C++ implements a simple thread pool

C++ thread pool, which inherits CDoit and implements start and end

The header file

 
#ifndef CTHREADPOOLMANAGE_H
#define CTHREADPOOLMANAGE_H
#include <iostream>
#include <pthread.h>
#include <unistd.h> 
#include <list>
#include <vector>
#include <time.h>
#include <asm/errno.h>
 
#define USLEEP_TIME 100
#define CHECK_TIME 1
 
 
using namespace std;
class CDoit
{
public:
 virtual int start(void *){};
 virtual int end(){};
};
 
 
class CthreadPoolManage
{
private:
 int _minThreads;  //Reserve at least a few threads
 int _maxThreads;  //You can have up to a few threads
 int _waitSec;      //Idle after how many seconds to shut down the thread
 class threadInfo{
  public:
  threadInfo(){
   isbusy = false; 
   doFlag = true;
  }
  //
  pthread_mutex_t mtx=PTHREAD_MUTEX_INITIALIZER;
  pthread_cond_t cond=PTHREAD_COND_INITIALIZER;
  bool isbusy;   //Whether free
  bool doFlag;
  //
  time_t beginTime;     //Thread does not work start time
  pthread_t cThreadPid; //Thread id
  pthread_attr_t cThreadAttr; //Thread attributes
  CDoit * doit;         //The task class
  void  * value;        //The value to be passed
 };
 //The thread function
 static void* startThread(void*);
 //Task queue lock
 pthread_mutex_t _duty_mutex;
 //Task queue
 list<threadInfo*> _dutyList;
 //Thread queue lock
 pthread_mutex_t _thread_mutex;
 //The thread queue
 list<threadInfo*> _threadList;
  
/// initialize, create the minimum number of threads ///
void initThread(); 
/// task assignment thread ///
static void* taskAllocation(void*arg);
pthread_t tasktPid;
/// thread destruction, status check thread ///
static void* checkThread(void* arg);
pthread_t checktPid;
bool  checkrun;
 
//Thread exception exits the cleanup
static void threadCleanUp(void* arg);
 
//
int addThread(list<threadInfo*> *plist,threadInfo* ptinfo);
 
public:
CthreadPoolManage();

CthreadPoolManage(int min,int max,int waitSec);
~CthreadPoolManage();
 
int start();
//Task injector
int putDuty(CDoit *,void *);
 
int getNowThreadNum();
 
};
 
#endif // CTHREADPOOLMANAGE_H

The CPP file

 
#include "cthreadpoolmanage.h"
 
CthreadPoolManage::CthreadPoolManage()
{
 _minThreads = 5;  //Reserve at least a few threads
 _maxThreads = 5;  //You can have up to a few threads
 _waitSec = 10;      //Idle after how many seconds to shut down the thread
 pthread_mutex_init(&_duty_mutex, NULL);
 pthread_mutex_init(&_thread_mutex, NULL);
 checkrun = true;
}
 
 
CthreadPoolManage::CthreadPoolManage(int min, int max, int waitSec)
{
  CthreadPoolManage();
  _minThreads = min;  //Reserve at least a few threads
  _maxThreads = max;  //You can have up to a few threads
  _waitSec = waitSec;      //Idle after how many seconds to shut down the thread
}
 
CthreadPoolManage::~CthreadPoolManage()
{
 
}
void CthreadPoolManage::threadCleanUp(void* arg)
{
 threadInfo* tinfo = (threadInfo*)arg;
 tinfo->isbusy = false;
 pthread_mutex_unlock(&tinfo->mtx);
 pthread_attr_destroy (&tinfo->cThreadAttr);
 delete tinfo;
}
 
void* CthreadPoolManage::startThread(void* arg)
{
 cout<<" Thread starts working "<<endl;
 threadInfo* tinfo = (threadInfo*)arg;
 pthread_cleanup_push(threadCleanUp,arg);
 while(tinfo->doFlag){
  pthread_mutex_lock(&tinfo->mtx);
  if(tinfo->doit == NULL)
  {
   cout<<" Start waiting for tasks "<<endl;
   pthread_cond_wait(&tinfo->cond,&tinfo->mtx);
   cout<<" Have the task "<<endl;
  }
  tinfo->isbusy = true;
  tinfo->doit->start(tinfo->value);
  tinfo->doit->end();
  tinfo->doit=NULL;
  tinfo->isbusy = false;
  time( &tinfo->beginTime);
  pthread_mutex_unlock(&tinfo->mtx);
 }
 //Okay, so 0 does not clean up until here, exception does
 pthread_cleanup_pop(0);
 pthread_attr_destroy (&tinfo->cThreadAttr);
 delete tinfo;
 cout<<" End of the thread "<<endl;
}
 
void CthreadPoolManage::initThread()
{
 int i = 0;
 for(i = 0;i<this->_minThreads;i++)
 {
   threadInfo *tinfo = new threadInfo;
   tinfo->doit = NULL;
   tinfo->value = NULL;
   tinfo->isbusy = false;
   tinfo->doFlag = true;
  //PTHREAD_CREATE_DETACHED separation (thread) and PTHREAD _CREATE_JOINABLE (not a separate thread)
   pthread_attr_init(&tinfo->cThreadAttr);
   pthread_attr_setdetachstate(&tinfo->cThreadAttr,PTHREAD_CREATE_DETACHED );
   cout<<"Initialize the I have a thread "<<endl;
   if(pthread_create(&tinfo->cThreadPid,&tinfo->cThreadAttr,startThread,(void *)tinfo) != 0)
  {
  cout<<" Thread creation failed "<<endl;
  break;
  }
  this->_threadList.push_back(tinfo);
 }
}
 
int CthreadPoolManage::addThread(std::list< CthreadPoolManage::threadInfo* >* plist, CthreadPoolManage::threadInfo* ptinfo)
{
   threadInfo *tinfo = new threadInfo;
   tinfo->doit = ptinfo->doit;
   tinfo->value = ptinfo->value;
   tinfo->isbusy = true;
   if(pthread_create(&tinfo->cThreadPid,NULL,startThread,(void *)tinfo) != 0)
  {
  cout<<" Thread creation failed "<<endl;
  return -1;
  }
  plist->push_back(tinfo);
  return 0;
}
 
 
int CthreadPoolManage::putDuty(CDoit* doit, void* value)
{
 threadInfo *tinfo = new threadInfo;
 time( &tinfo->beginTime);
 tinfo->doit= doit;
 tinfo->value = value;
 pthread_mutex_lock(&_duty_mutex);
  this->_dutyList.push_back(tinfo);
 pthread_mutex_unlock(&_duty_mutex);
 return 0;
}
 
void* CthreadPoolManage::taskAllocation(void*arg)
{
 CthreadPoolManage * ptmanage = (CthreadPoolManage*)arg;
 int size_1 = 0;
 int size_2 = 0;
 int i_1 = 0;
 int i_2 = 0;
 bool a_1 = true;
 bool a_2 = true;
 threadInfo* ptinfo;
 threadInfo* ptinfoTmp;
 while(true){
   size_1 = 0;
   size_2 = 0;
   pthread_mutex_lock(&ptmanage->_duty_mutex);
   pthread_mutex_lock(&ptmanage->_thread_mutex);
   size_1 = ptmanage->_dutyList.size();
   size_2 =ptmanage->_threadList.size();
   for(list<threadInfo*>::iterator itorti1 = ptmanage->_dutyList.begin();itorti1 !=ptmanage->_dutyList.end();)
   {
  ptinfo = *itorti1;
  a_1 = true;
  for(list<threadInfo*>::iterator itorti2 = ptmanage->_threadList.begin();itorti2!=ptmanage->_threadList.end();itorti2++){
   ptinfoTmp = *itorti2;
   if(EBUSY == pthread_mutex_trylock(&ptinfoTmp->mtx))
   {
    continue;
   }
   if(!ptinfoTmp->isbusy)
   {
    ptinfoTmp->doit = ptinfo->doit;
    ptinfoTmp->value = ptinfo->value;
    ptinfoTmp->isbusy = true;
    pthread_cond_signal(&ptinfoTmp->cond);
    pthread_mutex_unlock(&ptinfoTmp->mtx);
    a_1 = false;
    delete ptinfo;
    break;
   }
   pthread_mutex_unlock(&ptinfoTmp->mtx);
    }
    if(a_1){
   if(ptmanage->_threadList.size()>ptmanage->_maxThreads||ptmanage->addThread(&ptmanage->_threadList,ptinfo)!=0)
   {
    itorti1++;
    continue;
   }else{
    itorti1 = ptmanage->_dutyList.erase(itorti1);
   }
   delete ptinfo;
    }else{
   itorti1 = ptmanage->_dutyList.erase(itorti1);
    }
   }
   pthread_mutex_unlock(&ptmanage->_duty_mutex);
   pthread_mutex_unlock(&ptmanage->_thread_mutex);
   usleep(USLEEP_TIME);
 }
 return 0;
}
 
void* CthreadPoolManage::checkThread(void* arg)
{
 CthreadPoolManage * ptmanage = (CthreadPoolManage*)arg;
 threadInfo* ptinfo;
 time_t nowtime;
 while(ptmanage->checkrun){
  sleep(CHECK_TIME);
  pthread_mutex_lock(&ptmanage->_thread_mutex);
  if(ptmanage->_threadList.size()<=ptmanage->_minThreads)
  {
   continue;
  }
  for(list<threadInfo*>::iterator itorti2 = ptmanage->_threadList.begin();itorti2!=ptmanage->_threadList.end();){
   ptinfo = *itorti2;
   if(EBUSY == pthread_mutex_trylock(&ptinfo->mtx))
  {
   itorti2++;
   continue;
  }
  time(&nowtime);
  if(ptinfo->isbusy == false && nowtime-ptinfo->beginTime>ptmanage->_waitSec)
  {
   ptinfo->doFlag = false;
   itorti2 = ptmanage->_threadList.erase(itorti2);
  }else{
   itorti2++;
  }
  pthread_mutex_unlock(&ptinfo->mtx);
  }
  pthread_mutex_unlock(&ptmanage->_thread_mutex);
 }
}
 
int CthreadPoolManage::start()
{
 //Initialize the
 this->initThread();
 //Start the task assignment thread
  if(pthread_create(&tasktPid,NULL,taskAllocation,(void *)this) != 0)
  {
  cout<<" The task assignment thread failed to create "<<endl;
  return -1;
  }
  //Create a live state to allocate administrative threads
  if(pthread_create(&checktPid,NULL,checkThread,(void *)this) != 0)
  {
  cout<<" Failed to create thread state allocation management thread "<<endl;
  return -1;
  }
 return 0;
}
 
///////////////////////////////
int CthreadPoolManage::getNowThreadNum()
{
 int num = 0;
 pthread_mutex_lock(&this->_thread_mutex);
  num = this->_threadList.size();
 pthread_mutex_unlock(&this->_thread_mutex);
 return num ;
}

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