diff options
Diffstat (limited to 'security/nss/lib/libpkix/pkix_pl_nss/system/pkix_pl_rwlock.c')
-rwxr-xr-x | security/nss/lib/libpkix/pkix_pl_nss/system/pkix_pl_rwlock.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/security/nss/lib/libpkix/pkix_pl_nss/system/pkix_pl_rwlock.c b/security/nss/lib/libpkix/pkix_pl_nss/system/pkix_pl_rwlock.c new file mode 100755 index 000000000..662931e98 --- /dev/null +++ b/security/nss/lib/libpkix/pkix_pl_nss/system/pkix_pl_rwlock.c @@ -0,0 +1,217 @@ +/* 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 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ +/* + * 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); +} |