/* Atomic functions: similar to pycore_atomic.h, but don't need to declare variables as atomic. Py_ssize_t type: * value = _Py_atomic_size_get(&var) * _Py_atomic_size_set(&var, value) Use sequentially-consistent ordering (__ATOMIC_SEQ_CST memory order): enforce total ordering with all other atomic functions. */ #ifndef Py_ATOMIC_FUNC_H #define Py_ATOMIC_FUNC_H #ifdef __cplusplus extern "C" { #endif #ifndef Py_BUILD_CORE # error "this header requires Py_BUILD_CORE define" #endif #if defined(_MSC_VER) # include <intrin.h> // _InterlockedExchange() #endif // Use builtin atomic operations in GCC >= 4.7 and clang #ifdef HAVE_BUILTIN_ATOMIC static inline Py_ssize_t _Py_atomic_size_get(Py_ssize_t *var) { return __atomic_load_n(var, __ATOMIC_SEQ_CST); } static inline void _Py_atomic_size_set(Py_ssize_t *var, Py_ssize_t value) { __atomic_store_n(var, value, __ATOMIC_SEQ_CST); } #elif defined(_MSC_VER) static inline Py_ssize_t _Py_atomic_size_get(Py_ssize_t *var) { #if SIZEOF_VOID_P == 8 Py_BUILD_ASSERT(sizeof(__int64) == sizeof(*var)); volatile __int64 *volatile_var = (volatile __int64 *)var; __int64 old; do { old = *volatile_var; } while(_InterlockedCompareExchange64(volatile_var, old, old) != old); #else Py_BUILD_ASSERT(sizeof(long) == sizeof(*var)); volatile long *volatile_var = (volatile long *)var; long old; do { old = *volatile_var; } while(_InterlockedCompareExchange(volatile_var, old, old) != old); #endif return old; } static inline void _Py_atomic_size_set(Py_ssize_t *var, Py_ssize_t value) { #if SIZEOF_VOID_P == 8 Py_BUILD_ASSERT(sizeof(__int64) == sizeof(*var)); volatile __int64 *volatile_var = (volatile __int64 *)var; _InterlockedExchange64(volatile_var, value); #else Py_BUILD_ASSERT(sizeof(long) == sizeof(*var)); volatile long *volatile_var = (volatile long *)var; _InterlockedExchange(volatile_var, value); #endif } #else // Fallback implementation using volatile static inline Py_ssize_t _Py_atomic_size_get(Py_ssize_t *var) { volatile Py_ssize_t *volatile_var = (volatile Py_ssize_t *)var; return *volatile_var; } static inline void _Py_atomic_size_set(Py_ssize_t *var, Py_ssize_t value) { volatile Py_ssize_t *volatile_var = (volatile Py_ssize_t *)var; *volatile_var = value; } #endif #ifdef __cplusplus } #endif #endif /* Py_ATOMIC_FUNC_H */