pthread_equal()--Compare Two Threads

 #include <pthread.h>
 int pthread_equal(pthread_t t1, pthread_t t2);

The pthread_equal() function compares two Pthread handles for equality.

Authorities and Locks

None.

Parameters

t1

(Input) Pthread handle for thread 1

t2

(Input) Pthread handle for thread 2

Return Value

0

The Pthread handles do not refer to the same thread.

1

The Pthread handles refer to the same thread.

Error Conditions

None.

Related Information

• The <pthread.h> header file. See Header files for Pthread functions.
  
  
• pthread_self()--Get Pthread Handle
  
  
• pthread_create()--Create Thread

Example

See Code disclaimer information for information pertaining to code examples.

#define _MULTI_THREADED
#include <pthread.h>
#include <stdio.h>
#include "check.h"

pthread_t   theThread;

void *threadfunc(void *parm)
{
  printf("Inside secondary thread\n");
  theThread = pthread_self();
  return NULL;
}

int main(int argc, char **argv)
{
  pthread_t             thread;
  int                   rc=0;

  printf("Enter Testcase - %s\n", argv[0]);

  printf("Create thread using default attributes\n");
  rc = pthread_create(&thread, NULL, threadfunc, NULL);
  checkResults("pthread_create()\n", rc);

  /* sleep() is not a very robust way to wait for the thread */
  sleep(5);

  printf("Check if global vs local pthread_t are equal\n");
  if (!pthread_equal(thread, theThread)) {
     printf("Unexpected results on pthread_equal()!\n");
     exit(1);
  }
  printf("pthread_equal returns true\n");

  printf("Main completed\n");
  return 0;
}

Output:

Enter Testcase - QP0WTEST/TPEQU0
Create thread using default attributes
Inside secondary thread
Check if global vs local pthread_t are equal
pthread_equal returns true
Main completed