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 void dvmQuasiAtomicsStartup(); 27 void dvmQuasiAtomicsShutdown(); 28 29 /* 30 * NOTE: Two "quasiatomic" operations on the exact same memory address 31 * are guaranteed to operate atomically with respect to each other, 32 * but no guarantees are made about quasiatomic operations mixed with 33 * non-quasiatomic operations on the same address, nor about 34 * quasiatomic operations that are performed on partially-overlapping 35 * memory. 36 * 37 * Only the "Sync" versions of these provide a memory barrier. 38 */ 39 40 /* 41 * Swap the 64-bit value at "addr" with "value". Returns the previous 42 * value. 43 */ 44 extern "C" int64_t dvmQuasiAtomicSwap64(int64_t value, volatile int64_t* addr); 45 46 /* 47 * Swap the 64-bit value at "addr" with "value". Returns the previous 48 * value. Provides memory barriers. 49 */ 50 extern "C" int64_t dvmQuasiAtomicSwap64Sync(int64_t value, 51 volatile int64_t* addr); 52 53 /* 54 * Read the 64-bit value at "addr". 55 */ 56 extern "C" int64_t dvmQuasiAtomicRead64(volatile const int64_t* addr); 57 58 /* 59 * If the value at "addr" is equal to "oldvalue", replace it with "newvalue" 60 * and return 0. Otherwise, don't swap, and return nonzero. 61 */ 62 int dvmQuasiAtomicCas64(int64_t oldvalue, int64_t newvalue, 63 volatile int64_t* addr); 64 65 #endif // DALVIK_ATOMIC_H_ 66
