Files
Programming-POSIX-Threads/alarm_thread.c

60 lines
1.5 KiB
C

/*
* alarm_fork.c
*
* This version of alarm.c uses pthread_create to create a
* separate thread to wait for each alarm to expire.
*/
#include <pthread.h>
#include "errors.h"
typedef struct alarm_tag {
int seconds;
char message[64];
} alarm_t;
void *alarm_thread (void *arg)
{
alarm_t *alarm = (alarm_t*)arg;
int status;
status = pthread_detach (pthread_self ());
if (status != 0)
err_abort (status, "Detach thread");
sleep (alarm->seconds);
printf ("(%d) %s\n", alarm->seconds, alarm->message);
free (alarm);
return NULL;
}
int main (int argc, char *argv[])
{
int status;
char line[128];
alarm_t *alarm;
pthread_t thread;
while (1) {
printf ("Alarm> ");
if (fgets (line, sizeof (line), stdin) == NULL) exit (0);
if (strlen (line) <= 1) continue;
alarm = (alarm_t*)malloc (sizeof (alarm_t));
if (alarm == NULL)
errno_abort ("Allocate alarm");
/*
* Parse input line into seconds (%d) and a message
* (%64[^\n]), consisting of up to 64 characters
* separated from the seconds by whitespace.
*/
if (sscanf (line, "%d %64[^\n]",
&alarm->seconds, alarm->message) < 2) {
fprintf (stderr, "Bad command\n");
free (alarm);
} else {
status = pthread_create (
&thread, NULL, alarm_thread, alarm);
if (status != 0)
err_abort (status, "Create alarm thread");
}
}
}