nevertheless it should be there in latests vms. which version are you using?
Esteban > On 25 Jan 2017, at 15:04, p...@highoctane.be wrote: > > Tried it and it returns false for this Windows VM. > > Phil > > On Wed, Jan 25, 2017 at 2:14 PM, Clément Bera <bera.clem...@gmail.com > <mailto:bera.clem...@gmail.com>> wrote: > I introduced the method #supportsWriteBarrier in Pharo 6. > > You can backport it if you want: > > VirtualMachine>>#supportsWriteBarrier > "Answer whether the VM observes the per-object read-only flag and > consequently > aborts writes to inst vars of, and fails primitives that attempt to > write, to read-only objects." > > ^(self parameterAt: 65) > ifNil: [false] > ifNotNil: > [:param| "In older VMs this is a boolean reflecting > MULTIPLE_BYTECODE_SETS" > param isInteger "In newer VMs it is a set of integer > flags, bit 1 of which is IMMUTABILITY" > ifTrue: [param anyMask: 2] > ifFalse: [false]] > > > > On Wed, Jan 25, 2017 at 2:06 PM, p...@highoctane.be > <mailto:p...@highoctane.be> <p...@highoctane.be <mailto:p...@highoctane.be>> > wrote: > The "latest" Windows VM I do use has no such method. > > Virtual Machine > --------------- > C:\Users\Philippe\Dropbox\Sibelga\JiraAutomation\Pharo5.0\latestvm\pharo.exe > CoInterpreter * VMMaker.oscog-eem.2090 uuid: > 63a161b9-17e1-4911-a89a-1687d9ba9a1a Jan 15 2017 > StackToRegisterMappingCogit * VMMaker.oscog-eem.2090 uuid: > 63a161b9-17e1-4911-a89a-1687d9ba9a1a Jan 15 2017 > VM: 201701151442 https://github.com/pharo-project/pharo-vm.git > <https://github.com/pharo-project/pharo-vm.git> $ Date: Sun Jan 15 15:42:39 > 2017 +0100 $ Plugins: 201701151442 > https://github.com/pharo-project/pharo-vm.git > <https://github.com/pharo-project/pharo-vm.git> $ > > Win32 built on Jan 15 2017 15:59:52 CUT Compiler: 5.4.0 > VMMaker versionString VM: 201701151442 > https://github.com/pharo-project/pharo-vm.git > <https://github.com/pharo-project/pharo-vm.git> $ Date: Sun Jan 15 15:42:39 > 2017 +0100 $ Plugins: 201701151442 > https://github.com/pharo-project/pharo-vm.git > <https://github.com/pharo-project/pharo-vm.git> $ > CoInterpreter * VMMaker.oscog-eem.2090 uuid: > 63a161b9-17e1-4911-a89a-1687d9ba9a1a Jan 15 2017 > StackToRegisterMappingCogit * VMMaker.oscog-eem.2090 uuid: > 63a161b9-17e1-4911-a89a-1687d9ba9a1a Jan 15 2017 > > <image.png> > > > On Wed, Jan 25, 2017 at 1:54 PM, Clément Bera <bera.clem...@gmail.com > <mailto:bera.clem...@gmail.com>> wrote: > > > On Wed, Jan 25, 2017 at 11:35 AM, Norbert Hartl <norb...@hartl.name > <mailto:norb...@hartl.name>> wrote: > Does anyone know the state of immutability support in vm and image? The > latest vm downloadable is compiled with > > IMMUTABILITY=1 > > (Esteban said that). When I open a pharo6 image with this VM and do: > > ASUser new > setIsReadOnlyObject: true; > name: 'foo' > > with > > ASUser>>#name: arg1 > name := arg1 > > I don't get an exception. Is there something missing or am I not > understanding? > > Hi Norbert, > > Thank you very much for looking read-only objects. > > When mutating an instance variable, the VM triggers a call-back that by > default does nothing. In your case, running your code does not raise an > exception but the object should not be modified either. If you want an > exception, you need to change the call-back code, i.e., the method > Object>>#attemptToAssign: value withIndex: index. For example, you could > write: > > Object>>#attemptToAssign: value withIndex: index > | process | > self notify: 'object changed !'. > process := Processor activeProcess. > [ process suspendedContext: process suspendedContext sender ] forkAt: > Processor activePriority + 1. > Processor yield. > > Then, your code should open a notification window with 'object changed', and > proceeding keeps running the code without mutating the object. > > One needs to build a ModificationTracker framework on top of the VM support I > introduced. Multiple things are required, like default behavior in this > call-back and in primitive failure code. I am willing to support and help > anyone willing to build such a framework, but I won't build it myself. > > If you have any other questions or if you find bug don't hesitate to ask > further questions > > Best, > > PS: Make sure "Smalltalk vm supportsWriteBarrier" answers true in your > system, if this is not the case it means the VM does not support read-only > objects. > > Clement > > > > > > > Norbert > > > >
