使用boost :: asio提升線程池

Question

我正在嘗試使用帶有工作隊列的boost asio創建boost線程池。 但是我一at不振，我需要一個監視功能，該功能應保持運行並跟蹤隊列。 我不確定該怎么寫，目前我將其放在線程池類中。 我也試圖用全局函數編寫單獨的線程。 有人可以提出任何建議嗎？

#include <boost/thread/thread.hpp>
#include <boost/asio.hpp>
#include<memory>
#include<vector>
#include<list>

using namespace std;

class threadWork
{
public:
virtual void run()=0;
};

class thread_pool 
{ 
private: 
  boost::asio::io_service io_service_; 
  boost::asio::io_service::work work_; 
  boost::thread_group threads_; 
  std::size_t available_; 
  boost::mutex mutex_;

  list<shared_ptr<threadWork>> workQueue;

public: 


  thread_pool( std::size_t pool_size ) : work_( io_service_ ), available_( pool_size ) 
  { 
    for ( std::size_t i = 0; i < pool_size; ++i ) 
    { 
      threads_.create_thread( boost::bind( &boost::asio::io_service::run, &io_service_ ) ); 
    } 
  } 


  ~thread_pool() 
  { 

    io_service_.stop(); 

try 
    { 
      threads_.join_all(); 
    } 
    catch ( ... ) {} 
  } 

  void enqueue(shared_ptr<threadWork> work)
  {
  workQueue.push_back(work);
  }

  void keepRunning() // how to call this ?
  {
  while(true)
  {
      boost::unique_lock< boost::mutex > lock( mutex_ ); 

      if ( 0 == available_ ) // If no threads are available, then sleep. 
      {
          boost::this_thread::sleep(boost::posix_time::milliseconds(1000));
      }
      else
      {

          if(workQueue.empty() != true)
          {
               --available_;  
               io_service_.post( boost::bin(&thread_pool::wrap_task,this , workQueue));
               workQueue.pop_front();
          }
      }
  }
  }

 private: 

  void wrap_task(list<shared_ptr<threadWork>>& workQueue ) 
  { 
    try 
    { 
    workQueue.front()->run(); // Run the user supplied task. 
    } 

catch ( ... )  // Suppress all exceptions. 
{

} 

boost::unique_lock< boost::mutex > lock( mutex_ );  
    ++available_; 
  } 
}; 

class someWork:public threadWork
{
public:
virtual void run()
{
    cout<<"some long task \n";
     boost::this_thread::sleep(boost::posix_time::milliseconds(5000));
}
};

int main()
{

thread_pool pool(10);

pool.keepRunning(); // this stuck code so where to start this ?

shared_ptr<threadWork> w(new someWork);

pool.enqueue(w);



return 0;
}

Answer 1

您可以使用boost::asio::deadline_timer定期讓io_service更新一個表示隊列長度的原子變量。 類成員函數可以按需（按值）返回隊列長度。