mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-06 09:05:45 +00:00
161 lines
6.1 KiB
C
161 lines
6.1 KiB
C
/*
|
|
* 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 security libraries.
|
|
*
|
|
* The Initial Developer of the Original Code is Netscape
|
|
* Communications Corporation. Portions created by Netscape are
|
|
* Copyright (C) 1994-2000 Netscape Communications Corporation. All
|
|
* Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
*
|
|
* Alternatively, the contents of this file may be used under the
|
|
* terms of the GNU General Public License Version 2 or later (the
|
|
* "GPL"), in which case the provisions of the GPL are applicable
|
|
* instead of those above. If you wish to allow use of your
|
|
* version of this file only under the terms of the GPL and not to
|
|
* allow others to use your version of this file under the MPL,
|
|
* indicate your decision by deleting the provisions above and
|
|
* replace them with the notice and other provisions required by
|
|
* the GPL. If you do not delete the provisions above, a recipient
|
|
* may use your version of this file under either the MPL or the
|
|
* GPL.
|
|
*/
|
|
|
|
/*
|
|
** File: nsrwlock.h
|
|
** Description: API to basic reader-writer lock functions of NSS.
|
|
** These are re-entrant reader writer locks; that is,
|
|
** If I hold the write lock, I can ask for it and get it again.
|
|
** If I hold the write lock, I can also ask for and get a read lock.
|
|
** I can then release the locks in any order (read or write).
|
|
** I must release each lock type as many times as I acquired it.
|
|
** Otherwise, these are normal reader/writer locks.
|
|
**
|
|
** For deadlock detection, locks should be ranked, and no lock may be aquired
|
|
** while I hold a lock of higher rank number.
|
|
** If you don't want that feature, always use NSS_RWLOCK_RANK_NONE.
|
|
** Lock name is for debugging, and is optional (may be NULL)
|
|
**/
|
|
|
|
#ifndef nssrwlk_h___
|
|
#define nssrwlk_h___
|
|
|
|
#include "prtypes.h"
|
|
#include "nssrwlkt.h"
|
|
|
|
#define NSS_RWLOCK_RANK_NONE 0
|
|
|
|
/* SEC_BEGIN_PROTOS */
|
|
PR_BEGIN_EXTERN_C
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_New
|
|
** DESCRIPTION:
|
|
** Returns a pointer to a newly created reader-writer lock object.
|
|
** INPUTS: Lock rank
|
|
** Lock name
|
|
** OUTPUTS: void
|
|
** RETURN: NSSRWLock*
|
|
** If the lock cannot be created because of resource constraints, NULL
|
|
** is returned.
|
|
**
|
|
***********************************************************************/
|
|
PR_EXTERN(NSSRWLock*) NSSRWLock_New(PRUint32 lock_rank, const char *lock_name);
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_AtomicCreate
|
|
** DESCRIPTION:
|
|
** Given the address of a NULL pointer to a NSSRWLock,
|
|
** atomically initializes that pointer to a newly created NSSRWLock.
|
|
** Returns the value placed into that pointer, or NULL.
|
|
**
|
|
** INPUTS: address of NSRWLock pointer
|
|
** Lock rank
|
|
** Lock name
|
|
** OUTPUTS: NSSRWLock*
|
|
** RETURN: NSSRWLock*
|
|
** If the lock cannot be created because of resource constraints,
|
|
** the pointer will be left NULL.
|
|
**
|
|
***********************************************************************/
|
|
PR_EXTERN(NSSRWLock *)
|
|
nssRWLock_AtomicCreate( NSSRWLock ** prwlock,
|
|
PRUint32 lock_rank,
|
|
const char * lock_name);
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_Destroy
|
|
** DESCRIPTION:
|
|
** Destroys a given RW lock object.
|
|
** INPUTS: NSSRWLock *lock - Lock to be freed.
|
|
** OUTPUTS: void
|
|
** RETURN: None
|
|
***********************************************************************/
|
|
PR_EXTERN(void) NSSRWLock_Destroy(NSSRWLock *lock);
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_LockRead
|
|
** DESCRIPTION:
|
|
** Apply a read lock (non-exclusive) on a RWLock
|
|
** INPUTS: NSSRWLock *lock - Lock to be read-locked.
|
|
** OUTPUTS: void
|
|
** RETURN: None
|
|
***********************************************************************/
|
|
PR_EXTERN(void) NSSRWLock_LockRead(NSSRWLock *lock);
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_LockWrite
|
|
** DESCRIPTION:
|
|
** Apply a write lock (exclusive) on a RWLock
|
|
** INPUTS: NSSRWLock *lock - Lock to write-locked.
|
|
** OUTPUTS: void
|
|
** RETURN: None
|
|
***********************************************************************/
|
|
PR_EXTERN(void) NSSRWLock_LockWrite(NSSRWLock *lock);
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_UnlockRead
|
|
** DESCRIPTION:
|
|
** Release a Read lock. Unlocking an unlocked lock has undefined results.
|
|
** INPUTS: NSSRWLock *lock - Lock to unlocked.
|
|
** OUTPUTS: void
|
|
** RETURN: void
|
|
***********************************************************************/
|
|
PR_EXTERN(void) NSSRWLock_UnlockRead(NSSRWLock *lock);
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_UnlockWrite
|
|
** DESCRIPTION:
|
|
** Release a Write lock. Unlocking an unlocked lock has undefined results.
|
|
** INPUTS: NSSRWLock *lock - Lock to unlocked.
|
|
** OUTPUTS: void
|
|
** RETURN: void
|
|
***********************************************************************/
|
|
PR_EXTERN(void) NSSRWLock_UnlockWrite(NSSRWLock *lock);
|
|
|
|
/***********************************************************************
|
|
** FUNCTION: NSSRWLock_HaveWriteLock
|
|
** DESCRIPTION:
|
|
** Tells caller whether the current thread holds the write lock, or not.
|
|
** INPUTS: NSSRWLock *lock - Lock to test.
|
|
** OUTPUTS: void
|
|
** RETURN: PRBool PR_TRUE IFF the current thread holds the write lock.
|
|
***********************************************************************/
|
|
|
|
PR_EXTERN(PRBool) NSSRWLock_HaveWriteLock(NSSRWLock *rwlock);
|
|
|
|
/* SEC_END_PROTOS */
|
|
PR_END_EXTERN_C
|
|
|
|
#endif /* nsrwlock_h___ */
|