我正在使用 Boost ASIO 用 C++ 编写一个 ThreadPool 类。以下是我迄今为止编写的代码:
线程池类
using namespace std;
using namespace boost;
class ThreadPoolClass {
private:
/* The limit to the maximum number of threads to be
* instantiated within this pool
*/
int maxThreads;
/* Group of threads in the Pool */
thread_group threadPool;
asio::io_service asyncIOService;
void _Init()
{
maxThreads = 0;
}
public:
ThreadPoolClass();
ThreadPoolClass(int maxNumThreads);
ThreadPoolClass(const ThreadPoolClass& orig);
void CreateThreadPool();
void RunTask(JobClass * aJob);
virtual ~ThreadPoolClass();
};
ThreadPoolClass::ThreadPoolClass() {
_Init();
}
ThreadPoolClass::ThreadPoolClass(int maxNumThreads) {
_Init();
maxThreads = maxNumThreads;
}
void ThreadPoolClass::CreateThreadPool() {
asio::io_service::work work(asyncIOService);
for (int i = 0; i < maxThreads; i++) {
cout<<"Pushed"<<endl;
threadPool.create_thread(bind(&asio::io_service::run, &asyncIOService));
}
}
void ThreadPoolClass::RunTask(JobClass * aJob) {
cout<<"RunTask"<<endl;
asyncIOService.post(bind(&JobClass::Run,aJob));
}
ThreadPoolClass::ThreadPoolClass(const ThreadPoolClass& orig) {
}
ThreadPoolClass::~ThreadPoolClass() {
cout<<"Kill ye all"<<endl;
asyncIOService.stop();
threadPool.join_all();
}
工作类别
using namespace std;
class JobClass {
private:
int a;
int b;
int c;
public:
JobClass() {
//Empty Constructor
}
JobClass(int val) {
a = val;
b = val - 1;
c = val + 1;
}
void Run()
{
cout<<"a: "<<a<<endl;
cout<<"b: "<<b<<endl;
cout<<"c: "<<c<<endl;
}
};
Main
using namespace std;
int main(int argc, char** argv) {
ThreadPoolClass ccThrPool(20);
ccThrPool.CreateThreadPool();
JobClass ccJob(10);
cout << "Starting..." << endl;
while(1)
{
ccThrPool.RunTask(&ccJob);
}
return 0;
}
所以,基本上我正在创建 20 个线程,但截至目前仅发布一个由 ioservice 运行的(相同)任务(只是为了让事情简单并找到根本原因)。以下是我在 GDB 中运行该程序时的输出:
Pushed
[New Thread 0xb7cd2b40 (LWP 15809)]
Pushed
[New Thread 0xb74d1b40 (LWP 15810)]
Pushed
[New Thread 0xb68ffb40 (LWP 15811)]
Pushed
[New Thread 0xb60feb40 (LWP 15812)]
Pushed
[New Thread 0xb56fdb40 (LWP 15813)]
Pushed
[New Thread 0xb4efcb40 (LWP 15814)]
Pushed
[New Thread 0xb44ffb40 (LWP 15815)]
Pushed
[New Thread 0xb3affb40 (LWP 15816)]
Pushed
[New Thread 0xb30ffb40 (LWP 15817)]
Pushed
[New Thread 0xb28feb40 (LWP 15818)]
Pushed
[New Thread 0xb20fdb40 (LWP 15819)]
Pushed
[New Thread 0xb18fcb40 (LWP 15820)]
Pushed
[New Thread 0xb10fbb40 (LWP 15821)]
Pushed
[New Thread 0xb08fab40 (LWP 15822)]
Pushed
[New Thread 0xb00f9b40 (LWP 15823)]
Pushed
[New Thread 0xaf8f8b40 (LWP 15824)]
Pushed
[New Thread 0xaf0f7b40 (LWP 15825)]
Pushed
[New Thread 0xae8f6b40 (LWP 15826)]
Pushed
[New Thread 0xae0f5b40 (LWP 15827)]
Pushed
[New Thread 0xad8f4b40 (LWP 15828)]
Starting...
RunTask
Kill ye all
[Thread 0xb4efcb40 (LWP 15814) exited]
[Thread 0xb30ffb40 (LWP 15817) exited]
[Thread 0xaf8f8b40 (LWP 15824) exited]
[Thread 0xae8f6b40 (LWP 15826) exited]
[Thread 0xae0f5b40 (LWP 15827) exited]
[Thread 0xaf0f7b40 (LWP 15825) exited]
[Thread 0xb56fdb40 (LWP 15813) exited]
[Thread 0xb18fcb40 (LWP 15820) exited]
[Thread 0xb10fbb40 (LWP 15821) exited]
[Thread 0xb20fdb40 (LWP 15819) exited]
[Thread 0xad8f4b40 (LWP 15828) exited]
[Thread 0xb3affb40 (LWP 15816) exited]
[Thread 0xb7cd2b40 (LWP 15809) exited]
[Thread 0xb60feb40 (LWP 15812) exited]
[Thread 0xb08fab40 (LWP 15822) exited]
[Thread 0xb68ffb40 (LWP 15811) exited]
[Thread 0xb74d1b40 (LWP 15810) exited]
[Thread 0xb28feb40 (LWP 15818) exited]
[Thread 0xb00f9b40 (LWP 15823) exited]
[Thread 0xb44ffb40 (LWP 15815) exited]
[Inferior 1 (process 15808) exited normally]
我有两个问题:
- 为什么我的帖子会退出,即使我正在发帖
while 循环中的任务?
- 为什么 JobClass 的输出是变量 a,b 的值
并且 c 没有被打印?
我认为发生这种情况是因为您在 CreateThreadPool 方法中创建了工作对象,当超出范围时该对象会自动销毁 -> 在这种情况下 io_service 没有活动工作并且不处理您的任务。
尝试创建 ThreadPool 类的“工作”实例变量,而不是方法中的本地变量。
class ThreadPoolClass {
private:
thread_group threadPool;
asio::io_service asyncIOService;
std::auto_ptr<asio::io_service::work> work_;
public:
};
ThreadPoolClass::ThreadPoolClass(int maxNumThreads) {
_Init();
maxThreads = maxNumThreads;
}
void ThreadPoolClass::CreateThreadPool() {
work_.reset(new asio::io_service::work(asyncIOService));
for (int i = 0; i < maxThreads; i++) {
cout<<"Pushed"<<endl;
threadPool.create_thread(bind(&asio::io_service::run, &asyncIOService));
}
}
本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系:hwhale#tublm.com(使用前将#替换为@)