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| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2020-06-01 17:27:48 +0000 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2020-06-01 17:38:31 +0000 |
| commit | 8081702460726304af496be52234385094392a6f (patch) | |
| tree | 55606e2a42e6342aaed360c27c17e9675c9c478e /sysdeps/mach | |
| parent | a3e589d1f68d43d4c3f67d59497862875c2d5afc (diff) | |
| download | glibc-8081702460726304af496be52234385094392a6f.tar.gz | |
htl: Make pthread_cond_destroy wait for threads to be woken
This allows to reuse the storage after calling pthread_cond_destroy.
* sysdeps/htl/bits/types/struct___pthread_cond.h (__pthread_cond):
Replace unused struct __pthread_condimpl *__impl field with unsigned int
__wrefs.
(__PTHREAD_COND_INITIALIZER): Update accordingly.
* sysdeps/htl/pt-cond-timedwait.c (__pthread_cond_timedwait_internal):
Register as waiter in __wrefs field. On unregistering, wake any pending
pthread_cond_destroy.
* sysdeps/htl/pt-cond-destroy.c (__pthread_cond_destroy): Register wake
request in __wrefs.
* nptl/Makefile (tests): Move tst-cond20 tst-cond21 to...
* sysdeps/pthread/Makefile (tests): ... here.
* nptl/tst-cond20.c nptl/tst-cond21.c: Move to...
* sysdeps/pthread/tst-cond20.c sysdeps/pthread/tst-cond21.c: ... here.
Diffstat (limited to 'sysdeps/mach')
| -rw-r--r-- | sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c b/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c index 939ed568ba..4f63955d04 100644 --- a/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c +++ b/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c @@ -111,6 +111,10 @@ __pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond, /* Release MUTEX before blocking. */ __pthread_mutex_unlock (mutex); + /* Increase the waiter reference count. Relaxed MO is sufficient because + we only need to synchronize when decrementing the reference count. */ + atomic_fetch_add_relaxed (&cond->__wrefs, 2); + /* Block the thread. */ if (abstime != NULL) err = __pthread_timedblock (self, abstime, clock_id); @@ -144,6 +148,13 @@ __pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond, __pthread_block (self); } + /* If destruction is pending (i.e., the wake-request flag is nonzero) and we + are the last waiter (prior value of __wrefs was 1 << 1), then wake any + threads waiting in pthread_cond_destroy. Release MO to synchronize with + these threads. Don't bother clearing the wake-up request flag. */ + if ((atomic_fetch_add_release (&cond->__wrefs, -2)) == 3) + __gsync_wake (__mach_task_self (), (vm_offset_t) &cond->__wrefs, 0, 0); + /* Clear the hook, now that we are done blocking. */ ss->cancel_hook = NULL; /* Check the cancellation flag; we might have unblocked due to |