapping: numLivePages + <inline: true> + statNumMaps := statNumMaps + 1. + statPageCountWhenMappingSum := statPageCountWhenMappingSum + numLivePages. + statMaxPageCountWhenMapping := statMaxPageCountWhenMapping max: numLivePages! Item was added: + ----- Method: CogStackPages>>statMaxPageCountWhenMapping (in category 'statistics') ----- + statMaxPageCountWhenMapping + <cmacro: '() GIV(statMaxPageCountWhenMapping)'> + ^statMaxPageCountWhenMapping! Item was changed: ----- Method: StackInterpreter>>mapStackPages (in category 'object memory support') ----- mapStackPages <inline: #never> <var: #thePage type: #'StackPage *'> <var: #theSP type: #'char *'> <var: #theFP type: #'char *'> <var: #callerFP type: #'char *'> <var: #theIPPtr type: #'char *'> + | numLivePages | + numLivePages := 0. - stackPages countStackPagesMap. 0 to: numStackPages - 1 do: [:i| | thePage theSP theFP callerFP theIPPtr theIP oop | thePage := stackPages stackPageAt: i. thePage isFree ifFalse: [self assert: (self ifCurrentStackPageHasValidHeadPointers: thePage). + numLivePages := numLivePages + 1. - stackPages countLivePageWhenMapping. theSP := thePage headSP. theFP := thePage headFP. "Skip the instruction pointer on top of stack of inactive pages." thePage = stackPage ifTrue: [theIPPtr := 0] ifFalse: [theIPPtr := theSP. theSP := theSP + objectMemory wordSize]. [self assert: (thePage addressIsInPage: theFP). self assert: (thePage addressIsInPage: theSP). self assert: (theIPPtr = 0 or: [thePage addressIsInPage: theIPPtr]). [theSP <= (theFP + FoxReceiver)] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. theSP := theSP + objectMemory wordSize]. (self frameHasContext: theFP) ifTrue: [(objectMemory shouldRemapObj: (self frameContext: theFP)) ifTrue: [stackPages longAt: theFP + FoxThisContext put: (objectMemory remapObj: (self frameContext: theFP))]. "With SqueakV3 objectMemory can't assert since object body is yet to move." objectMemory hasSpurMemoryManagerAPI ifTrue: [self assert: ((self isMarriedOrWidowedContext: (self frameContext: theFP)) and: [(self frameOfMarriedContext: (self frameContext: theFP)) = theFP])]]. (objectMemory shouldRemapObj: (self frameMethod: theFP)) ifTrue: [theIPPtr ~= 0 ifTrue: [self assert: (stackPages longAt: theIPPtr) > (self frameMethod: theFP). theIP := (stackPages longAt: theIPPtr) - (self frameMethod: theFP)]. stackPages longAt: theFP + FoxMethod put: (objectMemory remapObj: (self frameMethod: theFP)). theIPPtr ~= 0 ifTrue: [stackPages longAt: theIPPtr put: theIP + (self frameMethod: theFP)]]. (callerFP := self frameCallerFP: theFP) ~= 0] whileTrue: [theSP := (theIPPtr := theFP + FoxCallerSavedIP) + objectMemory wordSize. theFP := callerFP]. theSP := theFP + FoxCallerContext. "a.k.a. FoxCallerSavedIP" [theSP <= thePage baseAddress] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. + theSP := theSP + objectMemory wordSize]]]. + stackPages recordLivePagesOnMapping: numLivePages! - theSP := theSP + objectMemory wordSize]]]! Item was changed: ----- Method: StackInterpreterPrimitives>>primitiveVMParameter (in category 'system control primitives') ----- (excessive size, no diff calculated)

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A stab at explaining Spur
by Chris Cunnington 15 Aug '15

15 Aug '15

On 12/08/15 05:23, Chris Muller wrote: > [1] -- A Partial Read Barrier for Efficient Support of Live > Object-oriented Programming > http://conf.researchr.org/event/ismm-2015/ismm-2015-papers-a-partial-read-b… <http://conf.researchr.org/event/ismm-2015/ismm-2015-papers-a-partial-read-b…> >For the paywall-free version: >https://hal.inria.fr/hal-01152610 <https://hal.inria.fr/hal-01152610> >Stephan I’m going to take a stab at explaining what I just read (as far as I read it). You’re an instance of Rectangle. You have an ivar with a Point in it. The point has ivars x and y. This great because you can get the values of the instance of Point’s x and y when you need to. Funny thing, though, Point was just recompiled to add methods or change ivars. Now all the instances, including yours, are junk. Not to worry, the system has a plan and two tools to deal with it: two primitives fronted by #allInstances and #become:. The system will find all the instances of Point with #allInstances. It will then find each and apply #become: to switch the old version with the new. In Rectangle we get a new number in our ivar slot for the Point instance. And things are caught up. But how does that actually work? The #become: part? I think that’s the story of three approaches to the problem with the last one being Spur. The first way is the way used by Cincom’s VisualWorks now. It’s a two step process. To get from Rectangle to the value of x in an instance of Point we need to make two object pointer calls. The first goes to the head object of the class Point. A second goes from there to the “body” which is a basket of slots, which in our case includes x an y. The beauty of this is that it gives #become: a focal point. a become: b at the location of the header object and you’ve neatly swapped the address from Rectangle’s ivar to where the x and y values are. There’s a problem. There’s trouble in paradise. We are not happy. It could be faster. We don’t want two steps. We don’t want a bridge between Rectangle and the “body” of values with the header object as the cornerstone. We want one step, not two. That’s faster. To do that, the first thing we do is fuse the header object with the “body”. They are no longer in separate places. One word for the header and the next word is slot 1, which is for us x. The next word will have y. The system is faster, but we have a problem. Where are all those references we need to renumber? We no longer have a neat nexus in the header object that #become: can use. No problem, we’ll sweep all of memory (aka “the heap”) to find them again. We’re getting such a boost from one step instead of two that we can afford to brute force the problem with a sweep. And we’re happy. For a while. And then we’re not. This does not scale. We find that the larger the memory gets, then the closer we get to where sweeping the heap becomes more expensive than the gains we’re getting. There’s a plateau point, a location on the graph beyond which the memory sweep is so costly it’s eating our gains. What to do? We want the speed of the one-step process, but we want it to scale. We create a solution called Spur. The salient passage here in the paper is: "This paper describes the design and implementation of efficient schema migration using direct pointers [That’s the “one step” business I’ve been talking about above], which consists mainly in hiding the cost of checking for forwarding pointers behind other checking operations that the system performs as part of its normal processing.” Did you get that part? Let’s repeat it: "hiding the cost of checking for forwarding pointers behind other checking operations that the system performs as part of its normal processing.” Normal processing. We want to be prepared. We want to do as much as we can in anticipation of the requirement that slows things down when the memory gets big. Anticipate. Do as much as you can beforehand. A little vague? OK, I’ll try again. Read this: "Become is therefore implemented lazily; copies of the pair of objects are created, and each original is forwarded to the matching copy; the forwarding pointer is followed when the object is encountered.” I don’t understand all of that, but I did catch “lazily”. In the first of our three systems, the system is preparing all possible avenues. In Spur, I think, it is only opening avenues that need to be opened when they need to be opened. They are being opened “lazily.” There seems to me a commonality to Spur, Cog and Sista. Don’t set the table for ten people. Wait to see how many show up. Don’t do unnecessary work. I think that’s what “lazily” means. These three also like to pay attention to what is happening over and over again and cache it for speed. One last thing. It seems to me the reason Spur and 64-bit are related has to do with fusing the header object with the “body” object. By definition that requires a new object format, does it not? That’s as far as I could make out. I’m sort of a big picture guy, so the details of “forwarding objects” and “partial read barriers” doesn’t interest me all that much. I like it more as a story of three versions with the last one being Spur. FWIW, Chris

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VM Maker: VMMaker.oscog-eem.1432.mcz
by commits＠source.squeak.org 15 Aug '15

15 Aug '15

Eliot Miranda uploaded a new version of VMMaker to project VM Maker: http://source.squeak.org/VMMaker/VMMaker.oscog-eem.1432.mcz ==================== Summary ==================== Name: VMMaker.oscog-eem.1432 Author: eem Time: 14 August 2015, 6:49:05.319 pm UUID: 926b6e9a-689f-411b-8b70-baa322cf73e7 Ancestors: VMMaker.oscog-tfel.1431 Finally erge and refactor [Co]InterpreterStackPages into these plus a common superclass CogStackPages. rename InterpreterStackPage to CogStackPage. Add stats to compute the average number of live pages at map. Move newStackPage into CogStackPages cuz that's where freeStackPage: is. Make marshallAbsentReceiverSendArguments: use wordSize instead of BytesperWord. =============== Diff against VMMaker.oscog-tfel.1431 =============== Item was removed: - ----- Method: CCodeGenerator>>structClasses: (in category 'accessing') ----- - structClasses: classes - structClasses := classes. - structClasses do: - [:structClass| self addStructClass: structClass]! Item was changed: ----- Method: CoInterpreter>>baseFrameReturn (in category 'return bytecodes') ----- baseFrameReturn "Return from a baseFrame (the bottom frame in a stackPage). The context to return to (which may be married) is stored in the first word of the stack." <inline: true> | contextToReturnTo retToContext theFP theSP thePage newPage frameAbove | <var: #theFP type: #'char *'> <var: #theSP type: #'char *'> <var: #thePage type: #'StackPage *'> <var: #newPage type: #'StackPage *'> <var: #frameAbove type: #'char *'> contextToReturnTo := self frameCallerContext: localFP. "The stack page is effectively free now, so free it. We must free it to be correct in determining if contextToReturnTo is still married, and in case makeBaseFrameFor: cogs a method, which may cause a code compaction, in which case the frame must be free to avoid the relocation machinery tracing the dead frame. Since freeing now temporarily violates the page-list ordering invariant, use the assert-free version." stackPages freeStackPageNoAssert: stackPage. retToContext := objectMemory isContext: contextToReturnTo. (retToContext and: [self isStillMarriedContext: contextToReturnTo]) ifTrue: [theFP := self frameOfMarriedContext: contextToReturnTo. thePage := stackPages stackPageFor: theFP. theFP = thePage headFP ifTrue: [theSP := thePage headSP] ifFalse: ["Returning to some interior frame, presumably because of a sender assignment. Move the frames above to another page (they may be in use, e.g. via coroutining). Make the interior frame the top frame." frameAbove := self findFrameAbove: theFP inPage: thePage. "Since we've just deallocated a page we know that newStackPage won't deallocate an existing one." + newPage := stackPages newStackPage. - newPage := self newStackPage. self assert: newPage = stackPage. self moveFramesIn: thePage through: frameAbove toPage: newPage. stackPages markStackPageMostRecentlyUsed: newPage. theFP := thePage headFP. theSP := thePage headSP]] ifFalse: [(retToContext and: [objectMemory isIntegerObject: (objectMemory fetchPointer: InstructionPointerIndex ofObject: contextToReturnTo)]) ifFalse: [| contextToReturnFrom | contextToReturnFrom := stackPages longAt: stackPage baseAddress - objectMemory wordSize. self tearDownAndRebuildFrameForCannotReturnBaseFrameReturnFrom: contextToReturnFrom to: contextToReturnTo returnValue: localReturnValue. ^self externalCannotReturn: localReturnValue from: contextToReturnFrom]. "We must void the instructionPointer to stop it being updated if makeBaseFrameFor: cogs a method, which may cause a code compaction." instructionPointer := 0. thePage := self makeBaseFrameFor: contextToReturnTo. theFP := thePage headFP. theSP := thePage headSP]. self setStackPageAndLimit: thePage. self assert: (stackPages stackPageFor: theFP) = stackPage. localSP := theSP. localFP := theFP. localIP := self pointerForOop: self internalStackTop. localIP asUnsignedInteger < objectMemory startOfMemory ifTrue: [localIP asUnsignedInteger ~= cogit ceReturnToInterpreterPC ifTrue: ["localIP in the cog method zone indicates a return to machine code." ^self returnToMachineCodeFrame]. localIP := self pointerForOop: (self iframeSavedIP: localFP)]. self assert: (self checkIsStillMarriedContext: contextToReturnTo currentFP: localFP). self setMethod: (self iframeMethod: localFP). self internalStackTopPut: localReturnValue. ^self fetchNextBytecode! Item was changed: ----- Method: CoInterpreter>>ceBaseFrameReturn: (in category 'trampolines') ----- ceBaseFrameReturn: returnValue "Return across a page boundary. The context to return to (which may be married) is stored in the first word of the stack. We get here when a return instruction jumps to the ceBaseFrameReturn: address that is the return pc for base frames. A consequence of this is that the current frame is no longer valid since an interrupt may have overwritten its state as soon as the stack pointer has been cut-back beyond the return pc. So to have a context to send the cannotReturn: message to we also store the base frame's context in the second word of the stack page." <api> | contextToReturnTo contextToReturnFrom isAContext thePage newPage frameAbove | <var: #thePage type: #'StackPage *'> <var: #newPage type: #'StackPage *'> <var: #frameAbove type: #'char *'> self assert: (stackPages stackPageFor: stackPointer) = stackPage. self assert: stackPages mostRecentlyUsedPage = stackPage. cogit assertCStackWellAligned. self assert: framePointer = 0. self assert: stackPointer <= (stackPage baseAddress - objectMemory wordSize). self assert: stackPage baseFP + (2 * objectMemory wordSize) < stackPage baseAddress. "We would like to use the following assert but we can't since the stack pointer will be above the base frame pointer in the base frame return and hence the 0 a base frame pointer points at could be overwritten which will cause the isBaseFrame assert in frameCallerContext: to fail." "self assert: (self frameCallerContext: stackPage baseFP) = (stackPages longAt: stackPage baseAddress)." self assert: ((objectMemory addressCouldBeObj: (stackPages longAt: stackPage baseAddress - objectMemory wordSize)) and: [objectMemory isContext: (stackPages longAt: stackPage baseAddress - objectMemory wordSize)]). self assert: ((objectMemory addressCouldBeObj: (stackPages longAt: stackPage baseAddress)) and: [objectMemory isContext: (stackPages longAt: stackPage baseAddress)]). contextToReturnTo := stackPages longAt: stackPage baseAddress. "The stack page is effectively free now, so free it. We must free it to be correct in determining if contextToReturnTo is still married, and in case makeBaseFrameFor: cogs a method, which may cause a code compaction, in which case the frame must be free to avoid the relocation machinery tracing the dead frame. Since freeing now temporarily violates the page-list ordering invariant, use the assert-free version." stackPages freeStackPageNoAssert: stackPage. isAContext := objectMemory isContext: contextToReturnTo. (isAContext and: [self isStillMarriedContext: contextToReturnTo]) ifTrue: [framePointer := self frameOfMarriedContext: contextToReturnTo. thePage := stackPages stackPageFor: framePointer. framePointer = thePage headFP ifTrue: [stackPointer := thePage headSP] ifFalse: ["Returning to some interior frame, presumably because of a sender assignment. Move the frames above to another page (they may be in use, e.g. via coroutining). Make the interior frame the top frame." frameAbove := self findFrameAbove: framePointer inPage: thePage. "Since we've just deallocated a page we know that newStackPage won't deallocate an existing one." + newPage := stackPages newStackPage. - newPage := self newStackPage. self assert: newPage = stackPage. self moveFramesIn: thePage through: frameAbove toPage: newPage. stackPages markStackPageMostRecentlyUsed: newPage. framePointer := thePage headFP. stackPointer := thePage headSP]] ifFalse: [(isAContext and: [objectMemory isIntegerObject: (objectMemory fetchPointer: InstructionPointerIndex ofObject: contextToReturnTo)]) ifFalse: [contextToReturnFrom := stackPages longAt: stackPage baseAddress - objectMemory wordSize. self tearDownAndRebuildFrameForCannotReturnBaseFrameReturnFrom: contextToReturnFrom to: contextToReturnTo returnValue: returnValue. ^self externalCannotReturn: returnValue from: contextToReturnFrom]. "void the instructionPointer to stop it being incorrectly updated in a code compaction in makeBaseFrameFor:." instructionPointer := 0. thePage := self makeBaseFrameFor: contextToReturnTo. framePointer := thePage headFP. stackPointer := thePage headSP]. self setStackPageAndLimit: thePage. self assert: (stackPages stackPageFor: framePointer) = stackPage. (self isMachineCodeFrame: framePointer) ifTrue: [self push: returnValue. cogit ceEnterCogCodePopReceiverReg. "NOTREACHED"]. instructionPointer := self stackTop. instructionPointer = cogit ceReturnToInterpreterPC ifTrue: [instructionPointer := self iframeSavedIP: framePointer]. self setMethod: (self iframeMethod: framePointer). self stackTopPut: returnValue. "a.k.a. pop saved ip then push result" self assert: (self checkIsStillMarriedContext: contextToReturnTo currentFP: framePointer). self siglong: reenterInterpreter jmp: ReturnToInterpreter. "NOTREACHED" ^nil! Item was changed: ----- Method: CoInterpreter>>makeBaseFrameFor: (in category 'frame access') ----- makeBaseFrameFor: aContext "<Integer>" "Marry aContext with the base frame of a new stack page. Build the base frame to reflect the context's state. Answer the new page. Override to hold the caller context in a different place, In the StackInterpreter we use the caller saved ip, but in the Cog VM caller saved ip is the ceBaseReturn: trampoline. Simply hold the caller context in the first word of the stack." <returnTypeC: #'StackPage *'> | page pointer theMethod theIP numArgs stackPtrIndex maybeClosure rcvr | <inline: false> <var: #page type: #'StackPage *'> <var: #pointer type: #'char *'> <var: #cogMethod type: #'CogMethod *'> "theIP must be typed as signed because it is assigned ceCannotResumePC and so maybe implicitly typed as unsigned." <var: #theIP type: #sqInt> self assert: (objectMemory isContext: aContext). self assert: (self isSingleContext: aContext). self assert: (objectMemory goodContextSize: aContext). theIP := objectMemory fetchPointer: InstructionPointerIndex ofObject: aContext. self assert: HasBeenReturnedFromMCPC signedIntFromLong < 0. theIP := (objectMemory isIntegerObject: theIP) ifTrue: [objectMemory integerValueOf: theIP] ifFalse: [HasBeenReturnedFromMCPC]. theMethod := objectMemory followObjField: MethodIndex ofObject: aContext. + page := stackPages newStackPage. - page := self newStackPage. "first word on stack is caller context of base frame" stackPages longAt: (pointer := page baseAddress) put: (objectMemory followObjField: SenderIndex ofObject: aContext). "second word is the context itself; needed for cannotReturn processing; see ceBaseReturn:." stackPages longAt: (pointer := pointer - objectMemory wordSize) put: aContext. rcvr := objectMemory followField: ReceiverIndex ofObject: aContext. "If the frame is a closure activation then the closure should be on the stack in the pushed receiver position (closures receiver the value[:value:] messages). Otherwise it should be the receiver proper." maybeClosure := objectMemory fetchPointer: ClosureIndex ofObject: aContext. maybeClosure ~= objectMemory nilObject ifTrue: [(objectMemory isForwarded: maybeClosure) ifTrue: [maybeClosure := objectMemory fixFollowedField: ClosureIndex ofObject: aContext withInitialValue: maybeClosure]. numArgs := self argumentCountOfClosure: maybeClosure. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: maybeClosure] ifFalse: [| header | header := objectMemory methodHeaderOf: theMethod. numArgs := self argumentCountOfMethodHeader: header. "If this is a synthetic context its IP could be pointing at the CallPrimitive opcode. If so, skip it." (theIP signedIntFromLong > 0 and: [(self methodHeaderHasPrimitive: header) and: [theIP = (1 + (objectMemory lastPointerOfMethodHeader: header))]]) ifTrue: [theIP := theIP + (self sizeOfCallPrimitiveBytecode: header)]. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: rcvr]. "Put the arguments on the stack" 1 to: numArgs do: [:i| stackPages longAt: (pointer := pointer - objectMemory wordSize) put: (objectMemory fetchPointer: ReceiverIndex + i ofObject: aContext)]. "saved caller ip is base return trampoline" stackPages longAt: (pointer := pointer - objectMemory wordSize) put: cogit ceBaseFrameReturnPC. "base frame's saved fp is null" stackPages longAt: (pointer := pointer - objectMemory wordSize) put: 0. "N.B. Don't set the baseFP, which marks the page as in use, until after ensureMethodIsCogged: and/or instructionPointer:forContext:frame:. These can cause a compiled code compaction which, if marked as in use, will examine this partially initialized page and crash." page headFP: pointer. "Create either a machine code frame or an interpreter frame based on the pc. If the pc is -ve it is a machine code pc and so we produce a machine code frame. If +ve an interpreter frame. N.B. Do *not* change this to try and map from a bytecode pc to a machine code frame under any circumstances. See ensureContextIsExecutionSafeAfterAssignToStackPointer:" theIP signedIntFromLong < 0 ifTrue: [| cogMethod | "Since we would have to generate a machine-code method to be able to map the native pc anyway we should create a native method and native frame." cogMethod := self ensureMethodIsCogged: theMethod. theMethod := cogMethod asInteger. maybeClosure ~= objectMemory nilObject ifTrue: ["If the pc is the special HasBeenReturnedFromMCPC pc set the pc appropriately so that the frame stays in the cannotReturn: state." theIP = HasBeenReturnedFromMCPC signedIntFromLong ifTrue: [theMethod := (cogit findMethodForStartBcpc: (self startPCOfClosure: maybeClosure) inHomeMethod: (self cCoerceSimple: theMethod to: #'CogMethod *')) asInteger. theMethod = 0 ifTrue: [self error: 'cannot find machine code block matching closure''s startpc']. theIP := cogit ceCannotResumePC] ifFalse: [self assert: (theIP signedBitShift: -16) < -1. "See contextInstructionPointer:frame:" theMethod := theMethod - ((theIP signedBitShift: -16) * cogit blockAlignment). theIP := theMethod - theIP signedIntFromShort]. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: theMethod + MFMethodFlagHasContextFlag + MFMethodFlagIsBlockFlag] ifFalse: [self assert: (theIP signedBitShift: -16) >= -1. "If the pc is the special HasBeenReturnedFromMCPC pc set the pc appropriately so that the frame stays in the cannotReturn: state." theIP := theIP = HasBeenReturnedFromMCPC signedIntFromLong ifTrue: [cogit ceCannotResumePC] ifFalse: [theMethod asInteger - theIP]. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: theMethod + MFMethodFlagHasContextFlag]. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: aContext] ifFalse: [stackPages longAt: (pointer := pointer - objectMemory wordSize) put: theMethod. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: aContext. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: (self encodeFrameFieldHasContext: true isBlock: maybeClosure ~= objectMemory nilObject numArgs: numArgs). stackPages longAt: (pointer := pointer - objectMemory wordSize) put: 0. "FoxIFSavedIP" theIP := self iframeInstructionPointerForIndex: theIP method: theMethod]. page baseFP: page headFP. self assert: (self frameHasContext: page baseFP). self assert: (self frameNumArgs: page baseFP) == numArgs. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: rcvr. stackPtrIndex := self quickFetchInteger: StackPointerIndex ofObject: aContext. self assert: ReceiverIndex + stackPtrIndex < (objectMemory lengthOf: aContext). numArgs + 1 to: stackPtrIndex do: [:i| stackPages longAt: (pointer := pointer - objectMemory wordSize) put: (objectMemory fetchPointer: ReceiverIndex + i ofObject: aContext)]. "top of stack is the instruction pointer" stackPages longAt: (pointer := pointer - objectMemory wordSize) put: theIP. page headSP: pointer. self assert: (self context: aContext hasValidInversePCMappingOf: theIP in: page baseFP). "Mark context as married by setting its sender to the frame pointer plus SmallInteger tags and the InstructionPointer to the saved fp (which ensures correct alignment w.r.t. the frame when we check for validity) plus SmallInteger tags." objectMemory storePointerUnchecked: SenderIndex ofObject: aContext withValue: (self withSmallIntegerTags: page baseFP). objectMemory storePointerUnchecked: InstructionPointerIndex ofObject: aContext withValue: (self withSmallIntegerTags: 0). self assert: (objectMemory isIntegerObject: (objectMemory fetchPointer: SenderIndex ofObject: aContext)). self assert: (self frameOfMarriedContext: aContext) = page baseFP. self assert: (self validStackPageBaseFrame: page). ^page! Item was changed: ----- Method: CoInterpreter>>mapStackPages (in category 'object memory support') ----- mapStackPages <inline: #never> <var: #thePage type: #'StackPage *'> <var: #theSP type: #'char *'> <var: #theFP type: #'char *'> <var: #frameRcvrOffset type: #'char *'> <var: #callerFP type: #'char *'> <var: #theIPPtr type: #'char *'> + stackPages countStackPagesMap. 0 to: numStackPages - 1 do: [:i| | thePage theSP theFP frameRcvrOffset callerFP theIPPtr theIP oop | thePage := stackPages stackPageAt: i. thePage isFree ifFalse: [self assert: (self ifCurrentStackPageHasValidHeadPointers: thePage). + stackPages countLivePageWhenMapping. theSP := thePage headSP. theFP := thePage headFP. "Skip the instruction pointer on top of stack of inactive pages." thePage = stackPage ifTrue: [theIPPtr := ((self isMachineCodeFrame: theFP) or: [(self iframeSavedIP: theFP) = 0]) ifTrue: [0] ifFalse: [theFP + FoxIFSavedIP]] ifFalse: [theIPPtr := theSP. theSP := theSP + objectMemory wordSize]. [self assert: (thePage addressIsInPage: theFP). self assert: (thePage addressIsInPage: theSP). self assert: (theIPPtr = 0 or: [thePage addressIsInPage: theIPPtr]). frameRcvrOffset := self frameReceiverLocation: theFP. [theSP <= frameRcvrOffset] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. theSP := theSP + objectMemory wordSize]. (self frameHasContext: theFP) ifTrue: [(objectMemory shouldRemapObj: (self frameContext: theFP)) ifTrue: [stackPages longAt: theFP + FoxThisContext put: (objectMemory remapObj: (self frameContext: theFP))]. "forwarding scheme in SqueakV3 obj rep makes this hard to check." objectMemory hasSpurMemoryManagerAPI ifTrue: [self assert: ((self isMarriedOrWidowedContext: (self frameContext: theFP)) and: [(self frameOfMarriedContext: (self frameContext: theFP)) = theFP])]]. (self isMachineCodeFrame: theFP) ifFalse: [(objectMemory shouldRemapObj: (self iframeMethod: theFP)) ifTrue: [theIPPtr ~= 0 ifTrue: [theIP := stackPages longAt: theIPPtr. theIP = cogit ceReturnToInterpreterPC ifTrue: [self assert: (self iframeSavedIP: theFP) > (self iframeMethod: theFP). theIPPtr := theFP + FoxIFSavedIP. theIP := stackPages longAt: theIPPtr] ifFalse: [self assert: theIP > (self iframeMethod: theFP)]. theIP := theIP - (self iframeMethod: theFP)]. stackPages longAt: theFP + FoxMethod put: (objectMemory remapObj: (self iframeMethod: theFP)). theIPPtr ~= 0 ifTrue: [stackPages longAt: theIPPtr put: theIP + (self iframeMethod: theFP)]]]. (callerFP := self frameCallerFP: theFP) ~= 0] whileTrue: [theSP := (theIPPtr := theFP + FoxCallerSavedIP) + objectMemory wordSize. theFP := callerFP]. theSP := theFP + FoxCallerSavedIP + objectMemory wordSize. [theSP <= thePage baseAddress] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. theSP := theSP + objectMemory wordSize]]]! Item was changed: + CogStackPages subclass: #CoInterpreterStackPages + instanceVariableNames: 'stackBasePlus1 pageMap minStackAddress maxStackAddress' - CogClass subclass: #CoInterpreterStackPages - instanceVariableNames: 'coInterpreter objectMemory stackBasePlus1 pages mostRecentlyUsedPage overflowLimit bytesPerPage pageMap minStackAddress maxStackAddress' classVariableNames: '' poolDictionaries: 'VMBasicConstants' category: 'VMMaker-JIT'! + !CoInterpreterStackPages commentStamp: 'eem 8/14/2015 16:10' prior: 0! - !CoInterpreterStackPages commentStamp: '<historical>' prior: 0! I am a class that helps organize the CoInterpreter's collection of stack pages. I hold the set of stack pages represented by CogStackPageSurrogate instances/StackPage structs. The pages are held in a doubly-linked list that notionally has two heads: mostRecentlyUsedPage-->used page<->used page<->used page<->used page<--leastRecentlyUsedPage ^ <-next-prev-> ^ | | v <-prev-next-> v free page<->free page<->free page<->free page In fact we don't need the least-recently-used page, and so it is only present conceptually. The point is that there is a possibly empty but contiguous sequence of free pages starting at mostRecentlyUsedPage nextPage. New pages are allocated preferentially from the free page next to the MRUP. + If there are no free pages then (effectively) the LRUP's frames are flushed to contexts and it is used instead. + + Instance Variables + maxStackAddress: <Integer> + minStackAddress: <Integer> + pageMap: <Dictionary> + stackBasePlus1: <Integer> + + maxStackAddress + - the maximum valid byte address in the stack zone + + minStackAddress + - the minimum valid byte address in the stack zone + + pageMap + - a map from address to the CogStackPageSurrogate for that address + + stackBasePlus1 + - the address of the 2nd byte in the stack memory, used for mapping stack addresses to page indices! - If there are no free pages then (effectively) the LRUP's frames are flushed to contexts and it is used instead.! Item was changed: ----- Method: CoInterpreterStackPages class>>declareCVarsIn: (in category 'translation') ----- declareCVarsIn: aCCodeGenerator aCCodeGenerator - var: #mostRecentlyUsedPage type: #'StackPage *'; var: #stackBasePlus1 type: #'char *'; - var: #pages type: #'StackPage *'. - aCCodeGenerator - removeVariable: 'coInterpreter'; "These are simulation/debugging things only" - removeVariable: 'objectMemory'; "These are simulation/debugging things only" removeVariable: 'pageMap'; "These are simulation/debugging things only" removeVariable: 'maxStackAddress'; "These are simulation/debugging things only" + removeVariable: 'minStackAddress' "These are simulation/debugging things only"! - removeVariable: 'minStackAddress'; "These are simulation/debugging things only" - removeMethodForSelector: #memIndexFor:! Item was removed: - ----- Method: CoInterpreterStackPages>>allPagesFree (in category 'assertions') ----- - allPagesFree - ^pages allSatisfy: [:page| page isFree]! Item was removed: - ----- Method: CoInterpreterStackPages>>byteAt: (in category 'memory access') ----- - byteAt: byteAddress "<Integer>" - self subclassResponsibility! Item was removed: - ----- Method: CoInterpreterStackPages>>extraStackBytes (in category 'initialization') ----- - extraStackBytes - "See initializeStack:numSlots:pageSize:stackLimitOffset:stackPageHeadroom: - ``Because stack pages grow down...''" - ^objectMemory wordSize! Item was removed: - ----- Method: CoInterpreterStackPages>>freeStackPage: (in category 'page access') ----- - freeStackPage: aPage "<InterpreterStackPage>" - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - <var: #aPage type: #'StackPage *'> - <inline: false> - self freeStackPageNoAssert: aPage. - self assert: self pageListIsWellFormed! Item was removed: - ----- Method: CoInterpreterStackPages>>freeStackPageNoAssert: (in category 'page access') ----- - freeStackPageNoAssert: aPage "<InterpreterStackPage>" - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - <var: #aPage type: #'StackPage *'> - <returnTypeC: #void> - | prev | - <var: #prev type: #'StackPage *'> - aPage baseFP: 0. - aPage == mostRecentlyUsedPage ifTrue: - [mostRecentlyUsedPage := mostRecentlyUsedPage prevPage. - ^nil]. - (prev := aPage prevPage) isFree ifTrue: - [^nil]. - prev nextPage: aPage nextPage. - aPage nextPage prevPage: prev. - aPage nextPage: mostRecentlyUsedPage nextPage. - mostRecentlyUsedPage nextPage prevPage: aPage. - aPage prevPage: mostRecentlyUsedPage. - mostRecentlyUsedPage nextPage: aPage! Item was changed: ----- Method: CoInterpreterStackPages>>initializeStack:numSlots:pageSize: (in category 'initialization') ----- initializeStack: theStackPages numSlots: stackSlots pageSize: slotsPerPage "Initialize the stack pages. In the C VM theStackPages will be alloca'ed memory to hold the stack pages on the C stack. In the simulator they are housed in the memory between the cogMethodZone and the heap." <var: #theStackPages type: #'char *'> <returnTypeC: #void> | numPages page structStackPageSize pageStructBase count | <var: #page type: #'StackPage *'> <var: #pageStructBase type: #'char *'> self cCode: [] inSmalltalk: [self assert: objectMemory startOfMemory - coInterpreter cogCodeSize - Cogit guardPageSize - coInterpreter methodCacheSize - coInterpreter primTraceLogSize - coInterpreter rumpCStackSize = (stackSlots * objectMemory wordSize roundUpTo: objectMemory allocationUnit)]. + structStackPageSize := coInterpreter sizeof: CogStackPage. - structStackPageSize := coInterpreter sizeof: InterpreterStackPage. bytesPerPage := slotsPerPage * objectMemory wordSize. numPages := coInterpreter numStkPages. "Because stack pages grow down baseAddress is at the top of a stack page and so to avoid subtracting BytesPerWord from baseAddress and lastAddress in the init loop below we simply push the stackPage array up one word to avoid the overlap. This word is extraStackBytes." pageStructBase := theStackPages + (numPages * bytesPerPage) + objectMemory wordSize. pages := self cCode: [self cCoerceSimple: pageStructBase to: #'StackPage *'] inSmalltalk: [pageMap := Dictionary new. ((0 to: numPages - 1) collect: [:i| + CogStackPage surrogateClass new - InterpreterStackPage surrogateClass new address: pageStructBase + (i * structStackPageSize) simulator: coInterpreter zoneBase: coInterpreter stackZoneBase zoneLimit: objectMemory startOfMemory]) do: [:pageSurrogate| pageMap at: pageSurrogate address put: pageSurrogate]; yourself]. "make sure there's enough headroom" self assert: coInterpreter stackPageByteSize - coInterpreter stackLimitBytes - coInterpreter stackLimitOffset >= coInterpreter stackPageHeadroom. 0 to: numPages - 1 do: [:index| page := self stackPageAt: index. page lastAddress: theStackPages + (index * bytesPerPage); baseAddress: page lastAddress + bytesPerPage; stackLimit: page baseAddress - coInterpreter stackLimitBytes; realStackLimit: page stackLimit; baseFP: 0; nextPage: (self stackPageAt: (index = (numPages - 1) ifTrue: [0] ifFalse: [index + 1])); prevPage: (self stackPageAt: (index = 0 ifTrue: [numPages - 1] ifFalse: [index - 1]))]. "Now compute stackBasePlus1 so that the pageIndexFor: call maps all addresses from aPage baseAddress to aBase limitAddress + 1 to the same index (stacks grow down)" stackBasePlus1 := (self cCoerceSimple: theStackPages to: #'char *') + 1. self cCode: [] inSmalltalk: [minStackAddress := theStackPages. maxStackAddress := theStackPages + (numPages * bytesPerPage) + objectMemory wordSize - 1]. "The overflow limit is the amount of stack to retain when moving frames from an overflowing stack to reduce thrashing. See stackOverflowOrEvent:mayContextSwitch:" page := self stackPageAt: 0. overflowLimit := page baseAddress - page realStackLimit * 3 // 5. 0 to: numPages - 1 do: [:index| page := self stackPageAt: index. self assert: (self pageIndexFor: page baseAddress) == index. self assert: (self pageIndexFor: page baseAddress - (slotsPerPage - 1 * objectMemory wordSize)) == index. self assert: (self stackPageFor: page baseAddress) == page. self assert: (self stackPageFor: page stackLimit) == page. self cCode: [] inSmalltalk: [| memIndex | memIndex := index * slotsPerPage + 1. "this is memIndex in the block above" self assert: (self memIndexFor: (self oopForPointer: page baseAddress)) == (memIndex + slotsPerPage - 1). index < (numPages - 1) ifTrue: [self assert: (self stackPageFor: page baseAddress + objectMemory wordSize) == (self stackPageAt: index + 1)]]. coInterpreter initializePageTraceToInvalid: page]. mostRecentlyUsedPage := self stackPageAt: 0. page := mostRecentlyUsedPage. count := 0. [| theIndex | count := count + 1. theIndex := self pageIndexFor: page baseAddress. self assert: (self stackPageAt: theIndex) == page. self assert: (self pageIndexFor: page baseAddress) == theIndex. self assert: (self pageIndexFor: page stackLimit) == theIndex. self assert: (self pageIndexFor: page lastAddress + 1) == theIndex. (page := page nextPage) ~= mostRecentlyUsedPage] whileTrue. self assert: count == numPages. self assert: self pageListIsWellFormed! Item was changed: ----- Method: CoInterpreterStackPages>>initializeWithByteSize:for: (in category 'initialization') ----- initializeWithByteSize: byteSize "<Integer>" for: anInterpreter "<CoInterpreter>" "^<Array of: <Integer>" "Initialize the stackPages memory for simulation. To keep access monitoring + in one place we defer to the coInterpreter for accessing memory. Answer the + base address of th ememory." - in one place we defer to the coInterpreter for accessing memory." <doNotGenerate> coInterpreter := anInterpreter. objectMemory := coInterpreter objectMemory. ^anInterpreter stackZoneBase! Item was removed: - ----- Method: CoInterpreterStackPages>>isFree: (in category 'page access') ----- - isFree: thePage - "This is an anachronism. Previously Slang couldn't generate the method correctly - from e.g. CogStackPageSurrogate>>isFree since Slang didn't do substitution on self. - Now it does, but there are still callers of isFree: so we keep this for simulation." - <doNotGenerate> - ^thePage baseFP = 0! Item was removed: - ----- Method: CoInterpreterStackPages>>markStackPageLeastMostRecentlyUsed: (in category 'page access') ----- - markStackPageLeastMostRecentlyUsed: page "<InterpreterStackPage>" - "This method is used to move a page to the end of the used pages. - This is to keep asserts checking pageListIsWellFormed happy." - - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - - <var: #page type: #'StackPage *'> - <returnTypeC: #void> - | lastUsedPage | - <var: #lastUsedPage type: #'StackPage *'> - self assert: page = mostRecentlyUsedPage nextPage. - lastUsedPage := page nextPage. - [lastUsedPage isFree] whileTrue: - [lastUsedPage := lastUsedPage nextPage]. - lastUsedPage nextPage = page ifTrue: - [^nil]. - page prevPage nextPage: page nextPage. - page nextPage prevPage: page prevPage. - lastUsedPage prevPage nextPage: page. - page prevPage: lastUsedPage prevPage. - page nextPage: lastUsedPage. - lastUsedPage prevPage: page. - self assert: self pageListIsWellFormed! Item was removed: - ----- Method: CoInterpreterStackPages>>markStackPageMostRecentlyUsed: (in category 'page access') ----- - markStackPageMostRecentlyUsed: page "<InterpreterStackPage>" - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - <var: #page type: #'StackPage *'> - <returnTypeC: #void> - page == mostRecentlyUsedPage ifTrue: - [^nil]. - "Common case; making new page most recently used." - page prevPage == mostRecentlyUsedPage ifTrue: - [mostRecentlyUsedPage := page. - self assert: self pageListIsWellFormed. - ^nil]. - page prevPage nextPage: page nextPage. - page nextPage prevPage: page prevPage. - mostRecentlyUsedPage nextPage prevPage: page. - page prevPage: mostRecentlyUsedPage. - page nextPage: mostRecentlyUsedPage nextPage. - mostRecentlyUsedPage nextPage: page. - mostRecentlyUsedPage := page. - self assert: self pageListIsWellFormed! Item was removed: - ----- Method: CoInterpreterStackPages>>markStackPageNextMostRecentlyUsed: (in category 'page access') ----- - markStackPageNextMostRecentlyUsed: page "<InterpreterStackPage>" - "This method is used to move a page to a position in the list such that it cannot - be deallocated when a new page is allocated, without changing the most recently - used page. There must be at least 3 pages in the system. So making the page - the MRU's prevPage is sufficient to ensure it won't be deallocated." - - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - - <var: #page type: #'StackPage *'> - <returnTypeC: #void> - self assert: page ~~ mostRecentlyUsedPage. - page nextPage == mostRecentlyUsedPage ifTrue: - [^nil]. - page prevPage nextPage: page nextPage. - page nextPage prevPage: page prevPage. - mostRecentlyUsedPage prevPage nextPage: page. - page prevPage: mostRecentlyUsedPage prevPage. - page nextPage: mostRecentlyUsedPage. - mostRecentlyUsedPage prevPage: page. - self assert: self pageListIsWellFormed! Item was changed: ----- Method: CoInterpreterStackPages>>memIndexFor: (in category 'page access') ----- memIndexFor: byteAddress + "Map an address into the stack zone into a word index into the slots in the stack zone." + <doNotGenerate> ^(self oopForPointer: byteAddress) - coInterpreter stackZoneBase - 1 // objectMemory wordSize + 1! Item was removed: - ----- Method: CoInterpreterStackPages>>mostRecentlyUsedPage (in category 'page access') ----- - mostRecentlyUsedPage - <cmacro: '() GIV(mostRecentlyUsedPage)'> - <returnTypeC: #'StackPage *'> "this is to guide Slang's inliner" - ^mostRecentlyUsedPage! Item was removed: - ----- Method: CoInterpreterStackPages>>overflowLimit (in category 'page access') ----- - overflowLimit - ^overflowLimit! Item was removed: - ----- Method: CoInterpreterStackPages>>pageListIsWellFormed (in category 'assertions') ----- - pageListIsWellFormed - "Answer if the stack page list is well-formed. - MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - | ok page count limit | - <inline: false> - <var: #page type: #'StackPage *'> - ok := true. - page := mostRecentlyUsedPage nextPage. - count := 1. - limit := coInterpreter numStkPages * 2. - [page isFree - and: [page ~= mostRecentlyUsedPage - and: [count <= limit]]] whileTrue: - [(self asserta: page nextPage prevPage == page) ifFalse: - [ok := false]. - page := page nextPage. - count := count + 1]. - [page ~= mostRecentlyUsedPage - and: [count <= limit]] whileTrue: - [(self asserta: page nextPage prevPage == page) ifFalse: - [ok := false]. - (self asserta: page isFree not) - ifTrue: - [(self asserta: ((page addressIsInPage: page baseFP) - and: [page addressIsInPage: page headSP])) ifFalse: - [ok := false]] - ifFalse: - [ok := false]. - page := page nextPage. - count := count + 1]. - (self asserta: count = coInterpreter numStkPages) ifFalse: - [ok := false]. - ^ok! Item was removed: - ----- Method: CoInterpreterStackPages>>pages (in category 'accessing') ----- - pages - <doNotGenerate> - ^pages! Item was removed: - ----- Method: CoInterpreterStackPages>>setInterpreter: (in category 'initialization') ----- - setInterpreter: anInterpreter - "Initialize the stackPages memory for simulation. To keep access monitoring - in one place we defer to the coInterpreter for accessing memory." - <doNotGenerate> - coInterpreter := anInterpreter. - objectMemory := coInterpreter objectMemory! Item was removed: - ----- Method: CoInterpreterStackPages>>somePageHasHeadFrameFP: (in category 'assertions') ----- - somePageHasHeadFrameFP: theFP - ^pages anySatisfy: [:page| page headFP = theFP]! Item was removed: - ----- Method: CoInterpreterStackPages>>stackPageAt: (in category 'page access') ----- - stackPageAt: index - "Answer the page for a page index. - N.B. This is a zero-relative index." - <returnTypeC: #'StackPage *'> - ^self stackPageAt: index pages: pages! Item was removed: - ----- Method: CoInterpreterStackPages>>stackPageAt:pages: (in category 'page access') ----- - stackPageAt: index pages: thePages - "Answer the page for a page index. - N.B. This is a zero-relative index." - <cmacro: '(index,pages) ((pages) + (index))'> - <returnTypeC: #'StackPage *'> "for Slang..." - ^thePages at: index + 1! Item was removed: - ----- Method: CoInterpreterStackPages>>stackPageClass (in category 'initialization') ----- - stackPageClass - <doNotGenerate> - ^InterpreterStackPage! Item was removed: - ----- Method: CoInterpreterStackPages>>stackPageFor: (in category 'page access') ----- - stackPageFor: pointer "<Integer>" - <inline: true> - <var: #pointer type: #'void *'> - <returnTypeC: #'StackPage *'> - ^self stackPageAt: (self pageIndexFor: pointer)! Item was changed: ----- Method: CoInterpreterStackPages>>whereIsMaybeStackThing: (in category 'debug printing') ----- whereIsMaybeStackThing: anOop + "If anOop is an address within the stack zone answer a string stating that, otherwise answer nil." <returnTypeC: 'char *'> (self oop: anOop isGreaterThanOrEqualTo: (stackBasePlus1 - 1) andLessThan: (self cCode: [pages] inSmalltalk: [(self stackPageAt: 0) asUnsignedInteger])) ifTrue: [^' is in the stack zone']. ^nil! Item was added: + VMStructType subclass: #CogStackPage + instanceVariableNames: 'stackLimit headSP headFP baseFP baseAddress realStackLimit lastAddress trace nextPage prevPage' + classVariableNames: '' + poolDictionaries: 'VMBasicConstants VMBytecodeConstants' + category: 'VMMaker-Interpreter'! + + !CogStackPage commentStamp: 'eem 8/14/2015 12:06' prior: 0! + I am a class that helps organize the StackInterpreter's collection of stack pages. I represent the control block for a single stack page in the collection of stack pages represented by an InterpreterStackPages or CoInterpreterStackPages instance.! Item was added: + ----- Method: CogStackPage class>>alignedByteSize (in category 'translation') ----- + alignedByteSize + ^self surrogateClass alignedByteSize! Item was added: + ----- Method: CogStackPage class>>alignedByteSizeOf:forClient: (in category 'translation') ----- + alignedByteSizeOf: anObject forClient: aVMClass + ^self surrogateClass alignedByteSize! Item was added: + ----- Method: CogStackPage class>>instVarNamesAndTypesForTranslationDo: (in category 'translation') ----- + instVarNamesAndTypesForTranslationDo: aBinaryBlock + "enumerate aBinaryBlock with the names and C type strings for the inst vars to include in a StackPage struct." + + self allInstVarNames do: + [:ivn| + ivn ~= 'stackPagesMemory' ifTrue: + [aBinaryBlock + value: ivn + value: (ivn = 'trace' + ifTrue: [#int] + ifFalse: + [(ivn endsWith: 'Page') + ifTrue: ['struct _StackPage *'] + ifFalse: [#'char *']])]]! Item was added: + ----- Method: CogStackPage class>>structTypeName (in category 'translation') ----- + structTypeName + ^'StackPage' "Drop initial Cog or Interpreter"! Item was added: + ----- Method: CogStackPage class>>surrogateClass (in category 'simulation only') ----- + surrogateClass + ^BytesPerWord = 4 + ifTrue: [CogStackPageSurrogate32] + ifFalse: [CogStackPageSurrogate64]! Item was added: + ----- Method: CogStackPage>>address (in category 'simulation only') ----- + address + <doNotGenerate> + ^baseAddress! Item was added: + ----- Method: CogStackPage>>addressIsInPage: (in category 'testing') ----- + addressIsInPage: address + <var: #address type: #'char *'> + "For assert-checking" + ^lastAddress < address and: [address < baseAddress]! Item was added: + ----- Method: CogStackPage>>baseAddress (in category 'accessing') ----- + baseAddress + ^baseAddress! Item was added: + ----- Method: CogStackPage>>baseAddress: (in category 'accessing') ----- + baseAddress: anAddress + ^baseAddress := anAddress! Item was added: + ----- Method: CogStackPage>>baseFP (in category 'accessing') ----- + baseFP + "Answer the value of baseFP" + + ^ baseFP! Item was added: + ----- Method: CogStackPage>>baseFP: (in category 'accessing') ----- + baseFP: pointer "<Integer>" + "Set the value of baseFP" + self assert: (pointer = 0 or: [pointer < baseAddress and: [realStackLimit < pointer]]). + ^baseFP := pointer! Item was added: + ----- Method: CogStackPage>>headFP (in category 'accessing') ----- + headFP + "Answer the value of headFP" + + ^headFP! Item was added: + ----- Method: CogStackPage>>headFP: (in category 'accessing') ----- + headFP: pointer "<Integer>" + "Set the value of headFP" + ^headFP := pointer! Item was added: + ----- Method: CogStackPage>>headSP (in category 'accessing') ----- + headSP + "Answer the value of headSP" + + ^headSP! Item was added: + ----- Method: CogStackPage>>headSP: (in category 'accessing') ----- + headSP: pointer "<Integer>" + "Set the value of headSP" + ^headSP := pointer! Item was added: + ----- Method: CogStackPage>>isFree (in category 'testing') ----- + isFree + ^baseFP = 0! Item was added: + ----- Method: CogStackPage>>lastAddress (in category 'accessing') ----- + lastAddress + ^lastAddress! Item was added: + ----- Method: CogStackPage>>lastAddress: (in category 'accessing') ----- + lastAddress: anAddress + ^lastAddress := anAddress! Item was added: + ----- Method: CogStackPage>>nextPage (in category 'accessing') ----- + nextPage + "Answer the value of nextPage" + + ^ nextPage! Item was added: + ----- Method: CogStackPage>>nextPage: (in category 'accessing') ----- + nextPage: anObject + "Set the value of nextPage" + + ^nextPage := anObject! Item was added: + ----- Method: CogStackPage>>prevPage (in category 'accessing') ----- + prevPage + "Answer the value of prevPage" + + ^ prevPage! Item was added: + ----- Method: CogStackPage>>prevPage: (in category 'accessing') ----- + prevPage: anObject + "Set the value of prevPage" + + ^prevPage := anObject! Item was added: + ----- Method: CogStackPage>>printOn: (in category 'printing') ----- + printOn: aStream + <doNotGenerate> + super printOn: aStream. + aStream nextPut: $@; print: baseAddress; space. + self isFree + ifTrue: [aStream nextPutAll: 'free'] + ifFalse: [aStream print: baseFP; nextPutAll: '<->'; print: headFP; space; nextPutAll: 'trace '; print: trace]! Item was added: + ----- Method: CogStackPage>>realStackLimit (in category 'accessing') ----- + realStackLimit + "Answer the value of realStackLimit" + + ^ realStackLimit! Item was added: + ----- Method: CogStackPage>>realStackLimit: (in category 'accessing') ----- + realStackLimit: anObject + "Set the value of realStackLimit" + + ^realStackLimit := anObject! Item was added: + ----- Method: CogStackPage>>stackLimit (in category 'accessing') ----- + stackLimit + "Answer the value of stackLimit" + + ^ stackLimit! Item was added: + ----- Method: CogStackPage>>stackLimit: (in category 'accessing') ----- + stackLimit: anObject + "Set the value of stackLimit" + + ^stackLimit := anObject! Item was added: + ----- Method: CogStackPage>>trace (in category 'accessing') ----- + trace + "Answer the page's trace state. + 0 = untraced. 1 = should be traced. 2 = has been traced. + -1 = invalid (for assertions)" + ^trace! Item was added: + ----- Method: CogStackPage>>trace: (in category 'accessing') ----- + trace: anInteger + "Set the page's trace state. + 0 = untraced. 1 = should be traced. 2 = has been traced. + -1 = invalid (for assertions)" + ^trace := anInteger! Item was added: + CogClass subclass: #CogStackPages + instanceVariableNames: 'coInterpreter objectMemory pages mostRecentlyUsedPage overflowLimit bytesPerPage statNumMaps statPageCountWhenMappingSum' + classVariableNames: '' + poolDictionaries: 'VMBasicConstants' + category: 'VMMaker-Interpreter'! + + !CogStackPages commentStamp: 'eem 8/14/2015 16:43' prior: 0! + I am a class that helps organize the StackInterpreter's collection of stack pages. I hold the set of stack pages represented by InterpreterStackPage instances/StackPage structs. The pages are held in a doubly-linked list that notionally has two heads: + + mostRecentlyUsedPage-->used page<->used page<->used page<->used page<--leastRecentlyUsedPage + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page + + In fact we don't need the least-recently-used page, and so it is only present conceptually. The point is that there is a possibly empty but contiguous sequence of free pages starting at mostRecentlyUsedPage nextPage. New pages are allocated preferentially from the free page next to the MRUP. + If there are no free pages then (effectively) the LRUP's frames are flushed to contexts and it is used instead. + + I have two concrete classes, one for the StackInterpreter and one for the CoInterpreter. + + Instance Variables + bytesPerPage: <Integer> + coInterpreter: <StackInterpreter> + mostRecentlyUsedPage: <CogStackPage> + objectMemory: <ObjectMemory|SpurMemoryManager> + overflowLimit: <Integer> + pages: <Array of: CogStackPage> + statNumMaps: <Integer> + statPageCountWhenMappingSum: <Integer> + + bytesPerPage + - the size of a page in bytes + + coInterpreter + - the interpreter the receiver is holding pages for + + mostRecentlyUsedPage + - the most recently used stack page + + objectMemory + - the objectMemory of the interpreter + + overflowLimit + - the length in bytes of the portion of teh stack that can be used for frames before the page is judged to have overflowed + + pages + - the collection of stack pages the receiver is managing + + statNumMaps + - the number of mapStackPages calls + + statPageCountWhenMappingSum: + - the sum of the number of in use pages at each mapStackPages, used to estimate the average number of in use pages at scavenge, which heavily influences scavenger performance + ! Item was added: + ----- Method: CogStackPages class>>declareCVarsIn: (in category 'translation') ----- + declareCVarsIn: aCCodeGenerator + aCCodeGenerator + var: #mostRecentlyUsedPage type: #'StackPage *'; + var: #pages type: #'StackPage *'. + aCCodeGenerator + removeVariable: 'coInterpreter'; "These are simulation/debugging things only" + removeVariable: 'objectMemory' "These are simulation/debugging things only"! Item was added: + ----- Method: CogStackPages>>allPagesFree (in category 'assertions') ----- + allPagesFree + <doNotGenerate> + ^pages allSatisfy: [:page| (self isFree: page)]! Item was added: + ----- Method: CogStackPages>>byteAt: (in category 'memory access') ----- + byteAt: byteAddress "<Integer>" + self subclassResponsibility! Item was added: + ----- Method: CogStackPages>>countLivePageWhenMapping (in category 'accessing') ----- + countLivePageWhenMapping + <inline: true> + statPageCountWhenMappingSum := statPageCountWhenMappingSum + 1! Item was added: + ----- Method: CogStackPages>>countStackPagesMap (in category 'accessing') ----- + countStackPagesMap + <inline: true> + statNumMaps := statNumMaps + 1! Item was added: + ----- Method: CogStackPages>>extraStackBytes (in category 'initialization') ----- + extraStackBytes + "See initializeStack:numSlots:pageSize:stackLimitOffset:stackPageHeadroom: + ``Because stack pages grow down...''" + ^objectMemory wordSize! Item was added: + ----- Method: CogStackPages>>freeStackPage: (in category 'page access') ----- + freeStackPage: aPage "<InterpreterStackPage>" + "MRUP-->used page<->used page<->used page<->used page<--LRUP + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page" + <var: #aPage type: #'StackPage *'> + <inline: false> + self freeStackPageNoAssert: aPage. + self assert: self pageListIsWellFormed! Item was added: + ----- Method: CogStackPages>>freeStackPageNoAssert: (in category 'page access') ----- + freeStackPageNoAssert: aPage "<InterpreterStackPage>" + "MRUP-->used page<->used page<->used page<->used page<--LRUP + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page" + <var: #aPage type: #'StackPage *'> + <returnTypeC: #void> + | prev | + <var: #prev type: #'StackPage *'> + aPage baseFP: 0. + aPage == mostRecentlyUsedPage ifTrue: + [mostRecentlyUsedPage := mostRecentlyUsedPage prevPage. + ^nil]. + (prev := aPage prevPage) isFree ifTrue: + [^nil]. + prev nextPage: aPage nextPage. + aPage nextPage prevPage: prev. + aPage nextPage: mostRecentlyUsedPage nextPage. + mostRecentlyUsedPage nextPage prevPage: aPage. + aPage prevPage: mostRecentlyUsedPage. + mostRecentlyUsedPage nextPage: aPage! Item was added: + ----- Method: CogStackPages>>initialize (in category 'initialization') ----- + initialize + "Here we can initialize the variables C initializes to zero. #initialize methods do /not/ get translated." + statNumMaps := statPageCountWhenMappingSum := 0! Item was added: + ----- Method: CogStackPages>>initializeStack:numSlots:pageSize: (in category 'initialization') ----- + initializeStack: theStackPages numSlots: stackSlots pageSize: slotsPerPage + "Initialize the stack pages. In the C VM theStackPages will be alloca'ed memory to hold the + stack pages on the C stack. In the simulator they are housed in the memory between the + cogMethodZone and the heap." + <returnTypeC: #void> + self subclassResponsibility! Item was added: + ----- Method: CogStackPages>>initializeWithByteSize:for: (in category 'initialization') ----- + initializeWithByteSize: byteSize "<Integer>" for: anInterpreter "<CoInterpreter>" "^<Array of: <Integer>" + "Initialize the stackPages memory for simulation. Answer the base address of the memory." + self subclassResponsibility! Item was added: + ----- Method: CogStackPages>>isFree: (in category 'page access') ----- + isFree: thePage + "This is an anachronism. Previously Slang couldn't generate the method correctly + from e.g. CogStackPageSurrogate>>isFree since Slang didn't do substitution on self. + Now it does, but there are still callers of isFree: so we keep this for simulation." + <doNotGenerate> + ^thePage baseFP = 0! Item was added: + ----- Method: CogStackPages>>markStackPageLeastMostRecentlyUsed: (in category 'page access') ----- + markStackPageLeastMostRecentlyUsed: page "<InterpreterStackPage>" + "This method is used to move a page to the end of the used pages. + This is to keep asserts checking pageListIsWellFormed happy." + + "MRUP-->used page<->used page<->used page<->used page<--LRUP + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page" + + <var: #page type: #'StackPage *'> + <returnTypeC: #void> + | lastUsedPage | + <var: #lastUsedPage type: #'StackPage *'> + self assert: page = mostRecentlyUsedPage nextPage. + lastUsedPage := page nextPage. + [lastUsedPage isFree] whileTrue: + [lastUsedPage := lastUsedPage nextPage]. + lastUsedPage nextPage = page ifTrue: + [^nil]. + page prevPage nextPage: page nextPage. + page nextPage prevPage: page prevPage. + lastUsedPage prevPage nextPage: page. + page prevPage: lastUsedPage prevPage. + page nextPage: lastUsedPage. + lastUsedPage prevPage: page. + self assert: self pageListIsWellFormed! Item was added: + ----- Method: CogStackPages>>markStackPageMostRecentlyUsed: (in category 'page access') ----- + markStackPageMostRecentlyUsed: page "<InterpreterStackPage>" + "MRUP-->used page<->used page<->used page<->used page<--LRUP + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page" + <var: #page type: #'StackPage *'> + <returnTypeC: #void> + page == mostRecentlyUsedPage ifTrue: + [^nil]. + "Common case; making new page most recently used." + page prevPage == mostRecentlyUsedPage ifTrue: + [mostRecentlyUsedPage := page. + self assert: self pageListIsWellFormed. + ^nil]. + page prevPage nextPage: page nextPage. + page nextPage prevPage: page prevPage. + mostRecentlyUsedPage nextPage prevPage: page. + page prevPage: mostRecentlyUsedPage. + page nextPage: mostRecentlyUsedPage nextPage. + mostRecentlyUsedPage nextPage: page. + mostRecentlyUsedPage := page. + self assert: self pageListIsWellFormed! Item was added: + ----- Method: CogStackPages>>markStackPageNextMostRecentlyUsed: (in category 'page access') ----- + markStackPageNextMostRecentlyUsed: page "<InterpreterStackPage>" + "This method is used to move a page to a position in the list such that it cannot + be deallocated when a new page is allocated, without changing the most recently + used page. There must be at least 3 pages in the system. So making the page + the MRU's prevPage is sufficient to ensure it won't be deallocated." + + "MRUP-->used page<->used page<->used page<->used page<--LRUP + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page" + + <var: #page type: #'StackPage *'> + <returnTypeC: #void> + self assert: page ~~ mostRecentlyUsedPage. + page nextPage == mostRecentlyUsedPage ifTrue: + [^nil]. + page prevPage nextPage: page nextPage. + page nextPage prevPage: page prevPage. + mostRecentlyUsedPage prevPage nextPage: page. + page prevPage: mostRecentlyUsedPage prevPage. + page nextPage: mostRecentlyUsedPage. + mostRecentlyUsedPage prevPage: page. + self assert: self pageListIsWellFormed! Item was added: + ----- Method: CogStackPages>>memIndexFor: (in category 'page access') ----- + memIndexFor: byteAddress + "Map an address into the stack zone into a word index into the slots in the stack zone." + <doNotGenerate> + self subclassResponsibility! Item was added: + ----- Method: CogStackPages>>mostRecentlyUsedPage (in category 'page access') ----- + mostRecentlyUsedPage + <cmacro: '() GIV(mostRecentlyUsedPage)'> + <returnTypeC: #'StackPage *'> "this is to guide Slang's inliner" + ^mostRecentlyUsedPage! Item was added: + ----- Method: CogStackPages>>newStackPage (in category 'page access') ----- + newStackPage + "MRUP-->used page<->used page<->used page<->used page<--LRUP + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page" + <returnTypeC: #'StackPage *'> + | lruOrFree | + <var: #lruOrFree type: #'StackPage *'> + lruOrFree := mostRecentlyUsedPage nextPage. + lruOrFree isFree ifTrue: + [^lruOrFree]. + coInterpreter divorceFramesIn: lruOrFree. + ^lruOrFree! Item was added: + ----- Method: CogStackPages>>overflowLimit (in category 'page access') ----- + overflowLimit + ^overflowLimit! Item was added: + ----- Method: CogStackPages>>pageIndexFor: (in category 'page access') ----- + pageIndexFor: pointer "<Integer>" + "Answer the page index for a pointer into stack memory, i.e. the index + for the page the address is in. N.B. This is a zero-relative index." + <var: #pointer type: #'void *'> + <inline: true> + self subclassResponsibility! Item was added: + ----- Method: CogStackPages>>pageListIsWellFormed (in category 'assertions') ----- + pageListIsWellFormed + "Answer if the stack page list is well-formed. + MRUP-->used page<->used page<->used page<->used page<--LRUP + ^ <-next-prev-> ^ + | | + v <-prev-next-> v + free page<->free page<->free page<->free page" + | ok page count limit | + <inline: false> + <var: #page type: #'StackPage *'> + ok := true. + page := mostRecentlyUsedPage nextPage. + count := 1. + limit := coInterpreter numStkPages * 2. + [page isFree + and: [page ~= mostRecentlyUsedPage + and: [count <= limit]]] whileTrue: + [(self asserta: page nextPage prevPage == page) ifFalse: + [ok := false]. + page := page nextPage. + count := count + 1]. + [page ~= mostRecentlyUsedPage + and: [count <= limit]] whileTrue: + [(self asserta: page nextPage prevPage == page) ifFalse: + [ok := false]. + (self asserta: page isFree not) + ifTrue: + [(self asserta: ((page addressIsInPage: page baseFP) + and: [page addressIsInPage: page headSP])) ifFalse: + [ok := false]] + ifFalse: + [ok := false]. + page := page nextPage. + count := count + 1]. + (self asserta: count = coInterpreter numStkPages) ifFalse: + [ok := false]. + ^ok! Item was added: + ----- Method: CogStackPages>>pages (in category 'accessing') ----- + pages + <doNotGenerate> + ^pages! Item was added: + ----- Method: CogStackPages>>setInterpreter: (in category 'initialization') ----- + setInterpreter: anInterpreter + "Initialize the stackPages memory for simulation. To keep access monitoring + in one place we defer to the coInterpreter for accessing memory." + <doNotGenerate> + coInterpreter := anInterpreter. + objectMemory := coInterpreter objectMemory! Item was added: + ----- Method: CogStackPages>>somePageHasHeadFrameFP: (in category 'assertions') ----- + somePageHasHeadFrameFP: theFP + <doNotGenerate> + ^pages anySatisfy: [:page| page headFP = theFP] + ! Item was added: + ----- Method: CogStackPages>>stackPageAt: (in category 'page access') ----- + stackPageAt: index + "Answer the page for a page index. + N.B. This is a zero-relative index." + <returnTypeC: #'StackPage *'> + <inline: true> + ^self stackPageAt: index pages: pages! Item was added: + ----- Method: CogStackPages>>stackPageAt:pages: (in category 'page access') ----- + stackPageAt: index pages: thePages + "Answer the page for a page index. + N.B. This is a zero-relative index." + <cmacro: '(index,pages) ((pages) + (index))'> + <returnTypeC: #'StackPage *'> "for Slang..." + ^thePages at: index + 1! Item was added: + ----- Method: CogStackPages>>stackPageFor: (in category 'page access') ----- + stackPageFor: pointer "<Integer>" + <inline: true> + <var: #pointer type: #'void *'> + <returnTypeC: #'StackPage *'> + ^self stackPageAt: (self pageIndexFor: pointer)! Item was added: + ----- Method: CogStackPages>>statAverageLivePagesWhenMapping (in category 'statistics') ----- + statAverageLivePagesWhenMapping + <returnTypeC: #double> + ^statPageCountWhenMappingSum asFloat / statNumMaps! Item was added: + ----- Method: CogStackPages>>whereIsMaybeStackThing: (in category 'debug printing') ----- + whereIsMaybeStackThing: anOop + "If anOop is an address within the stack zone answer a string stating that, otherwise answer nil." + <returnTypeC: 'char *'> + self subclassResponsibility! Item was removed: - VMStructType subclass: #InterpreterStackPage - instanceVariableNames: 'stackLimit headSP headFP baseFP baseAddress realStackLimit lastAddress trace nextPage prevPage' - classVariableNames: '' - poolDictionaries: 'VMBasicConstants VMBytecodeConstants' - category: 'VMMaker-Interpreter'! - - !InterpreterStackPage commentStamp: '<historical>' prior: 0! - I am a class that helps organize the StackInterpreter's collection of stack pages. I represent the control block for a single stack page in the collection of stack pages represented by an InterpreterStackPages instance.! Item was removed: - ----- Method: InterpreterStackPage class>>alignedByteSize (in category 'translation') ----- - alignedByteSize - ^self surrogateClass alignedByteSize! Item was removed: - ----- Method: InterpreterStackPage class>>alignedByteSizeOf:forClient: (in category 'translation') ----- - alignedByteSizeOf: anObject forClient: aVMClass - ^self surrogateClass alignedByteSize! Item was removed: - ----- Method: InterpreterStackPage class>>instVarNamesAndTypesForTranslationDo: (in category 'translation') ----- - instVarNamesAndTypesForTranslationDo: aBinaryBlock - "enumerate aBinaryBlock with the names and C type strings for the inst vars to include in a StackPage struct." - - self allInstVarNames do: - [:ivn| - ivn ~= 'stackPagesMemory' ifTrue: - [aBinaryBlock - value: ivn - value: (ivn = 'trace' - ifTrue: [#int] - ifFalse: - [(ivn endsWith: 'Page') - ifTrue: ['struct _StackPage *'] - ifFalse: [#'char *']])]]! Item was removed: - ----- Method: InterpreterStackPage class>>structTypeName (in category 'translation') ----- - structTypeName - ^'StackPage' "Drop initial Cog or Interpreter"! Item was removed: - ----- Method: InterpreterStackPage class>>surrogateClass (in category 'simulation only') ----- - surrogateClass - ^BytesPerWord = 4 - ifTrue: [CogStackPageSurrogate32] - ifFalse: [CogStackPageSurrogate64]! Item was removed: - ----- Method: InterpreterStackPage>>address (in category 'simulation only') ----- - address - <doNotGenerate> - ^baseAddress! Item was removed: - ----- Method: InterpreterStackPage>>addressIsInPage: (in category 'testing') ----- - addressIsInPage: address - <var: #address type: #'char *'> - "For assert-checking" - ^lastAddress < address and: [address < baseAddress]! Item was removed: - ----- Method: InterpreterStackPage>>baseAddress (in category 'accessing') ----- - baseAddress - ^baseAddress! Item was removed: - ----- Method: InterpreterStackPage>>baseAddress: (in category 'accessing') ----- - baseAddress: anAddress - ^baseAddress := anAddress! Item was removed: - ----- Method: InterpreterStackPage>>baseFP (in category 'accessing') ----- - baseFP - "Answer the value of baseFP" - - ^ baseFP! Item was removed: - ----- Method: InterpreterStackPage>>baseFP: (in category 'accessing') ----- - baseFP: pointer "<Integer>" - "Set the value of baseFP" - self assert: (pointer = 0 or: [pointer < baseAddress and: [realStackLimit < pointer]]). - ^baseFP := pointer! Item was removed: - ----- Method: InterpreterStackPage>>headFP (in category 'accessing') ----- - headFP - "Answer the value of headFP" - - ^headFP! Item was removed: - ----- Method: InterpreterStackPage>>headFP: (in category 'accessing') ----- - headFP: pointer "<Integer>" - "Set the value of headFP" - ^headFP := pointer! Item was removed: - ----- Method: InterpreterStackPage>>headSP (in category 'accessing') ----- - headSP - "Answer the value of headSP" - - ^headSP! Item was removed: - ----- Method: InterpreterStackPage>>headSP: (in category 'accessing') ----- - headSP: pointer "<Integer>" - "Set the value of headSP" - ^headSP := pointer! Item was removed: - ----- Method: InterpreterStackPage>>isFree (in category 'testing') ----- - isFree - ^baseFP = 0! Item was removed: - ----- Method: InterpreterStackPage>>lastAddress (in category 'accessing') ----- - lastAddress - ^lastAddress! Item was removed: - ----- Method: InterpreterStackPage>>lastAddress: (in category 'accessing') ----- - lastAddress: anAddress - ^lastAddress := anAddress! Item was removed: - ----- Method: InterpreterStackPage>>nextPage (in category 'accessing') ----- - nextPage - "Answer the value of nextPage" - - ^ nextPage! Item was removed: - ----- Method: InterpreterStackPage>>nextPage: (in category 'accessing') ----- - nextPage: anObject - "Set the value of nextPage" - - ^nextPage := anObject! Item was removed: - ----- Method: InterpreterStackPage>>prevPage (in category 'accessing') ----- - prevPage - "Answer the value of prevPage" - - ^ prevPage! Item was removed: - ----- Method: InterpreterStackPage>>prevPage: (in category 'accessing') ----- - prevPage: anObject - "Set the value of prevPage" - - ^prevPage := anObject! Item was removed: - ----- Method: InterpreterStackPage>>printOn: (in category 'printing') ----- - printOn: aStream - <doNotGenerate> - super printOn: aStream. - aStream nextPut: $@; print: baseAddress; space. - self isFree - ifTrue: [aStream nextPutAll: 'free'] - ifFalse: [aStream print: baseFP; nextPutAll: '<->'; print: headFP; space; nextPutAll: 'trace '; print: trace]! Item was removed: - ----- Method: InterpreterStackPage>>realStackLimit (in category 'accessing') ----- - realStackLimit - "Answer the value of realStackLimit" - - ^ realStackLimit! Item was removed: - ----- Method: InterpreterStackPage>>realStackLimit: (in category 'accessing') ----- - realStackLimit: anObject - "Set the value of realStackLimit" - - ^realStackLimit := anObject! Item was removed: - ----- Method: InterpreterStackPage>>stackLimit (in category 'accessing') ----- - stackLimit - "Answer the value of stackLimit" - - ^ stackLimit! Item was removed: - ----- Method: InterpreterStackPage>>stackLimit: (in category 'accessing') ----- - stackLimit: anObject - "Set the value of stackLimit" - - ^stackLimit := anObject! Item was removed: - ----- Method: InterpreterStackPage>>trace (in category 'accessing') ----- - trace - "Answer the page's trace state. - 0 = untraced. 1 = should be traced. 2 = has been traced. - -1 = invalid (for assertions)" - ^trace! Item was removed: - ----- Method: InterpreterStackPage>>trace: (in category 'accessing') ----- - trace: anInteger - "Set the page's trace state. - 0 = untraced. 1 = should be traced. 2 = has been traced. - -1 = invalid (for assertions)" - ^trace := anInteger! Item was changed: + CogStackPages subclass: #InterpreterStackPages + instanceVariableNames: 'stackMemory indexOffset pageSizeInSlots' - VMClass subclass: #InterpreterStackPages - instanceVariableNames: 'interpreter objectMemory stackMemory indexOffset pages mostRecentlyUsedPage overflowLimit numPages pageSizeInSlots bytesPerPage' classVariableNames: '' poolDictionaries: 'VMBasicConstants' category: 'VMMaker-Interpreter'! !InterpreterStackPages commentStamp: '<historical>' prior: 0! I am a class that helps organize the StackInterpreter's collection of stack pages. I hold the set of stack pages represented by InterpreterStackPage instances/StackPage structs. The pages are held in a doubly-linked list that notionally has two heads: mostRecentlyUsedPage-->used page<->used page<->used page<->used page<--leastRecentlyUsedPage ^ <-next-prev-> ^ | | v <-prev-next-> v free page<->free page<->free page<->free page In fact we don't need the least-recently-used page, and so it is only present conceptually. The point is that there is a possibly empty but contiguous sequence of free pages starting at mostRecentlyUsedPage nextPage. New pages are allocated preferentially from the free page next to the MRUP. If there are no free pages then (effectively) the LRUP's frames are flushed to contexts and it is used instead.! Item was changed: ----- Method: InterpreterStackPages class>>declareCVarsIn: (in category 'translation') ----- declareCVarsIn: aCCodeGenerator aCCodeGenerator var: #stackMemory type: 'char *'; + removeVariable: 'indexOffset'; "These are simulation/debugging things only" + removeVariable: 'pageSizeInSlots' "These are simulation/debugging things only"! - var: #mostRecentlyUsedPage type: 'StackPage *'; - var: #pages type: 'StackPage *'. - aCCodeGenerator "These are simulation/debugging things only" - removeVariable: 'interpreter'; - removeVariable: 'indexOffset'; - removeVariable: 'pageSizeInSlots'; - removeMethodForSelector: #memIndexFor:! Item was removed: - ----- Method: InterpreterStackPages>>allPagesFree (in category 'assertions') ----- - allPagesFree - <doNotGenerate> - ^pages allSatisfy: [:page| (self isFree: page)]! Item was removed: - ----- Method: InterpreterStackPages>>byteAt: (in category 'memory access') ----- - byteAt: byteAddress "<Integer>" - self subclassResponsibility! Item was changed: ----- Method: InterpreterStackPages>>extraStackBytes (in category 'initialization') ----- extraStackBytes "See initializeStack:numSlots:pageSize:stackLimitOffset:stackPageHeadroom: ``Because stack pages grow down...''" + ^self cCode: [objectMemory wordSize] inSmalltalk: [0]! - ^self cCode: 'BytesPerWord' inSmalltalk: [0]! Item was removed: - ----- Method: InterpreterStackPages>>freeStackPage: (in category 'page access') ----- - freeStackPage: aPage "<InterpreterStackPage>" - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - <var: #aPage type: #'StackPage *'> - self freeStackPageNoAssert: aPage. - self assert: self pageListIsWellFormed! Item was removed: - ----- Method: InterpreterStackPages>>freeStackPageNoAssert: (in category 'page access') ----- - freeStackPageNoAssert: aPage "<InterpreterStackPage>" - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - | prev | - <var: #aPage type: #'StackPage *'> - <var: #prev type: #'StackPage *'> - aPage baseFP: 0. - aPage == mostRecentlyUsedPage ifTrue: - [mostRecentlyUsedPage := mostRecentlyUsedPage prevPage. - ^nil]. - "lack of type inferrence means ``self isFree: aPage prevPage'' - isn't turned into a direct field test; sigh..." - prev := aPage prevPage. - (self isFree: prev) ifTrue: - [^nil]. - prev nextPage: aPage nextPage. - aPage nextPage prevPage: prev. - aPage nextPage: mostRecentlyUsedPage nextPage. - mostRecentlyUsedPage nextPage prevPage: aPage. - aPage prevPage: mostRecentlyUsedPage. - mostRecentlyUsedPage nextPage: aPage! Item was changed: ----- Method: InterpreterStackPages>>initializeStack:numSlots:pageSize: (in category 'initialization') ----- initializeStack: theStackPages numSlots: stackSlots pageSize: slotsPerPage "Initialize the stack pages. For testing I want stack addresses to be disjoint from normal memory addresses so stack addresses are negative. The first address is -pageSize bytes. So for example if there are 1024 bytes per page and 3 pages then the pages are organized as byte address: -1024 <-> -2047 | -2048 <-> -3071 | -3072 <-> -4096 | page 3 page 2 page 1 mem index: 769 <-> 513 | 512 <-> 257 | 256 <-> 1 | The byte address is the external address corresponding to a real address in the VM. mem index is the index in the memory Array holding the stack, an index internal to the stack pages. The first stack page allocated will be the last page in the array of pages at the highest effective address. Its base address be -1024 and grow down towards -2047." "The lFoo's are to get around the foo->variable scheme in the C call to allocStackPages below." <var: #theStackPages type: #'char *'> + | numPages page structStackPageSize pageStructBase count | - | page structStackPageSize pageStructBase count | <var: #page type: #'StackPage *'> <var: #pageStructBase type: #'char *'> self cCode: '' inSmalltalk: [self assert: stackMemory size = stackSlots. self assert: stackMemory == theStackPages]. stackMemory := theStackPages. "For initialization in the C code." self cCode: '' inSmalltalk: [pageSizeInSlots := slotsPerPage]. + structStackPageSize := coInterpreter sizeof: CogStackPage. - structStackPageSize := interpreter sizeof: InterpreterStackPage. bytesPerPage := slotsPerPage * objectMemory wordSize. + numPages := coInterpreter numStkPages. - numPages := stackSlots // (slotsPerPage + (structStackPageSize / objectMemory wordSize)). "Because stack pages grow down baseAddress is at the top of a stack page and so to avoid subtracting BytesPerWord from baseAddress and lastAddress in the init loop below we simply push the stackPage array up one word to avoid the overlap. This word is extraStackBytes." pageStructBase := theStackPages + (numPages * bytesPerPage) + objectMemory wordSize. pages := self cCode: '(StackPage *)pageStructBase' inSmalltalk: [pageStructBase class. + (1 to: numPages) collect: [:i| CogStackPage new]]. - (1 to: numPages) collect: [:i| InterpreterStackPage new]]. "Simulation only. Since addresses are negative the offset is positive. To make all stack addresses negative we make the offset a page more than it needs to be so the address of the last slot in memory (the highest address in the stack, or its start) is - pageByteSize and the address of the first slot (the lowest address, or its end) is - pageByteSize * (numPages + 1)" self cCode: '' inSmalltalk: [indexOffset := (numPages + 1) * slotsPerPage]. "make sure there's enough headroom" + self assert: coInterpreter stackPageByteSize - coInterpreter stackLimitBytes - coInterpreter stackLimitOffset + >= coInterpreter stackPageHeadroom. - self assert: interpreter stackPageByteSize - interpreter stackLimitBytes - interpreter stackLimitOffset - >= interpreter stackPageHeadroom. 0 to: numPages - 1 do: [:index| page := self stackPageAt: index. page lastAddress: (self cCode: '(char *)theStackPages + (index * GIV(bytesPerPage))' inSmalltalk: [(index * slotsPerPage - indexOffset) * objectMemory wordSize]); baseAddress: (page lastAddress + bytesPerPage); + stackLimit: page baseAddress - coInterpreter stackLimitBytes; - stackLimit: page baseAddress - interpreter stackLimitBytes; realStackLimit: page stackLimit; baseFP: 0; nextPage: (self stackPageAt: (index = (numPages - 1) ifTrue: [0] ifFalse: [index + 1])); prevPage: (self stackPageAt: (index = 0 ifTrue: [numPages - 1] ifFalse: [index - 1]))]. self cCode: '' inSmalltalk: [| lowestAddress highestAddress | lowestAddress := (pages at: 1) lastAddress + objectMemory wordSize. highestAddress := (pages at: numPages) baseAddress. "see InterpreterStackPages>>longAt:" self assert: lowestAddress // objectMemory wordSize + indexOffset = 1. self assert: highestAddress // objectMemory wordSize + indexOffset = (numPages * slotsPerPage)]. "The overflow limit is the amount of stack to retain when moving frames from an overflowing stack to reduce thrashing. See stackOverflowOrEvent:mayContextSwitch:" page := self stackPageAt: 0. overflowLimit := page baseAddress - page realStackLimit * 3 // 5. 0 to: numPages - 1 do: [:index| page := self stackPageAt: index. self assert: (self pageIndexFor: page baseAddress) == index. self assert: (self pageIndexFor: page baseAddress - (slotsPerPage - 1 * objectMemory wordSize)) == index. self assert: (self stackPageFor: page baseAddress) == page. self assert: (self stackPageFor: page stackLimit) == page. self cCode: '' inSmalltalk: [| memIndex | memIndex := index * slotsPerPage + 1. "this is memIndex in the block above" self assert: (self memIndexFor: (self oopForPointer: page baseAddress)) == (memIndex + slotsPerPage - 1). index < (numPages - 1) ifTrue: [self assert: (self stackPageFor: page baseAddress + objectMemory wordSize) == (self stackPageAt: index + 1)]]. + coInterpreter initializePageTraceToInvalid: page]. - interpreter initializePageTraceToInvalid: page]. mostRecentlyUsedPage := self stackPageAt: 0. page := mostRecentlyUsedPage. count := 0. [| theIndex | count := count + 1. theIndex := self pageIndexFor: page baseAddress. self assert: (self stackPageAt: theIndex) == page. self assert: (self pageIndexFor: page baseAddress) == theIndex. self assert: (self pageIndexFor: page stackLimit) == theIndex. self assert: (self pageIndexFor: page lastAddress + objectMemory wordSize) == theIndex. (page := page nextPage) ~= mostRecentlyUsedPage] whileTrue. self assert: count == numPages. self assert: self pageListIsWellFormed! Item was changed: ----- Method: InterpreterStackPages>>initializeWithByteSize:for: (in category 'initialization') ----- initializeWithByteSize: byteSize "<Integer>" for: anInterpreter "<StackInterpreter>" "^<Array of: <Integer>" + "Initialize the stackPages memory for simulation. Answer the base address of the memory." - "Initialize the stackPages memory for simulation." <doNotGenerate> + coInterpreter := anInterpreter. - interpreter := anInterpreter. objectMemory := anInterpreter objectMemory. ^stackMemory := Array new: byteSize / objectMemory wordSize withAll: 0! Item was removed: - ----- Method: InterpreterStackPages>>isFree: (in category 'page access') ----- - isFree: thePage - "This is an anachronism. Previously Slang couldn't generate the method correctly - from e.g. InterpreterStackPage>>isFree since Slang didn't do substitution on self. - Now it does, but there are still callers of isFree: so we keep this for simulation." - <doNotGenerate> - ^thePage baseFP = 0! Item was removed: - ----- Method: InterpreterStackPages>>markStackPageLeastMostRecentlyUsed: (in category 'page access') ----- - markStackPageLeastMostRecentlyUsed: page "<InterpreterStackPage>" - "This method is used to move a page to the end of the used pages. - This is to keep asserts checking pageListIsWellFormed happy." - - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - - <var: #page type: #'StackPage *'> - <returnTypeC: #void> - | lastUsedPage | - <var: #lastUsedPage type: #'StackPage *'> - self assert: page = mostRecentlyUsedPage nextPage. - lastUsedPage := page nextPage. - [lastUsedPage isFree] whileTrue: - [lastUsedPage := lastUsedPage nextPage]. - lastUsedPage nextPage = page ifTrue: - [^nil]. - page prevPage nextPage: page nextPage. - page nextPage prevPage: page prevPage. - lastUsedPage prevPage nextPage: page. - page prevPage: lastUsedPage prevPage. - page nextPage: lastUsedPage. - lastUsedPage prevPage: page. - self assert: self pageListIsWellFormed! Item was removed: - ----- Method: InterpreterStackPages>>markStackPageMostRecentlyUsed: (in category 'page access') ----- - markStackPageMostRecentlyUsed: page "<InterpreterStackPage>" - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - <var: #page type: #'StackPage *'> - page == mostRecentlyUsedPage ifTrue: - [^nil]. - "Common case; making new page most recently used." - page prevPage == mostRecentlyUsedPage ifTrue: - [mostRecentlyUsedPage := page. - self assert: self pageListIsWellFormed. - ^nil]. - page prevPage nextPage: page nextPage. - page nextPage prevPage: page prevPage. - mostRecentlyUsedPage nextPage prevPage: page. - page prevPage: mostRecentlyUsedPage. - page nextPage: mostRecentlyUsedPage nextPage. - mostRecentlyUsedPage nextPage: page. - mostRecentlyUsedPage := page. - self assert: self pageListIsWellFormed! Item was removed: - ----- Method: InterpreterStackPages>>markStackPageNextMostRecentlyUsed: (in category 'page access') ----- - markStackPageNextMostRecentlyUsed: page "<InterpreterStackPage>" - "This method is used to move a page to a position in the list such that it cannot - be deallocated when a new page is allocated, without changing the most recently - used page. There must be at least 3 pages in the system. So making the page - the MRU's prevPage is sufficient to ensure it won't be deallocated." - - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - - <var: #page type: #'StackPage *'> - self assert: page ~~ mostRecentlyUsedPage. - page nextPage == mostRecentlyUsedPage ifTrue: - [^nil]. - page prevPage nextPage: page nextPage. - page nextPage prevPage: page prevPage. - mostRecentlyUsedPage prevPage nextPage: page. - page prevPage: mostRecentlyUsedPage prevPage. - page nextPage: mostRecentlyUsedPage. - mostRecentlyUsedPage prevPage: page. - self assert: self pageListIsWellFormed! Item was changed: ----- Method: InterpreterStackPages>>memIndexFor: (in category 'page access') ----- memIndexFor: byteAddress + "Map an address into the stack zone into a word index into the slots in the stack zone." + <doNotGenerate> ^(self oopForPointer: byteAddress) // objectMemory wordSize + indexOffset! Item was removed: - ----- Method: InterpreterStackPages>>mostRecentlyUsedPage (in category 'page access') ----- - mostRecentlyUsedPage - <cmacro: '() GIV(mostRecentlyUsedPage)'> - <returnTypeC: #'StackPage *'> "this is to guide Slang's inliner" - ^mostRecentlyUsedPage! Item was removed: - ----- Method: InterpreterStackPages>>overflowLimit (in category 'page access') ----- - overflowLimit - ^overflowLimit! Item was removed: - ----- Method: InterpreterStackPages>>pageListIsWellFormed (in category 'assertions') ----- - pageListIsWellFormed - "Answer if the stack page list is well-formed. - MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - | ok page count limit | - <inline: false> - <var: #page type: #'StackPage *'> - ok := true. - page := mostRecentlyUsedPage nextPage. - count := 1. - limit := numPages * 2. - [page isFree - and: [page ~= mostRecentlyUsedPage - and: [count <= limit]]] whileTrue: - [(self asserta: page nextPage prevPage == page) ifFalse: - [ok := false]. - page := page nextPage. - count := count + 1]. - [page ~= mostRecentlyUsedPage - and: [count <= limit]] whileTrue: - [(self asserta: page nextPage prevPage == page) ifFalse: - [ok := false]. - (self asserta: page isFree not) - ifTrue: - [(self asserta: ((page addressIsInPage: page baseFP) - and: [page addressIsInPage: page headSP])) ifFalse: - [ok := false]] - ifFalse: - [ok := false]. - page := page nextPage. - count := count + 1]. - (self asserta: count = numPages) ifFalse: - [ok := false]. - ^ok! Item was removed: - ----- Method: InterpreterStackPages>>setInterpreter: (in category 'initialization') ----- - setInterpreter: anInterpreter - "Initialize the stackPages memory for simulation." - <doNotGenerate> - interpreter := anInterpreter. - objectMemory := interpreter objectMemory! Item was removed: - ----- Method: InterpreterStackPages>>somePageHasHeadFrameFP: (in category 'assertions') ----- - somePageHasHeadFrameFP: theFP - <doNotGenerate> - ^pages anySatisfy: [:page| page headFP = theFP] - ! Item was removed: - ----- Method: InterpreterStackPages>>stackPageAt: (in category 'page access') ----- - stackPageAt: index - "Answer the page for a page index. - N.B. This is a zero-relative index." - <returnTypeC: #'StackPage *'> - ^self stackPageAt: index pages: pages! Item was removed: - ----- Method: InterpreterStackPages>>stackPageAt:pages: (in category 'page access') ----- - stackPageAt: index pages: thePages - "Answer the page for a page index. - N.B. This is a zero-relative index." - <cmacro: '(index,pages) ((pages) + (index))'> - <returnTypeC: #'StackPage *'> "for Slang..." - ^thePages at: index + 1! Item was removed: - ----- Method: InterpreterStackPages>>stackPageClass (in category 'initialization') ----- - stackPageClass - <doNotGenerate> - ^InterpreterStackPage! Item was removed: - ----- Method: InterpreterStackPages>>stackPageFor: (in category 'page access') ----- - stackPageFor: pointer "<Integer>" - <inline: true> - <var: #pointer type: #'void *'> - <returnTypeC: #'StackPage *'> - ^self stackPageAt: (self pageIndexFor: pointer)! Item was changed: ----- Method: InterpreterStackPages>>whereIsMaybeStackThing: (in category 'debug printing') ----- whereIsMaybeStackThing: anOop + "If anOop is an address within the stack zone answer a string stating that, otherwise answer nil." <returnTypeC: 'char *'> (self cCode: [self oop: anOop isGreaterThanOrEqualTo: stackMemory andLessThan: pages] inSmalltalk: [(self memIndexFor: anOop) between: 1 and: stackMemory size]) ifTrue: [^' is in the stack zone']. ^nil! Item was changed: ----- Method: SimpleStackBasedCogit>>marshallAbsentReceiverSendArguments: (in category 'bytecode generators') ----- marshallAbsentReceiverSendArguments: numArgs self assert: needsFrame. self MoveMw: FoxMFReceiver r: FPReg R: ReceiverResultReg. "Shuffle arguments if necessary and push receiver." numArgs = 0 ifTrue: [self PushR: ReceiverResultReg] ifFalse: [self MoveMw: 0 r: SPReg R: TempReg. self PushR: TempReg. 2 to: numArgs do: [:index| + self MoveMw: index * objectMemory wordSize r: SPReg R: TempReg. - self MoveMw: index * BytesPerWord r: SPReg R: TempReg. self MoveR: TempReg Mw: index - 1 * BytesPerWord r: SPReg]. self MoveR: ReceiverResultReg Mw: numArgs * BytesPerWord r: SPReg].! Item was changed: ----- Method: StackInterpreter class>>ancilliaryClasses: (in category 'translation') ----- ancilliaryClasses: options "Answer any extra classes to be included in the translation." ^{ self objectMemoryClass. VMCallbackContext. + CogStackPages. InterpreterStackPages. + CogStackPage }! - InterpreterStackPage }! Item was changed: ----- Method: StackInterpreter>>commonReturn (in category 'return bytecodes') ----- commonReturn "Do an ^-return (return from method), checking for unwinds if this is a block activation. Note: Assumed to be inlined into the dispatch loop." <sharedCodeInCase: #returnReceiver> | closure home unwindContextOrNilOrZero frameToReturnTo contextToReturnTo theFP callerFP newPage | <var: #frameToReturnTo type: #'char *'> <var: #theFP type: #'char *'> <var: #callerFP type: #'char *'> <var: #newPage type: #'StackPage *'> <var: #thePage type: #'StackPage *'> "If this is a method simply return to the sender/caller." (self iframeIsBlockActivation: localFP) ifFalse: [^self commonCallerReturn]. "Since this is a block activation the closure is on the stack above any args and the frame." closure := self pushedReceiverOrClosureOfFrame: localFP. home := nil. "Walk the closure's lexical chain to find the context or frame to return from (home)." [closure ~= objectMemory nilObject] whileTrue: [home := objectMemory followField: ClosureOuterContextIndex ofObject: closure. closure := objectMemory followField: ClosureIndex ofObject: home]. "home is to be returned from provided there is no unwind-protect activation between this frame and home's sender. Search for an unwind. findUnwindThroughContext: will answer either the context for an unwind-protect activation or nilObj if the sender cannot be found or 0 if no unwind is found but the sender is. We must update the current page's headFrame pointers to enable the search to identify widowed contexts correctly." self writeBackHeadFramePointers. self externalizeIPandSP. unwindContextOrNilOrZero := self findUnwindThroughContext: home. unwindContextOrNilOrZero = objectMemory nilObject ifTrue: ["error: can't find home on chain; cannot return" ^self internalCannotReturn: localReturnValue]. unwindContextOrNilOrZero ~= 0 ifTrue: [^self internalAboutToReturn: localReturnValue through: unwindContextOrNilOrZero]. "Now we know home is on the sender chain. We could be returning to either a context or a frame. Find out which." contextToReturnTo := nil. (self isMarriedOrWidowedContext: home) ifTrue: [self assert: (self checkIsStillMarriedContext: home currentFP: localFP). theFP := self frameOfMarriedContext: home. (self isBaseFrame: theFP) ifTrue: [contextToReturnTo := self frameCallerContext: theFP] ifFalse: [frameToReturnTo := self frameCallerFP: theFP]] ifFalse: [contextToReturnTo := objectMemory fetchPointer: SenderIndex ofObject: home. ((objectMemory isContext: contextToReturnTo) and: [self isMarriedOrWidowedContext: contextToReturnTo]) ifTrue: [self assert: (self checkIsStillMarriedContext: contextToReturnTo currentFP: localFP). frameToReturnTo := self frameOfMarriedContext: contextToReturnTo. contextToReturnTo := nil]]. "If returning to a context we must make a frame for it unless it is dead." contextToReturnTo ~= nil ifTrue: [frameToReturnTo := self establishFrameForContextToReturnTo: contextToReturnTo. frameToReturnTo == 0 ifTrue: ["error: home's sender is dead; cannot return" ^self internalCannotReturn: localReturnValue]]. "Now we have a frame to return to. If it is on a different page we must free intervening pages and nil out intervening contexts. We must free intervening stack pages because if we leave the pages to be divorced then their contexts will be divorced with intact senders and instruction pointers. This code is similar to primitiveTerminateTo. We must move any frames on intervening pages above the frame linked to because these may be in use, e.g. via co-routining (see baseFrameReturn)." self assert: stackPages pageListIsWellFormed. newPage := stackPages stackPageFor: frameToReturnTo. newPage ~~ stackPage ifTrue: [| currentCtx thePage nextCntx | currentCtx := self frameCallerContext: stackPage baseFP. stackPages freeStackPage: stackPage. [self assert: (objectMemory isContext: currentCtx). (self isMarriedOrWidowedContext: currentCtx) and: [(stackPages stackPageFor: (theFP := self frameOfMarriedContext: currentCtx)) = newPage]] whileFalse: [(self isMarriedOrWidowedContext: currentCtx) ifTrue: [thePage := stackPages stackPageFor: theFP. theFP ~= thePage headFP ifTrue: ["Since we've just deallocated a page we know that newStackPage won't deallocate an existing one." + self moveFramesIn: thePage through: (self findFrameAbove: theFP inPage: thePage) toPage: stackPages newStackPage]. - self moveFramesIn: thePage through: (self findFrameAbove: theFP inPage: thePage) toPage: self newStackPage]. currentCtx := self frameCallerContext: thePage baseFP. stackPages freeStackPage: thePage] ifFalse: [nextCntx := objectMemory fetchPointer: SenderIndex ofObject: currentCtx. self markContextAsDead: currentCtx. currentCtx := nextCntx]]. self setStackPageAndLimit: newPage. localSP := stackPage headSP. localFP := stackPage headFP]. "Two cases. Returning to the top frame on a new page or an interior frame on the current page. The top frame has its instruction pointer on top of stack. An interior frame has its instruction pointer in the caller frame. We need to peel back any frames on the page until we get to the correct frame." localFP = frameToReturnTo ifTrue: "pop the saved IP, push the return value and continue." [localIP := self pointerForOop: self internalStackTop] ifFalse: [[callerFP := localFP. localFP := self frameCallerFP: localFP. localFP ~~ frameToReturnTo] whileTrue. localIP := self frameCallerSavedIP: callerFP. localSP := (self frameCallerSP: callerFP) - objectMemory wordSize]. self maybeReturnToMachineCodeFrame. self setMethod: (self frameMethod: localFP). self fetchNextBytecode. self internalStackTopPut: localReturnValue! Item was changed: ----- Method: StackInterpreter>>computeStackZoneSize (in category 'initialization') ----- computeStackZoneSize self cCode: [] inSmalltalk: [stackPages ifNil: [stackPages := self stackPagesClass new setInterpreter: self]]. + ^numStackPages * ((self sizeof: CogStackPage) + self stackPageByteSize) - ^numStackPages * ((self sizeof: InterpreterStackPage) + self stackPageByteSize) + stackPages extraStackBytes! Item was changed: ----- Method: StackInterpreter>>externalDivorceFrame:andContext: (in category 'frame access') ----- externalDivorceFrame: theFP andContext: ctxt "Divorce a single frame and its context. If it is not the top frame of a stack this means splitting its stack." | thePage onCurrent theSP callerCtx newPage frameAbove callerFP callerSP callerIP theIP | <inline: false> <var: #theFP type: #'char *'> <var: #thePage type: #'StackPage *'> <var: #theSP type: #'char *'> <var: #newPage type: #'StackPage *'> <var: #frameAbove type: #'char *'> <var: #callerFP type: #'char *'> <var: #callerSP type: #'char *'> "stackPage needs to have current head pointers to avoid confusion." self assert: (stackPage = 0 or: [stackPage = stackPages mostRecentlyUsedPage]). thePage := stackPages stackPageFor: theFP. (onCurrent := thePage = stackPage) ifFalse: [stackPages markStackPageNextMostRecentlyUsed: thePage]. theSP := self findSPOf: theFP on: thePage. self updateStateOfSpouseContextForFrame: theFP WithSP: theSP. callerCtx := self ensureCallerContext: theFP. (frameAbove := self findFrameAbove: theFP inPage: thePage) == 0 ifTrue: "If we're divorcing the top frame we can simply peel it off." [theIP := stackPages longAt: thePage headSP] ifFalse: "othewise move all frames above to a new stack and then peel the frame off." + [newPage := stackPages newStackPage. - [newPage := self newStackPage. theIP := self oopForPointer: (self frameCallerSavedIP: frameAbove). frameAbove := self moveFramesIn: thePage through: frameAbove toPage: newPage. onCurrent ifTrue: [self setStackPageAndLimit: newPage. framePointer := stackPage headFP. stackPointer := stackPage headSP] ifFalse: [stackPages markStackPageMostRecentlyUsed: newPage]. self assert: (self frameCallerContext: frameAbove) = ctxt]. objectMemory storePointerUnchecked: InstructionPointerIndex ofObject: ctxt withValue: (self contextInstructionPointer: theIP frame: theFP). objectMemory storePointer: SenderIndex ofObject: ctxt withValue: callerCtx. callerFP := self frameCallerFP: theFP. callerFP == 0 "theFP is a base frame; it is now alone; free the entire page" ifTrue: [stackPages freeStackPage: thePage] ifFalse: [callerIP := self oopForPointer: (self frameCallerSavedIP: theFP). callerSP := (self frameCallerSP: theFP) - objectMemory wordSize. stackPages longAt: callerSP put: callerIP. self setHeadFP: callerFP andSP: callerSP inPage: thePage] ! Item was changed: ----- Method: StackInterpreter>>externalSetStackPageAndPointersForSuspendedContextOfProcess: (in category 'frame access') ----- externalSetStackPageAndPointersForSuspendedContextOfProcess: aProcess "Set stackPage, instructionPointer, framePointer and stackPointer for the suspendedContext of aProcess, marrying the context if necessary, and niling the suspendedContext slot. This is used on process switch to ensure a context has a stack frame and so can continue execution." | newContext theFrame thePage newPage | <inline: true> <var: #theFrame type: #'char *'> <var: #thePage type: #'StackPage *'> <var: #newPage type: #'StackPage *'> newContext := objectMemory fetchPointer: SuspendedContextIndex ofObject: aProcess. self assert: (objectMemory isContext: newContext). (self isMarriedOrWidowedContext: newContext) ifTrue: [self assert: (self checkIsStillMarriedContext: newContext currentFP: framePointer)]. objectMemory storePointerUnchecked: SuspendedContextIndex ofObject: aProcess withValue: objectMemory nilObject. (self isStillMarriedContext: newContext) ifTrue: [theFrame := self frameOfMarriedContext: newContext. thePage := stackPages stackPageFor: theFrame. theFrame ~= thePage headFP ifTrue: ["explicit assignment of suspendedContext can cause switch to interior frame." + newPage := stackPages newStackPage. - newPage := self newStackPage. self moveFramesIn: thePage through: (self findFrameAbove: theFrame inPage: thePage) toPage: newPage. stackPages markStackPageLeastMostRecentlyUsed: newPage]. self assert: thePage headFP = theFrame] ifFalse: [thePage := self makeBaseFrameFor: newContext. theFrame := thePage baseFP]. self setStackPageAndLimit: thePage. stackPointer := thePage headSP. framePointer := thePage headFP. (self isMachineCodeFrame: framePointer) ifFalse: [self setMethod: (self iframeMethod: framePointer)]. instructionPointer := self popStack. self assertValidExecutionPointe: instructionPointer r: framePointer s: stackPointer! Item was changed: ----- Method: StackInterpreter>>handleStackOverflow (in category 'message sending') ----- handleStackOverflow "Check for stack overflow, moving frames to another stack if so." | newPage theFP callerFP overflowLimitAddress overflowCount | <var: #newPage type: #'StackPage *'> <var: #theFP type: #'char *'> <var: #callerFP type: #'char *'> <var: #overflowLimitAddress type: #'char *'> "After checkForInterrupts another event check may have been forced, setting both stackLimit and stackPage stackLimit to all ones. So here we must check against the real stackLimit, not the effective stackLimit." stackPointer < stackPage realStackLimit ifFalse: [^self]. self maybeTraceStackOverflow. statStackOverflow := statStackOverflow + 1. "The stack has overflowed this page. If the system is executing some recursive algorithm, e.g. fibonacci, then the system could thrash overflowing the stack if the call soon returns back to the current page. To avoid thrashing, since overflow is quite slow, we can move more than one frame. The idea is to record which page has overflowed, and the first time it overflows move one frame, the second time two frames, and so on. We move no more frames than would leave the page half occupied." theFP := framePointer. stackPage = overflowedPage ifTrue: [overflowLimitAddress := stackPage baseAddress - stackPages overflowLimit. overflowCount := extraFramesToMoveOnOverflow := extraFramesToMoveOnOverflow + 1. [(overflowCount := overflowCount - 1) >= 0 and: [(callerFP := self frameCallerFP: theFP) < overflowLimitAddress and: [(self isBaseFrame: callerFP) not]]] whileTrue: [theFP := callerFP]] ifFalse: [overflowedPage := stackPage. extraFramesToMoveOnOverflow := 0]. self ensureCallerContext: theFP. + newPage := stackPages newStackPage. - newPage := self newStackPage. self moveFramesIn: stackPage through: theFP toPage: newPage. self setStackPageAndLimit: newPage. framePointer := stackPage headFP. stackPointer := stackPage headSP. self isCog ifFalse: "To overflow the stack this must be a new frame, but in Cog base frames are married." [self assert: (self frameHasContext: framePointer) not. self assert: (self validInstructionPointer: instructionPointer + 1 inMethod: method framePointer: framePointer)] ifTrue: [self assert: (self validInstructionPointer: instructionPointer + 1 inFrame: framePointer). self assert: ((self frameHasContext: framePointer) not or: [objectMemory isContext: (self frameContext: framePointer)])]! Item was changed: ----- Method: StackInterpreter>>makeBaseFrameFor: (in category 'frame access') ----- makeBaseFrameFor: aContext "<Integer>" "Marry aContext with the base frame of a new stack page. Build the base frame to reflect the context's state. Answer the new page." <returnTypeC: #'StackPage *'> | page pointer theMethod theIP numArgs stackPtrIndex maybeClosure rcvr | <inline: false> <var: #page type: #'StackPage *'> <var: #pointer type: #'char *'> self assert: (objectMemory isContext: aContext). self assert: (self isSingleContext: aContext). self assert: (objectMemory goodContextSize: aContext). + page := stackPages newStackPage. - page := self newStackPage. pointer := page baseAddress. theIP := objectMemory fetchPointer: InstructionPointerIndex ofObject: aContext. theMethod := objectMemory followObjField: MethodIndex ofObject: aContext. (objectMemory isIntegerObject: theIP) ifFalse: [self error: 'context is not resumable']. theIP := objectMemory integerValueOf: theIP. rcvr := objectMemory followField: ReceiverIndex ofObject: aContext. "If the frame is a closure activation then the closure should be on the stack in the pushed receiver position (closures receiver the value[:value:] messages). Otherwise it should be the receiver proper." maybeClosure := objectMemory fetchPointer: ClosureIndex ofObject: aContext. maybeClosure ~= objectMemory nilObject ifTrue: [(objectMemory isForwarded: maybeClosure) ifTrue: [maybeClosure := objectMemory fixFollowedField: ClosureIndex ofObject: aContext withInitialValue: maybeClosure]. numArgs := self argumentCountOfClosure: maybeClosure. stackPages longAt: pointer put: maybeClosure] ifFalse: [| header | header := objectMemory methodHeaderOf: theMethod. numArgs := self argumentCountOfMethodHeader: header. "If this is a synthetic context its IP could be pointing at the CallPrimitive opcode. If so, skip it." (theIP signedIntFromLong > 0 and: [(self methodHeaderHasPrimitive: header) and: [theIP = (1 + (objectMemory lastPointerOfMethodHeader: header))]]) ifTrue: [theIP := theIP + (self sizeOfCallPrimitiveBytecode: header)]. stackPages longAt: pointer put: rcvr]. "Put the arguments on the stack" 1 to: numArgs do: [:i| stackPages longAt: (pointer := pointer - objectMemory wordSize) put: (objectMemory fetchPointer: ReceiverIndex + i ofObject: aContext)]. "saved caller ip is sender context in base frame" stackPages longAt: (pointer := pointer - objectMemory wordSize) put: (objectMemory followObjField: SenderIndex ofObject: aContext). "base frame's saved fp is null" stackPages longAt: (pointer := pointer - objectMemory wordSize) put: 0. page baseFP: pointer; headFP: pointer. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: theMethod. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: (self encodeFrameFieldHasContext: true isBlock: maybeClosure ~= objectMemory nilObject numArgs: numArgs). self assert: (self frameHasContext: page baseFP). self assert: (self frameNumArgs: page baseFP) == numArgs. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: aContext. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: rcvr. stackPtrIndex := self quickFetchInteger: StackPointerIndex ofObject: aContext. self assert: ReceiverIndex + stackPtrIndex < (objectMemory lengthOf: aContext). numArgs + 1 to: stackPtrIndex do: [:i| stackPages longAt: (pointer := pointer - objectMemory wordSize) put: (objectMemory fetchPointer: ReceiverIndex + i ofObject: aContext)]. "top of stack is the instruction pointer" theIP := self iframeInstructionPointerForIndex: theIP method: theMethod. stackPages longAt: (pointer := pointer - objectMemory wordSize) put: theIP. page headSP: pointer. self assert: (self context: aContext hasValidInversePCMappingOf: theIP in: page baseFP). "Mark context as married by setting its sender to the frame pointer plus SmallInteger tags and the InstructionPointer to the saved fp (which ensures correct alignment w.r.t. the frame when we check for validity) plus SmallInteger tags." objectMemory storePointerUnchecked: SenderIndex ofObject: aContext withValue: (self withSmallIntegerTags: page baseFP). objectMemory storePointerUnchecked: InstructionPointerIndex ofObject: aContext withValue: (self withSmallIntegerTags: 0). self assert: (objectMemory isIntegerObject: (objectMemory fetchPointer: SenderIndex ofObject: aContext)). self assert: (self frameOfMarriedContext: aContext) = page baseFP. self assert: (self validStackPageBaseFrame: page). ^page! Item was changed: ----- Method: StackInterpreter>>mapStackPages (in category 'object memory support') ----- mapStackPages <inline: #never> <var: #thePage type: #'StackPage *'> <var: #theSP type: #'char *'> <var: #theFP type: #'char *'> <var: #callerFP type: #'char *'> <var: #theIPPtr type: #'char *'> + stackPages countStackPagesMap. 0 to: numStackPages - 1 do: [:i| | thePage theSP theFP callerFP theIPPtr theIP oop | thePage := stackPages stackPageAt: i. thePage isFree ifFalse: [self assert: (self ifCurrentStackPageHasValidHeadPointers: thePage). + stackPages countLivePageWhenMapping. theSP := thePage headSP. theFP := thePage headFP. "Skip the instruction pointer on top of stack of inactive pages." thePage = stackPage ifTrue: [theIPPtr := 0] ifFalse: [theIPPtr := theSP. theSP := theSP + objectMemory wordSize]. [self assert: (thePage addressIsInPage: theFP). self assert: (thePage addressIsInPage: theSP). self assert: (theIPPtr = 0 or: [thePage addressIsInPage: theIPPtr]). [theSP <= (theFP + FoxReceiver)] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. theSP := theSP + objectMemory wordSize]. (self frameHasContext: theFP) ifTrue: [(objectMemory shouldRemapObj: (self frameContext: theFP)) ifTrue: [stackPages longAt: theFP + FoxThisContext put: (objectMemory remapObj: (self frameContext: theFP))]. "With SqueakV3 objectMemory can't assert since object body is yet to move." objectMemory hasSpurMemoryManagerAPI ifTrue: [self assert: ((self isMarriedOrWidowedContext: (self frameContext: theFP)) and: [(self frameOfMarriedContext: (self frameContext: theFP)) = theFP])]]. (objectMemory shouldRemapObj: (self frameMethod: theFP)) ifTrue: [theIPPtr ~= 0 ifTrue: [self assert: (stackPages longAt: theIPPtr) > (self frameMethod: theFP). theIP := (stackPages longAt: theIPPtr) - (self frameMethod: theFP)]. stackPages longAt: theFP + FoxMethod put: (objectMemory remapObj: (self frameMethod: theFP)). theIPPtr ~= 0 ifTrue: [stackPages longAt: theIPPtr put: theIP + (self frameMethod: theFP)]]. (callerFP := self frameCallerFP: theFP) ~= 0] whileTrue: [theSP := (theIPPtr := theFP + FoxCallerSavedIP) + objectMemory wordSize. theFP := callerFP]. theSP := theFP + FoxCallerContext. "a.k.a. FoxCallerSavedIP" [theSP <= thePage baseAddress] whileTrue: [oop := stackPages longAt: theSP. (objectMemory shouldRemapOop: oop) ifTrue: [stackPages longAt: theSP put: (objectMemory remapObj: oop)]. theSP := theSP + objectMemory wordSize]]]! Item was removed: - ----- Method: StackInterpreter>>newStackPage (in category 'stack pages') ----- - newStackPage - "MRUP-->used page<->used page<->used page<->used page<--LRUP - ^ <-next-prev-> ^ - | | - v <-prev-next-> v - free page<->free page<->free page<->free page" - | lruOrFree | - <var: #lruOrFree type: #'StackPage *'> - <returnTypeC: #'StackPage *'> - lruOrFree := stackPages mostRecentlyUsedPage nextPage. - (stackPages isFree: lruOrFree) ifTrue: - [^lruOrFree]. - self divorceFramesIn: lruOrFree. - ^lruOrFree! Item was changed: ----- Method: StackInterpreter>>numStkPages (in category 'stack pages') ----- numStkPages + <inline: true> ^numStackPages! Item was changed: ----- Method: StackInterpreter>>storeSenderOfFrame:withValue: (in category 'frame access') ----- storeSenderOfFrame: theFP withValue: anOop "Set the sender of a frame. If the frame is a base frame then this is trivial; merely store into the FoxCallerSavedIP/FoxCallerContext field. If not, then split the stack at the frame, moving the frame and those hotter than it to a new stack page. In the new stack page the frame will be the base frame and storing trivial. Answer the possibly changed location of theFP." | thePage onCurrentPage newPage theMovedFP | <var: #theFP type: #'char *'> <var: #thePage type: #'StackPage *'> <var: #newPage type: #'StackPage *'> <var: #theMovedFP type: #'char *'> <returnTypeC: #'char *'> (self isBaseFrame: theFP) ifTrue: [self frameCallerContext: theFP put: anOop. ^theFP]. self ensureCallerContext: theFP. thePage := stackPages stackPageFor: theFP. self assert: stackPage = stackPages mostRecentlyUsedPage. onCurrentPage := thePage = stackPage. onCurrentPage ifFalse: ["Make sure the frame's page isn't divorced when a new page is allocated." stackPages markStackPageNextMostRecentlyUsed: thePage]. + newPage := stackPages newStackPage. - newPage := self newStackPage. theMovedFP := self moveFramesIn: thePage through: theFP toPage: newPage. onCurrentPage ifTrue: [self setStackPageAndLimit: newPage] ifFalse: [stackPages markStackPageMostRecentlyUsed: newPage]. self assert: (self isBaseFrame: theMovedFP). self frameCallerContext: theMovedFP put: anOop. ^theMovedFP! Item was changed: ----- Method: StackInterpreterPrimitives>>primitiveVMParameter (in category 'system control primitives') ----- (excessive size, no diff calculated)

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Suggestion for a performance analysis project, suitable for a masters student
by Eliot Miranda 13 Aug '15

13 Aug '15

Hi All, I had occasion to compare VW (vw7.7nc) and Spur recently and was pleasantly surprised to see that Spur is on average -40% faster than VW on a large subset of the benchmarks from the shootout (I didn't include three because of Regex syntax issues). Now Spur gets some of its speed from having direct pointers vs VisualWorks' object header/table indirection, but it could get other speedups from various other differences. It would be great to know exactly how much speedup comes from what, and indeed how much cost Sour pays for its lazy become:. I'd like to propose a project to exactly determine the costs of an explicit read barrier and of lazy forwarding compared to no check at all. Spur, part of VMMaker.oscog, is implemented by a hierarchy of classes that implement a 32-bit and a 64-bit memory manager. Spur is a sibling to the old ObjectMemory class that implements the V3 object representation. The current Spur does "lazy forwarding" where two objects are become by cloning each object, making the old versions point to the opposite copy, and relying on send-time checks to lazily follow forwarding pointers when sends to forwarded objects fail a message lookup. The project would create two additional variations on Spur, both of which dispense with the lazy check. One would explicitly test for a forwarding pointers on every access, and one would never check, not need send-time checking either and would reimplement become: like the old ObjectMemory, by scanning the entire heap to exchange all references. These variations could be implemented as subclasses or siblings of Spur. The project isn't trivial because it also means making changes to the JIT, albeit within its framework for multiple object representations. Because this is probably some months' work I can't do it myself but I'm extremely interested in the results and I think it would make a really good paper, e.g. for ISMM, or one of the dynamic language workshops. If what I've said makes any sense at all to any academics out there who are looking for a challenging but nicely contained and far from open ended Masters project then please get in touch and we can see if we can take this any further. _,,,^..^,,,_ best, Eliot

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pharo-vm-spur status & strategy
by Ben Coman 13 Aug '15

13 Aug '15

>From the github network graph for pharo-vm https://github.com/pharo-project/pharo-vm/network ... * I see pharo-vm-spur branch was forked from pharo-vm-master by Esteban ~ July 2014 with lots of commits to align with and keep synchronised with Eliot's Cog trunk * I presume Esteban's pharo-vm-spur branch will become the 64-bit-VM for Pharo 5? * What is the plan for the current pharo-vm-master branch? Will it be retagged pharo-vm-legacy? I see ongoing commits (mostly libgit?) to the (presumed)-pharo-vm-legacy, which sparks the questions: ** Is it feasible to merge pharo-vm-legacy into pharo-vm-spur? Maybe we'll need to cherrypick commits? (Actually later I noticed pharo-project/pharo-vm ** At what point would it make sense for people to start contributing to pharo-vm-spur rather than pharo-vm-legacy * When should Esteban's spur branch be pulled into the official pharo-project/pharo-vm repository (continuing tagged as spur)? Possibly making it more inviting for other to contribute to that branch? ------------ On a slightly different track... * Regarding the work on CMakeVMMaker. Was that was somewhat based off PharoVMMaker? How feasible is it to merge PharoVMMaker into CMakeVMMaker and retire PharoVMMaker ? * How is the synchronising between Cog svn repo and pharo-vm git repo currently being done? Is something like git-svn run manually? * I remember one major concern with moving CogVM trunk to github was learning new tools. I just noticed subversion clients can work directly with github to support hybrid teams [2] [3]. Any interest in exploring that? [2] https://github.com/blog/1178-collaborating-on-github-with-subversion [3] https://github.com/blog/966-improved-subversion-client-support cheers -ben

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Sorry, wrong mailing list [Re: A stab at explaining Spur]
by Chris Cunnington 13 Aug '15

13 Aug '15

Sorry about that. Chris

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Re: A question about #become: (was: Re: [squeak-dev] [ANN] Squeak 5)
by Eliot Miranda 12 Aug '15

12 Aug '15

On Wed, Aug 12, 2015 at 11:58 AM, Eliot Miranda <eliot.miranda(a)gmail.com> wrote: > > > On Wed, Aug 12, 2015 at 11:57 AM, tim Rowledge <tim(a)rowledge.org> wrote: > >> >> On 12-08-2015, at 11:20 AM, Eliot Miranda <eliot.miranda(a)gmail.com> >> wrote: >> >> > >> > >> > On Wed, Aug 12, 2015 at 11:09 AM, Levente Uzonyi <leves(a)elte.hu> wrote: >> > I wonder if you're creating two forwarders in case of #become:, with >> objects of different size, or just one forwarder for the larger object >> while copying the smaller object over the larger one (when possible). >> > >> > Right now it's the simplest thing that could possibly work. I think >> this is a great idea though. It would potentially eliminate the >> post-become stack scan if all objects can be becomed either by exchanging >> contents or (in one-way) shortening. Alas I don't have time for this right >> now. Any volunteers interested? >> >> Huh; I thought you had done that ages ago. I recall suggesting it really >> early in your spur work and could have sworn you did it right then. >> > > I think I did exchange of contents when the objects are of the same size, > at your prompting, but I definitely know I /didn't/ do shortening in > one-way as per Levente's suggestion. > > _,,,^..^,,,_ > Note that there are a fair few potential cases to cover here. An object may be the last object in eden, or the survivor spaces and may have room beyond it to lengthen it, so it could become a larger object by stretching and copying. It may be in old space and followed by a free object and so again be amenable to stretching. I suggest that someone collect data on how often shrinking and/or stretching is an option before expending effort here. _,,,^..^,,,_ best, Eliot

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Re: [squeak-dev] Update stream transition
by Eliot Miranda 12 Aug '15

12 Aug '15

On Wed, Aug 12, 2015 at 11:11 AM, Levente Uzonyi <leves(a)elte.hu> wrote: > Hi Dave, > > I'm afraid it would be rather difficult to backport all changes to 4.6. > The changes made by the Spur bootstrap would have to be reverted (Compiler, > Collections, Kernel, System packages) along with all Spur-specific > optimizations (e.g. #become:, immediate characters, etc) in future changes. Right. Some of this can be automated as long as the differences between the two systems are trivial. But soon enough the gulf will be too far because the differences will be in larger semantic units (for example a rewriting of finalization support to use Ephemerons could cause significant changes to the way file streams are finalized) and at that point automatic back-port will be impossible. I think a much more fruitful direction is to work on developing an up-to-date Interpreter in VMMaker.oscog that can hence be mated to both the V3 memory manager and the Spur one. > > Levente > > > On Mon, 10 Aug 2015, David T. Lewis wrote: > > On Thu, Aug 06, 2015 at 09:47:46AM -0500, Chris Muller wrote: >> >>> We currently have the trunk update stream, which is governed by update >>>> maps >>>> called 'update' in the source.squeak.org/trunk repository. This update >>>> stream is applicable to Squeak images up to the initial release of the >>>> Squeak 4.6 image. These are images in the non-Spur image formats (6504 >>>> or 6505 for 32-bit images, and 68002 for a 64-bit image). >>>> >>> >>> The .spur branch has already been collapsed onto trunk. There is no >>> way to advance a non-spur image except through commits to the release >>> repositories (e.g., 'squea46'). >>> >>> During the development period leading up to Squeak 5.0, which uses the >>>> new Spur image (format number 6521 for the 32-bit Spur image), the >>>> update stream has been governed by update maps called 'update.spur' in >>>> source.squeak.org/trunk. >>>> >>>> For Squeak 5.0, the update stream will continue to be governed by update >>>> maps called 'update' in the source.squeak.org/trunk repository. Users >>>> of >>>> Squeak 5.0 will see a normal trunk update stream from that point >>>> forward, >>>> and will now be using the Spur image format. >>>> >>> >>> Yes. >>> >>> For Squeak 4.6, the update stream will continue to be called 'update', >>>> but will now be in the source.squeak.org/squeak46 repository. These >>>> update >>>> maps are not yet in the squeak46 repository, >>>> >>> >>> I just made the first one in 'squeak46'. >>> >>> but will be added as required. >>>> The Squeak 4.6 release image points to this update stream. An effort >>>> will >>>> be made to keep the squeak46 update stream in sync with trunk through >>>> the >>>> next Squeak release cycle. >>>> >>> >>> Oh really, who is going to do that? >>> >>> >> I fully understand that nothing gets done unless someone actually puts >> in the effort to do it. Within reasonable limits, this is something that >> I am willing to work on through the course of the next release cycle. I >> am expecting that this means 6 to 12 months, depending on how long it >> takes >> to go through another release cycle. >> >> My assumptions were, and still are, as follows: >> >> 1) We are moving the main trunk development to the new Spur image format >> for Squeak 5.0. This is not a reversible change. Some things may break, >> but we are going to make it work and we are going to make it successful. >> >> 2) We will attempt to do this during a transition period of one release >> cycle (whatever that might turn out to be). This allows us to learn >> during the transition period, and to work out any unanticipated problems. >> During that time period, we will make an effort to keep the classic image >> format (Squeak 4.6) healthy. My own assumption is that this should include >> a working update stream. >> >> 3) We will not rely on Eliot to do all the work. Once we get to Squeak >> 5.0 with Spur, other people (such as me) need to step forward if any >> backward compatibility with non-Spur images is going to be maintained. >> If nobody does it, then it will not get done. >> >> Hopefully these are reasonable objectives, and from my point of view >> I will be happy to put some time and effort into objective #3 in the >> coming months. >> >> Having said that, I do not actually know *how* to maintain an update >> stream for 4.6 to track the main trunk 5.0 stream. >> >> Dave >> >> >> >> For an existing trunk image, such as a Squeak 4.5 image that has been kept >>>> up to date with the trunk, it will be necessary to switch from >>>> source.squeak.org/trunk with update map name 'update', to a new setting >>>> of source.squeak.org/squeak46 with update map name 'update', This >>>> change >>>> must be made more or less concurrently with the Squeak 5.0 release. >>>> >>>> Questions: >>>> >>>> 1) Is the above summary correct? >>>> >>>> 2) Is it possible for the trunk update stream to force an existing trunk >>>> image (originating from Squeak 4.5 or earlier) to switch over to the >>>> squeak46 >>>> repository automatically, such that updates can proceed without loading >>>> Spur-specific changes into a non-Spur trunk image? >>>> >>> >>> You would need to make sure not to update past update-topa.322.mcm. >>> Probably the code is not set up to do a limited updated. >>> >>> No, you have to update the updateURL in Preferences. >>> >>> 3) Previously, the release-specific repository (e.g. >>>> source.squeak.org/squeak45 >>>> for Squeak 4.5) was used for applying a few important fixes to a stable >>>> release. Assuming that this is also the intent for Squeak 4.6, and that >>>> we >>>> also want to make an effort to permit non-Spur images to stay in sync >>>> with >>>> trunk for some period of time (nominally one release cycle), then would >>>> it >>>> be helpful to consider providing a trunk-compatible update stream for >>>> non-Spur >>>> images during the transition period? I am not sure how that should work >>>> (possibly something involving an 'update.classic' update map), but I >>>> would >>>> like to know if conceptually it is something we should be trying to do. >>>> >>> >>> Basically you are talking about a fork of Squeak. Unless someone has >>> some kind of compatibility issue with their application, I don't know >>> why anyone would want to expend resources maintaining an old fork.. >>> >> >> >> > -- _,,,^..^,,,_ best, Eliot

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Vm-dev August 2015