1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/nsprpub/pr/include/obsolete/prsem.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,64 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef prsem_h___
1.10 +#define prsem_h___
1.11 +
1.12 +/*
1.13 +** API for counting semaphores. Semaphores are counting synchronizing
1.14 +** variables based on a lock and a condition variable. They are lightweight
1.15 +** contention control for a given count of resources.
1.16 +*/
1.17 +#include "prtypes.h"
1.18 +
1.19 +PR_BEGIN_EXTERN_C
1.20 +
1.21 +typedef struct PRSemaphore PRSemaphore;
1.22 +
1.23 +/*
1.24 +** Create a new semaphore object.
1.25 +*/
1.26 +NSPR_API(PRSemaphore*) PR_NewSem(PRUintn value);
1.27 +
1.28 +/*
1.29 +** Destroy the given semaphore object.
1.30 +**
1.31 +*/
1.32 +NSPR_API(void) PR_DestroySem(PRSemaphore *sem);
1.33 +
1.34 +/*
1.35 +** Wait on a Semaphore.
1.36 +**
1.37 +** This routine allows a calling thread to wait or proceed depending upon the
1.38 +** state of the semahore sem. The thread can proceed only if the counter value
1.39 +** of the semaphore sem is currently greater than 0. If the value of semaphore
1.40 +** sem is positive, it is decremented by one and the routine returns immediately
1.41 +** allowing the calling thread to continue. If the value of semaphore sem is 0,
1.42 +** the calling thread blocks awaiting the semaphore to be released by another
1.43 +** thread.
1.44 +**
1.45 +** This routine can return PR_PENDING_INTERRUPT if the waiting thread
1.46 +** has been interrupted.
1.47 +*/
1.48 +NSPR_API(PRStatus) PR_WaitSem(PRSemaphore *sem);
1.49 +
1.50 +/*
1.51 +** This routine increments the counter value of the semaphore. If other threads
1.52 +** are blocked for the semaphore, then the scheduler will determine which ONE
1.53 +** thread will be unblocked.
1.54 +*/
1.55 +NSPR_API(void) PR_PostSem(PRSemaphore *sem);
1.56 +
1.57 +/*
1.58 +** Returns the value of the semaphore referenced by sem without affecting
1.59 +** the state of the semaphore. The value represents the semaphore vaule
1.60 +F** at the time of the call, but may not be the actual value when the
1.61 +** caller inspects it.
1.62 +*/
1.63 +NSPR_API(PRUintn) PR_GetValueSem(PRSemaphore *sem);
1.64 +
1.65 +PR_END_EXTERN_C
1.66 +
1.67 +#endif /* prsem_h___ */
