linux timer 优先级

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>

void timer_handler(int signum) {
    printf("Timer expired!\n");
}

int main() {
    struct sigaction sa;
    struct itimerspec its;

    // 设置信号处理函数
    sa.sa_handler = &timer_handler;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;
    sigaction(SIGALRM, &sa, NULL);

    // 设置定时器
    its.it_value.tv_sec = 5;  // 初始时间间隔为5秒
    its.it_value.tv_nsec = 0;
    its.it_interval.tv_sec = 5;  // 重复间隔为5秒
    its.it_interval.tv_nsec = 0;

    timer_t timerid;
    if (timer_create(CLOCK_REALTIME, NULL, &timerid) == -1) {
        perror("timer_create");
        exit(EXIT_FAILURE);
    }

    if (timer_settime(timerid, 0, &its, NULL) == -1) {
        perror("timer_settime");
        exit(EXIT_FAILURE);
    }

    while (1) {
        pause();  // 等待信号
    }

    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>

void short_task_handler(int signum) {
    printf("Short task executed!\n");
}

void long_task_handler(int signum) {
    printf("Long task started!\n");
    // 模拟长时间任务
    sleep(10);
    printf("Long task finished!\n");
}

int main() {
    struct sigaction sa_short, sa_long;
    struct itimerspec its_short, its_long;

    // 设置短任务信号处理函数
    sa_short.sa_handler = &short_task_handler;
    sigemptyset(&sa_short.sa_mask);
    sa_short.sa_flags = 0;
    sigaction(SIGUSR1, &sa_short, NULL);

    // 设置长任务信号处理函数
    sa_long.sa_handler = &long_task_handler;
    sigemptyset(&sa_long.sa_mask);
    sa_long.sa_flags = 0;
    sigaction(SIGUSR2, &sa_long, NULL);

    // 设置短定时器
    its_short.it_value.tv_sec = 1;  // 初始时间间隔为1秒
    its_short.it_value.tv_nsec = 0;
    its_short.it_interval.tv_sec = 1;  // 重复间隔为1秒
    its_short.it_interval.tv_nsec = 0;

    timer_t timerid_short;
    if (timer_create(CLOCK_REALTIME, NULL, &timerid_short) == -1) {
        perror("timer_create short");
        exit(EXIT_FAILURE);
    }

    if (timer_settime(timerid_short, 0, &its_short, NULL) == -1) {
        perror("timer_settime short");
        exit(EXIT_FAILURE);
    }

    // 设置长定时器
    its_long.it_value.tv_sec = 10;  // 初始时间间隔为10秒
    its_long.it_value.tv_nsec = 0;
    its_long.it_interval.tv_sec = 10;  // 重复间隔为10秒
    its_long.it_interval.tv_nsec = 0;

    timer_t timerid_long;
    if (timer_create(CLOCK_REALTIME, NULL, &timerid_long) == -1) {
        perror("timer_create long");
        exit(EXIT_FAILURE);
    }

    if (timer_settime(timerid_long, 0, &its_long, NULL) == -1) {
        perror("timer_settime long");
        exit(EXIT_FAILURE);
    }

    while (1) {
        pause();  // 等待信号
    }

    return 0;
}