[squeak-dev] The Inbox: Kernel-ct.1448.mcz

Thiede, Christoph Christoph.Thiede at student.hpi.uni-potsdam.de
Mon Mar 14 00:37:07 UTC 2022


Hi Eliot, thanks for the fast feedback.


> Wow that's a huge side-effect for such a basic operation.  Not only that, the method lives in the method dictionary until the ensure: block us run and that could potentially be never.  Isn't it preferable to determine if compiledMethod has a primitive, if so to use the doPrimitive:.../tryNamedPrimitiveIn:/tryPrimitive: machinery to execute the primitive, and then if the primitive fails create an activation of compiledMethod via Context class>>sender:receiver:method:arguments: and set that going via swapSender: tricks?

Very nice idea! So basically Context>>#send:to:with:lookupIn: without the lookup part. I'm looking forward to implementing this, but it might take me some more days ... Busy times ... :-)

Best,
Christoph

________________________________
Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im Auftrag von Eliot Miranda <eliot.miranda at gmail.com>
Gesendet: Samstag, 12. März 2022 02:41:49
An: The general-purpose Squeak developers list
Betreff: Re: [squeak-dev] The Inbox: Kernel-ct.1448.mcz

Hi Christoph,

     your fixes look good.  I was on the verge of moving them to trunk when I looked at the failure code in Object>>withArgs:executeMethod:

Object>>withArgs: argArray executeMethod: compiledMethod
    "Execute compiledMethod against the receiver and args in argArray"

    | selector |
    <primitive: 188>
    selector := Symbol new.
    self class addSelectorSilently: selector withMethod: compiledMethod.
    ^ [self perform: selector withArguments: argArray]
        ensure: [self class basicRemoveSelector: selector]

Wow that's a huge side-effect for such a basic operation.  Not only that, the method lives in the method dictionary until the ensure: block us run and that could potentially be never.  Isn't it preferable to determine if compiledMethod has a primitive, if so to use the doPrimitive:.../tryNamedPrimitiveIn:/tryPrimitive: machinery to execute the primitive, and then if the primitive fails create an activation of compiledMethod via Context class>>sender:receiver:method:arguments: and set that going via swapSender: tricks?

If you agree can I ask you to submit a Kernel with the implementation?

On Fri, Mar 11, 2022 at 4:56 PM Thiede, Christoph <Christoph.Thiede at student.hpi.uni-potsdam.de<mailto:Christoph.Thiede at student.hpi.uni-potsdam.de>> wrote:

Hi Eliot, hi all,


I have dropped a few versions in the inbox that improve the simulation of primitive 189, 183, 184 and also add tests for them. Please see: KernelTests-ct.420, Kernel-ct.1448, KernelTests-ct.421, and Kernel-ct.1449. Also, there are even more primitive tests in KernelTests-ct.409 (inbox), but they do not need to be reviewed together. I am looking forward to your feedback, please let me know when I can move these changes to the Trunk! :-)


Best,

Christoph


________________________________
Von: Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org<mailto:squeak-dev-bounces at lists.squeakfoundation.org>> im Auftrag von commits at source.squeak.org<mailto:commits at source.squeak.org> <commits at source.squeak.org<mailto:commits at source.squeak.org>>
Gesendet: Samstag, 12. März 2022 00:42:12
An: squeak-dev at lists.squeakfoundation.org<mailto:squeak-dev at lists.squeakfoundation.org>
Betreff: [squeak-dev] The Inbox: Kernel-ct.1448.mcz

A new version of Kernel was added to project The Inbox:
http://source.squeak.org/inbox/Kernel-ct.1448.mcz

==================== Summary ====================

Name: Kernel-ct.1448
Author: ct
Time: 12 March 2022, 12:42:08.516359 am
UUID: 7659c202-5fcc-084e-84b4-a5d233717b2d
Ancestors: Kernel-nice.1447

Implements missing simulation of primitive 189 primitiveExecuteMethod (Object>>with:...executeMethod:).

=============== Diff against Kernel-nice.1447 ===============

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 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:...]"
                 [| selector |
                 selector := arguments at: 1 ifAbsent:
                         [^ self class primitiveFailTokenFor: #'bad argument'].
                 arguments size - 1 = selector numArgs ifFalse:
                         [^ self class primitiveFailTokenFor: #'bad number of arguments'].
                 ^self send: selector to: receiver with: arguments allButFirst].
         primitiveIndex = 84 ifTrue: "afr 9/11/1998 19:50 & eem 8/18/2009 17:04" "Object>>perform:withArguments:"
                 [| selector args |
                 arguments size = 2 ifFalse:
                         [^ self class primitiveFailTokenFor: #'bad argument'].
                 selector := arguments first.
                 args := arguments second.
                 args isArray ifFalse:
                         [^ self class primitiveFailTokenFor: #'bad argument'].
                 args size = selector numArgs ifFalse:
                         [^ self class primitiveFailTokenFor: #'bad number of arguments'].
                 ^self send: selector to: receiver with: args].
         primitiveIndex = 100 ifTrue: "eem 8/18/2009 16:57" "Object>>perform:withArguments:inSuperclass:"
                 [| rcvr selector args superclass |
                 arguments size
                         caseOf: {
                                 [3] -> [
                                         rcvr := receiver.
                                         selector := arguments first.
                                         args := arguments second.
                                         superclass := arguments third].
                                 [4] -> ["mirror primitive"
                                         rcvr := arguments first.
                                         selector := arguments second.
                                         args := arguments third.
                                         superclass := arguments fourth] }
                         otherwise: [^ self class primitiveFailTokenFor: #'bad argument'].
                 args isArray ifFalse:
                         [^ self class primitiveFailTokenFor: #'bad argument'].
                 args size = selector numArgs ifFalse:
                         [^ self class primitiveFailTokenFor: #'bad number of arguments'].
                 ((self objectClass: rcvr) includesBehavior: superclass) ifFalse:
                         [^ self class primitiveFailTokenFor: #'bad argument'].
                 ^self send: selector to: rcvr with: args lookupIn: superclass].

         "Mutex>>primitiveEnterCriticalSection
          Mutex>>primitiveTestAndSetOwnershipOfCriticalSection"
         (primitiveIndex = 186 or: [primitiveIndex = 187]) ifTrue:
                 [| 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 or: [primitiveIndex = 189]) ifTrue:
-
-        primitiveIndex = 188 ifTrue:    "Object>>withArgs:executeMethod:
-                                                                        CompiledMethod class>>receiver:withArguments:executeMethod:
-                                                                        VMMirror>>ifFail:object:with:executeMethod: et al"
                 [| n args methodArg thisReceiver |
+                 primitiveIndex caseOf:
+                        {[188 "primitiveExecuteMethodArgsArray"] ->
+                                ["Object>>withArgs:executeMethod:
+                                  CompiledMethod class>>receiver:withArguments:executeMethod:
+                                  VMMirror>>ifFail:object:with:executeMethod: et al"
+                                 ((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'].
+                                 thisReceiver := arguments at: n - 2 ifAbsent: [receiver]].
+                         [189 "primitiveExecuteMethod"] ->
+                                ["Object>>executeMethod:
+                                  Object>>with:...executeMethod:"
+                                 (arguments size > 0) ifFalse:
+                                        [^self class primitiveFailTokenFor: #'bad argument'].
+                                 ((self objectClass: (methodArg := arguments atLast: 1)) includesBehavior: CompiledMethod) ifFalse:
+                                        [^self class primitiveFailTokenFor: #'bad argument'].
+                                 args := arguments allButLast.
+                                 thisReceiver := receiver]}.
-                 ((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].
                  ^self
                         activateMethod: methodArg
                         withArgs: args
                         receiver: thisReceiver].

         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]!





--
_,,,^..^,,,_
best, Eliot
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