1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* 18 * Atomic operations 19 */ 20 #ifndef DALVIK_ATOMIC_H_ 21 #define DALVIK_ATOMIC_H_ 22 23 #include <cutils/atomic.h> /* use common Android atomic ops */ 24 #include <cutils/atomic-inline.h> /* and some uncommon ones */ 25 26 /* 27 * NOTE: Two "quasiatomic" operations on the exact same memory address 28 * are guaranteed to operate atomically with respect to each other, 29 * but no guarantees are made about quasiatomic operations mixed with 30 * non-quasiatomic operations on the same address, nor about 31 * quasiatomic operations that are performed on partially-overlapping 32 * memory. 33 * 34 * Only the "Sync" versions of these provide a memory barrier. 35 */ 36 37 /* 38 * Swap the 64-bit value at "addr" with "value". Returns the previous 39 * value. 40 */ 41 extern "C" int64_t dvmQuasiAtomicSwap64(int64_t value, volatile int64_t* addr); 42 43 /* 44 * Swap the 64-bit value at "addr" with "value". Returns the previous 45 * value. Provides memory barriers. 46 */ 47 extern "C" int64_t dvmQuasiAtomicSwap64Sync(int64_t value, 48 volatile int64_t* addr); 49 50 /* 51 * Read the 64-bit value at "addr". 52 */ 53 extern "C" int64_t dvmQuasiAtomicRead64(volatile const int64_t* addr); 54 55 /* 56 * If the value at "addr" is equal to "oldvalue", replace it with "newvalue" 57 * and return 0. Otherwise, don't swap, and return nonzero. 58 */ 59 int dvmQuasiAtomicCas64(int64_t oldvalue, int64_t newvalue, 60 volatile int64_t* addr); 61 62 #endif // DALVIK_ATOMIC_H_ 63
