emscripten/tests/pthread/test_pthread_barrier.cpp at incoming · JavaScriptIOT/emscripten · GitHub

History

83 lines (69 loc) · 1.87 KB

Raw

// This file tests pthread barrier usage.

#include <emscripten/threading.h>

#include <pthread.h>

#include <stdlib.h>

#include <stdio.h>

#include <assert.h>

#define N 100

#define THREADS 8

int matrix[N][N] = {};

int intermediate[N] = {};

// Barrier variable

pthread_barrier_t barr;

// Sums a single row of a matrix.

int sum_row(int r)

{

int sum = 0;

for(int i = 0; i < N; ++i)

sum += matrix[r][i];

return sum;

}

void *thread_main(void *arg)

{

// Each thread sums individual rows.

int id = (int)arg;

for(int i = id; i < N; i += THREADS)

intermediate[i] = sum_row(i);

// Synchronization point

int rc = pthread_barrier_wait(&barr);

if (rc != 0 && rc != PTHREAD_BARRIER_SERIAL_THREAD)

{

printf("Could not wait on barrier\n");

exit(-1);

}

// Then each thread sums the one intermediate vector.

int totalSum = 0;

for(int i = 0; i < N; ++i)

totalSum += intermediate[i];

pthread_exit((void*)totalSum);

}

int main(int argc, char **argv)

{

pthread_t thr[THREADS];

// Create the matrix and compute the expected result.

int expectedTotalSum = 0;

srand(time(NULL));

for(int i = 0; i < N; ++i)

for(int j = 0; j < N; ++j)

{

matrix[i][j] = rand();

expectedTotalSum += matrix[i][j];

}

printf("The sum of the matrix is %d.\n", expectedTotalSum);

// Barrier initialization

int ret = pthread_barrier_init(&barr, NULL, THREADS);

assert(ret == 0);

for(int i = 0; i < THREADS; ++i) pthread_create(&thr[i], NULL, &thread_main, (void*)i);

if (emscripten_has_threading_support())

{

for(int i = 0; i < THREADS; ++i)

{

int totalSum = 0;

pthread_join(thr[i], (void**)&totalSum);

assert(totalSum == expectedTotalSum);

}

#ifdef REPORT_RESULT

REPORT_RESULT(0);

#endif

}

emscripten/tests/pthread/test_pthread_barrier.cpp at incoming · JavaScriptIOT/emscripten · GitHub

Uh oh!

Expand file tree

Breadcrumbs

test_pthread_barrier.cpp

Latest commit

History

Breadcrumbs

test_pthread_barrier.cpp

File metadata and controls