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Diffstat (limited to 'nsprpub/pr/include/prrwlock.h')
-rw-r--r-- | nsprpub/pr/include/prrwlock.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/nsprpub/pr/include/prrwlock.h b/nsprpub/pr/include/prrwlock.h new file mode 100644 index 0000000000..ab47b53fb0 --- /dev/null +++ b/nsprpub/pr/include/prrwlock.h @@ -0,0 +1,88 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* 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/. */ + +/* +** File: prrwlock.h +** Description: API to basic reader-writer lock functions of NSPR. +** +**/ + +#ifndef prrwlock_h___ +#define prrwlock_h___ + +#include "prtypes.h" + +PR_BEGIN_EXTERN_C + +/* + * PRRWLock -- + * + * The reader writer lock, PRRWLock, is an opaque object to the clients + * of NSPR. All routines operate on a pointer to this opaque entity. + */ + + +typedef struct PRRWLock PRRWLock; + +#define PR_RWLOCK_RANK_NONE 0 + + +/*********************************************************************** +** FUNCTION: PR_NewRWLock +** DESCRIPTION: +** Returns a pointer to a newly created reader-writer lock object. +** INPUTS: Lock rank +** Lock name +** OUTPUTS: void +** RETURN: PRRWLock* +** If the lock cannot be created because of resource constraints, NULL +** is returned. +** +***********************************************************************/ +NSPR_API(PRRWLock*) PR_NewRWLock(PRUint32 lock_rank, const char *lock_name); + +/*********************************************************************** +** FUNCTION: PR_DestroyRWLock +** DESCRIPTION: +** Destroys a given RW lock object. +** INPUTS: PRRWLock *lock - Lock to be freed. +** OUTPUTS: void +** RETURN: None +***********************************************************************/ +NSPR_API(void) PR_DestroyRWLock(PRRWLock *lock); + +/*********************************************************************** +** FUNCTION: PR_RWLock_Rlock +** DESCRIPTION: +** Apply a read lock (non-exclusive) on a RWLock +** INPUTS: PRRWLock *lock - Lock to be read-locked. +** OUTPUTS: void +** RETURN: None +***********************************************************************/ +NSPR_API(void) PR_RWLock_Rlock(PRRWLock *lock); + +/*********************************************************************** +** FUNCTION: PR_RWLock_Wlock +** DESCRIPTION: +** Apply a write lock (exclusive) on a RWLock +** INPUTS: PRRWLock *lock - Lock to write-locked. +** OUTPUTS: void +** RETURN: None +***********************************************************************/ +NSPR_API(void) PR_RWLock_Wlock(PRRWLock *lock); + +/*********************************************************************** +** FUNCTION: PR_RWLock_Unlock +** DESCRIPTION: +** Release a RW lock. Unlocking an unlocked lock has undefined results. +** INPUTS: PRRWLock *lock - Lock to unlocked. +** OUTPUTS: void +** RETURN: void +***********************************************************************/ +NSPR_API(void) PR_RWLock_Unlock(PRRWLock *lock); + +PR_END_EXTERN_C + +#endif /* prrwlock_h___ */ |