zengine-old/engine/3rdparty/zlib/test/03semaphore.cpp
2024-03-13 22:29:47 +08:00

67 lines
1.6 KiB
C++

#include <iostream>
#include <thread>
#include <queue>
#include <mutex>
#include <semaphore>
using namespace std;
#define LOOP_TIMES 1
void test1() {
int res = 0;
binary_semaphore bs(0);
thread t1([&]() {
this_thread::sleep_for(chrono::milliseconds(1000));
res = 12;
bs.release();
});
t1.detach();
bs.acquire();
std::cout << "test1:: res "<< res << endl;
}
void test2() {
int res = 0;
counting_semaphore<> cs(0);
queue<int> mq;
mutex mtx;
auto p = [&]() {
for (int i = 0; i < LOOP_TIMES * 2; i++) {
{ //保证res 与 mq 的修改线程安全
std::this_thread::sleep_for(std::chrono::milliseconds(1000));
lock_guard<mutex> lock(mtx);
mq.push(i / 2);
res = res + 1;
}
cs.release();
}
std::cout << "product end " << res << "\n";
};
auto c = [&](int id) {
for (int i = 0; i < LOOP_TIMES; i++) {
cs.acquire();//这里不存在虚假唤醒,一定能抢到资源,只是资源顺序不确定
{
lock_guard<mutex> lock(mtx);
mq.pop();
res = res - 1;
}
}
std::cout << "consume end " << id << " -> " << res << "\n";
};
thread t1(p);
thread t2(c, 1);
thread t3(c, 2);
t1.join();
t2.join();
t3.join();
std::cout << "test1:: res " << res << " mq " << mq.size() << endl;
}
int main() {
test1();
test2();
//信号量可以实现一批资源的分配
//信号量可由条件变量与锁实现
//信号量封装后可以实现chanel效果
std::cout << "binary_semaphore size:: " << sizeof(binary_semaphore) <<
" counting_semaphore<3> size:: " << sizeof(counting_semaphore<3>)<<
" counting_semaphore<10> size:: " << sizeof(counting_semaphore<10>) << endl;
return 1;
}