The threa_cancel() is used to cancel one particular thread by the thread id. This function sends one cancellation request to the thread for termination. The syntax of the pthread_cancel() is like below −
int pthread_cancel(pthread_t th);
Now, let us see how to cancel threads using this function.
Example
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <pthread.h>
int count = 0;
pthread_t sample_thread;
void* thread_one_func(void* p) {
while (1) {
printf("This is thread 1\n");
sleep(1); // wait for 1 seconds
count++;
if (count == 5) {
//if the counter is 5, then request to cancel thread two and exit from current thread
pthread_cancel(sample_thread);
pthread_exit(NULL);
}
}
}
void* thread_two_func(void* p) {
sample_thread = pthread_self(); //store the id of thread 2
while (1) {
printf("This is thread 2\n");
sleep(2); // wit for 2 seconds
}
}
main() {
pthread_t t1, t2;
//create two threads
pthread_create(&t1, NULL, thread_one_func, NULL);
pthread_create(&t2, NULL, thread_two_func, NULL);
//wait for completing threads
pthread_join(t1, NULL);
pthread_join(t2, NULL);
}
Output
This is thread 2
This is thread 1
This is thread 1
This is thread 2
This is thread 1
This is thread 1
This is thread 1
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2
This is thread 2