On 2/2/2017 1:24 PM, Branko Čibej wrote:
On 02.02.2017 12:49, Stefan Hett wrote:
On 2/2/2017 12:04 PM, Nick Kew wrote:
On Wed, 2017-02-01 at 00:23 +0100, Stefan wrote:
Hi,
the issue was discovered as part of tracing down a deadlock
condition in
an SVN test [1].
As far as I understand it, the problem lies in the C-standard not
explicitly defining when a function registered with atexit() is called
in the context of thread termination [2].
I had no idea atexit() was called on thread termination. I guess the
manpage must be misleading in telling us it happens at process exit?
I expressed myself poorly a bit here. I didn't want to suggest
atexit()-registered functions are called on thread termination but
rather that threads can be terminated before the atexit-registered
functions are called.
So if apr_terminate is registered in a function called from a DLL via
atexit(), it can happen (and in my scenario does happen) that threads
got terminated before apr_terminate() is called.
But that should not matter. apr_thread_join() does not terminate a
thread, it waits for the thread to terminate. The thread handle should
remain valid until apr_thread_join() is called, even if the thread
terminated before the join().
This is correct. The problem is that thd_cnt is not decremented (thd->td
is valid, apr_thread_join() waits until the thread is (which it is
already) and then returns APR_INCOMPLETE - nothing decrements the
thd_cnt value for the already terminated thread).
--
Regards,
Stefan Hett
