/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
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*
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* distribution.
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* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
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* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* .
*
* Portions of this software are based upon public domain software
* originally written at the National Center for Supercomputing Applications,
* University of Illinois, Urbana-Champaign.
*/
#ifndef APR_ATOMIC_H
#define APR_ATOMIC_H
#ifdef __cplusplus
extern "C" {
#endif
#include "apr_pools.h"
/**
* @file apr_atomic.h
* @brief APR Atomic Operations
*/
/**
* @defgroup APR_Atomic Atomic operations
* @ingroup APR
* @{
*/
/* easiest way to get these documented for the moment */
#if defined(DOXYGEN)
/**
* structure for holding a atomic value.
* this number >only< has a 24 bit size on some platforms
*/
typedef apr_atomic_t;
/**
* @param pool
* this function is required on some platforms to initialize the
* atomic operation's internal structures
* returns APR_SUCCESS on successfull completion
*/
apr_status_t apr_atomic_init(apr_pool_t *p);
/**
* read the value stored in a atomic variable
* @param the pointer
* @warning on certain platforms this number is not stored
* directly in the pointer. in others it is
*/
apr_uint32_t apr_atomic_read(volatile apr_atomic_t *mem);
/**
* set the value for atomic.
* @param the pointer
* @param the value
*/
void apr_atomic_set(volatile apr_atomic_t *mem, apr_uint32_t val);
/**
* Add 'val' to the atomic variable
* @param mem pointer to the atomic value
* @param val the addition
*/
void apr_atomic_add(volatile apr_atomic_t *mem, apr_uint32_t val);
/**
* increment the atomic variable by 1
* @param mem pointer to the atomic value
*/
void apr_atomic_inc(volatile apr_atomic_t *mem);
/**
* decrement the atomic variable by 1
* @param mem pointer to the atomic value
* @returns zero if the value is zero, otherwise non-zero
*/
int apr_atomic_dec(volatile apr_atomic_t *mem);
/**
* compare the atomic's value with cmp.
* If they are the same swap the value with 'with'
* @param mem pointer to the atomic value
* @param with what to swap it with
* @param the value to compare it to
* @return the old value of the atomic
* @warning do not mix apr_atomic's with the CAS function.
* on some platforms they may be implemented by different mechanisms
*/
apr_uint32_t apr_atomic_cas(volatile apr_uint32_t *mem,long with,long cmp);
#else /* !DOXYGEN */
#if APR_FORCE_ATOMIC_GENERIC
#if APR_HAS_THREADS
#define APR_ATOMIC_NEED_DEFAULT 1
#define APR_ATOMIC_NEED_CAS_DEFAULT 1
#endif /* APR_HAS_THREADS */
#elif defined(WIN32)
#define apr_atomic_t LONG
#define apr_atomic_add(mem, val) InterlockedExchangeAdd(mem,val)
#define apr_atomic_dec(mem) InterlockedDecrement(mem)
#define apr_atomic_inc(mem) InterlockedIncrement(mem)
#define apr_atomic_set(mem, val) InterlockedExchange(mem, val)
#define apr_atomic_read(mem) (*mem)
#define apr_atomic_cas(mem,with,cmp) InterlockedCompareExchange(mem,with,cmp)
#define apr_atomic_init(pool) APR_SUCCESS
#elif defined(NETWARE)
#include
#define apr_atomic_t unsigned long
#define apr_atomic_add(mem, val) atomic_add(mem,val)
APR_DECLARE(int) apr_atomic_dec(apr_atomic_t *mem);
#define apr_atomic_inc(mem) atomic_inc(mem)
#define apr_atomic_set(mem, val) (*mem = val)
#define apr_atomic_read(mem) (*mem)
#define apr_atomic_init(pool) APR_SUCCESS
#define apr_atomic_cas(mem,with,cmp) atomic_cmpxchg(mem,with,cmp)
#elif defined(__FreeBSD__)
#include
#define apr_atomic_t apr_uint32_t
#define apr_atomic_add(mem, val) atomic_add_int(mem,val)
#define apr_atomic_dec(mem) atomic_subtract_int(mem,1)
#define apr_atomic_inc(mem) atomic_add_int(mem,1)
#define apr_atomic_set(mem, val) atomic_set_int(mem, val)
#define apr_atomic_read(mem) (*mem)
#define APR_ATOMIC_NEED_CAS_DEFAULT 1
#elif defined(__sparc__) || defined(sparc)
#define apr_atomic_t apr_uint32_t
#define apr_atomic_read(p) *p
#define apr_atomic_add(mem, val) apr_atomic_add_sparc(mem,val)
#define apr_atomic_dec(mem) apr_atomic_sub_sparc(mem,1)
#define apr_atomic_inc(mem) apr_atomic_add_sparc(mem,1)
#define apr_atomic_cas(mem,val,cond) apr_atomic_cas_sparc(mem,val,cond)
#define apr_atomic_set(mem, val) (*mem = val)
#define apr_atomic_init(pool) APR_SUCCESS
apr_uint32_t apr_atomic_add_sparc(volatile apr_atomic_t *mem, apr_uint32_t add);
apr_uint32_t apr_atomic_sub_sparc(volatile apr_atomic_t *mem, apr_uint32_t sub);
apr_uint32_t apr_atomic_cas_sparc(volatile apr_uint32_t *mem, long with, long cmp);
#elif defined(__MVS__) /* OS/390 */
#include
#define apr_atomic_t cs_t
apr_int32_t apr_atomic_add(volatile apr_atomic_t *mem, apr_int32_t val);
apr_uint32_t apr_atomic_cas(volatile apr_atomic_t *mem, apr_uint32_t swap,
apr_uint32_t cmp);
#define apr_atomic_inc(mem) apr_atomic_add(mem, 1)
#define apr_atomic_dec(mem) apr_atomic_add(mem, -1)
#define apr_atomic_init(pool) APR_SUCCESS
/* warning: the following two operations, _read and _set, are atomic
* if the memory variables are aligned (the usual case).
*
* If you try really hard and manage to mis-align them, they are not
* guaranteed to be atomic on S/390. But then your program will blow up
* with SIGBUS on a sparc, or with a S0C6 abend if you use the mis-aligned
* variables with other apr_atomic_* operations on OS/390.
*/
#define apr_atomic_read(p) (*p)
#define apr_atomic_set(mem, val) (*mem = val)
#else
#if APR_HAS_THREADS
#define APR_ATOMIC_NEED_DEFAULT 1
#define APR_ATOMIC_NEED_CAS_DEFAULT 1
#endif /* APR_HAS_THREADS */
#endif /* !defined(WIN32) */
#if defined(APR_ATOMIC_NEED_DEFAULT)
#define apr_atomic_t apr_uint32_t
#define apr_atomic_read(p) *p
apr_status_t apr_atomic_init(apr_pool_t *p);
void apr_atomic_set(volatile apr_atomic_t *mem, apr_uint32_t val);
void apr_atomic_add(volatile apr_atomic_t *mem, apr_uint32_t val);
void apr_atomic_inc(volatile apr_atomic_t *mem);
int apr_atomic_dec(volatile apr_atomic_t *mem);
#endif
#if defined(APR_ATOMIC_NEED_CAS_DEFAULT)
apr_status_t apr_atomic_init(apr_pool_t *p);
apr_uint32_t apr_atomic_cas(volatile apr_uint32_t *mem,long with,long cmp);
#endif
#endif /* DOXYGEN */
#ifdef __cplusplus
}
#endif
#endif /* !APR_ATOMIC_H */