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#include "pthread_impl.h" int pthread_cond_broadcast(pthread_cond_t *c) { pthread_mutex_t *m; if (!c->_c_waiters) return 0; a_inc(&c->_c_seq); /* If cond var is process-shared, simply wake all waiters. */ if (c->_c_mutex == (void *)-1) { __wake(&c->_c_seq, -1, 0); return 0; } /* Block waiters from returning so we can use the mutex. */ while (a_swap(&c->_c_lock, 1)) __wait(&c->_c_lock, &c->_c_lockwait, 1, 1); if (!c->_c_waiters) goto out; m = c->_c_mutex; /* Move waiter count to the mutex */ a_fetch_add(&m->_m_waiters, c->_c_waiters2); c->_c_waiters2 = 0; /* Perform the futex requeue, waking one waiter unless we know * that the calling thread holds the mutex. */ __syscall(SYS_futex, &c->_c_seq, FUTEX_REQUEUE, !m->_m_type || (m->_m_lock&INT_MAX)!=pthread_self()->tid, INT_MAX, &m->_m_lock); out: a_store(&c->_c_lock, 0); if (c->_c_lockwait) __wake(&c->_c_lock, 1, 0); return 0; } |