diff options
Diffstat (limited to 'nptl/sysdeps/pthread/pthread_cond_wait.c')
| -rw-r--r-- | nptl/sysdeps/pthread/pthread_cond_wait.c | 191 |
1 files changed, 0 insertions, 191 deletions
diff --git a/nptl/sysdeps/pthread/pthread_cond_wait.c b/nptl/sysdeps/pthread/pthread_cond_wait.c deleted file mode 100644 index f5f5cec5a8..0000000000 --- a/nptl/sysdeps/pthread/pthread_cond_wait.c +++ /dev/null @@ -1,191 +0,0 @@ -/* Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003. - - 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 <endian.h> -#include <errno.h> -#include <sysdep.h> -#include <lowlevellock.h> -#include <pthread.h> -#include <pthreadP.h> - -#include <shlib-compat.h> - - -struct _condvar_cleanup_buffer -{ - int oldtype; - pthread_cond_t *cond; - pthread_mutex_t *mutex; - unsigned int bc_seq; -}; - - -void -__attribute__ ((visibility ("hidden"))) -__condvar_cleanup (void *arg) -{ - struct _condvar_cleanup_buffer *cbuffer = - (struct _condvar_cleanup_buffer *) arg; - unsigned int destroying; - - /* We are going to modify shared data. */ - lll_mutex_lock (cbuffer->cond->__data.__lock); - - if (cbuffer->bc_seq == cbuffer->cond->__data.__broadcast_seq) - { - /* This thread is not waiting anymore. Adjust the sequence counters - appropriately. We do not increment WAKEUP_SEQ if this would - bump it over the value of TOTAL_SEQ. This can happen if a thread - was woken and then canceled. */ - if (cbuffer->cond->__data.__wakeup_seq - < cbuffer->cond->__data.__total_seq) - { - ++cbuffer->cond->__data.__wakeup_seq; - ++cbuffer->cond->__data.__futex; - } - ++cbuffer->cond->__data.__woken_seq; - } - - cbuffer->cond->__data.__nwaiters -= 1 << COND_CLOCK_BITS; - - /* If pthread_cond_destroy was called on this variable already, - notify the pthread_cond_destroy caller all waiters have left - and it can be successfully destroyed. */ - destroying = 0; - if (cbuffer->cond->__data.__total_seq == -1ULL - && cbuffer->cond->__data.__nwaiters < (1 << COND_CLOCK_BITS)) - { - lll_futex_wake (&cbuffer->cond->__data.__nwaiters, 1); - destroying = 1; - } - - /* We are done. */ - lll_mutex_unlock (cbuffer->cond->__data.__lock); - - /* Wake everybody to make sure no condvar signal gets lost. */ - if (! destroying) - lll_futex_wake (&cbuffer->cond->__data.__futex, INT_MAX); - - /* Get the mutex before returning unless asynchronous cancellation - is in effect. */ - __pthread_mutex_cond_lock (cbuffer->mutex); -} - - -int -__pthread_cond_wait (cond, mutex) - pthread_cond_t *cond; - pthread_mutex_t *mutex; -{ - struct _pthread_cleanup_buffer buffer; - struct _condvar_cleanup_buffer cbuffer; - int err; - - /* Make sure we are along. */ - lll_mutex_lock (cond->__data.__lock); - - /* Now we can release the mutex. */ - err = __pthread_mutex_unlock_usercnt (mutex, 0); - if (__builtin_expect (err, 0)) - { - lll_mutex_unlock (cond->__data.__lock); - return err; - } - - /* We have one new user of the condvar. */ - ++cond->__data.__total_seq; - ++cond->__data.__futex; - cond->__data.__nwaiters += 1 << COND_CLOCK_BITS; - - /* Remember the mutex we are using here. If there is already a - different address store this is a bad user bug. Do not store - anything for pshared condvars. */ - if (cond->__data.__mutex != (void *) ~0l) - cond->__data.__mutex = mutex; - - /* Prepare structure passed to cancellation handler. */ - cbuffer.cond = cond; - cbuffer.mutex = mutex; - - /* Before we block we enable cancellation. Therefore we have to - install a cancellation handler. */ - __pthread_cleanup_push (&buffer, __condvar_cleanup, &cbuffer); - - /* The current values of the wakeup counter. The "woken" counter - must exceed this value. */ - unsigned long long int val; - unsigned long long int seq; - val = seq = cond->__data.__wakeup_seq; - /* Remember the broadcast counter. */ - cbuffer.bc_seq = cond->__data.__broadcast_seq; - - do - { - unsigned int futex_val = cond->__data.__futex; - - /* Prepare to wait. Release the condvar futex. */ - lll_mutex_unlock (cond->__data.__lock); - - /* Enable asynchronous cancellation. Required by the standard. */ - cbuffer.oldtype = __pthread_enable_asynccancel (); - - /* Wait until woken by signal or broadcast. */ - lll_futex_wait (&cond->__data.__futex, futex_val); - - /* Disable asynchronous cancellation. */ - __pthread_disable_asynccancel (cbuffer.oldtype); - - /* We are going to look at shared data again, so get the lock. */ - lll_mutex_lock (cond->__data.__lock); - - /* If a broadcast happened, we are done. */ - if (cbuffer.bc_seq != cond->__data.__broadcast_seq) - goto bc_out; - - /* Check whether we are eligible for wakeup. */ - val = cond->__data.__wakeup_seq; - } - while (val == seq || cond->__data.__woken_seq == val); - - /* Another thread woken up. */ - ++cond->__data.__woken_seq; - - bc_out: - - cond->__data.__nwaiters -= 1 << COND_CLOCK_BITS; - - /* If pthread_cond_destroy was called on this varaible already, - notify the pthread_cond_destroy caller all waiters have left - and it can be successfully destroyed. */ - if (cond->__data.__total_seq == -1ULL - && cond->__data.__nwaiters < (1 << COND_CLOCK_BITS)) - lll_futex_wake (&cond->__data.__nwaiters, 1); - - /* We are done with the condvar. */ - lll_mutex_unlock (cond->__data.__lock); - - /* The cancellation handling is back to normal, remove the handler. */ - __pthread_cleanup_pop (&buffer, 0); - - /* Get the mutex before returning. */ - return __pthread_mutex_cond_lock (mutex); -} - -versioned_symbol (libpthread, __pthread_cond_wait, pthread_cond_wait, - GLIBC_2_3_2); |