diff options
Diffstat (limited to 'libpthread/pthread/pt-dealloc.c')
| -rw-r--r-- | libpthread/pthread/pt-dealloc.c | 33 |
1 files changed, 16 insertions, 17 deletions
diff --git a/libpthread/pthread/pt-dealloc.c b/libpthread/pthread/pt-dealloc.c index 879608b..92fe1fd 100644 --- a/libpthread/pthread/pt-dealloc.c +++ b/libpthread/pthread/pt-dealloc.c @@ -1,5 +1,5 @@ /* Deallocate a thread structure. - Copyright (C) 2000 Free Software Foundation, Inc. + Copyright (C) 2000, 2008 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -23,13 +23,12 @@ #include <pt-internal.h> -#include <atomic.h> - /* List of thread structures corresponding to free thread IDs. */ -extern atomicptr_t __pthread_free_threads; +extern struct __pthread *__pthread_free_threads; +extern pthread_mutex_t __pthread_free_threads_lock; + -/* Deallocate the thread structure for PTHREAD and the resources - associated with it. */ +/* Deallocate the thread structure for PTHREAD. */ void __pthread_dealloc (struct __pthread *pthread) { @@ -44,22 +43,22 @@ __pthread_dealloc (struct __pthread *pthread) pthread_join is completely bogus, but unfortunately allowed by the standards. */ __pthread_mutex_lock (&pthread->state_lock); - pthread->state = PTHREAD_TERMINATED; if (pthread->state != PTHREAD_EXITED) pthread_cond_broadcast (&pthread->state_cond); __pthread_mutex_unlock (&pthread->state_lock); /* We do not actually deallocate the thread structure, but add it to a list of re-usable thread structures. */ - while (1) - { - pthread->next = (struct __pthread *)__pthread_free_threads; - if (atomic_compare_and_exchange_val_acq (&__pthread_free_threads, - (uintptr_t) pthread, - (uintptr_t) pthread->next) - == (uintptr_t) pthread->next) - break; - } + pthread_mutex_lock (&__pthread_free_threads_lock); + __pthread_enqueue (&__pthread_free_threads, pthread); + pthread_mutex_unlock (&__pthread_free_threads_lock); - /* NOTREACHED */ + /* Setting PTHREAD->STATE to PTHREAD_TERMINATED makes this TCB + available for reuse. After that point, we can no longer assume + that PTHREAD is valid. + + Note that it is safe to not lock this update to PTHREAD->STATE: + the only way that it can now be accessed is in __pthread_alloc, + which reads this variable. */ + pthread->state = PTHREAD_TERMINATED; } |