pthread_cancel() in C with example

prerequisite: Multithreading, pthread_self() in C with Example

pthread_cancel() = This function cancel a particular thread using thread id. This function send a cancellation request to the thread.

Syntax : – int pthread_cancel(pthread_t thread);

First Program : – Cancel self thread

// C program to demonstrates cancellation of self thread  
// using thread id 
#include <stdio.h> 
#include <stdlib.h> 
#include <pthread.h> 
  
void* calls(void* ptr) 
{ 
    printf("GeeksForGeeks"); 
  
    // To exit the current thread 
    // pthread_self() return the particular thread id 
    pthread_cancel(pthread_self());  
      
    return NULL; 
} 
  
int main() 
{ 
    // NULL when no attribute 
    pthread_t thread; 
  
    // calls is a function name 
    pthread_create(&thread, NULL, calls, NULL);  
  
    // Waiting for when thread is completed 
    pthread_join(thread, NULL);  
  
    return 0; 
}

Output:

GeeksForGeeks

If you use Linux then compile this program gcc program_name.c -lpthread

Second Program : – Cancel other thread

// C program to demonstrates cancellation of another thread  
// using thread id 
#include <stdio.h> 
#include <unistd.h> 
#include <sys/types.h> 
#include <pthread.h> 
  
// To Count 
int counter = 0;  
  
// for temporary thread which will be  
// store thread id of second thread 
pthread_t tmp_thread;  
  
// thread_one call func 
void* func(void* p)  
{ 
    while (1) { 
  
        printf("thread number one
"); 
        sleep(1);   // sleep 1 second 
        counter++;    
        
        // for exiting if counter = = 5 
        if (counter = = 2) { 
  
            // for cancel thread_two 
            pthread_cancel(tmp_thread);  
  
            // for exit from thread_one  
            pthread_exit(NULL);   
        } 
    } 
} 
  
// thread_two call func2 
void* func2(void* p)  
{ 
  
    // store thread_two id to tmp_thread 
    tmp_thread = pthread_self();  
  
    while (1) { 
        printf("thread Number two"); 
        sleep(1); // sleep 1 second 
    } 
} 
  
// Driver code 
int main() 
{ 
  
    // declare two thread 
    pthread_t thread_one, thread_two;  
  
    // create thread_one 
    pthread_create(&thread_one, NULL, func, NULL); 
  
    // create thread_two  
    pthread_create(&thread_two, NULL, func2, NULL);  
  
    // waiting for when thread_one is completed 
    pthread_join(thread_one, NULL);  
  
    // waiting for when thread_two is completed 
    pthread_join(thread_two, NULL);  
  
}

Output:

thread number one
thread number two
thread number one 
thread number two

If you use Linux then compile this program gcc program_name.c -lpthread

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

pthread_cancel() in C with example

tags:

You Might Also Like

leave a comment

0 Comments

Subscribe to Our Newsletter

Top Followed books