diff options
Diffstat (limited to 'nptl/pthread_cond_wait.c')
-rw-r--r-- | nptl/pthread_cond_wait.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/nptl/pthread_cond_wait.c b/nptl/pthread_cond_wait.c new file mode 100644 index 0000000000..37c5ffe846 --- /dev/null +++ b/nptl/pthread_cond_wait.c @@ -0,0 +1,66 @@ +/* Copyright (C) 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include "pthreadP.h" +#include <lowlevellock.h> + + +int +pthread_cond_wait (cond, mutex) + pthread_cond_t *cond; + pthread_mutex_t *mutex; +{ + int err; + + /* This function is a cancellation point. Test before we potentially + go to sleep. */ + CANCELLATION_P (THREAD_SELF); + + /* Make sure the condition is modified atomically. */ + lll_mutex_lock (cond->__data.__lock); + + /* Release the mutex. This might fail. */ + err = pthread_mutex_unlock (mutex); + if (__builtin_expect (err != 0, 0)) + { + lll_mutex_unlock (cond->__data.__lock); + return err; + } + + /* One more tread waiting. */ + ++cond->__data.__nr_sleepers; + + /* The actual conditional variable implementation. */ + lll_cond_wait (cond); + + if (--cond->__data.__nr_sleepers == 0) + /* Forget about the current wakeups now that they are done. */ + cond->__data.__nr_wakers = 0; + + /* Lose the condvar lock. */ + lll_mutex_unlock (cond->__data.__lock); + + /* We have to get the mutex before returning. */ + err = pthread_mutex_lock (mutex); + + /* Cancellation handling. */ + CANCELLATION_P (THREAD_SELF); + + return err; +} |