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