// 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 <assert.h>

#include <stdio.h>

#include <pthread.h>

#include <emscripten.h>

#include <emscripten/threading.h>

// This file tests the old GCC built-in atomic operations.

// See https://gcc.gnu.org/onlinedocs/gcc-4.6.4/gcc/Atomic-Builtins.html

#define NUM_THREADS 8

#define T int

// TEMP: Fastcomp backend doesn't implement these as atomic, so #define these to library

// implementations that are properly atomic. TODO: Implement these in fastcomp.

#define __sync_lock_test_and_set(...) emscripten_atomic_fence()

#define __sync_lock_release(...) emscripten_atomic_fence()

#define Bool int

Bool atomic_bool_cas_u32(T *ptr, T oldVal, T newVal)

{

T old = emscripten_atomic_cas_u32(ptr, oldVal, newVal);

return old == oldVal;

}

// Test __sync_val_compare_and_swap.

T nand_and_fetch(T *ptr, T x)

{

for(;;)

{

T old = emscripten_atomic_load_u32(ptr);

T newVal = ~(old & x);

T old2 = __sync_val_compare_and_swap(ptr, old, newVal);

if (old2 == old) return newVal;

}

}

// Test __sync_bool_compare_and_swap.

T nand_and_fetch_bool(T *ptr, T x)

{

for(;;)

{

T old = emscripten_atomic_load_u32(ptr);

T newVal = ~(old & x);

Bool success = __sync_bool_compare_and_swap(ptr, old, newVal);

if (success) return newVal;

}

}

volatile int nand_and_fetch_data = 0;

void *thread_nand_and_fetch(void *arg)

{

for(int i = 0; i < 999; ++i) // Odd number of times so that the operation doesn't cancel itself out.

nand_and_fetch((int*)&nand_and_fetch_data, (int)(long)arg);

pthread_exit(0);

}

void *thread_nand_and_fetch_bool(void *arg)

{

for(int i = 0; i < 999; ++i) // Odd number of times so that the operation doesn't cancel itself out.

nand_and_fetch_bool((int*)&nand_and_fetch_data, (int)(long)arg);

pthread_exit(0);

}

pthread_t thread[NUM_THREADS];

int main()

{

{

T x = 5;

T y = nand_and_fetch(&x, 9);

assert(y == -2);

assert(x == -2);

const int oddNThreads = NUM_THREADS-1;

for(int x = 0; x < 100; ++x) // Test a few times for robustness, since this test is so short-lived.

{

nand_and_fetch_data = 0;

__sync_synchronize(); // This has no effect in this code, but called in here just to test that the compiler generates a valid expression for this.

if (emscripten_has_threading_support())

{

for(int i = 0; i < oddNThreads; ++i) pthread_create(&thread[i], NULL, thread_nand_and_fetch, (void*)-1);

for(int i = 0; i < oddNThreads; ++i) pthread_join(thread[i], NULL);

assert(nand_and_fetch_data == -1);

}

}

}

{

T x = 5;

T y = nand_and_fetch_bool(&x, 9);

assert(y == -2);

assert(x == -2);

const int oddNThreads = NUM_THREADS-1;

for(int x = 0; x < 100; ++x) // Test a few times for robustness, since this test is so short-lived.

{

nand_and_fetch_data = 0;

if (emscripten_has_threading_support())

{

for(int i = 0; i < oddNThreads; ++i) pthread_create(&thread[i], NULL, thread_nand_and_fetch_bool, (void*)-1);

for(int i = 0; i < oddNThreads; ++i) pthread_join(thread[i], NULL);

assert(nand_and_fetch_data == -1);

}

}

}

return 0;

}