转自: http://blog.csdn.net/leo9150285/article/details/8271910
直接上程序
程序1:采用新线程派驻的通知方式
#include <stdio.h> #include <signal.h> #include <time.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #define CLOCKID CLOCK_REALTIME void timer_thread(union sigval v) { printf("timer_thread function! %d\n", v.sival_int); } int main() { // XXX int timer_create(clockid_t clockid, struct sigevent *evp, timer_t *timerid); // clockid--值:CLOCK_REALTIME,CLOCK_MONOTONIC,CLOCK_PROCESS_CPUTIME_ID,CLOCK_THREAD_CPUTIME_ID // evp--存放环境值的地址,结构成员说明了定时器到期的通知方式和处理方式等 // timerid--定时器标识符 timer_t timerid; struct sigevent evp; memset(&evp, 0, sizeof(struct sigevent)); //清零初始化 evp.sigev_value.sival_int = 111; //也是标识定时器的,这和timerid有什么区别?回调函数可以获得 evp.sigev_notify = SIGEV_THREAD; //线程通知的方式,派驻新线程 evp.sigev_notify_function = timer_thread; //线程函数地址 if (timer_create(CLOCKID, &evp, &timerid) == -1) { perror("fail to timer_create"); exit(-1); } // XXX int timer_settime(timer_t timerid, int flags, const struct itimerspec *new_value,struct itimerspec *old_value); // timerid--定时器标识 // flags--0表示相对时间,1表示绝对时间 // new_value--定时器的新初始值和间隔,如下面的it // old_value--取值通常为0,即第四个参数常为NULL,若不为NULL,则返回定时器的前一个值 //第一次间隔it.it_value这么长,以后每次都是it.it_interval这么长,就是说it.it_value变0的时候会装载it.it_interval的值 struct itimerspec it; it.it_interval.tv_sec = 1; it.it_interval.tv_nsec = 0; it.it_value.tv_sec = 1; it.it_value.tv_nsec = 0; if (timer_settime(timerid, 0, &it, NULL) == -1) { perror("fail to timer_settime"); exit(-1); } pause(); return 0; } /* * int timer_gettime(timer_t timerid, struct itimerspec *curr_value); * 获取timerid指定的定时器的值,填入curr_value * */
#include <stdio.h> #include <time.h> #include <stdlib.h> #include <signal.h> #include <string.h> #include <unistd.h> #define CLOCKID CLOCK_REALTIME void sig_handler(int signo) { printf("timer_signal function! %d\n", signo); } int main() { // XXX int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact); // signum--指定的信号编号,可以指定SIGKILL和SIGSTOP以外的所有信号编号 // act结构体--设置信号编号为signum的处理方式 // oldact结构体--保存上次的处理方式 // // struct sigaction // { // void (*sa_handler)(int); //信号响应函数地址 // void (*sa_sigaction)(int, siginfo_t *, void *); //但sa_flags为SA——SIGINFO时才使用 // sigset_t sa_mask; //说明一个信号集在调用捕捉函数之前,会加入进程的屏蔽中,当捕捉函数返回时,还原 // int sa_flags; // void (*sa_restorer)(void); //未用 // }; // timer_t timerid; struct sigevent evp; struct sigaction act; memset(&act, 0, sizeof(act)); act.sa_handler = sig_handler; act.sa_flags = 0; // XXX int sigaddset(sigset_t *set, int signum); //将signum指定的信号加入set信号集 // XXX int sigemptyset(sigset_t *set); //初始化信号集 sigemptyset(&act.sa_mask); if (sigaction(SIGUSR1, &act, NULL) == -1) { perror("fail to sigaction"); exit(-1); } memset(&evp, 0, sizeof(struct sigevent)); evp.sigev_signo = SIGUSR1; evp.sigev_notify = SIGEV_SIGNAL; if (timer_create(CLOCK_REALTIME, &evp, &timerid) == -1) { perror("fail to timer_create"); exit(-1); } struct itimerspec it; it.it_interval.tv_sec = 2; it.it_interval.tv_nsec = 0; it.it_value.tv_sec = 1; it.it_value.tv_nsec = 0; if (timer_settime(timerid, 0, &it, 0) == -1) { perror("fail to timer_settime"); exit(-1); } pause(); return 0; }