/* * POSIX.4 Timers test program * * Written by J. Vidal * Copyright (C) Dec, 2002 OCERA Consortium. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * published by the Free Software Foundation version 2. * * Name: timers.c * Description: Check that a timer can be programed by different threads * * Procedure: 1.- Create two tasks. *            2.- The first time both arm a timer. Only the last is the owner *            and therefore the one that will receive notification of timer expiraition. *            3.- The handler for that timer wakes up the other task, allowing it to *            program an action for the signal of the timer and set the timer. *            4.- The proces is repeated printing the time passed since last timer expiration. *            5.- Each time the timer is being programmed by a different thread.  *  * Author: J. Vidal <jvidal@disca.upv.es> */#include <rtl.h>#include <time.h>#include <pthread.h>#include <signal.h>#define MY_SIGNAL RTL_SIGUSR1#define NTASKS 2#define MAXITERS 100pthread_t thread[NTASKS];timer_t timer;#define ONESEC 1000*1000*1000#define ONEMILI 1000*1000//#define PERIODIC_CLOCK_MODE#define pthread_kill rtl_pthread_killvoid timer_intr(int sig){  static int rec=0;  rtl_printf("Timer handler called for thread %d. Receiving signal:%d %d times\n",pthread_self()->user[0],sig,rec++);    if (pthread_self()->user[0]){    rtl_printf("I am thread 1, sending the signal to other thread after three shoots.\n");     pthread_wakeup_np(thread[0]);  } else {    rtl_printf("I am thread 0, sending the signal to other thread after three shoots.\n");     pthread_wakeup_np(thread[1]);  }  }void print_info(timer_t timer){  struct itimerspec current_timer_specs;  hrtime_t now=0;  static hrtime_t last_expiration=0;  now=gethrtime();  timer_gettime(timer,&current_timer_specs);  rtl_printf("timer armed. Specs: value:%lu interval:%lu (in nanoseconds)\n",(unsigned long)timespec_to_ns(&(current_timer_specs.it_value)),(unsigned long)timespec_to_ns(&(current_timer_specs.it_interval)));  rtl_printf("time passed since last expiration:%lu (in nanoseconds)\n",(unsigned long)(now-last_expiration));    last_expiration=now;}void *start_routine(void *arg){  struct sched_param p;  struct itimerspec new_setting,old_setting;  struct sigaction sa;  int signal,err=0;  int count=0;   pthread_self()->user[0]=arg;  signal=MY_SIGNAL;  p . sched_priority = 5;  pthread_setschedparam (pthread_self(), SCHED_FIFO, &p);    sa.sa_handler=timer_intr;  sa.sa_mask=0;  sa.sa_flags=0;  new_setting.it_interval.tv_sec=0;  new_setting.it_interval.tv_nsec=0;  new_setting.it_value.tv_sec=0;  new_setting.it_value.tv_nsec=100*ONEMILI+(unsigned) arg*100*ONEMILI;    if ((err=sigaction(signal,&sa,NULL))<0 ){    rtl_printf("sigaction(signal,&sa,NULL) FAILING, err:%d.\n",err);  }    // last that programs succesfully programs it, is the owner.  err=timer_settime(timer,0,&new_setting,&old_setting);  rtl_printf("timer_settime(timer,0,&new_setting,&old_setting) by thread %d returns %d\n",(unsigned) arg,err);     while (count ++< MAXITERS) {     pthread_suspend_np(pthread_self());     print_info(timer);     if ((err=sigaction(signal,&sa,NULL))<0 ){      rtl_printf("sigaction(signal,&sa,NULL) FAILING, err:%d.\n",err);     }     // last that succesfully programs it, is the owner.    err=timer_settime(timer,0,&new_setting,&old_setting);    rtl_printf("timer_settime(timer,0,&new_setting,&old_setting) by thread %d returns %d\n",(unsigned) arg,err);  }  return (void *)0;  }int init_module(void) {  int ret,i;  sigevent_t signal; #ifdef CLOCK_MODE_PERIODIC  hrtime_t period=1000*1000; // 1 milisecond.  clockid_t cl=rtl_getschedclock();  rtl_setclockmode(cl,RTL_CLOCK_MODE_PERIODIC,period); #endif  signal.sigev_notify=SIGEV_SIGNAL;  signal.sigev_signo=MY_SIGNAL;  ret=timer_create(CLOCK_REALTIME,&signal,&(timer));    if (!ret) {    rtl_printf("Timer created succesfully\n");  } else {    rtl_printf("Error creating timer\n");    return -1;  }    // Threads creation.  for (i=0;i<NTASKS;i++)    pthread_create (&(thread[i]), NULL, start_routine,(void *) i);     return 0;}void cleanup_module(void) {  int i;    timer_delete(timer);    for (i=0;i<NTASKS;i++)    pthread_delete_np (thread[i]);    }