diff options
Diffstat (limited to 'mozilla/nsprpub/pr/src/bthreads/btsem.c')
-rw-r--r-- | mozilla/nsprpub/pr/src/bthreads/btsem.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/mozilla/nsprpub/pr/src/bthreads/btsem.c b/mozilla/nsprpub/pr/src/bthreads/btsem.c new file mode 100644 index 0000000..bce2814 --- /dev/null +++ b/mozilla/nsprpub/pr/src/bthreads/btsem.c @@ -0,0 +1,130 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * The contents of this file are subject to the Mozilla Public License Version + * 1.1 (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * Software distributed under the License is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License + * for the specific language governing rights and limitations under the + * License. + * + * The Original Code is the Netscape Portable Runtime (NSPR). + * + * The Initial Developer of the Original Code is + * Netscape Communications Corporation. + * Portions created by the Initial Developer are Copyright (C) 1998-2000 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * + * Alternatively, the contents of this file may be used under the terms of + * either the GNU General Public License Version 2 or later (the "GPL"), or + * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +#include <kernel/OS.h> + +#include "primpl.h" + +/* +** Create a new semaphore object. +*/ +PR_IMPLEMENT(PRSemaphore*) + PR_NewSem (PRUintn value) +{ + PRSemaphore *semaphore; + + if (!_pr_initialized) _PR_ImplicitInitialization(); + + semaphore = PR_NEWZAP(PRSemaphore); + if (NULL != semaphore) { + if ((semaphore->sem = create_sem(value, "nspr_sem")) < B_NO_ERROR) + return NULL; + else + return semaphore; + } + return NULL; +} + +/* +** Destroy the given semaphore object. +** +*/ +PR_IMPLEMENT(void) + PR_DestroySem (PRSemaphore *sem) +{ + status_t result; + + PR_ASSERT(sem != NULL); + result = delete_sem(sem->sem); + PR_ASSERT(result == B_NO_ERROR); + PR_DELETE(sem); +} + +/* +** Wait on a Semaphore. +** +** This routine allows a calling thread to wait or proceed depending upon +** the state of the semahore sem. The thread can proceed only if the +** counter value of the semaphore sem is currently greater than 0. If the +** value of semaphore sem is positive, it is decremented by one and the +** routine returns immediately allowing the calling thread to continue. If +** the value of semaphore sem is 0, the calling thread blocks awaiting the +** semaphore to be released by another thread. +** +** This routine can return PR_PENDING_INTERRUPT if the waiting thread +** has been interrupted. +*/ +PR_IMPLEMENT(PRStatus) + PR_WaitSem (PRSemaphore *sem) +{ + PR_ASSERT(sem != NULL); + if (acquire_sem(sem->sem) == B_NO_ERROR) + return PR_SUCCESS; + else + return PR_FAILURE; +} + +/* +** This routine increments the counter value of the semaphore. If other +** threads are blocked for the semaphore, then the scheduler will +** determine which ONE thread will be unblocked. +*/ +PR_IMPLEMENT(void) + PR_PostSem (PRSemaphore *sem) +{ + status_t result; + + PR_ASSERT(sem != NULL); + result = release_sem_etc(sem->sem, 1, B_DO_NOT_RESCHEDULE); + PR_ASSERT(result == B_NO_ERROR); +} + +/* +** Returns the value of the semaphore referenced by sem without affecting +** the state of the semaphore. The value represents the semaphore value +** at the time of the call, but may not be the actual value when the +** caller inspects it. +*/ +PR_IMPLEMENT(PRUintn) + PR_GetValueSem (PRSemaphore *sem) +{ + sem_info info; + + PR_ASSERT(sem != NULL); + get_sem_info(sem->sem, &info); + return info.count; +} |