Prerequisite : Multithreading, pthread_self() in C with Example
pthread_equal() = This compares two thread which is equal or not. This function compares two thread identifiers. It return ‘0’ and non zero value. If it is equal then return non zero value else return 0.
Syntax:- int pthread_equal (pthread_t t1, pthread_t t2);
First Method :- Compare with self thread
// C program to demonstrate working of pthread_equal() #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <pthread.h> pthread_t tmp_thread; void* func_one(void* ptr) { // in this field we can compare two thread // pthread_self gives a current thread id if (pthread_equal(tmp_thread, pthread_self())) { printf("equal\n"); } else { printf("not equal\n"); } } // driver code int main() { // thread one pthread_t thread_one; // assign the id of thread one in temporary // thread which is global declared r tmp_thread = thread_one; // create a thread pthread_create(&thread_one, NULL, func_one, NULL); // wait for thread pthread_join(thread_one, NULL); } |
Output:
equal
Second Method :- Compare with other thread
// C program to demonstrate working of pthread_equal() #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <pthread.h> // global declared pthread_t variable pthread_t tmp_thread; void* func_one(void* ptr) { tmp_thread = pthread_self(); // assign the id of thread one in // temporary thread which is global declared } void* func_two(void* ptr) { pthread_t thread_two = pthread_self(); // compare two thread if (pthread_equal(tmp_thread, thread_two)) { printf("equal\n"); } else { printf("not equal\n"); } } int main() { pthread_t thread_one, thread_two; // creating thread one pthread_create(&thread_one, NULL, func_one, NULL); // creating thread two pthread_create(&thread_two, NULL, func_two, NULL); // wait for thread one pthread_join(thread_one, NULL); // wait for thread two pthread_join(thread_two, NULL); } |
Output:
not equal
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