omp_test_lock

Attempts to set a lock but does not block thread execution.

Syntax

int omp_test_lock(  
   omp_lock_t *lock  
);  

Remarks

where,

lock
A variable of type omp_lock_t that was initialized with omp_init_lock.

Remarks

For more information, see 3.2.5 omp_test_lock and omp_test_nest_lock Functions.

Example

// omp_test_lock.cpp  
// compile with: /openmp  
#include <stdio.h>  
#include <omp.h>  
  
omp_lock_t simple_lock;                   
  
int main() {  
    omp_init_lock(&simple_lock);  
  
    #pragma omp parallel num_threads(4)  
    {  
        int tid = omp_get_thread_num();  
  
        while (!omp_test_lock(&simple_lock))  
            printf_s("Thread %d - failed to acquire simple_lock\n",  
                     tid);  
  
        printf_s("Thread %d - acquired simple_lock\n", tid);  
  
        printf_s("Thread %d - released simple_lock\n", tid);  
        omp_unset_lock(&simple_lock);  
    }  
  
    omp_destroy_lock(&simple_lock);  
}  

Thread 1 - acquired simple_lock  
Thread 1 - released simple_lock  
Thread 0 - failed to acquire simple_lock  
Thread 3 - failed to acquire simple_lock  
Thread 0 - failed to acquire simple_lock  
Thread 3 - failed to acquire simple_lock  
Thread 2 - acquired simple_lock  
Thread 0 - failed to acquire simple_lock  
Thread 3 - failed to acquire simple_lock  
Thread 0 - failed to acquire simple_lock  
Thread 3 - failed to acquire simple_lock  
Thread 2 - released simple_lock  
Thread 0 - failed to acquire simple_lock  
Thread 3 - failed to acquire simple_lock  
Thread 0 - acquired simple_lock  
Thread 3 - failed to acquire simple_lock  
Thread 0 - released simple_lock  
Thread 3 - failed to acquire simple_lock  
Thread 3 - acquired simple_lock  
Thread 3 - released simple_lock  

See Also

Functions