/*
* Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
#ifndef SHARE_VM_RUNTIME_ATOMIC_HPP
#define SHARE_VM_RUNTIME_ATOMIC_HPP
#include "memory/allocation.hpp"
class Atomic : AllStatic {
public:
// Atomic operations on jlong types are not available on all 32-bit
// platforms. If atomic ops on jlongs are defined here they must only
// be used from code that verifies they are available at runtime and
// can provide an alternative action if not - see supports_cx8() for
// a means to test availability.
// Atomically store to a location
static void store (jbyte store_value, jbyte* dest);
static void store (jshort store_value, jshort* dest);
static void store (jint store_value, jint* dest);
// See comment above about using jlong atomics on 32-bit platforms
static void store (jlong store_value, jlong* dest);
static void store_ptr(intptr_t store_value, intptr_t* dest);
static void store_ptr(void* store_value, void* dest);
static void store (jbyte store_value, volatile jbyte* dest);
static void store (jshort store_value, volatile jshort* dest);
static void store (jint store_value, volatile jint* dest);
// See comment above about using jlong atomics on 32-bit platforms
static void store (jlong store_value, volatile jlong* dest);
static void store_ptr(intptr_t store_value, volatile intptr_t* dest);
static void store_ptr(void* store_value, volatile void* dest);
// See comment above about using jlong atomics on 32-bit platforms
static jlong load(volatile jlong* src);
// Atomically add to a location, return updated value
static jint add (jint add_value, volatile jint* dest);
static intptr_t add_ptr(intptr_t add_value, volatile intptr_t* dest);
static void* add_ptr(intptr_t add_value, volatile void* dest);
// See comment above about using jlong atomics on 32-bit platforms
static jlong add (jlong add_value, volatile jlong* dest);
// Atomically increment location
static void inc (volatile jint* dest);
static void inc_ptr(volatile intptr_t* dest);
static void inc_ptr(volatile void* dest);
// Atomically decrement a location
static void dec (volatile jint* dest);
static void dec_ptr(volatile intptr_t* dest);
static void dec_ptr(volatile void* dest);
// Performs atomic exchange of *dest with exchange_value. Returns old prior value of *dest.
static jint xchg(jint exchange_value, volatile jint* dest);
static unsigned int xchg(unsigned int exchange_value,
volatile unsigned int* dest);
static intptr_t xchg_ptr(intptr_t exchange_value, volatile intptr_t* dest);
static void* xchg_ptr(void* exchange_value, volatile void* dest);
// Performs atomic compare of *dest and compare_value, and exchanges *dest with exchange_value
// if the comparison succeeded. Returns prior value of *dest. Guarantees a two-way memory
// barrier across the cmpxchg. I.e., it's really a 'fence_cmpxchg_acquire'.
static jbyte cmpxchg (jbyte exchange_value, volatile jbyte* dest, jbyte compare_value);
static jint cmpxchg (jint exchange_value, volatile jint* dest, jint compare_value);
// See comment above about using jlong atomics on 32-bit platforms
static jlong cmpxchg (jlong exchange_value, volatile jlong* dest, jlong compare_value);
static unsigned int cmpxchg(unsigned int exchange_value,
volatile unsigned int* dest,
unsigned int compare_value);
static intptr_t cmpxchg_ptr(intptr_t exchange_value, volatile intptr_t* dest, intptr_t compare_value);
static void* cmpxchg_ptr(void* exchange_value, volatile void* dest, void* compare_value);
};
#endif // SHARE_VM_RUNTIME_ATOMIC_HPP