Threading experts?

[Mike Hearn]

I assume you tried both with NPTL support compiled in and without,
right?

Having said that I've also seen wierd freezes inside pthreads, despite
most other apps working correctly (with rhymbox in particular). So,
there might be some other strange issue here. I'll try an strace on RB
to see if it's a similar problem.

On Sun, 2003-08-10 at 16:33, Jason Edmeades wrote:
> Hi,
> 
> I seem to have found a recreatable threading problem and I am not 
> convinced it it wines fault either. Are there any experts here who want 
> to offer any advice on where to go to persue this please?
> 
> Problem:
> 'wine appname' hangs when it creates one of its threads. The hang is 
> inside pthread_create and control is never returned to the caller
> 
> Environment
> uname -a returns kernel 2.4.21-0.13mdk, and its basically Mandrake Linux 
> 9.1 with no updates. Wine is cvs as of today, configured with --with-nptl
> 
> More info:
> Looking through an strace, I can see a difference between a working and 
> failing case, and it would appear there is a timing issue inside the 
> pthread routines. However, I would normally expect it far more likely 
> that it is a wine bug than a kernel / threading bug, so I dont really 
> know how to proceed. I can recreate this about 95% of the time with one 
> app and one app only, so I really suspect it to be a wine problem, but I 
> just cant see why.
> 
> Here's a working case
> ===============
>  (Note SY3 and SY4 are fixmes I added each side of the pthread_create)
> 
> 394 issues a create thread.
> [pid   394] write(2, "fixme:thread:SYSDEPS_SpawnThread"..., 
> 38fixme:thread:SYSDEPS_SpawnThread SY 3) = 38
> [pid   394] rt_sigprocmask(SIG_SETMASK, NULL, [RTMIN], 8) = 0
> [pid   394] write(12, 
> "\240 at 4@\0\0\0\0\230,s@\240\177\v@\0000\20J\0\0\0\200\0"..., 148 
> <unfinished ...>
> :
> 398 is the pthread thread manager thread
> [pid   398] getppid()                   = 394
> [pid   398] read(10, 
> "\240 at 4@\0\0\0\0\230,s@\240\177\v@\0000\20J\0\0\0\200\0"..., 148) = 148
> [pid   398] clone(child_stack=0x4a102bd0, 
> flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|0x21) = 400
> :
> It wakes up 394 to indicate it can continue
> [pid   398] kill(394, SIGRTMIN)         = 0
> :
> [pid   394] <... write resumed> )       = 148
> [pid   394] rt_sigprocmask(SIG_SETMASK, NULL, [RTMIN], 8) = 0
> [pid   394] rt_sigsuspend([] <unfinished ...>
> *** sigsuspend gets back a SIGRTMIN to wake it up.
> [pid   394] --- SIGRTMIN (Unknown signal 32) @ 0 (0) ---
> [pid   394] <... rt_sigsuspend resumed> ) = -1 EINTR (Interrupted system 
> call)
> [pid   394] sigreturn()                 = ? (mask now [RTMIN])
> [pid   394] write(2, "fixme:thread:SYSDEPS_SpawnThread"..., 
> 38fixme:thread:SYSDEPS_SpawnThread SY 4
> 
> Failing case
> ========
> 394 issues a create thread.
> [pid   394] write(2, "fixme:thread:SYSDEPS_SpawnThread"..., 
> 38fixme:thread:SYSDEPS_SpawnThread SY 3) = 38
> [pid   394] rt_sigprocmask(SIG_SETMASK, NULL, [], 8) = 0
> [pid   394] write(12, 
> "\240 at 4@\0\0\0\0$&s@\240\177\v@\0000xJ\0\0\0\0\0\0\0\0`"..., 148 
> <unfinished ...>
> :
> 398 is the pthread thread manager thread
> [pid   398] <... poll resumed> [{fd=10, events=POLLIN, revents=POLLIN}], 
> 1, 2000) = 1
> [pid   398] getppid()                   = 394
> [pid   398] read(10, 
> "\240 at 4@\0\0\0\0$&s@\240\177\v@\0000xJ\0\0\0\0\0\0\0\0`"..., 148) = 148
> [pid   398] clone(child_stack=0x4a782bd0, 
> flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|0x21) = 401
> :
> It wakes up 394 to indicate it can continue
> [pid   398] kill(394, SIGRTMIN)         = 0
> :
> (Now for the difference...)
> [pid   394] <... write resumed> )       = 148
> :
> vvv What is this, and why is it getting the signal
> [pid   394] --- SIGRTMIN (Unknown signal 32) @ 0 (0) ---
> [pid   394] sigreturn()                 = ? (mask now [])
> :
> vvv Since the signal is absorbed already, suspend just hangs forever.
> [pid   394] rt_sigprocmask(SIG_SETMASK, NULL, [], 8) = 0
> [pid   394] rt_sigsuspend([] <unfinished ...>
> 
> Any help? Its really annoying
> Jason
> 
>