[squeak-dev] The Trunk: Kernel-ct.1382.mcz

commits at source.squeak.org commits at source.squeak.org
Fri Mar 26 11:51:53 UTC 2021


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-td5127443.html and http://forum.world.st/Please-try-out-Fixes-for-debugger-invocation-during-code-simulation-td5127684.html 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]!



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