Preempt Rt例程

原文:https://wiki.linuxfoundation.org/realtime/documentation/howto/applications/application_base

 /*$gcc -o thisfile thisfile.c -lpthread -lrt -Wall   $sudo ./thisfile *//*                                                                   * POSIX Real Time Example * using a single pthread as RT thread */#include <limits.h>#include <pthread.h>#include <sched.h>#include <stdio.h>#include <stdlib.h>#include <sys/mman.h>void *thread_func(void *data){        /* Do RT specific stuff here */        return NULL;}int main(int argc, char* argv[]){        struct sched_param param;        pthread_attr_t attr;        pthread_t thread;        int ret;        /* Lock memory */        if(mlockall(MCL_CURRENT|MCL_FUTURE) == -1) {                printf("mlockall failed: %m\n");                exit(-2);        }        /* Initialize pthread attributes (default values) */        ret = pthread_attr_init(&attr);        if (ret) {                printf("init pthread attributes failed\n");                goto out;        }        /* Set a specific stack size  */        ret = pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN);        if (ret) {            printf("pthread setstacksize failed\n");            goto out;        }        /* Set scheduler policy and priority of pthread */        ret = pthread_attr_setschedpolicy(&attr, SCHED_FIFO);        if (ret) {                printf("pthread setschedpolicy failed\n");                goto out;        }        param.sched_priority = 80;        ret = pthread_attr_setschedparam(&attr, &param);        if (ret) {                printf("pthread setschedparam failed\n");                goto out;        }        /* Use scheduling parameters of attr */        ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);        if (ret) {                printf("pthread setinheritsched failed\n");                goto out;        }        /* Create a pthread with specified attributes */        ret = pthread_create(&thread, &attr, thread_func, NULL);        if (ret) {                printf("create pthread failed\n");                goto out;        }        /* Join the thread and wait until it is done */        ret = pthread_join(thread, NULL);        if (ret)                printf("join pthread failed: %m\n");out:        return ret;}