diff options
Diffstat (limited to 'libpthread/nptl/sysdeps/pthread/pthread_cond_wait.c')
| -rw-r--r-- | libpthread/nptl/sysdeps/pthread/pthread_cond_wait.c | 51 |
1 files changed, 31 insertions, 20 deletions
diff --git a/libpthread/nptl/sysdeps/pthread/pthread_cond_wait.c b/libpthread/nptl/sysdeps/pthread/pthread_cond_wait.c index 79245b7c1..2fac02d83 100644 --- a/libpthread/nptl/sysdeps/pthread/pthread_cond_wait.c +++ b/libpthread/nptl/sysdeps/pthread/pthread_cond_wait.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2003, 2004 Free Software Foundation, Inc. +/* Copyright (C) 2003, 2004, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003. @@ -41,38 +41,46 @@ __condvar_cleanup (void *arg) struct _condvar_cleanup_buffer *cbuffer = (struct _condvar_cleanup_buffer *) arg; unsigned int destroying; + int pshared = (cbuffer->cond->__data.__mutex == (void *) ~0l) + ? LLL_SHARED : LLL_PRIVATE; /* We are going to modify shared data. */ - lll_mutex_lock (cbuffer->cond->__data.__lock); + lll_lock (cbuffer->cond->__data.__lock, pshared); if (cbuffer->bc_seq == cbuffer->cond->__data.__broadcast_seq) { /* This thread is not waiting anymore. Adjust the sequence counters - appropriately. */ - ++cbuffer->cond->__data.__wakeup_seq; + 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.__futex; } - cbuffer->cond->__data.__nwaiters -= 1 << COND_CLOCK_BITS; + cbuffer->cond->__data.__nwaiters -= 1 << COND_NWAITERS_SHIFT; /* 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)) + && cbuffer->cond->__data.__nwaiters < (1 << COND_NWAITERS_SHIFT)) { - lll_futex_wake (&cbuffer->cond->__data.__nwaiters, 1); + lll_futex_wake (&cbuffer->cond->__data.__nwaiters, 1, pshared); destroying = 1; } /* We are done. */ - lll_mutex_unlock (cbuffer->cond->__data.__lock); + lll_unlock (cbuffer->cond->__data.__lock, pshared); /* Wake everybody to make sure no condvar signal gets lost. */ if (! destroying) - lll_futex_wake (&cbuffer->cond->__data.__futex, INT_MAX); + lll_futex_wake (&cbuffer->cond->__data.__futex, INT_MAX, pshared); /* Get the mutex before returning unless asynchronous cancellation is in effect. */ @@ -88,22 +96,24 @@ __pthread_cond_wait ( struct _pthread_cleanup_buffer buffer; struct _condvar_cleanup_buffer cbuffer; int err; + int pshared = (cond->__data.__mutex == (void *) ~0l) + ? LLL_SHARED : LLL_PRIVATE; /* Make sure we are along. */ - lll_mutex_lock (cond->__data.__lock); + lll_lock (cond->__data.__lock, pshared); /* Now we can release the mutex. */ err = __pthread_mutex_unlock_usercnt (mutex, 0); if (__builtin_expect (err, 0)) { - lll_mutex_unlock (cond->__data.__lock); + lll_unlock (cond->__data.__lock, pshared); return err; } /* We have one new user of the condvar. */ ++cond->__data.__total_seq; ++cond->__data.__futex; - cond->__data.__nwaiters += 1 << COND_CLOCK_BITS; + cond->__data.__nwaiters += 1 << COND_NWAITERS_SHIFT; /* Remember the mutex we are using here. If there is already a different address store this is a bad user bug. Do not store @@ -132,19 +142,19 @@ __pthread_cond_wait ( unsigned int futex_val = cond->__data.__futex; /* Prepare to wait. Release the condvar futex. */ - lll_mutex_unlock (cond->__data.__lock); + lll_unlock (cond->__data.__lock, pshared); /* 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); + lll_futex_wait (&cond->__data.__futex, futex_val, pshared); /* 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); + lll_lock (cond->__data.__lock, pshared); /* If a broadcast happened, we are done. */ if (cbuffer.bc_seq != cond->__data.__broadcast_seq) @@ -160,17 +170,17 @@ __pthread_cond_wait ( bc_out: - cond->__data.__nwaiters -= 1 << COND_CLOCK_BITS; + cond->__data.__nwaiters -= 1 << COND_NWAITERS_SHIFT; /* 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); + && cond->__data.__nwaiters < (1 << COND_NWAITERS_SHIFT)) + lll_futex_wake (&cond->__data.__nwaiters, 1, pshared); /* We are done with the condvar. */ - lll_mutex_unlock (cond->__data.__lock); + lll_unlock (cond->__data.__lock, pshared); /* The cancellation handling is back to normal, remove the handler. */ __pthread_cleanup_pop (&buffer, 0); @@ -178,4 +188,5 @@ __pthread_cond_wait ( /* Get the mutex before returning. */ return __pthread_mutex_cond_lock (mutex); } + weak_alias(__pthread_cond_wait, pthread_cond_wait) |