1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/nsprpub/pr/include/pratom.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,199 @@
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 +/* GLOBAL FUNCTIONS:
1.10 +** DESCRIPTION:
1.11 +** PR Atomic operations
1.12 +*/
1.13 +
1.14 +#ifndef pratom_h___
1.15 +#define pratom_h___
1.16 +
1.17 +#include "prtypes.h"
1.18 +#include "prlock.h"
1.19 +
1.20 +PR_BEGIN_EXTERN_C
1.21 +
1.22 +/*
1.23 +** FUNCTION: PR_AtomicIncrement
1.24 +** DESCRIPTION:
1.25 +** Atomically increment a 32 bit value.
1.26 +** INPUTS:
1.27 +** val: a pointer to the value to increment
1.28 +** RETURN:
1.29 +** the returned value is the result of the increment
1.30 +*/
1.31 +NSPR_API(PRInt32) PR_AtomicIncrement(PRInt32 *val);
1.32 +
1.33 +/*
1.34 +** FUNCTION: PR_AtomicDecrement
1.35 +** DESCRIPTION:
1.36 +** Atomically decrement a 32 bit value.
1.37 +** INPUTS:
1.38 +** val: a pointer to the value to decrement
1.39 +** RETURN:
1.40 +** the returned value is the result of the decrement
1.41 +*/
1.42 +NSPR_API(PRInt32) PR_AtomicDecrement(PRInt32 *val);
1.43 +
1.44 +/*
1.45 +** FUNCTION: PR_AtomicSet
1.46 +** DESCRIPTION:
1.47 +** Atomically set a 32 bit value.
1.48 +** INPUTS:
1.49 +** val: A pointer to a 32 bit value to be set
1.50 +** newval: The newvalue to assign to val
1.51 +** RETURN:
1.52 +** Returns the prior value
1.53 +*/
1.54 +NSPR_API(PRInt32) PR_AtomicSet(PRInt32 *val, PRInt32 newval);
1.55 +
1.56 +/*
1.57 +** FUNCTION: PR_AtomicAdd
1.58 +** DESCRIPTION:
1.59 +** Atomically add a 32 bit value.
1.60 +** INPUTS:
1.61 +** ptr: a pointer to the value to increment
1.62 +** val: value to be added
1.63 +** RETURN:
1.64 +** the returned value is the result of the addition
1.65 +*/
1.66 +NSPR_API(PRInt32) PR_AtomicAdd(PRInt32 *ptr, PRInt32 val);
1.67 +
1.68 +/*
1.69 +** MACRO: PR_ATOMIC_INCREMENT
1.70 +** MACRO: PR_ATOMIC_DECREMENT
1.71 +** MACRO: PR_ATOMIC_SET
1.72 +** MACRO: PR_ATOMIC_ADD
1.73 +** DESCRIPTION:
1.74 +** Macro versions of the atomic operations. They may be implemented
1.75 +** as compiler intrinsics.
1.76 +**
1.77 +** IMPORTANT NOTE TO NSPR MAINTAINERS:
1.78 +** Implement these macros with compiler intrinsics only on platforms
1.79 +** where the PR_AtomicXXX functions are truly atomic (i.e., where the
1.80 +** configuration macro _PR_HAVE_ATOMIC_OPS is defined). Otherwise,
1.81 +** the macros and functions won't be compatible and can't be used
1.82 +** interchangeably.
1.83 +*/
1.84 +#if defined(_WIN32) && !defined(_WIN32_WCE) && \
1.85 + (!defined(_MSC_VER) || (_MSC_VER >= 1310))
1.86 +
1.87 +long __cdecl _InterlockedIncrement(long volatile *Addend);
1.88 +long __cdecl _InterlockedDecrement(long volatile *Addend);
1.89 +long __cdecl _InterlockedExchange(long volatile *Target, long Value);
1.90 +long __cdecl _InterlockedExchangeAdd(long volatile *Addend, long Value);
1.91 +
1.92 +#ifdef _MSC_VER
1.93 +#pragma intrinsic(_InterlockedIncrement)
1.94 +#pragma intrinsic(_InterlockedDecrement)
1.95 +#pragma intrinsic(_InterlockedExchange)
1.96 +#pragma intrinsic(_InterlockedExchangeAdd)
1.97 +#endif
1.98 +
1.99 +#define PR_ATOMIC_INCREMENT(val) _InterlockedIncrement((long volatile *)(val))
1.100 +#define PR_ATOMIC_DECREMENT(val) _InterlockedDecrement((long volatile *)(val))
1.101 +#define PR_ATOMIC_SET(val, newval) \
1.102 + _InterlockedExchange((long volatile *)(val), (long)(newval))
1.103 +#define PR_ATOMIC_ADD(ptr, val) \
1.104 + (_InterlockedExchangeAdd((long volatile *)(ptr), (long)(val)) + (val))
1.105 +
1.106 +#elif ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)) && \
1.107 + ((defined(__APPLE__) && \
1.108 + (defined(__ppc__) || defined(__i386__) || defined(__x86_64__))) || \
1.109 + (defined(__linux__) && \
1.110 + ((defined(__i386__) && \
1.111 + defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)) || \
1.112 + defined(__ia64__) || defined(__x86_64__) || \
1.113 + defined(__powerpc__) || \
1.114 + (defined(__arm__) && \
1.115 + defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)) || \
1.116 + defined(__aarch64__) || defined(__alpha))))
1.117 +
1.118 +/*
1.119 + * Because the GCC manual warns that some processors may support
1.120 + * reduced functionality of __sync_lock_test_and_set, we test for the
1.121 + * processors that we believe support a full atomic exchange operation.
1.122 + */
1.123 +
1.124 +#define PR_ATOMIC_INCREMENT(val) __sync_add_and_fetch(val, 1)
1.125 +#define PR_ATOMIC_DECREMENT(val) __sync_sub_and_fetch(val, 1)
1.126 +#define PR_ATOMIC_SET(val, newval) __sync_lock_test_and_set(val, newval)
1.127 +#define PR_ATOMIC_ADD(ptr, val) __sync_add_and_fetch(ptr, val)
1.128 +
1.129 +#else
1.130 +
1.131 +#define PR_ATOMIC_INCREMENT(val) PR_AtomicIncrement(val)
1.132 +#define PR_ATOMIC_DECREMENT(val) PR_AtomicDecrement(val)
1.133 +#define PR_ATOMIC_SET(val, newval) PR_AtomicSet(val, newval)
1.134 +#define PR_ATOMIC_ADD(ptr, val) PR_AtomicAdd(ptr, val)
1.135 +
1.136 +#endif
1.137 +
1.138 +/*
1.139 +** LIFO linked-list (stack)
1.140 +*/
1.141 +typedef struct PRStackElemStr PRStackElem;
1.142 +
1.143 +struct PRStackElemStr {
1.144 + PRStackElem *prstk_elem_next; /* next pointer MUST be at offset 0;
1.145 + assembly language code relies on this */
1.146 +};
1.147 +
1.148 +typedef struct PRStackStr PRStack;
1.149 +
1.150 +/*
1.151 +** FUNCTION: PR_CreateStack
1.152 +** DESCRIPTION:
1.153 +** Create a stack, a LIFO linked list
1.154 +** INPUTS:
1.155 +** stack_name: a pointer to string containing the name of the stack
1.156 +** RETURN:
1.157 +** A pointer to the created stack, if successful, else NULL.
1.158 +*/
1.159 +NSPR_API(PRStack *) PR_CreateStack(const char *stack_name);
1.160 +
1.161 +/*
1.162 +** FUNCTION: PR_StackPush
1.163 +** DESCRIPTION:
1.164 +** Push an element on the top of the stack
1.165 +** INPUTS:
1.166 +** stack: pointer to the stack
1.167 +** stack_elem: pointer to the stack element
1.168 +** RETURN:
1.169 +** None
1.170 +*/
1.171 +NSPR_API(void) PR_StackPush(PRStack *stack, PRStackElem *stack_elem);
1.172 +
1.173 +/*
1.174 +** FUNCTION: PR_StackPop
1.175 +** DESCRIPTION:
1.176 +** Remove the element on the top of the stack
1.177 +** INPUTS:
1.178 +** stack: pointer to the stack
1.179 +** RETURN:
1.180 +** A pointer to the stack element removed from the top of the stack,
1.181 +** if non-empty,
1.182 +** else NULL
1.183 +*/
1.184 +NSPR_API(PRStackElem *) PR_StackPop(PRStack *stack);
1.185 +
1.186 +/*
1.187 +** FUNCTION: PR_DestroyStack
1.188 +** DESCRIPTION:
1.189 +** Destroy the stack
1.190 +** INPUTS:
1.191 +** stack: pointer to the stack
1.192 +** RETURN:
1.193 +** PR_SUCCESS - if successfully deleted
1.194 +** PR_FAILURE - if the stack is not empty
1.195 +** PR_GetError will return
1.196 +** PR_INVALID_STATE_ERROR - stack is not empty
1.197 +*/
1.198 +NSPR_API(PRStatus) PR_DestroyStack(PRStack *stack);
1.199 +
1.200 +PR_END_EXTERN_C
1.201 +
1.202 +#endif /* pratom_h___ */
