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Diffstat (limited to 'pthreads/ptw32_callUserDestroyRoutines.c')
| -rw-r--r-- | pthreads/ptw32_callUserDestroyRoutines.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/pthreads/ptw32_callUserDestroyRoutines.c b/pthreads/ptw32_callUserDestroyRoutines.c new file mode 100644 index 000000000..a583f188d --- /dev/null +++ b/pthreads/ptw32_callUserDestroyRoutines.c @@ -0,0 +1,220 @@ +/* + * ptw32_callUserDestroyRoutines.c + * + * Description: + * This translation unit implements routines which are private to + * the implementation and may be used throughout it. + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2005 Pthreads-win32 contributors + * + * Contact Email: rpj@callisto.canberra.edu.au + * + * The current list of contributors is contained + * in the file CONTRIBUTORS included with the source + * code distribution. The list can also be seen at the + * following World Wide Web location: + * http://sources.redhat.com/pthreads-win32/contributors.html + * + * This 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 of the License, or (at your option) any later version. + * + * This 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 this library in the file COPYING.LIB; + * if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include "pthread.h" +#include "implement.h" + +#ifdef __cplusplus +# if ! defined (_MSC_VER) && ! (defined(__GNUC__) && __GNUC__ < 3) && ! defined(__WATCOMC__) +using + std::terminate; +# endif +#endif + +void +ptw32_callUserDestroyRoutines (pthread_t thread) + /* + * ------------------------------------------------------------------- + * DOCPRIVATE + * + * This the routine runs through all thread keys and calls + * the destroy routines on the user's data for the current thread. + * It simulates the behaviour of POSIX Threads. + * + * PARAMETERS + * thread + * an instance of pthread_t + * + * RETURNS + * N/A + * ------------------------------------------------------------------- + */ +{ + ThreadKeyAssoc * assoc; + + if (thread.p != NULL) + { + int assocsRemaining; + int iterations = 0; + ptw32_thread_t * sp = (ptw32_thread_t *) thread.p; + + /* + * Run through all Thread<-->Key associations + * for the current thread. + * + * Do this process at most PTHREAD_DESTRUCTOR_ITERATIONS times. + */ + do + { + assocsRemaining = 0; + iterations++; + + (void) pthread_mutex_lock(&(sp->threadLock)); + /* + * The pointer to the next assoc is stored in the thread struct so that + * the assoc destructor in pthread_key_delete can adjust it + * if it deletes this assoc. This can happen if we fail to acquire + * both locks below, and are forced to release all of our locks, + * leaving open the opportunity for pthread_key_delete to get in + * before us. + */ + sp->nextAssoc = sp->keys; + (void) pthread_mutex_unlock(&(sp->threadLock)); + + for (;;) + { + void * value; + pthread_key_t k; + void (*destructor) (void *); + + /* + * First we need to serialise with pthread_key_delete by locking + * both assoc guards, but in the reverse order to our convention, + * so we must be careful to avoid deadlock. + */ + (void) pthread_mutex_lock(&(sp->threadLock)); + + if ((assoc = (ThreadKeyAssoc *)sp->nextAssoc) == NULL) + { + /* Finished */ + pthread_mutex_unlock(&(sp->threadLock)); + break; + } + else + { + /* + * assoc->key must be valid because assoc can't change or be + * removed from our chain while we hold at least one lock. If + * the assoc was on our key chain then the key has not been + * deleted yet. + * + * Now try to acquire the second lock without deadlocking. + * If we fail, we need to relinquish the first lock and the + * processor and then try to acquire them all again. + */ + if (pthread_mutex_trylock(&(assoc->key->keyLock)) == EBUSY) + { + pthread_mutex_unlock(&(sp->threadLock)); + Sleep(1); // Ugly but necessary to avoid priority effects. + /* + * Go around again. + * If pthread_key_delete has removed this assoc in the meantime, + * sp->nextAssoc will point to a new assoc. + */ + continue; + } + } + + /* We now hold both locks */ + + sp->nextAssoc = assoc->nextKey; + + /* + * Key still active; pthread_key_delete + * will block on these same mutexes before + * it can release actual key; therefore, + * key is valid and we can call the destroy + * routine; + */ + k = assoc->key; + destructor = k->destructor; + value = TlsGetValue(k->key); + TlsSetValue (k->key, NULL); + + // Every assoc->key exists and has a destructor + if (value != NULL && iterations <= PTHREAD_DESTRUCTOR_ITERATIONS) + { + /* + * Unlock both locks before the destructor runs. + * POSIX says pthread_key_delete can be run from destructors, + * and that probably includes with this key as target. + * pthread_setspecific can also be run from destructors and + * also needs to be able to access the assocs. + */ + (void) pthread_mutex_unlock(&(sp->threadLock)); + (void) pthread_mutex_unlock(&(k->keyLock)); + + assocsRemaining++; + +#ifdef __cplusplus + + try + { + /* + * Run the caller's cleanup routine. + */ + destructor (value); + } + catch (...) + { + /* + * A system unexpected exception has occurred + * running the user's destructor. + * We get control back within this block in case + * the application has set up it's own terminate + * handler. Since we are leaving the thread we + * should not get any internal pthreads + * exceptions. + */ + terminate (); + } + +#else /* __cplusplus */ + + /* + * Run the caller's cleanup routine. + */ + destructor (value); + +#endif /* __cplusplus */ + + } + else + { + /* + * Remove association from both the key and thread chains + * and reclaim it's memory resources. + */ + ptw32_tkAssocDestroy (assoc); + (void) pthread_mutex_unlock(&(sp->threadLock)); + (void) pthread_mutex_unlock(&(k->keyLock)); + } + } + } + while (assocsRemaining); + } +} /* ptw32_callUserDestroyRoutines */ |