有时候需要确定某个事件的准确时间,就得把精度提高到毫秒(millsecond)、微秒(microsecond)、纳秒(nanosecond,很少用)。这里将讲解并演示如何使用。 C语言中所支持的精度在秒之下有微秒和纳秒,所以需要精度为毫秒的话建议直接使用微秒这个更高精度的时间值。 文章结构: 高精度时间结构体 时间函数 宏:计算时间差 示例...
nanosecond 纳秒 ns 1e-9秒 picosecond 皮秒 ps 1e-12秒 常用C类型 __time_t和__suseconds_t 我们可以使用ANSI标准库中的time.h头文件,。这个头文件中定义的时间和日期所使用的方法,无论是在结构定义,还是命名,都具有明显的C语言风格。下面,我将说明在C/C++中怎样使用日期的时间功能。估计是因为GCC采用C++...
默认是nanosecond 级精度,是系统调用(_sys_clock_gettime()),会有开销。调用频繁的话,可能造成损失性能。但是Linux 2.6.32后可以指定参数CLOCK_REALTIME_COARSE和CLOCK_MONOTONIC_COARSE,粗粒度地获取时间,而不需要发生上下文切换(和gettimeofday()一样也是vdso技术,https://access.redhat.com/documentation/en-us/red...
但是Linux 2.6.32后可以指定参数CLOCK_REALTIME_COARSE和CLOCK_MONOTONIC_COARSE,粗粒度地获取时间,而不需要发生上下文切换(和gettimeofday()一样也是vdso技术,https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux_for_real_time/7/html/reference_...
The nanosecond is a multiple of thesecond, which is theSIbase unit for time. In the metric system, "nano" is the prefix for billionths, or 10-9. Nanoseconds can be abbreviated asns; for example, 1 nanosecond can be written as 1 ns. ...
time_t time2 = time(nullptr); double time_diff = difftime(time2, time1); cout <<'time1: '<< time1 << endl; cout <<'time2: '<< time2 << endl; cout <<'time_diff: '<< time_diff <<'s'<< endl; 其输出如下,可以看到这正是time1和time2两个整数相减的结果: ...
默认是nanosecond 级精度,是系统调用(_sys_clock_gettime()),会有开销。调用频繁的话,可能造成损失性能。但是Linux 2.6.32后可以指定参数CLOCK_REALTIME_COARSE和CLOCK_MONOTONIC_COARSE,粗粒度地获取时间,而不需要发生上下文切换(和gettimeofday()一样也是vdso技术,https://access.redhat.com/documentation/en-us/red...
nanosecond time intervals that have elapsed since 12:00:00, January 1, 0001. It can be used in anXMLrequest or as a string inJSONresponse text. The value can represent time intervals through 23:59:59.9999999, December 31, 9999. It can also specify whether a local,UTC, or notime zone...
Nanolog: Nanolog is an extremely performant nanosecond scale logging system for C++ that exposes a simple printf-like API. quill: Asynchronous Low Latency C++ Logging Library reckless: Reckless logging. Low-latency, high-throughput, asynchronous logging library for C++. spdlog: Fast C++ logging ...
Design and Analysis of Nanosecond Time Synchronization System of Each Station of Each Chain of Chinese LORAN-CstationcalibratedsynchronizationChinese LORAN-C system includes BPL long wave timing system and "Chang He 2" navigation system. At present, LORAN-C is irreplaceable as the complement of s ...