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// Copyright 2015 The Emscripten Authors. All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License. Both these licenses can be
// found in the LICENSE file.
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <emscripten/emscripten.h>
#include <emscripten/threading.h>
#include <unistd.h> // usleep
#include <assert.h>
volatile int counter = 0; // Shared data
volatile int lock = 0; // spinlock "mutex" variable
void *ThreadMain(void *arg)
{
printf("Thread started.\n");
for(int i = 0; i < 100; ++i)
{
#ifdef USE_EMSCRIPTEN_INTRINSICS
while(emscripten_atomic_exchange_u32((void*)&lock, 1))
#else
while(__sync_lock_test_and_set(&lock, 1))
#endif
{
/*nop*/;
}
int c = counter;
usleep(5 * 1000); // Create contention on the lock.
++c;
counter = c;
#ifdef USE_EMSCRIPTEN_INTRINSICS
emscripten_atomic_store_u32((void*)&lock, 0);
#else
__sync_lock_release(&lock);
#endif
}
printf("Thread done.\n");
pthread_exit(0);
}
#define NUM_THREADS 8
int main()
{
int result = 0;
if (!emscripten_has_threading_support())
{
#ifdef REPORT_RESULT
REPORT_RESULT(800);
#endif
printf("Skipped: Threading is not supported.\n");
return 0;
}
pthread_t thread[NUM_THREADS];
for(int i = 0; i < NUM_THREADS; ++i)
{
int rc = pthread_create(&thread[i], NULL, ThreadMain, 0);
if (rc != 0 || thread[i] == 0)
printf("Failed to create thread!\n");
}
for(int i = 0; i < NUM_THREADS; ++i)
{
int rc = pthread_join(thread[i], 0);
assert(rc == 0);
}
printf("counter: %d\n", counter);
#ifdef REPORT_RESULT
REPORT_RESULT(counter);
#endif
}
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