gecko/nsprpub/pr/include/pratom.h

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2008-06-06 05:36:51 -07:00
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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 ***** */
/* GLOBAL FUNCTIONS:
** DESCRIPTION:
** PR Atomic operations
*/
#ifndef pratom_h___
#define pratom_h___
#include "prtypes.h"
#include "prlock.h"
PR_BEGIN_EXTERN_C
/*
** FUNCTION: PR_AtomicIncrement
** DESCRIPTION:
** Atomically increment a 32 bit value.
** INPUTS:
** val: a pointer to the value to increment
** RETURN:
** the returned value is the result of the increment
*/
NSPR_API(PRInt32) PR_AtomicIncrement(PRInt32 *val);
/*
** FUNCTION: PR_AtomicDecrement
** DESCRIPTION:
** Atomically decrement a 32 bit value.
** INPUTS:
** val: a pointer to the value to decrement
** RETURN:
** the returned value is the result of the decrement
*/
NSPR_API(PRInt32) PR_AtomicDecrement(PRInt32 *val);
/*
** FUNCTION: PR_AtomicSet
** DESCRIPTION:
** Atomically set a 32 bit value.
** INPUTS:
** val: A pointer to a 32 bit value to be set
** newval: The newvalue to assign to val
** RETURN:
** Returns the prior value
*/
NSPR_API(PRInt32) PR_AtomicSet(PRInt32 *val, PRInt32 newval);
/*
** FUNCTION: PR_AtomicAdd
** DESCRIPTION:
** Atomically add a 32 bit value.
** INPUTS:
** ptr: a pointer to the value to increment
** val: value to be added
** RETURN:
** the returned value is the result of the addition
*/
NSPR_API(PRInt32) PR_AtomicAdd(PRInt32 *ptr, PRInt32 val);
/*
** MACRO: PR_ATOMIC_INCREMENT
** MACRO: PR_ATOMIC_DECREMENT
** MACRO: PR_ATOMIC_SET
** MACRO: PR_ATOMIC_ADD
** DESCRIPTION:
** Macro versions of the atomic operations. They may be implemented
** as compiler intrinsics.
**
** IMPORTANT NOTE TO NSPR MAINTAINERS:
** Implement these macros with compiler intrinsics only on platforms
** where the PR_AtomicXXX functions are truly atomic (i.e., where the
** configuration macro _PR_HAVE_ATOMIC_OPS is defined). Otherwise,
** the macros and functions won't be compatible and can't be used
** interchangeably.
*/
#if defined(_WIN32) && (_MSC_VER >= 1310)
long __cdecl _InterlockedIncrement(long volatile *Addend);
#pragma intrinsic(_InterlockedIncrement)
long __cdecl _InterlockedDecrement(long volatile *Addend);
#pragma intrinsic(_InterlockedDecrement)
long __cdecl _InterlockedExchange(long volatile *Target, long Value);
#pragma intrinsic(_InterlockedExchange)
long __cdecl _InterlockedExchangeAdd(long volatile *Addend, long Value);
#pragma intrinsic(_InterlockedExchangeAdd)
#define PR_ATOMIC_INCREMENT(val) _InterlockedIncrement(val)
#define PR_ATOMIC_DECREMENT(val) _InterlockedDecrement(val)
#define PR_ATOMIC_SET(val, newval) _InterlockedExchange(val, newval)
#define PR_ATOMIC_ADD(ptr, val) (_InterlockedExchangeAdd(ptr, val) + (val))
#elif ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)) && \
((defined(DARWIN) && \
(defined(__ppc__) || defined(__i386__))) || \
(defined(LINUX) && \
(defined(__i386__) || defined(__ia64__) || defined(__x86_64__) || \
(defined(__powerpc__) && !defined(__powerpc64__)) || \
defined(__alpha))))
/*
* Because the GCC manual warns that some processors may support
* reduced functionality of __sync_lock_test_and_set, we test for the
* processors that we believe support a full atomic exchange operation.
*/
#define PR_ATOMIC_INCREMENT(val) __sync_add_and_fetch(val, 1)
#define PR_ATOMIC_DECREMENT(val) __sync_sub_and_fetch(val, 1)
#define PR_ATOMIC_SET(val, newval) __sync_lock_test_and_set(val, newval)
#define PR_ATOMIC_ADD(ptr, val) __sync_add_and_fetch(ptr, val)
#else
#define PR_ATOMIC_INCREMENT(val) PR_AtomicIncrement(val)
#define PR_ATOMIC_DECREMENT(val) PR_AtomicDecrement(val)
#define PR_ATOMIC_SET(val, newval) PR_AtomicSet(val, newval)
#define PR_ATOMIC_ADD(ptr, val) PR_AtomicAdd(ptr, val)
#endif
/*
** LIFO linked-list (stack)
*/
typedef struct PRStackElemStr PRStackElem;
struct PRStackElemStr {
PRStackElem *prstk_elem_next; /* next pointer MUST be at offset 0;
assembly language code relies on this */
};
typedef struct PRStackStr PRStack;
/*
** FUNCTION: PR_CreateStack
** DESCRIPTION:
** Create a stack, a LIFO linked list
** INPUTS:
** stack_name: a pointer to string containing the name of the stack
** RETURN:
** A pointer to the created stack, if successful, else NULL.
*/
NSPR_API(PRStack *) PR_CreateStack(const char *stack_name);
/*
** FUNCTION: PR_StackPush
** DESCRIPTION:
** Push an element on the top of the stack
** INPUTS:
** stack: pointer to the stack
** stack_elem: pointer to the stack element
** RETURN:
** None
*/
NSPR_API(void) PR_StackPush(PRStack *stack, PRStackElem *stack_elem);
/*
** FUNCTION: PR_StackPop
** DESCRIPTION:
** Remove the element on the top of the stack
** INPUTS:
** stack: pointer to the stack
** RETURN:
** A pointer to the stack element removed from the top of the stack,
** if non-empty,
** else NULL
*/
NSPR_API(PRStackElem *) PR_StackPop(PRStack *stack);
/*
** FUNCTION: PR_DestroyStack
** DESCRIPTION:
** Destroy the stack
** INPUTS:
** stack: pointer to the stack
** RETURN:
** PR_SUCCESS - if successfully deleted
** PR_FAILURE - if the stack is not empty
** PR_GetError will return
** PR_INVALID_STATE_ERROR - stack is not empty
*/
NSPR_API(PRStatus) PR_DestroyStack(PRStack *stack);
PR_END_EXTERN_C
#endif /* pratom_h___ */