I wanted to download a file from Internet while I find the wget may stuck when the network is not good enough .
"wget" command accepts -T / --timeout , however, it doesn't work right as I tried .
So I create a thread to handle this job , using pthread_cond_timedwait .
the following program run like this : main thread create a sub_thread call thread_download in order to handle the job of download a file . If thread_download finished in time ,it signal the main thread to stop waiting and continue somes tasks. If not, (While time's up,) it cancel the thread_download.
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <pthread.h>
#include <time.h>
#include <sys/time.h>
pthread_mutex_t count_lock = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t count_cond = PTHREAD_COND_INITIALIZER;
unsigned int count = 0;
/*if it = 1 then it means download job finished in time*/
void *thread_download(void *arg)
{
system("wget ftp://192.168.100.3:22/ftpdir/1.rmvb -O 1.rmvb ");
count += 1;
pthread_mutex_lock(&count_lock);
pthread_cond_signal(&count_cond);
pthread_mutex_unlock(&count_lock);
pthread_exit(NULL);
}
int main(int argc, char *argv[])
{
struct timespec m_time;
pthread_t reader2;
int res = 0;
int msec; /*time out millionsec */
msec = atoi(argv[1]);
pthread_create(&reader2, NULL, thread_download, NULL);
/* get the current time */
struct timeval now;
gettimeofday(&now, NULL);
/* add the offset to get timeout value */
m_time.tv_nsec = now.tv_usec * 1000 + (msec % 1000) * 1000000;
m_time.tv_sec = now.tv_sec + msec / 1000;
pthread_mutex_lock(&count_lock);
while(count == 0 && res != ETIMEDOUT)
res = pthread_cond_timedwait(&count_cond, &count_lock, (const struct timespec *)&m_time);
pthread_mutex_unlock(&count_lock);
printf("res:%d\n", res);
if(res==ETIMEDOUT)
{
printf("\n\n********* timeout **********\n\n");
// if (pthread_kill(reader2,0)!=0)
{
printf("\n********* pthread_cancel **********\n");
pthread_cancel(reader2);
}
}
else
{
printf(" finish in time ,res = %d, count =%d\n", res , count);
}
pthread_join(reader2, NULL);
return 0;
}