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Diffstat (limited to 'pr/include/pratom.h')
| -rw-r--r-- | pr/include/pratom.h | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/pr/include/pratom.h b/pr/include/pratom.h new file mode 100644 index 0000000..ef306e9 --- /dev/null +++ b/pr/include/pratom.h @@ -0,0 +1,231 @@ +/* -*- 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) && !defined(_WIN32_WCE) && \ + (!defined(_MSC_VER) || (_MSC_VER >= 1310)) + +long __cdecl _InterlockedIncrement(long volatile *Addend); +long __cdecl _InterlockedDecrement(long volatile *Addend); +long __cdecl _InterlockedExchange(long volatile *Target, long Value); +long __cdecl _InterlockedExchangeAdd(long volatile *Addend, long Value); + +#ifdef _MSC_VER +#pragma intrinsic(_InterlockedIncrement) +#pragma intrinsic(_InterlockedDecrement) +#pragma intrinsic(_InterlockedExchange) +#pragma intrinsic(_InterlockedExchangeAdd) +#endif + +#define PR_ATOMIC_INCREMENT(val) _InterlockedIncrement((long volatile *)(val)) +#define PR_ATOMIC_DECREMENT(val) _InterlockedDecrement((long volatile *)(val)) +#define PR_ATOMIC_SET(val, newval) \ + _InterlockedExchange((long volatile *)(val), (long)(newval)) +#define PR_ATOMIC_ADD(ptr, val) \ + (_InterlockedExchangeAdd((long volatile *)(ptr), (long)(val)) + (val)) + +#elif ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)) && \ + ((defined(__APPLE__) && \ + (defined(__ppc__) || defined(__i386__) || defined(__x86_64__))) || \ + (defined(__linux__) && \ + ((defined(__i386__) && \ + defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)) || \ + defined(__ia64__) || defined(__x86_64__) || \ + (defined(__powerpc__) && !defined(__powerpc64__)) || \ + (defined(__arm__) && \ + defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)) || \ + 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___ */ |