stackManageTest.cpp

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>

#define NTHREADS 4
#define N 1000
#define MEGEXTRA 1000000

pthread_attr_t attr;

void *dowork(void *threadid)
{
    double A[N][N];
    int i, j;
    long tid;
    size_t mystacksize;

    tid = (long)threadid;
    pthread_attr_getstacksize(&attr, &mystacksize);
    printf("Thread %ld: stack size =%li bytes \n", tid, mystacksize);
    for (i = 0; i < N; i++)
    {
        for (j = 0; j < N; j++)
        {
            A[i][j] = ((i * j) / 3.452) + (N - i);
        }
    }
    pthread_exit(NULL);
}

int main(int argc, char *argv[])
{
    pthread_t threads[NTHREADS];
    size_t stacksize;
    int rc;
    long t;
    pthread_attr_init(&attr);
    pthread_attr_getstacksize(&attr, &stacksize);
    printf("Default stack size = %li\n", stacksize);

    stacksize = sizeof(double) * N * N + MEGEXTRA;
    printf("Amount of stack needed per thread = %li\n", stacksize);
    pthread_attr_setstacksize(&attr, stacksize);

    printf("creating threads with stack size = %li bytes\n", stacksize);
    for (t = 0; t < NTHREADS; t++)
    {
        rc = pthread_create(&threads[t], &attr, dowork, (void *)t);
        if (rc)
        {
            printf("Error; return code from pthread_create() is %d\n", rc);
            exit(-1);
        }
    }
    printf("Create %ld threads.\n", t);
    pthread_exit(NULL);
}