On 08.11.2010 06:39, Igor Stasenko wrote:
Hello,
i just found that Squeak images Process class contains unused ivars: island env
in Pharo image, env ivar is used for holding a process-specific state, which is convenient, so one could use: Processor activeProcess environmentAt: put:...
but in Squeak image there is even no such methods.
There are also some caveats with such thing: during process termination, Processor activeProcess could point to different process, and so, accessing to process environment may lead to error(s).
To avoid issues like these, the process termination action (stack unwinding) should be always performed only for active process. One of a trick i think, is to replace the suspendedContext with own context, and then activate given process in order to unwind its stack etc.
Another way is to remember environment somewhere else during process termination, and use different method to access it i.e. instead of: Processor activeProcess environmentAt: use self processEnvironmentAt:
where #processEnvironmentAt: is implemented in Object class, and can handle termination gracefully.
But i think replacing suspendedContext is more generic. What you think?
Not so convinced. Fast thread locals are important and a Symbol lookup in an IdentityDictionary is pretty fast. And polluting Object with stuff that doesn't belong there isn't a very convincing alternative to me. Cheers PHilippe