Structure of OpenMP Program

omp_get_thread_num(): Thread ID [Master thread has id == 0]

#pragma omp parallel : a parallel region is marked in a scope

Type 1: Loop iterations

#pragma omp parallel shared() private()
{
    #pragma omp for schedule (static chunksize)
    for (/* */) {

    }
}

$n$ iterations divided into chunks of size chunksize
assignment to threads is static

Type 2: Sections

#pragma omp parallel 
{
    #pragma omp sections
    {
        #pragma omp section
        {
            work1();
        }

        #pragma omp section
        {
            work2();
        }

        #pragma omp master
        {
            master();
        }
    }
}

manually declaring the sections to be sent to different threads for execution
master construct for only the master section

Synchronization constructs

#pragma omp parallel 
{
    #pragma omp critical
    {
        // critical section
    }

    #pragma omp atomic
    // atomic statement (the atomic operation on the storage location 
    // designated as x is a unit of work)
}