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| author | Rich Felker <dalias@aerifal.cx> | 2011-09-22 21:08:55 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2011-09-22 21:08:55 -0400 |
| commit | 4b153ac42428447a148e6da543ebe6df017078db (patch) | |
| tree | d9a5b8035f98b8cec47fc6044e38305ea5cdb91a /src/thread | |
| parent | 2eff02e4a032323a45541c79967638d8c77d79e4 (diff) | |
| download | musl-4b153ac42428447a148e6da543ebe6df017078db.tar.gz | |
fix deadlock in condition wait whenever there are multiple waiters
it's amazing none of the conformance tests i've run even bothered to
check whether something so basic works...
Diffstat (limited to 'src/thread')
| -rw-r--r-- | src/thread/pthread_cond_broadcast.c | 3 | ||||
| -rw-r--r-- | src/thread/pthread_cond_signal.c | 3 | ||||
| -rw-r--r-- | src/thread/pthread_cond_timedwait.c | 16 |
3 files changed, 17 insertions, 5 deletions
diff --git a/src/thread/pthread_cond_broadcast.c b/src/thread/pthread_cond_broadcast.c index 30f7f6df..6002c535 100644 --- a/src/thread/pthread_cond_broadcast.c +++ b/src/thread/pthread_cond_broadcast.c @@ -2,7 +2,8 @@ int pthread_cond_broadcast(pthread_cond_t *c) { - if (a_swap(&c->_c_block, 0)) + int w = c->_c_waiters; + if (a_swap(&c->_c_block, 0) || w) __wake(&c->_c_block, -1, 0); return 0; } diff --git a/src/thread/pthread_cond_signal.c b/src/thread/pthread_cond_signal.c index a0211287..e8ed71cc 100644 --- a/src/thread/pthread_cond_signal.c +++ b/src/thread/pthread_cond_signal.c @@ -2,7 +2,8 @@ int pthread_cond_signal(pthread_cond_t *c) { - if (a_swap(&c->_c_block, 0)); + int w = c->_c_waiters; + if (a_swap(&c->_c_block, 0) || w) __wake(&c->_c_block, 1, 0); return 0; } diff --git a/src/thread/pthread_cond_timedwait.c b/src/thread/pthread_cond_timedwait.c index ee874a36..ec5aa6f4 100644 --- a/src/thread/pthread_cond_timedwait.c +++ b/src/thread/pthread_cond_timedwait.c @@ -1,12 +1,20 @@ #include "pthread_impl.h" -static void relock(void *m) +struct cm { + pthread_cond_t *c; + pthread_mutex_t *m; +}; + +static void cleanup(void *p) { - pthread_mutex_lock(m); + struct cm *cm = p; + a_dec(&cm->c->_c_waiters); + pthread_mutex_lock(cm->m); } int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct timespec *ts) { + struct cm cm = { .c=c, .m=m }; int r, e=0; if (ts && ts->tv_nsec >= 1000000000UL) @@ -17,8 +25,10 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t c->_c_block = 1; if ((r=pthread_mutex_unlock(m))) return r; - do e = __timedwait(&c->_c_block, 1, c->_c_clock, ts, relock, m, 0); + a_inc(&c->_c_waiters); + do e = __timedwait(&c->_c_block, 1, c->_c_clock, ts, cleanup, &cm, 0); while (e == EINTR); + a_dec(&c->_c_waiters); if ((r=pthread_mutex_lock(m))) return r; |