1 2 /* 3 * Copyright 2006 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkThread_platform_DEFINED 11 #define SkThread_platform_DEFINED 12 13 #if defined(SK_BUILD_FOR_ANDROID) 14 15 #if defined(SK_BUILD_FOR_ANDROID_NDK) 16 17 #include <stdint.h> 18 19 /* Just use the GCC atomic intrinsics. They're supported by the NDK toolchain, 20 * have reasonable performance, and provide full memory barriers 21 */ 22 static __attribute__((always_inline)) int32_t sk_atomic_inc(int32_t *addr) { 23 return __sync_fetch_and_add(addr, 1); 24 } 25 26 static __attribute__((always_inline)) int32_t sk_atomic_dec(int32_t *addr) { 27 return __sync_fetch_and_add(addr, -1); 28 } 29 30 #else // !SK_BUILD_FOR_ANDROID_NDK 31 32 /* The platform atomics operations are slightly more efficient than the 33 * GCC built-ins, so use them. 34 */ 35 #include <utils/Atomic.h> 36 37 #define sk_atomic_inc(addr) android_atomic_inc(addr) 38 #define sk_atomic_dec(addr) android_atomic_dec(addr) 39 40 #endif // !SK_BUILD_FOR_ANDROID_NDK 41 42 #else // !SK_BUILD_FOR_ANDROID 43 44 /** Implemented by the porting layer, this function adds 1 to the int specified 45 by the address (in a thread-safe manner), and returns the previous value. 46 */ 47 SK_API int32_t sk_atomic_inc(int32_t* addr); 48 /** Implemented by the porting layer, this function subtracts 1 to the int 49 specified by the address (in a thread-safe manner), and returns the previous 50 value. 51 */ 52 SK_API int32_t sk_atomic_dec(int32_t* addr); 53 54 #endif // !SK_BUILD_FOR_ANDROID 55 56 #ifdef SK_USE_POSIX_THREADS 57 58 #include <pthread.h> 59 60 // A SkBaseMutex is a POD structure that can be directly initialized 61 // at declaration time with SK_DECLARE_STATIC/GLOBAL_MUTEX. This avoids the 62 // generation of a static initializer in the final machine code (and 63 // a corresponding static finalizer). 64 // 65 struct SkBaseMutex { 66 void acquire() { pthread_mutex_lock(&fMutex); } 67 void release() { pthread_mutex_unlock(&fMutex); } 68 pthread_mutex_t fMutex; 69 }; 70 71 // Using POD-style initialization prevents the generation of a static initializer 72 // and keeps the acquire() implementation small and fast. 73 #define SK_DECLARE_STATIC_MUTEX(name) static SkBaseMutex name = { PTHREAD_MUTEX_INITIALIZER } 74 75 // Special case used when the static mutex must be available globally. 76 #define SK_DECLARE_GLOBAL_MUTEX(name) SkBaseMutex name = { PTHREAD_MUTEX_INITIALIZER } 77 78 #define SK_DECLARE_MUTEX_ARRAY(name, count) SkBaseMutex name[count] = { PTHREAD_MUTEX_INITIALIZER } 79 80 // A normal mutex that requires to be initialized through normal C++ construction, 81 // i.e. when it's a member of another class, or allocated on the heap. 82 class SkMutex : public SkBaseMutex, SkNoncopyable { 83 public: 84 SkMutex(); 85 ~SkMutex(); 86 }; 87 88 #else // !SK_USE_POSIX_THREADS 89 90 // In the generic case, SkBaseMutex and SkMutex are the same thing, and we 91 // can't easily get rid of static initializers. 92 // 93 class SkMutex : SkNoncopyable { 94 public: 95 SkMutex(); 96 ~SkMutex(); 97 98 void acquire(); 99 void release(); 100 101 private: 102 bool fIsGlobal; 103 enum { 104 kStorageIntCount = 64 105 }; 106 uint32_t fStorage[kStorageIntCount]; 107 }; 108 109 typedef SkMutex SkBaseMutex; 110 111 #define SK_DECLARE_STATIC_MUTEX(name) static SkBaseMutex name 112 #define SK_DECLARE_GLOBAL_MUTEX(name) SkBaseMutex name 113 #define SK_DECLARE_MUTEX_ARRAY(name, count) SkBaseMutex name[count] 114 115 #endif // !SK_USE_POSIX_THREADS 116 117 118 #endif 119
