From: Ross Johnson <rpj@ise.canberra.edu.au>
To: pthreads-win32 <pthreads-win32@sources.redhat.com>
Subject: Re: snap-2004-11-03 breakage
Date: Wed, 03 Nov 2004 16:19:00 -0000 [thread overview]
Message-ID: <418904F7.8070108@ise.canberra.edu.au> (raw)
In-Reply-To: <OF1A7C794E.5AC63D51-ONC1256F41.00533C1C-C1256F41.00556751@de.ibm.com>
Alexander Terekhov wrote:
>>Code like (from Ettercap)
>> pthread_t pid = ec_thread_getpid("golem");
>> if (pid != 0)
>> ec_thread_destroy(pid);
>>
>>
>
>Code it like
>
> pthread_t tid;
> if (ec_thread_getpid("golem",&tid)
> ec_thread_destroy(tid);
>
>
>
But how does ec_thread_getpid() portably determine if the thread
exists or not?
>Don't rely on idiotic pthread_kill() "testing". The standard
>doesn't preclude the use of pointers for thread IDs (e.g.
>inside pthread_t structure).
>
Oops. I should have recognised that because ...
>Pointers become indeterminate and
>trigger undefined behavior for any nonassignment access once
>the reference storage gets freed. Conforming implementations
>are allowed to reclaim/free that referenced storage when
>detached thread is terminated or joinable thread is terminated
>and joined. Use of "retired" pthread_t values (e.g. as
>pthread_kill() argument) after that moment will trigger
>undefined behavior.
>
>
>
... that's exactly why pthread_t was changed in pthreads-win32.
Every function that takes a thread ID argument has the same problem
as pthread_kill() if pointers are used.
Ross
>regards,
>alexander.
>
>
>
next prev parent reply other threads:[~2004-11-03 16:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-03 13:18 Gisle Vanem
2004-11-03 14:28 ` Robert Kindred
2004-11-03 16:18 ` Ross Johnson
2004-11-03 16:30 ` Peter Slacik
2004-11-04 18:06 ` Robert Kindred
2004-11-03 14:33 ` Ross Johnson
[not found] ` <4188EB13.8000100@ise.canberra.edu.au>
2004-11-03 15:02 ` Gisle Vanem
2004-11-03 15:38 ` Ross Johnson
2004-11-03 15:32 ` Alexander Terekhov
2004-11-03 16:19 ` Ross Johnson [this message]
2004-11-03 16:32 ` Alexander Terekhov
2004-11-03 16:15 Bossom, John
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