4ea
Subj : Re: a thread question
To   : comp.programming.threads
From : Chris Thomasson
Date : Thu May 12 2005 07:07 pm

>> How could thread_c modify and/or read a_local and/or b_local "without" 
>> deliberately passing a pointer or corrupting anything?
>
>    If you're asking how can it happen accidentally, the answer is of 
> course through some bug that causes thread_c to happen to hit the address 
> of a_local or b_local. You can only not do something deliberately through 
> a bug. However, if you want other threads to access it, it's not difficult 
> to set up.

OK. I think I misunderstood you. You are correct in saying that all threads 
can see every variable though there address.




> As for "corrupting anything", what are you talking about?

thread_c can corrupt memory and alter a/b_local's value.




> Threads are supposed to share variables -- that's the whole point of them.

Well, there is the concept of thread-local ( unshared ) variables...



I generally try to keep all of my variables filed under two main categories:

1. thread-local

address only visible to the single thread that owns the variable.



2. shared

address can be visible to a variable number of different threads.

.

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