Marcel Taeumel uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-ct.1382.mcz
==================== Summary ====================
Name: Kernel-ct.1382 Author: ct Time: 15 March 2021, 1:52:03.249869 pm UUID: e108423f-661f-4d4f-9ad8-c667c3995b32 Ancestors: Kernel-mt.1381
Proposal: Revises usage and handling of primitive 19, also known as the simulation guard. Don't use it in #newProcess and variants since they don't involve any actual control logic. Instead, also show a simulation warning when debugging a control primitive (primitiveSignal primitiveWait primitiveResume primitiveSuspend). Improves integration of simulation guard warnings by signaling a Warning on the simulator stack rather than spawning a debugger on the debugged process. This also makes it easier to handle these warnings in a non-interactive context. See http://forum.world.st/Simulation-guard-lt-primitive-19-gt-crashes-the-image-... and http://forum.world.st/Please-try-out-Fixes-for-debugger-invocation-during-co... for more information.
Reuploaded to resolve merge conflict with Kernel-mt.1381. Replaces Kernel-ct.1381, which can be moved into the treated inbox.
=============== Diff against Kernel-mt.1381 ===============
Item was changed: ----- Method: BlockClosure>>newProcess (in category 'scheduling') ----- newProcess + "Answer a Process running the code in the receiver. The process is not scheduled." - "Answer a Process running the code in the receiver. The process is not - scheduled." - <primitive: 19> "Simulation guard" ^Process forContext: [self value. + "Since control is now at the bottom, there is no need to terminate (which runs unwinds) since all unwinds have been run. Simply suspend. + Note that we must use this form rather than e.g. Processor suspendActive so that isTerminated answers true. isTerminated requires that if there is a suspended context it is the bottom-most, but using a send would result in the process's suspendedContext /not/ being the bottom-most." - "Since control is now at the bottom there is no need to terminate (which - runs unwinds) since all unwnds have been run. Simply suspend. - Note that we must use this form rather than e.g. Processor suspendActive - so that isTerminated answers true. isTerminated requires that if there is a - suspended context it is the bottom-most, but using a send would result in - the process's suspendedContext /not/ being the bottom-most." Processor activeProcess suspend] asContext priority: Processor activePriority!
Item was changed: ----- Method: BlockClosure>>newProcessWith: (in category 'scheduling') ----- newProcessWith: anArray + "Answer a Process running the code in the receiver. The receiver's block arguments are bound to the contents of the argument, anArray. The process is not scheduled." - "Answer a Process running the code in the receiver. The receiver's block - arguments are bound to the contents of the argument, anArray. The - process is not scheduled." - <primitive: 19> "Simulation guard" ^Process forContext: [self valueWithArguments: anArray. + "Since control is now at the bottom, there is no need to terminate (which runs unwinds) since all unwinds have been run. Simply suspend. + Note that we must use this form rather than e.g. Processor suspendActive so that isTerminated answers true. isTerminated requires that if there is a suspended context it is the bottom-most, but using a send would result in the process's suspendedContext /not/ being the bottom-most." - "Since control is now at the bottom there is no need to terminate (which - runs unwinds) since all unwnds have been run. Simply suspend. - Note that we must use this form rather than e.g. Processor suspendActive - so that isTerminated answers true. isTerminated requires that if there is a - suspended context it is the bottom-most, but using a send would result in - the process's suspendedContext /not/ being the bottom-most." Processor activeProcess suspend] asContext priority: Processor activePriority!
Item was changed: ----- Method: Context>>doPrimitive:method:receiver:args: (in category 'private') ----- doPrimitive: primitiveIndex method: meth receiver: receiver args: arguments "Simulate a primitive method whose index is primitiveIndex. The simulated receiver and arguments are given as arguments to this message. If successful, push result and return resuming context, else ^ {errCode, PrimitiveFailToken}. Any primitive which provokes execution needs to be intercepted and simulated to avoid execution running away."
| value | "Judicious use of primitive 19 (a null primitive that doesn't do anything) prevents the debugger from entering various run-away activities such as spawning a new process, etc. Injudicious use results in the debugger not being able to debug interesting code, such as the debugger itself. Hence use primitive 19 with care :-)" "SystemNavigation new browseAllSelect: [:m| m primitive = 19]" + (primitiveIndex = 19 or: [primitiveIndex >= 85 and: [primitiveIndex <= 88] "control primitives"]) ifTrue: [ - primitiveIndex = 19 ifTrue: [ [self notify: ('The code being simulated is trying to control a process ({1}). Process controlling cannot be simulated. If you proceed, things may happen outside the observable area of the simulator.' translated format: {meth reference})] ifCurtailed: [self push: nil "Cheap fix of the context's internal state"]]. ((primitiveIndex between: 201 and: 222) and: [(self objectClass: receiver) includesBehavior: BlockClosure]) ifTrue: [(primitiveIndex = 206 or: [primitiveIndex = 208]) ifTrue: "[Full]BlockClosure>>valueWithArguments:" [^receiver simulateValueWithArguments: arguments first caller: self]. ((primitiveIndex between: 201 and: 209) "[Full]BlockClosure>>value[:value:...]" or: [primitiveIndex between: 221 and: 222]) ifTrue: "[Full]BlockClosure>>valueNoContextSwitch[:]" [^receiver simulateValueWithArguments: arguments caller: self]].
primitiveIndex = 83 ifTrue: "afr 9/11/1998 19:50" "Object>>perform:[with:...]" [^self send: arguments first to: receiver with: arguments allButFirst]. primitiveIndex = 84 ifTrue: "afr 9/11/1998 19:50 & eem 8/18/2009 17:04" "Object>>perform:withArguments:" [^self send: arguments first to: receiver with: (arguments at: 2) lookupIn: (self objectClass: receiver)]. primitiveIndex = 100 ifTrue: "eem 8/18/2009 16:57" "Object>>perform:withArguments:inSuperclass:" [^self send: arguments first to: receiver with: (arguments at: 2) lookupIn: (arguments at: 3)].
"Mutex>>primitiveEnterCriticalSection Mutex>>primitiveTestAndSetOwnershipOfCriticalSection" (primitiveIndex = 186 or: [primitiveIndex = 187]) ifTrue: + ["Transcript + cr; + nextPutAll: 'Processor activeProcess '; + nextPutAll: (Processor activeProcess == receiver owningProcess ifTrue: [#==] ifFalse: [#~~]); + nextPutAll: ' owner'; + flush." + value := primitiveIndex = 186 + ifTrue: [receiver primitiveEnterCriticalSectionOnBehalfOf: Processor activeProcess] + ifFalse: [receiver primitiveTestAndSetOwnershipOfCriticalSectionOnBehalfOf: Processor activeProcess]. - [| effective | - effective := Processor activeProcess effectiveProcess. - "active == effective" - value := primitiveIndex = 186 - ifTrue: [receiver primitiveEnterCriticalSectionOnBehalfOf: effective] - ifFalse: [receiver primitiveTestAndSetOwnershipOfCriticalSectionOnBehalfOf: effective]. ^(self isPrimFailToken: value) ifTrue: [value] ifFalse: [self push: value]].
primitiveIndex = 188 ifTrue: "Object>>withArgs:executeMethod: CompiledMethod class>>receiver:withArguments:executeMethod: VMMirror>>ifFail:object:with:executeMethod: et al" [| n args methodArg thisReceiver | ((n := arguments size) between: 2 and: 4) ifFalse: [^self class primitiveFailTokenFor: #'unsupported operation']. ((self objectClass: (args := arguments at: n - 1)) == Array and: [(self objectClass: (methodArg := arguments at: n)) includesBehavior: CompiledMethod]) ifFalse: [^self class primitiveFailTokenFor: #'bad argument']. methodArg numArgs = args size ifFalse: [^self class primitiveFailTokenFor: #'bad number of arguments']. thisReceiver := arguments at: n - 2 ifAbsent: [receiver]. methodArg primitive > 0 ifTrue: [methodArg isQuick ifTrue: [^self push: (methodArg valueWithReceiver: thisReceiver arguments: args)]. ^self doPrimitive: methodArg primitive method: meth receiver: thisReceiver args: args]. ^Context sender: self receiver: thisReceiver method: methodArg arguments: args].
primitiveIndex = 118 ifTrue: "[receiver:]tryPrimitive:withArgs:; avoid recursing in the VM" [(arguments size = 3 and: [(self objectClass: arguments second) == SmallInteger and: [(self objectClass: arguments last) == Array]]) ifTrue: [^self doPrimitive: arguments second method: meth receiver: arguments first args: arguments last]. (arguments size = 2 and: [(self objectClass: arguments first) == SmallInteger and: [(self objectClass: arguments last) == Array]]) ifFalse: [^self class primitiveFailTokenFor: nil]. ^self doPrimitive: arguments first method: meth receiver: receiver args: arguments last].
value := primitiveIndex = 120 "FFI method" ifTrue: [(meth literalAt: 1) tryInvokeWithArguments: arguments] ifFalse: [primitiveIndex = 117 "named primitives" ifTrue: [self tryNamedPrimitiveIn: meth for: receiver withArgs: arguments] ifFalse: "should use self receiver: receiver tryPrimitive: primitiveIndex withArgs: arguments but this is only in later VMs (and appears to be broken)" [receiver tryPrimitive: primitiveIndex withArgs: arguments]].
^(self isPrimFailToken: value) ifTrue: [value] ifFalse: [self push: value]!