器Linux实现高精度定时器的方法（linux高精度定时）
High-precision Timers Implementation in Linux
Linux is a powerful and popular operating system, and it supports a variety of timer types. For certain applications,high-precision timers are critical to get accurate timing
information. The Linux kernel provides a high-precision timer API that can be used to set timers with microsecond accuracy. In this article, we’ll explore this API and look at how one can use it to achieve a high-precision timer on Linux.
A timer is used to keep track of the elapsed time since an event occurred, or of the time remaining until the occurrence of an event. The accuracy of the timer used to measure these values will affect the accuracy of the results. A high-precision timer is one that can measure time with very high accuracy, in microseconds or even nanoseconds. A high-precision timer can be used to measure response times and other small-scale differences in applications.
Linux provides two main methods of implementing a high-precision timer. The first is using the gettimeofday() system call. This system call returns the current time in microseconds since the epoch, which can be used to measure time with an accuracy of a microsecond.
The second method is to use the clock_gettime() system call, which returns an accurate representation of the current time as a struct timespec object. This struct contains two fields, tv_sec and tv_nsec, which contain the seconds and nanoseconds, respectively, since the epoch. This means that the accuracy of the time returned by the clock_gettime() system call is in nanoseconds.
In addition to the two main methods, Linux also provides additional APIs that can be used to implement high-precision timers. These APIs include the timerfd_create(), timerfd_settime() and timerfd_gettime() functions, which can be used to create and set/get timers with microsecond accuracy. The nanosleep() system call can also be used to put the current thread to sleep for a given amount of time in nanoseconds.
In summary, Linux provides multiple ways of implementing high-precision timers, ranging from microsecond accuracy to nanosecond accuracy. The gettimeofday() and clock_gettime() system calls can be used to get the current time with respective accuracies. Additionally, timerfd_create(), timerfd_settime() and timerfd_gettime() functions, as well as the nanosleep() system call, can be used to set up high-precision timers with microsecond and nanosecond accuracy.
