diff options
Diffstat (limited to 'src/thread/pthread_mutex_timedlock.c')
| -rw-r--r-- | src/thread/pthread_mutex_timedlock.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/src/thread/pthread_mutex_timedlock.c b/src/thread/pthread_mutex_timedlock.c index 0f171c00..6b893627 100644 --- a/src/thread/pthread_mutex_timedlock.c +++ b/src/thread/pthread_mutex_timedlock.c @@ -1,5 +1,40 @@ #include "pthread_impl.h" +static int pthread_mutex_timedlock_pi(pthread_mutex_t *restrict m, const struct timespec *restrict at) +{ + int type = m->_m_type; + int priv = (type & 128) ^ 128; + pthread_t self = __pthread_self(); + int e; + + if (!priv) self->robust_list.pending = &m->_m_next; + + do e = -__syscall(SYS_futex, &m->_m_lock, FUTEX_LOCK_PI|priv, 0, at); + while (e==EINTR); + if (e) self->robust_list.pending = 0; + + switch (e) { + case 0: + /* Catch spurious success for non-robust mutexes. */ + if (!(type&4) && ((m->_m_lock & 0x40000000) || m->_m_waiters)) { + a_store(&m->_m_waiters, -1); + __syscall(SYS_futex, &m->_m_lock, FUTEX_UNLOCK_PI|priv); + self->robust_list.pending = 0; + break; + } + /* Signal to trylock that we already have the lock. */ + m->_m_count = -1; + return __pthread_mutex_trylock(m); + case ETIMEDOUT: + return e; + case EDEADLK: + if ((type&3) == PTHREAD_MUTEX_ERRORCHECK) return e; + } + do e = __timedwait(&(int){0}, 0, CLOCK_REALTIME, at, 1); + while (e != ETIMEDOUT); + return e; +} + int __pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec *restrict at) { if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL @@ -11,6 +46,8 @@ int __pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec r = __pthread_mutex_trylock(m); if (r != EBUSY) return r; + + if (type&8) return pthread_mutex_timedlock_pi(m, at); int spins = 100; while (spins-- && m->_m_lock && !m->_m_waiters) a_spin(); |