mirror of
https://github.com/OpenMP/Examples.git
synced 2025-04-10 08:22:11 +01:00
40 lines
899 B
C
40 lines
899 B
C
/*
|
|
* @@name: mem_model.4a
|
|
* @@type: C
|
|
* @@operation: compile
|
|
* @@expect: unspecified
|
|
* @@version: omp_3.1
|
|
*/
|
|
#include <omp.h>
|
|
|
|
void flush_incorrect()
|
|
{
|
|
int a, b;
|
|
a = b = 0;
|
|
#pragma omp parallel num_threads(2)
|
|
{
|
|
int myid = omp_get_thread_num();
|
|
int tmp;
|
|
|
|
if ( myid == 0 ) { // thread 0
|
|
#pragma omp atomic write
|
|
b = 1;
|
|
#pragma omp flush(b) // flushes are not ordered
|
|
#pragma omp flush(a) // compiler may move them around
|
|
#pragma omp atomic read
|
|
tmp = a;
|
|
}
|
|
else { // thread 1
|
|
#pragma omp atomic write
|
|
a = 1;
|
|
#pragma omp flush(a) // flushes are not ordered
|
|
#pragma omp flush(b) // compiler may move them around
|
|
#pragma omp atomic read
|
|
tmp = b;
|
|
}
|
|
if ( tmp == 0 ) { // exclusive access not guaranteed
|
|
/* protected section */
|
|
}
|
|
}
|
|
}
|