clock
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在头文件 <time.h> 中定义
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clock_t clock(); |
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返回近似使用的处理器时间的过程,因为一个实现定义的时代的开始程序的执行。将结果转换到秒的值除以它的CLOCKS_PER_SEC。因为开始的clock时代不具有一致的程序的开始,只由不同的呼叫返回到clock两个值之间的差异是有意义的。如果是由其他进程共享CPU,clock时间可能会提前比挂钟慢。如果当前进程是多线程的多个执行核心是,clock时间可能提前的速度比挂钟.....
原文:
Returns the approximate processor time used by the process since the beginning of an implementation-defined era related to the program's execution. To convert result value to seconds divide it by CLOCKS_PER_SEC. Because the beginning of the clock era does not have to coincide with the start of the program, only the difference between two values returned by different calls to clock is meaningful. If the CPU is shared by other processes, clock time may advance slower than wall clock. If the current process is multithreaded and more than one execution core is available, clock time may advance faster than wall clock.
目录 |
[编辑] 参数
(无)
[编辑] 返回值
至今(clock_t)(-1)如果该信息不可用程序所使用的处理器时间.
原文:
Processor time used by the program so far or (clock_t)(-1) if that information is unavailable.
[编辑] 注释
在POSIX兼容的系统上,clock_gettime与时钟编号CLOCK_PROCESS_CPUTIME_ID,为您提供更好的分辨率.
原文:
On POSIX-compatible systems, clock_gettime with clock id CLOCK_PROCESS_CPUTIME_ID offers better resolution.
在某些实现中返回的值的
clock()
环绕。例如,在32位clock_t的机器,它把,后2147秒或36分钟.原文:
The value returned by
clock()
may wrap around on some implementations. For example, on a machine with 32-bit clock_t, it wraps after 2147 seconds or 36 minutes.clock()
并不需要是线程安全的.原文:
clock()
is not required to be thread-safe.[编辑] 示例
本章尚未完成 原因:暂无示例 |
[编辑] 另请参阅
一个 tm 对象转换为文本表示原文: converts a tm object to a textual representation(函数) | |
返回当前时间的划时代的时间,因为系统 原文: returns the current time of the system as time since epoch (函数) | |
C++ documentation for clock
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