1 /*
2 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_ATOMIC_HPP
26 #define SHARE_VM_RUNTIME_ATOMIC_HPP
27
28 #include "memory/allocation.hpp"
29
30 class Atomic : AllStatic {
31 public:
32 // Atomically store to a location
33 static void store (jbyte store_value, jbyte* dest);
34 static void store (jshort store_value, jshort* dest);
35 static void store (jint store_value, jint* dest);
36 static void store (jlong store_value, jlong* dest);
37 static void store_ptr(intptr_t store_value, intptr_t* dest);
38 static void store_ptr(void* store_value, void* dest);
39
40 static void store (jbyte store_value, volatile jbyte* dest);
41 static void store (jshort store_value, volatile jshort* dest);
42 static void store (jint store_value, volatile jint* dest);
43 static void store (jlong store_value, volatile jlong* dest);
44 static void store_ptr(intptr_t store_value, volatile intptr_t* dest);
45 static void store_ptr(void* store_value, volatile void* dest);
46
47 static jlong load(volatile jlong* src);
48
49 // Atomically add to a location, return updated value
50 static jint add (jint add_value, volatile jint* dest);
51 static intptr_t add_ptr(intptr_t add_value, volatile intptr_t* dest);
52 static void* add_ptr(intptr_t add_value, volatile void* dest);
53
54 // Atomically increment location
55 static void inc (volatile jint* dest);
56 static void inc_ptr(volatile intptr_t* dest);
57 static void inc_ptr(volatile void* dest);
58
59 // Atomically decrement a location
60 static void dec (volatile jint* dest);
61 static void dec_ptr(volatile intptr_t* dest);
62 static void dec_ptr(volatile void* dest);
63
64 // Performs atomic exchange of *dest with exchange_value. Returns old prior value of *dest.
65 static jint xchg(jint exchange_value, volatile jint* dest);
66 static unsigned int xchg(unsigned int exchange_value,
67 volatile unsigned int* dest);
68
69 static intptr_t xchg_ptr(intptr_t exchange_value, volatile intptr_t* dest);
70 static void* xchg_ptr(void* exchange_value, volatile void* dest);
71
72 // Performs atomic compare of *dest and compare_value, and exchanges *dest with exchange_value
73 // if the comparison succeeded. Returns prior value of *dest. Guarantees a two-way memory
74 // barrier across the cmpxchg. I.e., it's really a 'fence_cmpxchg_acquire'.
75 static jbyte cmpxchg (jbyte exchange_value, volatile jbyte* dest, jbyte compare_value);
76 static jint cmpxchg (jint exchange_value, volatile jint* dest, jint compare_value);
77 static jlong cmpxchg (jlong exchange_value, volatile jlong* dest, jlong compare_value);
78
79 static unsigned int cmpxchg(unsigned int exchange_value,
80 volatile unsigned int* dest,
81 unsigned int compare_value);
82
83 static intptr_t cmpxchg_ptr(intptr_t exchange_value, volatile intptr_t* dest, intptr_t compare_value);
84 static void* cmpxchg_ptr(void* exchange_value, volatile void* dest, void* compare_value);
85 };
86
87 #endif // SHARE_VM_RUNTIME_ATOMIC_HPP