blob: 6ce929b4b4790d8da79539f780c507eac3785b55 [file] [log] [blame]
/*
* Copyright 2020 Google, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <gtest/gtest.h>
#include <mutex>
#include <thread>
#include <vector>
#include "base/uncontended_mutex.hh"
TEST(UncontendedMutex, Lock)
{
int data = 0;
UncontendedMutex m;
std::thread t1([&] () {
std::lock_guard<UncontendedMutex> g(m);
// Simulate += operation with a racing change between read and write.
int tmp = data;
std::this_thread::sleep_for(std::chrono::milliseconds(200));
data = tmp + 1;
});
std::thread t2([&] () {
std::this_thread::sleep_for(std::chrono::milliseconds(100));
std::lock_guard<UncontendedMutex> g(m);
data = data + 1;
});
std::thread t3([&] () {
std::this_thread::sleep_for(std::chrono::milliseconds(100));
std::lock_guard<UncontendedMutex> g(m);
data = data + 1;
});
t1.join();
t2.join();
t3.join();
EXPECT_EQ(data, 3);
}
TEST(UncontendedMutex, HeavyContention)
{
int num_of_iter = 1000;
int num_of_thread = 1000;
std::vector<std::thread> threads;
int data = 0;
UncontendedMutex m;
for (int t = 0 ; t < num_of_thread; ++t) {
threads.emplace_back([&] () {
for (int k = 0; k < num_of_iter; ++k) {
std::lock_guard<UncontendedMutex> g(m);
data++;
}
});
}
for (auto& t : threads) {
t.join();
}
EXPECT_EQ(data, num_of_iter * num_of_thread);
}