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

Eliot Miranda eliot.miranda at gmail.com
Sat Mar 12 01:41:49 UTC 2022


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> 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> im
> Auftrag von commits at source.squeak.org <commits at source.squeak.org>
> *Gesendet:* Samstag, 12. März 2022 00:42:12
> *An:* 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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