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			557 lines
		
	
	
	
		
			17 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			557 lines
		
	
	
	
		
			17 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef Py_ATOMIC_H
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| #define Py_ATOMIC_H
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| #ifdef __cplusplus
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| extern "C" {
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| #endif
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| 
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| #ifndef Py_BUILD_CORE
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| #  error "this header requires Py_BUILD_CORE define"
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| #endif
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| 
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| #include "dynamic_annotations.h"   /* _Py_ANNOTATE_MEMORY_ORDER */
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| #include "pyconfig.h"
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| 
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| #ifdef HAVE_STD_ATOMIC
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| #  include <stdatomic.h>
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| #endif
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| 
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| 
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| #if defined(_MSC_VER)
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| #include <intrin.h>
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| #if defined(_M_IX86) || defined(_M_X64)
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| #  include <immintrin.h>
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| #endif
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| #endif
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| 
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| /* This is modeled after the atomics interface from C1x, according to
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|  * the draft at
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|  * http://www.open-std.org/JTC1/SC22/wg14/www/docs/n1425.pdf.
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|  * Operations and types are named the same except with a _Py_ prefix
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|  * and have the same semantics.
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|  *
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|  * Beware, the implementations here are deep magic.
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|  */
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| 
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| #if defined(HAVE_STD_ATOMIC)
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| 
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| typedef enum _Py_memory_order {
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|     _Py_memory_order_relaxed = memory_order_relaxed,
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|     _Py_memory_order_acquire = memory_order_acquire,
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|     _Py_memory_order_release = memory_order_release,
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|     _Py_memory_order_acq_rel = memory_order_acq_rel,
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|     _Py_memory_order_seq_cst = memory_order_seq_cst
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| } _Py_memory_order;
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| 
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| typedef struct _Py_atomic_address {
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|     atomic_uintptr_t _value;
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| } _Py_atomic_address;
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| 
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| typedef struct _Py_atomic_int {
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|     atomic_int _value;
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| } _Py_atomic_int;
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| 
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| #define _Py_atomic_signal_fence(/*memory_order*/ ORDER) \
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|     atomic_signal_fence(ORDER)
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| 
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| #define _Py_atomic_thread_fence(/*memory_order*/ ORDER) \
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|     atomic_thread_fence(ORDER)
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| 
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| #define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|     atomic_store_explicit(&((ATOMIC_VAL)->_value), NEW_VAL, ORDER)
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| 
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| #define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER) \
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|     atomic_load_explicit(&((ATOMIC_VAL)->_value), ORDER)
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| 
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| // Use builtin atomic operations in GCC >= 4.7 and clang
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| #elif defined(HAVE_BUILTIN_ATOMIC)
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| 
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| typedef enum _Py_memory_order {
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|     _Py_memory_order_relaxed = __ATOMIC_RELAXED,
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|     _Py_memory_order_acquire = __ATOMIC_ACQUIRE,
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|     _Py_memory_order_release = __ATOMIC_RELEASE,
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|     _Py_memory_order_acq_rel = __ATOMIC_ACQ_REL,
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|     _Py_memory_order_seq_cst = __ATOMIC_SEQ_CST
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| } _Py_memory_order;
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| 
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| typedef struct _Py_atomic_address {
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|     uintptr_t _value;
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| } _Py_atomic_address;
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| 
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| typedef struct _Py_atomic_int {
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|     int _value;
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| } _Py_atomic_int;
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| 
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| #define _Py_atomic_signal_fence(/*memory_order*/ ORDER) \
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|     __atomic_signal_fence(ORDER)
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| 
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| #define _Py_atomic_thread_fence(/*memory_order*/ ORDER) \
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|     __atomic_thread_fence(ORDER)
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| 
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| #define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|     (assert((ORDER) == __ATOMIC_RELAXED                       \
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|             || (ORDER) == __ATOMIC_SEQ_CST                    \
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|             || (ORDER) == __ATOMIC_RELEASE),                  \
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|      __atomic_store_n(&((ATOMIC_VAL)->_value), NEW_VAL, ORDER))
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| 
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| #define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER)           \
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|     (assert((ORDER) == __ATOMIC_RELAXED                       \
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|             || (ORDER) == __ATOMIC_SEQ_CST                    \
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|             || (ORDER) == __ATOMIC_ACQUIRE                    \
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|             || (ORDER) == __ATOMIC_CONSUME),                  \
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|      __atomic_load_n(&((ATOMIC_VAL)->_value), ORDER))
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| 
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| /* Only support GCC (for expression statements) and x86 (for simple
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|  * atomic semantics) and MSVC x86/x64/ARM */
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| #elif defined(__GNUC__) && (defined(__i386__) || defined(__amd64))
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| typedef enum _Py_memory_order {
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|     _Py_memory_order_relaxed,
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|     _Py_memory_order_acquire,
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|     _Py_memory_order_release,
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|     _Py_memory_order_acq_rel,
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|     _Py_memory_order_seq_cst
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| } _Py_memory_order;
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| 
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| typedef struct _Py_atomic_address {
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|     uintptr_t _value;
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| } _Py_atomic_address;
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| 
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| typedef struct _Py_atomic_int {
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|     int _value;
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| } _Py_atomic_int;
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| 
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| 
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| static __inline__ void
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| _Py_atomic_signal_fence(_Py_memory_order order)
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| {
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|     if (order != _Py_memory_order_relaxed)
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|         __asm__ volatile("":::"memory");
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| }
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| 
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| static __inline__ void
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| _Py_atomic_thread_fence(_Py_memory_order order)
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| {
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|     if (order != _Py_memory_order_relaxed)
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|         __asm__ volatile("mfence":::"memory");
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| }
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| 
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| /* Tell the race checker about this operation's effects. */
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| static __inline__ void
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| _Py_ANNOTATE_MEMORY_ORDER(const volatile void *address, _Py_memory_order order)
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| {
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|     (void)address;              /* shut up -Wunused-parameter */
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|     switch(order) {
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|     case _Py_memory_order_release:
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|     case _Py_memory_order_acq_rel:
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|     case _Py_memory_order_seq_cst:
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|         _Py_ANNOTATE_HAPPENS_BEFORE(address);
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|         break;
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|     case _Py_memory_order_relaxed:
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|     case _Py_memory_order_acquire:
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|         break;
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|     }
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|     switch(order) {
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|     case _Py_memory_order_acquire:
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|     case _Py_memory_order_acq_rel:
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|     case _Py_memory_order_seq_cst:
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|         _Py_ANNOTATE_HAPPENS_AFTER(address);
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|         break;
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|     case _Py_memory_order_relaxed:
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|     case _Py_memory_order_release:
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|         break;
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|     }
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| }
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| 
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| #define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|     __extension__ ({ \
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|         __typeof__(ATOMIC_VAL) atomic_val = ATOMIC_VAL; \
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|         __typeof__(atomic_val->_value) new_val = NEW_VAL;\
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|         volatile __typeof__(new_val) *volatile_data = &atomic_val->_value; \
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|         _Py_memory_order order = ORDER; \
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|         _Py_ANNOTATE_MEMORY_ORDER(atomic_val, order); \
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|         \
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|         /* Perform the operation. */ \
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|         _Py_ANNOTATE_IGNORE_WRITES_BEGIN(); \
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|         switch(order) { \
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|         case _Py_memory_order_release: \
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|             _Py_atomic_signal_fence(_Py_memory_order_release); \
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|             /* fallthrough */ \
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|         case _Py_memory_order_relaxed: \
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|             *volatile_data = new_val; \
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|             break; \
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|         \
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|         case _Py_memory_order_acquire: \
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|         case _Py_memory_order_acq_rel: \
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|         case _Py_memory_order_seq_cst: \
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|             __asm__ volatile("xchg %0, %1" \
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|                          : "+r"(new_val) \
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|                          : "m"(atomic_val->_value) \
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|                          : "memory"); \
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|             break; \
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|         } \
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|         _Py_ANNOTATE_IGNORE_WRITES_END(); \
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|     })
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| 
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| #define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER) \
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|     __extension__ ({  \
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|         __typeof__(ATOMIC_VAL) atomic_val = ATOMIC_VAL; \
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|         __typeof__(atomic_val->_value) result; \
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|         volatile __typeof__(result) *volatile_data = &atomic_val->_value; \
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|         _Py_memory_order order = ORDER; \
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|         _Py_ANNOTATE_MEMORY_ORDER(atomic_val, order); \
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|         \
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|         /* Perform the operation. */ \
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|         _Py_ANNOTATE_IGNORE_READS_BEGIN(); \
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|         switch(order) { \
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|         case _Py_memory_order_release: \
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|         case _Py_memory_order_acq_rel: \
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|         case _Py_memory_order_seq_cst: \
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|             /* Loads on x86 are not releases by default, so need a */ \
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|             /* thread fence. */ \
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|             _Py_atomic_thread_fence(_Py_memory_order_release); \
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|             break; \
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|         default: \
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|             /* No fence */ \
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|             break; \
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|         } \
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|         result = *volatile_data; \
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|         switch(order) { \
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|         case _Py_memory_order_acquire: \
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|         case _Py_memory_order_acq_rel: \
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|         case _Py_memory_order_seq_cst: \
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|             /* Loads on x86 are automatically acquire operations so */ \
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|             /* can get by with just a compiler fence. */ \
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|             _Py_atomic_signal_fence(_Py_memory_order_acquire); \
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|             break; \
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|         default: \
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|             /* No fence */ \
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|             break; \
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|         } \
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|         _Py_ANNOTATE_IGNORE_READS_END(); \
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|         result; \
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|     })
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| 
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| #elif defined(_MSC_VER)
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| /*  _Interlocked* functions provide a full memory barrier and are therefore
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|     enough for acq_rel and seq_cst. If the HLE variants aren't available
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|     in hardware they will fall back to a full memory barrier as well.
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| 
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|     This might affect performance but likely only in some very specific and
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|     hard to measure scenario.
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| */
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| #if defined(_M_IX86) || defined(_M_X64)
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| typedef enum _Py_memory_order {
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|     _Py_memory_order_relaxed,
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|     _Py_memory_order_acquire,
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|     _Py_memory_order_release,
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|     _Py_memory_order_acq_rel,
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|     _Py_memory_order_seq_cst
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| } _Py_memory_order;
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| 
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| typedef struct _Py_atomic_address {
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|     volatile uintptr_t _value;
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| } _Py_atomic_address;
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| 
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| typedef struct _Py_atomic_int {
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|     volatile int _value;
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| } _Py_atomic_int;
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| 
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| 
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| #if defined(_M_X64)
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| #define _Py_atomic_store_64bit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|     switch (ORDER) { \
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|     case _Py_memory_order_acquire: \
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|       _InterlockedExchange64_HLEAcquire((__int64 volatile*)&((ATOMIC_VAL)->_value), (__int64)(NEW_VAL)); \
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|       break; \
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|     case _Py_memory_order_release: \
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|       _InterlockedExchange64_HLERelease((__int64 volatile*)&((ATOMIC_VAL)->_value), (__int64)(NEW_VAL)); \
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|       break; \
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|     default: \
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|       _InterlockedExchange64((__int64 volatile*)&((ATOMIC_VAL)->_value), (__int64)(NEW_VAL)); \
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|       break; \
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|   }
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| #else
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| #define _Py_atomic_store_64bit(ATOMIC_VAL, NEW_VAL, ORDER) ((void)0);
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| #endif
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| 
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| #define _Py_atomic_store_32bit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|   switch (ORDER) { \
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|   case _Py_memory_order_acquire: \
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|     _InterlockedExchange_HLEAcquire((volatile long*)&((ATOMIC_VAL)->_value), (int)(NEW_VAL)); \
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|     break; \
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|   case _Py_memory_order_release: \
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|     _InterlockedExchange_HLERelease((volatile long*)&((ATOMIC_VAL)->_value), (int)(NEW_VAL)); \
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|     break; \
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|   default: \
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|     _InterlockedExchange((volatile long*)&((ATOMIC_VAL)->_value), (int)(NEW_VAL)); \
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|     break; \
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|   }
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| 
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| #if defined(_M_X64)
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| /*  This has to be an intptr_t for now.
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|     gil_created() uses -1 as a sentinel value, if this returns
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|     a uintptr_t it will do an unsigned compare and crash
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| */
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| inline intptr_t _Py_atomic_load_64bit_impl(volatile uintptr_t* value, int order) {
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|     __int64 old;
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|     switch (order) {
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|     case _Py_memory_order_acquire:
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|     {
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|       do {
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|         old = *value;
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|       } while(_InterlockedCompareExchange64_HLEAcquire((volatile __int64*)value, old, old) != old);
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|       break;
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|     }
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|     case _Py_memory_order_release:
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|     {
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|       do {
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|         old = *value;
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|       } while(_InterlockedCompareExchange64_HLERelease((volatile __int64*)value, old, old) != old);
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|       break;
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|     }
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|     case _Py_memory_order_relaxed:
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|       old = *value;
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|       break;
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|     default:
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|     {
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|       do {
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|         old = *value;
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|       } while(_InterlockedCompareExchange64((volatile __int64*)value, old, old) != old);
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|       break;
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|     }
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|     }
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|     return old;
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| }
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| 
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| #define _Py_atomic_load_64bit(ATOMIC_VAL, ORDER) \
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|     _Py_atomic_load_64bit_impl((volatile uintptr_t*)&((ATOMIC_VAL)->_value), (ORDER))
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| 
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| #else
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| #define _Py_atomic_load_64bit(ATOMIC_VAL, ORDER) ((ATOMIC_VAL)->_value)
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| #endif
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| 
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| inline int _Py_atomic_load_32bit_impl(volatile int* value, int order) {
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|     long old;
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|     switch (order) {
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|     case _Py_memory_order_acquire:
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|     {
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|       do {
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|         old = *value;
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|       } while(_InterlockedCompareExchange_HLEAcquire((volatile long*)value, old, old) != old);
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|       break;
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|     }
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|     case _Py_memory_order_release:
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|     {
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|       do {
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|         old = *value;
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|       } while(_InterlockedCompareExchange_HLERelease((volatile long*)value, old, old) != old);
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|       break;
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|     }
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|     case _Py_memory_order_relaxed:
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|       old = *value;
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|       break;
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|     default:
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|     {
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|       do {
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|         old = *value;
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|       } while(_InterlockedCompareExchange((volatile long*)value, old, old) != old);
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|       break;
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|     }
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|     }
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|     return old;
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| }
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| 
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| #define _Py_atomic_load_32bit(ATOMIC_VAL, ORDER) \
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|     _Py_atomic_load_32bit_impl((volatile int*)&((ATOMIC_VAL)->_value), (ORDER))
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| 
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| #define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|   if (sizeof((ATOMIC_VAL)->_value) == 8) { \
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|     _Py_atomic_store_64bit((ATOMIC_VAL), NEW_VAL, ORDER) } else { \
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|     _Py_atomic_store_32bit((ATOMIC_VAL), NEW_VAL, ORDER) }
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| 
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| #define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER) \
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|   ( \
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|     sizeof((ATOMIC_VAL)->_value) == 8 ? \
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|     _Py_atomic_load_64bit((ATOMIC_VAL), ORDER) : \
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|     _Py_atomic_load_32bit((ATOMIC_VAL), ORDER) \
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|   )
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| #elif defined(_M_ARM) || defined(_M_ARM64)
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| typedef enum _Py_memory_order {
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|     _Py_memory_order_relaxed,
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|     _Py_memory_order_acquire,
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|     _Py_memory_order_release,
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|     _Py_memory_order_acq_rel,
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|     _Py_memory_order_seq_cst
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| } _Py_memory_order;
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| 
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| typedef struct _Py_atomic_address {
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|     volatile uintptr_t _value;
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| } _Py_atomic_address;
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| 
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| typedef struct _Py_atomic_int {
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|     volatile int _value;
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| } _Py_atomic_int;
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| 
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| 
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| #if defined(_M_ARM64)
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| #define _Py_atomic_store_64bit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|     switch (ORDER) { \
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|     case _Py_memory_order_acquire: \
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|       _InterlockedExchange64_acq((__int64 volatile*)&((ATOMIC_VAL)->_value), (__int64)NEW_VAL); \
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|       break; \
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|     case _Py_memory_order_release: \
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|       _InterlockedExchange64_rel((__int64 volatile*)&((ATOMIC_VAL)->_value), (__int64)NEW_VAL); \
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|       break; \
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|     default: \
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|       _InterlockedExchange64((__int64 volatile*)&((ATOMIC_VAL)->_value), (__int64)NEW_VAL); \
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|       break; \
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|   }
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| #else
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| #define _Py_atomic_store_64bit(ATOMIC_VAL, NEW_VAL, ORDER) ((void)0);
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| #endif
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| 
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| #define _Py_atomic_store_32bit(ATOMIC_VAL, NEW_VAL, ORDER) \
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|   switch (ORDER) { \
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|   case _Py_memory_order_acquire: \
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|     _InterlockedExchange_acq((volatile long*)&((ATOMIC_VAL)->_value), (int)NEW_VAL); \
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|     break; \
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|   case _Py_memory_order_release: \
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|     _InterlockedExchange_rel((volatile long*)&((ATOMIC_VAL)->_value), (int)NEW_VAL); \
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|     break; \
 | |
|   default: \
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|     _InterlockedExchange((volatile long*)&((ATOMIC_VAL)->_value), (int)NEW_VAL); \
 | |
|     break; \
 | |
|   }
 | |
| 
 | |
| #if defined(_M_ARM64)
 | |
| /*  This has to be an intptr_t for now.
 | |
|     gil_created() uses -1 as a sentinel value, if this returns
 | |
|     a uintptr_t it will do an unsigned compare and crash
 | |
| */
 | |
| inline intptr_t _Py_atomic_load_64bit_impl(volatile uintptr_t* value, int order) {
 | |
|     uintptr_t old;
 | |
|     switch (order) {
 | |
|     case _Py_memory_order_acquire:
 | |
|     {
 | |
|       do {
 | |
|         old = *value;
 | |
|       } while(_InterlockedCompareExchange64_acq(value, old, old) != old);
 | |
|       break;
 | |
|     }
 | |
|     case _Py_memory_order_release:
 | |
|     {
 | |
|       do {
 | |
|         old = *value;
 | |
|       } while(_InterlockedCompareExchange64_rel(value, old, old) != old);
 | |
|       break;
 | |
|     }
 | |
|     case _Py_memory_order_relaxed:
 | |
|       old = *value;
 | |
|       break;
 | |
|     default:
 | |
|     {
 | |
|       do {
 | |
|         old = *value;
 | |
|       } while(_InterlockedCompareExchange64(value, old, old) != old);
 | |
|       break;
 | |
|     }
 | |
|     }
 | |
|     return old;
 | |
| }
 | |
| 
 | |
| #define _Py_atomic_load_64bit(ATOMIC_VAL, ORDER) \
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|     _Py_atomic_load_64bit_impl((volatile uintptr_t*)&((ATOMIC_VAL)->_value), (ORDER))
 | |
| 
 | |
| #else
 | |
| #define _Py_atomic_load_64bit(ATOMIC_VAL, ORDER) ((ATOMIC_VAL)->_value)
 | |
| #endif
 | |
| 
 | |
| inline int _Py_atomic_load_32bit_impl(volatile int* value, int order) {
 | |
|     int old;
 | |
|     switch (order) {
 | |
|     case _Py_memory_order_acquire:
 | |
|     {
 | |
|       do {
 | |
|         old = *value;
 | |
|       } while(_InterlockedCompareExchange_acq(value, old, old) != old);
 | |
|       break;
 | |
|     }
 | |
|     case _Py_memory_order_release:
 | |
|     {
 | |
|       do {
 | |
|         old = *value;
 | |
|       } while(_InterlockedCompareExchange_rel(value, old, old) != old);
 | |
|       break;
 | |
|     }
 | |
|     case _Py_memory_order_relaxed:
 | |
|       old = *value;
 | |
|       break;
 | |
|     default:
 | |
|     {
 | |
|       do {
 | |
|         old = *value;
 | |
|       } while(_InterlockedCompareExchange(value, old, old) != old);
 | |
|       break;
 | |
|     }
 | |
|     }
 | |
|     return old;
 | |
| }
 | |
| 
 | |
| #define _Py_atomic_load_32bit(ATOMIC_VAL, ORDER) \
 | |
|     _Py_atomic_load_32bit_impl((volatile int*)&((ATOMIC_VAL)->_value), (ORDER))
 | |
| 
 | |
| #define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
 | |
|   if (sizeof((ATOMIC_VAL)->_value) == 8) { \
 | |
|     _Py_atomic_store_64bit((ATOMIC_VAL), (NEW_VAL), (ORDER)) } else { \
 | |
|     _Py_atomic_store_32bit((ATOMIC_VAL), (NEW_VAL), (ORDER)) }
 | |
| 
 | |
| #define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER) \
 | |
|   ( \
 | |
|     sizeof((ATOMIC_VAL)->_value) == 8 ? \
 | |
|     _Py_atomic_load_64bit((ATOMIC_VAL), (ORDER)) : \
 | |
|     _Py_atomic_load_32bit((ATOMIC_VAL), (ORDER)) \
 | |
|   )
 | |
| #endif
 | |
| #else  /* !gcc x86  !_msc_ver */
 | |
| typedef enum _Py_memory_order {
 | |
|     _Py_memory_order_relaxed,
 | |
|     _Py_memory_order_acquire,
 | |
|     _Py_memory_order_release,
 | |
|     _Py_memory_order_acq_rel,
 | |
|     _Py_memory_order_seq_cst
 | |
| } _Py_memory_order;
 | |
| 
 | |
| typedef struct _Py_atomic_address {
 | |
|     uintptr_t _value;
 | |
| } _Py_atomic_address;
 | |
| 
 | |
| typedef struct _Py_atomic_int {
 | |
|     int _value;
 | |
| } _Py_atomic_int;
 | |
| /* Fall back to other compilers and processors by assuming that simple
 | |
|    volatile accesses are atomic.  This is false, so people should port
 | |
|    this. */
 | |
| #define _Py_atomic_signal_fence(/*memory_order*/ ORDER) ((void)0)
 | |
| #define _Py_atomic_thread_fence(/*memory_order*/ ORDER) ((void)0)
 | |
| #define _Py_atomic_store_explicit(ATOMIC_VAL, NEW_VAL, ORDER) \
 | |
|     ((ATOMIC_VAL)->_value = NEW_VAL)
 | |
| #define _Py_atomic_load_explicit(ATOMIC_VAL, ORDER) \
 | |
|     ((ATOMIC_VAL)->_value)
 | |
| #endif
 | |
| 
 | |
| /* Standardized shortcuts. */
 | |
| #define _Py_atomic_store(ATOMIC_VAL, NEW_VAL) \
 | |
|     _Py_atomic_store_explicit((ATOMIC_VAL), (NEW_VAL), _Py_memory_order_seq_cst)
 | |
| #define _Py_atomic_load(ATOMIC_VAL) \
 | |
|     _Py_atomic_load_explicit((ATOMIC_VAL), _Py_memory_order_seq_cst)
 | |
| 
 | |
| /* Python-local extensions */
 | |
| 
 | |
| #define _Py_atomic_store_relaxed(ATOMIC_VAL, NEW_VAL) \
 | |
|     _Py_atomic_store_explicit((ATOMIC_VAL), (NEW_VAL), _Py_memory_order_relaxed)
 | |
| #define _Py_atomic_load_relaxed(ATOMIC_VAL) \
 | |
|     _Py_atomic_load_explicit((ATOMIC_VAL), _Py_memory_order_relaxed)
 | |
| 
 | |
| #ifdef __cplusplus
 | |
| }
 | |
| #endif
 | |
| #endif  /* Py_ATOMIC_H */
 | 
