michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkAtomics_android_DEFINED
michael@0: #define SkAtomics_android_DEFINED
michael@0: 
michael@0: /** Android framework atomics. */
michael@0: 
michael@0: #include <cutils/atomic.h>
michael@0: #include <stdint.h>
michael@0: 
michael@0: static inline __attribute__((always_inline)) int32_t sk_atomic_inc(int32_t* addr) {
michael@0:     return android_atomic_inc(addr);
michael@0: }
michael@0: 
michael@0: static inline __attribute__((always_inline)) int32_t sk_atomic_add(int32_t* addr, int32_t inc) {
michael@0:     return android_atomic_add(inc, addr);
michael@0: }
michael@0: 
michael@0: static inline __attribute__((always_inline)) int32_t sk_atomic_dec(int32_t* addr) {
michael@0:     return android_atomic_dec(addr);
michael@0: }
michael@0: 
michael@0: static inline __attribute__((always_inline)) void sk_membar_acquire__after_atomic_dec() {
michael@0:     //HACK: Android is actually using full memory barriers.
michael@0:     //      Should this change, uncomment below.
michael@0:     //int dummy;
michael@0:     //android_atomic_acquire_store(0, &dummy);
michael@0: }
michael@0: 
michael@0: static inline __attribute__((always_inline)) int32_t sk_atomic_conditional_inc(int32_t* addr) {
michael@0:     while (true) {
michael@0:         int32_t value = *addr;
michael@0:         if (value == 0) {
michael@0:             return 0;
michael@0:         }
michael@0:         if (0 == android_atomic_release_cas(value, value + 1, addr)) {
michael@0:             return value;
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: static inline __attribute__((always_inline)) bool sk_atomic_cas(int32_t* addr,
michael@0:                                                                  int32_t before,
michael@0:                                                                  int32_t after) {
michael@0:     // android_atomic_release_cas returns 0 for success (if *addr == before and it wrote after).
michael@0:     return android_atomic_release_cas(before, after, addr) == 0;
michael@0: }
michael@0: 
michael@0: static inline __attribute__((always_inline)) void sk_membar_acquire__after_atomic_conditional_inc() {
michael@0:     //HACK: Android is actually using full memory barriers.
michael@0:     //      Should this change, uncomment below.
michael@0:     //int dummy;
michael@0:     //android_atomic_acquire_store(0, &dummy);
michael@0: }
michael@0: 
michael@0: #endif