diff options
Diffstat (limited to 'nptl/pthread_mutex_trylock.c')
-rw-r--r-- | nptl/pthread_mutex_trylock.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c index f3a18569a1..94d519233b 100644 --- a/nptl/pthread_mutex_trylock.c +++ b/nptl/pthread_mutex_trylock.c @@ -297,6 +297,79 @@ __pthread_mutex_trylock (mutex) return 0; } + case PTHREAD_MUTEX_PP_RECURSIVE_NP: + case PTHREAD_MUTEX_PP_ERRORCHECK_NP: + case PTHREAD_MUTEX_PP_NORMAL_NP: + case PTHREAD_MUTEX_PP_ADAPTIVE_NP: + { + int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP; + + oldval = mutex->__data.__lock; + + /* Check whether we already hold the mutex. */ + if (mutex->__data.__owner == id) + { + if (kind == PTHREAD_MUTEX_ERRORCHECK_NP) + return EDEADLK; + + if (kind == PTHREAD_MUTEX_RECURSIVE_NP) + { + /* Just bump the counter. */ + if (__builtin_expect (mutex->__data.__count + 1 == 0, 0)) + /* Overflow of the counter. */ + return EAGAIN; + + ++mutex->__data.__count; + + return 0; + } + } + + int oldprio = -1, ceilval; + do + { + int ceiling = (oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) + >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT; + + if (__pthread_current_priority () > ceiling) + { + if (oldprio != -1) + __pthread_tpp_change_priority (oldprio, -1); + return EINVAL; + } + + int retval = __pthread_tpp_change_priority (oldprio, ceiling); + if (retval) + return retval; + + ceilval = ceiling << PTHREAD_MUTEX_PRIO_CEILING_SHIFT; + oldprio = ceiling; + + oldval + = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock, + ceilval | 1, ceilval); + + if (oldval == ceilval) + break; + } + while ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval); + + if (oldval != ceilval) + { + __pthread_tpp_change_priority (oldprio, -1); + break; + } + + assert (mutex->__data.__owner == 0); + /* Record the ownership. */ + mutex->__data.__owner = id; + ++mutex->__data.__nusers; + mutex->__data.__count = 1; + + return 0; + } + break; + default: /* Correct code cannot set any other type. */ return EINVAL; |