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在头文件<stdatomic.h>中定义



_Bool atomic_is_lock_free（const volatile A * obj）;


（自C11以来）

确定类型的所有对象A（被指向的对象的类型）的原子操作是否obj都是无锁的。在任何给定的程序执行中，调用的结果atomic_is_lock_free对于相同类型的所有指针是相同的。

这是为所有原子对象类型定义的通用函数A。该参数是指向易失性原子类型的指针，以接受非易失性和易失性（例如内存映射I/O）原子变量的地址。

参数

obj

-

指向要检查的原子对象的指针

返回值

true如果对类型的所有对象的操作A都是无锁的，否则false。

注意

正如已发布的C11所指出的那样，该函数是按对象而不是按类型的。这由DR 465纠正。

示例

#include <stdio.h>#include <stdatomic.h>
 _Atomic struct A { int a[100]; } a;_Atomic struct B { int x, y; } b;int main(void){    printf("_Atomic struct A is lock free? %s\n", 
            atomic_is_lock_free(&a) ? "true" : "false");    printf("_Atomic struct B is lock free? %s\n", 
            atomic_is_lock_free(&b) ? "true" : "false");}

可能的输出：

_Atomic struct A is lock free? false_Atomic struct B is lock free? true

参考

  • C11标准（ISO/IEC 9899:2011）：

    • 7.17.5.1 atomic_is_lock_free通用函数（p: 280）

另请参阅

ATOMIC_BOOL_LOCK_FREEATOMIC_CHAR_LOCK_FREEATOMIC_CHAR16_T_LOCK_FREEATOMIC_CHAR32_T_LOCK_FREEATOMIC_WCHAR_T_LOCK_FREEATOMIC_SHORT_LOCK_FREEATOMIC_INT_LOCK_FREEATOMIC_LONG_LOCK_FREEATOMIC_LLONG_LOCK_FREEATOMIC_POINTER_LOCK_FREE (C11)

indicates that the given atomic type is lock-free  (macro constant)

| 针对atomic_is_lock_free |的C ++文档

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