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//===-- Tests for mtx_t operations ----------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "src/threads/mtx_destroy.h"
#include "src/threads/mtx_init.h"
#include "src/threads/mtx_lock.h"
#include "src/threads/mtx_unlock.h"
#include "src/threads/thrd_create.h"
#include "src/threads/thrd_join.h"
#include "test/IntegrationTest/test.h"
#include <threads.h>
constexpr int START = 0;
constexpr int MAX = 10000;
mtx_t mutex;
static int shared_int = START;
int counter([[maybe_unused]] void *arg) {
int last_count = START;
while (true) {
LIBC_NAMESPACE::mtx_lock(&mutex);
if (shared_int == last_count + 1) {
shared_int++;
last_count = shared_int;
}
LIBC_NAMESPACE::mtx_unlock(&mutex);
if (last_count >= MAX)
break;
}
return 0;
}
void relay_counter() {
ASSERT_EQ(LIBC_NAMESPACE::mtx_init(&mutex, mtx_plain),
static_cast<int>(thrd_success));
// The idea of this test is that two competing threads will update
// a counter only if the other thread has updated it.
thrd_t thread;
LIBC_NAMESPACE::thrd_create(&thread, counter, nullptr);
int last_count = START;
while (true) {
ASSERT_EQ(LIBC_NAMESPACE::mtx_lock(&mutex), static_cast<int>(thrd_success));
if (shared_int == START) {
++shared_int;
last_count = shared_int;
} else if (shared_int != last_count) {
ASSERT_EQ(shared_int, last_count + 1);
++shared_int;
last_count = shared_int;
}
ASSERT_EQ(LIBC_NAMESPACE::mtx_unlock(&mutex),
static_cast<int>(thrd_success));
if (last_count > MAX)
break;
}
int retval = 123;
LIBC_NAMESPACE::thrd_join(thread, &retval);
ASSERT_EQ(retval, 0);
LIBC_NAMESPACE::mtx_destroy(&mutex);
}
mtx_t start_lock, step_lock;
bool started, step;
int stepper([[maybe_unused]] void *arg) {
LIBC_NAMESPACE::mtx_lock(&start_lock);
started = true;
LIBC_NAMESPACE::mtx_unlock(&start_lock);
LIBC_NAMESPACE::mtx_lock(&step_lock);
step = true;
LIBC_NAMESPACE::mtx_unlock(&step_lock);
return 0;
}
void wait_and_step() {
ASSERT_EQ(LIBC_NAMESPACE::mtx_init(&start_lock, mtx_plain),
static_cast<int>(thrd_success));
ASSERT_EQ(LIBC_NAMESPACE::mtx_init(&step_lock, mtx_plain),
static_cast<int>(thrd_success));
// In this test, we start a new thread but block it before it can make a
// step. Once we ensure that the thread is blocked, we unblock it.
// After unblocking, we then verify that the thread was indeed unblocked.
step = false;
started = false;
ASSERT_EQ(LIBC_NAMESPACE::mtx_lock(&step_lock),
static_cast<int>(thrd_success));
thrd_t thread;
LIBC_NAMESPACE::thrd_create(&thread, stepper, nullptr);
while (true) {
// Make sure the thread actually started.
ASSERT_EQ(LIBC_NAMESPACE::mtx_lock(&start_lock),
static_cast<int>(thrd_success));
bool s = started;
ASSERT_EQ(LIBC_NAMESPACE::mtx_unlock(&start_lock),
static_cast<int>(thrd_success));
if (s)
break;
}
// Since |step_lock| is still locked, |step| should be false.
ASSERT_FALSE(step);
// Unlock the step lock and wait until the step is made.
ASSERT_EQ(LIBC_NAMESPACE::mtx_unlock(&step_lock),
static_cast<int>(thrd_success));
while (true) {
ASSERT_EQ(LIBC_NAMESPACE::mtx_lock(&step_lock),
static_cast<int>(thrd_success));
bool current_step_value = step;
ASSERT_EQ(LIBC_NAMESPACE::mtx_unlock(&step_lock),
static_cast<int>(thrd_success));
if (current_step_value)
break;
}
int retval = 123;
LIBC_NAMESPACE::thrd_join(thread, &retval);
ASSERT_EQ(retval, 0);
LIBC_NAMESPACE::mtx_destroy(&start_lock);
LIBC_NAMESPACE::mtx_destroy(&step_lock);
}
static constexpr int THREAD_COUNT = 10;
static mtx_t multiple_waiter_lock;
static mtx_t counter_lock;
static int wait_count = 0;
int waiter_func(void *) {
LIBC_NAMESPACE::mtx_lock(&counter_lock);
++wait_count;
LIBC_NAMESPACE::mtx_unlock(&counter_lock);
// Block on the waiter lock until the main
// thread unblocks.
LIBC_NAMESPACE::mtx_lock(&multiple_waiter_lock);
LIBC_NAMESPACE::mtx_unlock(&multiple_waiter_lock);
LIBC_NAMESPACE::mtx_lock(&counter_lock);
--wait_count;
LIBC_NAMESPACE::mtx_unlock(&counter_lock);
return 0;
}
void multiple_waiters() {
LIBC_NAMESPACE::mtx_init(&multiple_waiter_lock, mtx_plain);
LIBC_NAMESPACE::mtx_init(&counter_lock, mtx_plain);
LIBC_NAMESPACE::mtx_lock(&multiple_waiter_lock);
thrd_t waiters[THREAD_COUNT];
for (int i = 0; i < THREAD_COUNT; ++i) {
LIBC_NAMESPACE::thrd_create(waiters + i, waiter_func, nullptr);
}
// Spin until the counter is incremented to the desired
// value.
while (true) {
LIBC_NAMESPACE::mtx_lock(&counter_lock);
if (wait_count == THREAD_COUNT) {
LIBC_NAMESPACE::mtx_unlock(&counter_lock);
break;
}
LIBC_NAMESPACE::mtx_unlock(&counter_lock);
}
LIBC_NAMESPACE::mtx_unlock(&multiple_waiter_lock);
int retval;
for (int i = 0; i < THREAD_COUNT; ++i) {
LIBC_NAMESPACE::thrd_join(waiters[i], &retval);
}
ASSERT_EQ(wait_count, 0);
LIBC_NAMESPACE::mtx_destroy(&multiple_waiter_lock);
LIBC_NAMESPACE::mtx_destroy(&counter_lock);
}
TEST_MAIN() {
relay_counter();
wait_and_step();
multiple_waiters();
return 0;
}
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