Send timeout is set to 10 ms. Without timeout PLC can be blocked by CAN driver: if CAN bus is not connected to controller CAN driver never returns and therfore PLC application halts. This is a temporary solution.
#include <stdlib.h>
#include <sys/time.h>
#include <pthread.h>
#include <signal.h>
#include <time.h>
#include <applicfg.h>
#include <timer.h>
static pthread_mutex_t CanFestival_mutex = PTHREAD_MUTEX_INITIALIZER;
static struct timeval last_sig;
static timer_t timer;
void TimerCleanup(void)
{
/* only used in realtime apps */
}
void EnterMutex(void)
{
if(pthread_mutex_lock(&CanFestival_mutex)) {
fprintf(stderr, "pthread_mutex_lock() failed\n");
}
}
void LeaveMutex(void)
{
if(pthread_mutex_unlock(&CanFestival_mutex)) {
fprintf(stderr, "pthread_mutex_unlock() failed\n");
}
}
void timer_notify(sigval_t val)
{
if(gettimeofday(&last_sig,NULL)) {
perror("gettimeofday()");
}
EnterMutex();
TimeDispatch();
LeaveMutex();
// printf("getCurrentTime() return=%u\n", p.tv_usec);
}
void TimerInit(void)
{
struct sigevent sigev;
// Take first absolute time ref.
if(gettimeofday(&last_sig,NULL)){
perror("gettimeofday()");
}
#if defined(__UCLIBC__)
int ret;
ret = timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &timer);
signal(SIGALRM, timer_notify);
#else
memset (&sigev, 0, sizeof (struct sigevent));
sigev.sigev_value.sival_int = 0;
sigev.sigev_notify = SIGEV_THREAD;
sigev.sigev_notify_attributes = NULL;
sigev.sigev_notify_function = timer_notify;
if(timer_create (CLOCK_REALTIME, &sigev, &timer)) {
perror("timer_create()");
}
#endif
}
void StopTimerLoop(TimerCallback_t exitfunction)
{
EnterMutex();
if(timer_delete (timer)) {
perror("timer_delete()");
}
exitfunction(NULL,0);
LeaveMutex();
}
void StartTimerLoop(TimerCallback_t init_callback)
{
EnterMutex();
// At first, TimeDispatch will call init_callback.
SetAlarm(NULL, 0, init_callback, 0, 0);
LeaveMutex();
}
void canReceiveLoop_signal(int sig)
{
}
/* We assume that ReceiveLoop_task_proc is always the same */
static void (*unixtimer_ReceiveLoop_task_proc)(CAN_PORT) = NULL;
/**
* Enter in realtime and start the CAN receiver loop
* @param port
*/
void* unixtimer_canReceiveLoop(void* port)
{
/*get signal*/
// if(signal(SIGTERM, canReceiveLoop_signal) == SIG_ERR) {
// perror("signal()");
//}
// Set the cancelation state for immediatly cancel the task
int ret;
ret = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
if (ret != 0)
perror("Can't enable the cancelation of the receiving task");
ret = pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
if (ret != 0)
perror("Can't set the asynchronous cancel typ");
unixtimer_ReceiveLoop_task_proc((CAN_PORT)port);
return NULL;
}
void CreateReceiveTask(CAN_PORT port, TASK_HANDLE* Thread, void* ReceiveLoopPtr)
{
unixtimer_ReceiveLoop_task_proc = ReceiveLoopPtr;
if(pthread_create(Thread, NULL, unixtimer_canReceiveLoop, (void*)port)) {
perror("pthread_create()");
}
}
void WaitReceiveTaskEnd(TASK_HANDLE *Thread)
{
if(pthread_cancel(*Thread)) {
perror("pthread_cancel()");
}
if(pthread_join(*Thread, NULL)) {
perror("pthread_join()");
}
}
#define maxval(a,b) ((a>b)?a:b)
void setTimer(TIMEVAL value)
{
// printf("setTimer(TIMEVAL value=%d)\n", value);
// TIMEVAL is us whereas setitimer wants ns...
long tv_nsec = 1000 * (maxval(value,1)%1000000);
time_t tv_sec = value/1000000;
struct itimerspec timerValues;
timerValues.it_value.tv_sec = tv_sec;
timerValues.it_value.tv_nsec = tv_nsec;
timerValues.it_interval.tv_sec = 0;
timerValues.it_interval.tv_nsec = 0;
timer_settime (timer, 0, &timerValues, NULL);
}
TIMEVAL getElapsedTime(void)
{
struct timeval p;
if(gettimeofday(&p,NULL)) {
perror("gettimeofday()");
}
// printf("getCurrentTime() return=%u\n", p.tv_usec);
return (p.tv_sec - last_sig.tv_sec)* 1000000 + p.tv_usec - last_sig.tv_usec;
}