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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*
* pkix_pl_rwlock.c
*
* Read/Write Lock Functions
*
*/
#include "pkix_pl_rwlock.h"
/* --Private-Functions-------------------------------------------- */
static PKIX_Error *
pkix_pl_RWLock_Destroy(
PKIX_PL_Object *object,
void *plContext)
{
PKIX_PL_RWLock* rwlock = NULL;
PKIX_ENTER(RWLOCK, "pkix_pl_RWLock_Destroy");
PKIX_NULLCHECK_ONE(object);
PKIX_CHECK(pkix_CheckType(object, PKIX_RWLOCK_TYPE, plContext),
PKIX_OBJECTNOTRWLOCK);
rwlock = (PKIX_PL_RWLock*) object;
PKIX_RWLOCK_DEBUG("Calling PR_DestroyRWLock)\n");
PR_DestroyRWLock(rwlock->lock);
rwlock->lock = NULL;
cleanup:
PKIX_RETURN(RWLOCK);
}
/*
* FUNCTION: pkix_pl_RWLock_RegisterSelf
* DESCRIPTION:
* Registers PKIX_RWLOCK_TYPE and its related functions with systemClasses[]
* THREAD SAFETY:
* Not Thread Safe - for performance and complexity reasons
*
* Since this function is only called by PKIX_PL_Initialize, which should
* only be called once, it is acceptable that this function is not
* thread-safe.
*/
PKIX_Error *
pkix_pl_RWLock_RegisterSelf(
void *plContext)
{
extern pkix_ClassTable_Entry systemClasses[PKIX_NUMTYPES];
pkix_ClassTable_Entry entry;
PKIX_ENTER(RWLOCK, "pkix_pl_RWLock_RegisterSelf");
entry.description = "RWLock";
entry.objCounter = 0;
entry.typeObjectSize = sizeof(PKIX_PL_RWLock);
entry.destructor = pkix_pl_RWLock_Destroy;
entry.equalsFunction = NULL;
entry.hashcodeFunction = NULL;
entry.toStringFunction = NULL;
entry.comparator = NULL;
entry.duplicateFunction = NULL;
systemClasses[PKIX_RWLOCK_TYPE] = entry;
PKIX_RETURN(RWLOCK);
}
/* --Public-Functions--------------------------------------------- */
PKIX_Error *
PKIX_PL_RWLock_Create(
PKIX_PL_RWLock **pNewLock,
void *plContext)
{
PKIX_PL_RWLock *rwLock = NULL;
PKIX_ENTER(RWLOCK, "PKIX_PL_RWLock_Create");
PKIX_NULLCHECK_ONE(pNewLock);
PKIX_CHECK(PKIX_PL_Object_Alloc
(PKIX_RWLOCK_TYPE,
sizeof (PKIX_PL_RWLock),
(PKIX_PL_Object **)&rwLock,
plContext),
PKIX_ERRORALLOCATINGRWLOCK);
PKIX_RWLOCK_DEBUG("\tCalling PR_NewRWLock)\n");
rwLock->lock = PR_NewRWLock(PR_RWLOCK_RANK_NONE, "PKIX RWLock");
if (rwLock->lock == NULL) {
PKIX_DECREF(rwLock);
PKIX_ERROR(PKIX_OUTOFMEMORY);
}
rwLock->readCount = 0;
rwLock->writeLocked = PKIX_FALSE;
*pNewLock = rwLock;
cleanup:
PKIX_RETURN(RWLOCK);
}
PKIX_Error *
PKIX_PL_AcquireReaderLock(
PKIX_PL_RWLock *lock,
void *plContext)
{
PKIX_ENTER(RWLOCK, "PKIX_PL_AcquireReaderLock");
PKIX_NULLCHECK_ONE(lock);
PKIX_RWLOCK_DEBUG("\tCalling PR_RWLock_Rlock)\n");
(void) PR_RWLock_Rlock(lock->lock);
lock->readCount++;
PKIX_RETURN(RWLOCK);
}
PKIX_Error *
PKIX_PL_ReleaseReaderLock(
PKIX_PL_RWLock *lock,
void *plContext)
{
PKIX_ENTER(RWLOCK, "PKIX_PL_ReleaseReaderLock");
PKIX_NULLCHECK_ONE(lock);
PKIX_RWLOCK_DEBUG("\tCalling PR_RWLock_Unlock)\n");
(void) PR_RWLock_Unlock(lock->lock);
lock->readCount--;
PKIX_RETURN(RWLOCK);
}
PKIX_Error *
PKIX_PL_IsReaderLockHeld(
PKIX_PL_RWLock *lock,
PKIX_Boolean *pIsHeld,
void *plContext)
{
PKIX_ENTER(RWLOCK, "PKIX_PL_IsReaderLockHeld");
PKIX_NULLCHECK_TWO(lock, pIsHeld);
*pIsHeld = (lock->readCount > 0)?PKIX_TRUE:PKIX_FALSE;
PKIX_RETURN(RWLOCK);
}
PKIX_Error *
PKIX_PL_AcquireWriterLock(
PKIX_PL_RWLock *lock,
void *plContext)
{
PKIX_ENTER(RWLOCK, "PKIX_PL_AcquireWriterLock");
PKIX_NULLCHECK_ONE(lock);
PKIX_RWLOCK_DEBUG("\tCalling PR_RWLock_Wlock\n");
(void) PR_RWLock_Wlock(lock->lock);
if (lock->readCount > 0) {
PKIX_ERROR(PKIX_LOCKHASNONZEROREADCOUNT);
}
/* We should never acquire a write lock if the lock is held */
lock->writeLocked = PKIX_TRUE;
cleanup:
PKIX_RETURN(RWLOCK);
}
PKIX_Error *
PKIX_PL_ReleaseWriterLock(
PKIX_PL_RWLock *lock,
void *plContext)
{
PKIX_ENTER(RWLOCK, "PKIX_PL_ReleaseWriterLock");
PKIX_NULLCHECK_ONE(lock);
if (lock->readCount > 0) {
PKIX_ERROR(PKIX_LOCKHASNONZEROREADCOUNT);
}
PKIX_RWLOCK_DEBUG("\tCalling PR_RWLock_Unlock)\n");
(void) PR_RWLock_Unlock(lock->lock);
/* XXX Need to think about thread safety here */
/* There should be a single lock holder */
lock->writeLocked = PKIX_FALSE;
cleanup:
PKIX_RETURN(RWLOCK);
}
PKIX_Error *
PKIX_PL_IsWriterLockHeld(
PKIX_PL_RWLock *lock,
PKIX_Boolean *pIsHeld,
void *plContext)
{
PKIX_ENTER(RWLOCK, "PKIX_PL_IsWriterLockHeld");
PKIX_NULLCHECK_TWO(lock, pIsHeld);
*pIsHeld = lock->writeLocked;
PKIX_RETURN(RWLOCK);
}