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/*
* Copyright (c) 2020, Sergey Bugaev <bugaevc@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Assertions.h>
#include <LibMain/Main.h>
#include <LibThreading/Thread.h>
#include <errno.h>
#include <pthread.h>
#include <semaphore.h>
#include <unistd.h>
static ErrorOr<void> test_once()
{
constexpr size_t threads_count = 10;
static Vector<int> v;
v.clear();
pthread_once_t once = PTHREAD_ONCE_INIT;
Vector<NonnullRefPtr<Threading::Thread>, threads_count> threads;
for (size_t i = 0; i < threads_count; i++) {
threads.unchecked_append(TRY(Threading::Thread::try_create([&] {
return pthread_once(&once, [] {
v.append(35);
sleep(1);
});
})));
threads.last()->start();
}
// clang-format off
// It wants to put [[maybe_unused]] on its own line, for some reason.
for (auto& thread : threads)
[[maybe_unused]] auto res = thread->join();
// clang-format on
VERIFY(v.size() == 1);
return {};
}
static ErrorOr<void> test_mutex()
{
constexpr size_t threads_count = 10;
constexpr size_t num_times = 100;
Vector<int> v;
Vector<NonnullRefPtr<Threading::Thread>, threads_count> threads;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
for (size_t i = 0; i < threads_count; i++) {
threads.unchecked_append(TRY(Threading::Thread::try_create([&] {
for (size_t j = 0; j < num_times; j++) {
pthread_mutex_lock(&mutex);
v.append(35);
sched_yield();
pthread_mutex_unlock(&mutex);
sched_yield();
}
return 0;
})));
threads.last()->start();
}
// clang-format off
// It wants to put [[maybe_unused]] on its own line, for some reason.
for (auto& thread : threads)
[[maybe_unused]] auto res = thread->join();
// clang-format on
VERIFY(v.size() == threads_count * num_times);
VERIFY(pthread_mutex_trylock(&mutex) == 0);
VERIFY(pthread_mutex_trylock(&mutex) == EBUSY);
return {};
}
static ErrorOr<void> test_semaphore_as_lock()
{
constexpr size_t threads_count = 10;
constexpr size_t num_times = 100;
Vector<int> v;
Vector<NonnullRefPtr<Threading::Thread>, threads_count> threads;
sem_t semaphore;
sem_init(&semaphore, 0, 1);
for (size_t i = 0; i < threads_count; i++) {
threads.unchecked_append(TRY(Threading::Thread::try_create([&] {
for (size_t j = 0; j < num_times; j++) {
sem_wait(&semaphore);
v.append(35);
sched_yield();
sem_post(&semaphore);
sched_yield();
}
return 0;
})));
threads.last()->start();
}
// clang-format off
// It wants to put [[maybe_unused]] on its own line, for some reason.
for (auto& thread : threads)
[[maybe_unused]] auto res = thread->join();
// clang-format on
VERIFY(v.size() == threads_count * num_times);
VERIFY(sem_trywait(&semaphore) == 0);
VERIFY(sem_trywait(&semaphore) == -1);
VERIFY(errno == EAGAIN);
return {};
}
static ErrorOr<void> test_semaphore_as_event()
{
Vector<int> v;
sem_t semaphore;
sem_init(&semaphore, 0, 0);
auto reader = TRY(Threading::Thread::try_create([&] {
sem_wait(&semaphore);
VERIFY(v.size() == 1);
return 0;
}));
reader->start();
auto writer = TRY(Threading::Thread::try_create([&] {
sched_yield();
v.append(35);
sem_post(&semaphore);
return 0;
}));
writer->start();
[[maybe_unused]] auto r1 = reader->join();
[[maybe_unused]] auto r2 = writer->join();
VERIFY(sem_trywait(&semaphore) == -1);
VERIFY(errno == EAGAIN);
return {};
}
static ErrorOr<void> test_semaphore_nonbinary()
{
constexpr size_t num = 5;
constexpr size_t threads_count = 10;
constexpr size_t num_times = 100;
Vector<NonnullRefPtr<Threading::Thread>, threads_count> threads;
sem_t semaphore;
sem_init(&semaphore, 0, num);
Atomic<u32, AK::memory_order_relaxed> value = 0;
Atomic<bool, AK::memory_order_relaxed> seen_more_than_two = false;
for (size_t i = 0; i < threads_count; i++) {
threads.unchecked_append(TRY(Threading::Thread::try_create([&] {
for (size_t j = 0; j < num_times; j++) {
sem_wait(&semaphore);
u32 v = 1 + value.fetch_add(1);
VERIFY(v <= num);
if (v > 2)
seen_more_than_two.store(true);
sched_yield();
value.fetch_sub(1);
sem_post(&semaphore);
}
return 0;
})));
threads.last()->start();
}
// clang-format off
// It wants to put [[maybe_unused]] on its own line, for some reason.
for (auto& thread : threads)
[[maybe_unused]] auto res = thread->join();
// clang-format on
VERIFY(value.load() == 0);
VERIFY(seen_more_than_two.load());
for (size_t i = 0; i < num; i++) {
VERIFY(sem_trywait(&semaphore) == 0);
}
VERIFY(sem_trywait(&semaphore) == -1);
VERIFY(errno == EAGAIN);
return {};
}
ErrorOr<int> serenity_main(Main::Arguments)
{
TRY(test_once());
TRY(test_mutex());
TRY(test_semaphore_as_lock());
TRY(test_semaphore_as_event());
TRY(test_semaphore_nonbinary());
return 0;
}
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