/*
* 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 */