c++线程池

下面是线程池的类，下面是threadpool.h文件

/*
 * threadpool.h
 *
 *  Created on: 2015年1月8日
 *      Author: xk
 */

#ifndef THREADPOOL_THREADPOOL_H_
#define THREADPOOL_THREADPOOL_H_
    /*
    Thread Pool implementation for unix / linux environments
    Copyright (C) 2008 Shobhit Gupta

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
    */
#include <unistd.h>
#include <pthread.h>
#include <semaphore.h>
#include <iostream>
#include <vector>
using namespace std;
    /*
    WorkerThread class
    This class needs to be sobclassed by the user.
    */
    class WorkerThread{
    public:
        int id;

        unsigned virtual executeThis()
        {
            return 0;
        }

        WorkerThread(int id) : id(id) {}
        virtual ~WorkerThread(){}
    };

    /*
    ThreadPool class manages all the ThreadPool related activities.
    This includes keeping track of idle threads and ynchronizations between all threads.
    */
    class ThreadPool{
    public:
        ThreadPool();
        ThreadPool(int maxThreadsTemp);
        virtual ~ThreadPool();

        void destroyPool(int maxPollSecs);

        bool assignWork(WorkerThread *worker);
        bool fetchWork(WorkerThread **worker);

        void initializeThreads();

        static void *threadExecute(void *param);

        static pthread_mutex_t mutexSync;
        static pthread_mutex_t mutexWorkCompletion;

    private:
        int maxThreads;

        pthread_cond_t  condCrit;
        sem_t availableWork;
        sem_t availableThreads;

        //WorkerThread ** workerQueue;
        vector<WorkerThread *> workerQueue;

        int topIndex;
        int bottomIndex;

        int incompleteWork;

        int queueSize;

    };


#endif /* THREADPOOL_THREADPOOL_H_ */

下面是threadpool.cpp文件

/*
 * threadpool.cpp
 *
 *  Created on: 2015年1月8日
 *      Author: xk
 */
/*
Thread Pool implementation for unix / linux environments
Copyright (C) 2008 Shobhit Gupta

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdlib.h>
#include "threadpool.h"

using namespace std;

pthread_mutex_t ThreadPool::mutexSync = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t ThreadPool::mutexWorkCompletion = PTHREAD_MUTEX_INITIALIZER;



ThreadPool::ThreadPool()
{
    ThreadPool(2);
}

ThreadPool::ThreadPool(int maxThreads)
{
    if (maxThreads < 1)  maxThreads = 1;

    //mutexSync = PTHREAD_MUTEX_INITIALIZER;
    //mutexWorkCompletion = PTHREAD_MUTEX_INITIALIZER;

    pthread_mutex_lock(&mutexSync);
    this->maxThreads = maxThreads;
    this->queueSize = maxThreads;
    //workerQueue = new WorkerThread *[maxThreads];
    workerQueue.resize(maxThreads, NULL);
    topIndex = 0;
    bottomIndex = 0;
    incompleteWork = 0;
    sem_init(&availableWork, 0, 0);
    sem_init(&availableThreads, 0, queueSize);
    pthread_mutex_unlock(&mutexSync);
}

void ThreadPool::initializeThreads()
{
    for (int i = 0; i<maxThreads; ++i)
    {
        pthread_t tempThread;
        pthread_create(&tempThread, NULL, &ThreadPool::threadExecute, (void *) this);
        //threadIdVec[i] = tempThread;
    }

}

ThreadPool::~ThreadPool()
{
    workerQueue.clear();
}



void ThreadPool::destroyPool(int maxPollSecs = 2)
{
    while (incompleteWork>0)
    {
        cout << "Work is still incomplete=" << incompleteWork << endl;
        sleep(maxPollSecs);
    }
    cout << "All Done!! Wow! That was a lot of work!" << endl;
    sem_destroy(&availableWork);
    sem_destroy(&availableThreads);
    pthread_mutex_destroy(&mutexSync);
    pthread_mutex_destroy(&mutexWorkCompletion);

}


bool ThreadPool::assignWork(WorkerThread *workerThread)
{
    pthread_mutex_lock(&mutexWorkCompletion);
    incompleteWork++;
    //cout << "assignWork...incomapleteWork=" << incompleteWork << endl;
    pthread_mutex_unlock(&mutexWorkCompletion);

    sem_wait(&availableThreads);

    pthread_mutex_lock(&mutexSync);
    //workerVec[topIndex] = workerThread;
    workerQueue[topIndex] = workerThread;
    cout << "Assigning Worker[" << workerThread->id << "] Address:[" << workerThread << "] to Queue index [" << topIndex << "]" << endl;
    if (queueSize != 1)
        topIndex = (topIndex + 1) % (queueSize);
    sem_post(&availableWork);
    pthread_mutex_unlock(&mutexSync);
    return true;
}

bool ThreadPool::fetchWork(WorkerThread **workerArg)
{
    sem_wait(&availableWork);

    pthread_mutex_lock(&mutexSync);
    WorkerThread * workerThread = workerQueue[bottomIndex];
    workerQueue[bottomIndex] = NULL;
    *workerArg = workerThread;
    if (queueSize != 1)
        bottomIndex = (bottomIndex + 1) % (queueSize);
    sem_post(&availableThreads);
    pthread_mutex_unlock(&mutexSync);
    return true;
}

void *ThreadPool::threadExecute(void *param)
{
    WorkerThread *worker = NULL;

    while (((ThreadPool *)param)->fetchWork(&worker))
    {
        if (worker)
        {
            worker->executeThis();
            //cout << "worker[" << worker->id << "]	delete address: [" << worker << "]" << endl;
            delete worker;
            worker = NULL;
        }

        pthread_mutex_lock(&(((ThreadPool *)param)->mutexWorkCompletion));
        //cout << "Thread " << pthread_self() << " has completed a Job !" << endl;
        ((ThreadPool *)param)->incompleteWork--;
        pthread_mutex_unlock(&(((ThreadPool *)param)->mutexWorkCompletion));
    }
    return 0;
}

下面是main.cpp文件

/*
 * main.cpp
 *
 *  Created on: 2015年1月8日
 *      Author: xk
 */
/*
Thread Pool implementation for unix / linux environments
Copyright (C) 2008 Shobhit Gupta

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <iostream>
#include "threadpool.h"

using namespace std;

#define ITERATIONS 200

class SampleWorkerThread : public WorkerThread
{
public:
    int id;

    unsigned virtual executeThis()
    {
        // Instead of sleep() we could do anytime consuming work here.
        //Using ThreadPools is advantageous only when the work to be done is really time consuming. (atleast 1 or 2 seconds)
        sleep(2);

        return(0);
    }


    SampleWorkerThread(int id) : WorkerThread(id), id(id)
    {
        //           cout << "Creating SampleWorkerThread " << id << "	 address=" << this << endl;
    }

    ~SampleWorkerThread()
    {
        //           cout << "Deleting SampleWorkerThread " << id << "	 address=" << this << endl;
    }
};


int main(int argc, char **argv)
{
    //ThreadPool(N);
    //Create a Threadpool with N number of threads
    ThreadPool* myPool = new ThreadPool(25);
    myPool->initializeThreads();

    //We will count time elapsed after initializeThreads()
    time_t t1 = time(NULL);

    //Lets start bullying ThreadPool with tonnes of work !!!
    for (unsigned int i = 0; i<ITERATIONS; i++){
        SampleWorkerThread* myThread = new SampleWorkerThread(i);
        //cout << "myThread[" << myThread->id << "] = [" << myThread << "]" << endl;
        myPool->assignWork(myThread);
    }

    // destroyPool(int maxPollSecs)
    // Before actually destroying the ThreadPool, this function checks if all the pending work is completed.
    // If the work is still not done, then it will check again after maxPollSecs
    // The default value for maxPollSecs is 2 seconds.
    // And ofcourse the user is supposed to adjust it for his needs.

    myPool->destroyPool(2);

    time_t t2 = time(NULL);
    cout << t2 - t1 << " seconds elapsed
" << endl;
    delete myPool;

    return 0;
}

我是在ubuntu下利用eclipse编译运行的程序，在编译前右击项目->properties->C/C++ Build->Settings->GCC C++ Linker->Librareis,在Librabires(-l)中添加pthread然后编译运行即可

下面是结果

Assigning Worker[0] Address:[0x147bb60] to Queue index [0]
Assigning Worker[1] Address:[0x147bb80] to Queue index [1]
Assigning Worker[2] Address:[0x147bba0] to Queue index [2]
Assigning Worker[3] Address:[0x147bbc0] to Queue index [3]
Assigning Worker[4] Address:[0x147bbe0] to Queue index [4]
Assigning Worker[5] Address:[0x147bc00] to Queue index [5]
Assigning Worker[6] Address:[0x147bc20] to Queue index [6]
Assigning Worker[7] Address:[0x147bc40] to Queue index [7]
Assigning Worker[8] Address:[0x147bc60] to Queue index [8]
Assigning Worker[9] Address:[0x147bc80] to Queue index [9]
Assigning Worker[10] Address:[0x147bca0] to Queue index [10]
Assigning Worker[11] Address:[0x147bcc0] to Queue index [11]
Assigning Worker[12] Address:[0x147bce0] to Queue index [12]
Assigning Worker[13] Address:[0x147bd00] to Queue index [13]
Assigning Worker[14] Address:[0x147bd20] to Queue index [14]
Assigning Worker[15] Address:[0x147bd40] to Queue index [15]
Assigning Worker[16] Address:[0x147bd60] to Queue index [16]
Assigning Worker[17] Address:[0x147bd80] to Queue index [17]
Assigning Worker[18] Address:[0x147bda0] to Queue index [18]
Assigning Worker[19] Address:[0x147bdc0] to Queue index [19]
Assigning Worker[20] Address:[0x147bde0] to Queue index [20]
Assigning Worker[21] Address:[0x147be00] to Queue index [21]
Assigning Worker[22] Address:[0x147be20] to Queue index [22]
Assigning Worker[23] Address:[0x147be40] to Queue index [23]
Assigning Worker[24] Address:[0x147be60] to Queue index [24]
Assigning Worker[25] Address:[0x147be80] to Queue index [0]
Assigning Worker[26] Address:[0x147bea0] to Queue index [1]
Assigning Worker[27] Address:[0x147bec0] to Queue index [2]
Assigning Worker[28] Address:[0x147bee0] to Queue index [3]
Assigning Worker[29] Address:[0x147bf00] to Queue index [4]
Assigning Worker[30] Address:[0x147bf20] to Queue index [5]
Assigning Worker[31] Address:[0x147bf40] to Queue index [6]
Assigning Worker[32] Address:[0x147bf60] to Queue index [7]
Assigning Worker[33] Address:[0x147bf80] to Queue index [8]
Assigning Worker[34] Address:[0x147bfa0] to Queue index [9]
Assigning Worker[35] Address:[0x147bfc0] to Queue index [10]
Assigning Worker[36] Address:[0x147bfe0] to Queue index [11]
Assigning Worker[37] Address:[0x147c000] to Queue index [12]
Assigning Worker[38] Address:[0x147c020] to Queue index [13]
Assigning Worker[39] Address:[0x147c040] to Queue index [14]
Assigning Worker[40] Address:[0x147c060] to Queue index [15]
Assigning Worker[41] Address:[0x147c080] to Queue index [16]
Assigning Worker[42] Address:[0x147c0a0] to Queue index [17]
Assigning Worker[43] Address:[0x147c0c0] to Queue index [18]
Assigning Worker[44] Address:[0x147c0e0] to Queue index [19]
Assigning Worker[45] Address:[0x147c100] to Queue index [20]
Assigning Worker[46] Address:[0x147c120] to Queue index [21]
Assigning Worker[47] Address:[0x147c140] to Queue index [22]
Assigning Worker[48] Address:[0x147c160] to Queue index [23]
Assigning Worker[49] Address:[0x147c180] to Queue index [24]
Assigning Worker[50] Address:[0x147c1a0] to Queue index [0]
Assigning Worker[51] Address:[0x147bd80] to Queue index [1]
Assigning Worker[52] Address:[0x147be00] to Queue index [2]
Assigning Worker[53] Address:[0x147be20] to Queue index [3]
Assigning Worker[54] Address:[0x147be60] to Queue index [4]
Assigning Worker[55] Address:[0x147be40] to Queue index [5]
Assigning Worker[56] Address:[0x147bdc0] to Queue index [6]
Assigning Worker[57] Address:[0x147bda0] to Queue index [7]
Assigning Worker[58] Address:[0x147bd60] to Queue index [8]
Assigning Worker[59] Address:[0x147bd40] to Queue index [9]
Assigning Worker[60] Address:[0x147bd20] to Queue index [10]
Assigning Worker[61] Address:[0x147bd00] to Queue index [11]
Assigning Worker[62] Address:[0x147bce0] to Queue index [12]
Assigning Worker[63] Address:[0x147bcc0] to Queue index [13]
Assigning Worker[64] Address:[0x147bca0] to Queue index [14]
Assigning Worker[65] Address:[0x147bc80] to Queue index [15]
Assigning Worker[66] Address:[0x147bc60] to Queue index [16]
Assigning Worker[67] Address:[0x147bc40] to Queue index [17]
Assigning Worker[68] Address:[0x147bde0] to Queue index [18]
Assigning Worker[69] Address:[0x147bc20] to Queue index [19]
Assigning Worker[70] Address:[0x147bc00] to Queue index [20]
Assigning Worker[71] Address:[0x147bbe0] to Queue index [21]
Assigning Worker[72] Address:[0x147bbc0] to Queue index [22]
Assigning Worker[73] Address:[0x147bba0] to Queue index [23]
Assigning Worker[74] Address:[0x147bb80] to Queue index [24]
Assigning Worker[75] Address:[0x147bb60] to Queue index [0]
Assigning Worker[76] Address:[0x147bee0] to Queue index [1]
Assigning Worker[77] Address:[0x147bf00] to Queue index [2]
Assigning Worker[78] Address:[0x147bec0] to Queue index [3]
Assigning Worker[79] Address:[0x147bea0] to Queue index [4]
Assigning Worker[80] Address:[0x147bf40] to Queue index [5]
Assigning Worker[81] Address:[0x147bf20] to Queue index [6]
Assigning Worker[82] Address:[0x147be80] to Queue index [7]
Assigning Worker[83] Address:[0x147bf60] to Queue index [8]
Assigning Worker[84] Address:[0x147bfa0] to Queue index [9]
Assigning Worker[85] Address:[0x147bf80] to Queue index [10]
Assigning Worker[86] Address:[0x147bfc0] to Queue index [11]
Assigning Worker[87] Address:[0x147c080] to Queue index [12]
Assigning Worker[88] Address:[0x147c0c0] to Queue index [13]
Assigning Worker[89] Address:[0x147c020] to Queue index [14]
Assigning Worker[90] Address:[0x147c040] to Queue index [15]
Assigning Worker[91] Address:[0x147c0a0] to Queue index [16]
Assigning Worker[92] Address:[0x147c060] to Queue index [17]
Assigning Worker[93] Address:[0x147c000] to Queue index [18]
Assigning Worker[94] Address:[0x147c0e0] to Queue index [19]
Assigning Worker[95] Address:[0x147c100] to Queue index [20]
Assigning Worker[96] Address:[0x147bfe0] to Queue index [21]
Assigning Worker[97] Address:[0x147c160] to Queue index [22]
Assigning Worker[98] Address:[0x147c140] to Queue index [23]
Assigning Worker[99] Address:[0x147c180] to Queue index [24]
Assigning Worker[100] Address:[0x147c120] to Queue index [0]
Assigning Worker[101] Address:[0x147be00] to Queue index [1]
Assigning Worker[102] Address:[0x147be20] to Queue index [2]
Assigning Worker[103] Address:[0x147be60] to Queue index [3]
Assigning Worker[104] Address:[0x147bd80] to Queue index [4]
Assigning Worker[105] Address:[0x147c1a0] to Queue index [5]
Assigning Worker[106] Address:[0x147bd60] to Queue index [6]
Assigning Worker[107] Address:[0x147bdc0] to Queue index [7]
Assigning Worker[108] Address:[0x147bda0] to Queue index [8]
Assigning Worker[109] Address:[0x147be40] to Queue index [9]
Assigning Worker[110] Address:[0x147bd20] to Queue index [10]
Assigning Worker[111] Address:[0x147bd40] to Queue index [11]
Assigning Worker[112] Address:[0x147bd00] to Queue index [12]
Assigning Worker[113] Address:[0x147bca0] to Queue index [13]
Assigning Worker[114] Address:[0x147bcc0] to Queue index [14]
Assigning Worker[115] Address:[0x147bde0] to Queue index [15]
Assigning Worker[116] Address:[0x147bc80] to Queue index [16]
Assigning Worker[117] Address:[0x147bc40] to Queue index [17]
Assigning Worker[118] Address:[0x147bc60] to Queue index [18]
Assigning Worker[119] Address:[0x147bce0] to Queue index [19]
Assigning Worker[120] Address:[0x147bc00] to Queue index [20]
Assigning Worker[121] Address:[0x147bc20] to Queue index [21]
Assigning Worker[122] Address:[0x147bb80] to Queue index [22]
Assigning Worker[123] Address:[0x147bba0] to Queue index [23]
Assigning Worker[124] Address:[0x147bbc0] to Queue index [24]
Assigning Worker[125] Address:[0x147bbe0] to Queue index [0]
Assigning Worker[126] Address:[0x147bea0] to Queue index [1]
Assigning Worker[127] Address:[0x147bec0] to Queue index [2]
Assigning Worker[128] Address:[0x147bee0] to Queue index [3]
Assigning Worker[129] Address:[0x147bf40] to Queue index [4]
Assigning Worker[130] Address:[0x147be80] to Queue index [5]
Assigning Worker[131] Address:[0x147bf20] to Queue index [6]
Assigning Worker[132] Address:[0x147bf60] to Queue index [7]
Assigning Worker[133] Address:[0x147bf00] to Queue index [8]
Assigning Worker[134] Address:[0x147bb60] to Queue index [9]
Assigning Worker[135] Address:[0x147bfa0] to Queue index [10]
Assigning Worker[136] Address:[0x147bf80] to Queue index [11]
Assigning Worker[137] Address:[0x147bfc0] to Queue index [12]
Assigning Worker[138] Address:[0x147c0c0] to Queue index [13]
Assigning Worker[139] Address:[0x147c040] to Queue index [14]
Assigning Worker[140] Address:[0x147c020] to Queue index [15]
Assigning Worker[141] Address:[0x147c080] to Queue index [16]
Assigning Worker[142] Address:[0x147c060] to Queue index [17]
Assigning Worker[143] Address:[0x147c0a0] to Queue index [18]
Assigning Worker[144] Address:[0x147c000] to Queue index [19]
Assigning Worker[145] Address:[0x147c0e0] to Queue index [20]
Assigning Worker[146] Address:[0x147c140] to Queue index [21]
Assigning Worker[147] Address:[0x147c160] to Queue index [22]
Assigning Worker[148] Address:[0x147c180] to Queue index [23]
Assigning Worker[149] Address:[0x147bfe0] to Queue index [24]
Assigning Worker[150] Address:[0x147c100] to Queue index [0]
Assigning Worker[151] Address:[0x147be20] to Queue index [1]
Assigning Worker[152] Address:[0x147bd80] to Queue index [2]
Assigning Worker[153] Address:[0x147be60] to Queue index [3]
Assigning Worker[154] Address:[0x147be00] to Queue index [4]
Assigning Worker[155] Address:[0x147bdc0] to Queue index [5]
Assigning Worker[156] Address:[0x147bd60] to Queue index [6]
Assigning Worker[157] Address:[0x147c1a0] to Queue index [7]
Assigning Worker[158] Address:[0x147be40] to Queue index [8]
Assigning Worker[159] Address:[0x147c120] to Queue index [9]
Assigning Worker[160] Address:[0x147bd20] to Queue index [10]
Assigning Worker[161] Address:[0x147bda0] to Queue index [11]
Assigning Worker[162] Address:[0x147bd40] to Queue index [12]
Assigning Worker[163] Address:[0x147bca0] to Queue index [13]
Assigning Worker[164] Address:[0x147bcc0] to Queue index [14]
Assigning Worker[165] Address:[0x147bde0] to Queue index [15]
Assigning Worker[166] Address:[0x147bd00] to Queue index [16]
Assigning Worker[167] Address:[0x147bc80] to Queue index [17]
Assigning Worker[168] Address:[0x147bc40] to Queue index [18]
Assigning Worker[169] Address:[0x147bc60] to Queue index [19]
Assigning Worker[170] Address:[0x147bce0] to Queue index [20]
Assigning Worker[171] Address:[0x147bb80] to Queue index [21]
Assigning Worker[172] Address:[0x147bba0] to Queue index [22]
Assigning Worker[173] Address:[0x147bbc0] to Queue index [23]
Assigning Worker[174] Address:[0x147bc20] to Queue index [24]
Assigning Worker[175] Address:[0x147bc00] to Queue index [0]
Assigning Worker[176] Address:[0x147bec0] to Queue index [1]
Assigning Worker[177] Address:[0x147bbe0] to Queue index [2]
Assigning Worker[178] Address:[0x147be80] to Queue index [3]
Assigning Worker[179] Address:[0x147bf40] to Queue index [4]
Assigning Worker[180] Address:[0x147bf20] to Queue index [5]
Assigning Worker[181] Address:[0x147bf00] to Queue index [6]
Assigning Worker[182] Address:[0x147bf60] to Queue index [7]
Assigning Worker[183] Address:[0x147bee0] to Queue index [8]
Assigning Worker[184] Address:[0x147bb60] to Queue index [9]
Assigning Worker[185] Address:[0x147bfa0] to Queue index [10]
Assigning Worker[186] Address:[0x147bea0] to Queue index [11]
Assigning Worker[187] Address:[0x147bf80] to Queue index [12]
Assigning Worker[188] Address:[0x147c0c0] to Queue index [13]
Assigning Worker[189] Address:[0x147c020] to Queue index [14]
Assigning Worker[190] Address:[0x147c040] to Queue index [15]
Assigning Worker[191] Address:[0x147bfc0] to Queue index [16]
Assigning Worker[192] Address:[0x147c080] to Queue index [17]
Assigning Worker[193] Address:[0x147c060] to Queue index [18]
Assigning Worker[194] Address:[0x147c0a0] to Queue index [19]
Assigning Worker[195] Address:[0x147c000] to Queue index [20]
Assigning Worker[196] Address:[0x147c160] to Queue index [21]
Assigning Worker[197] Address:[0x147c180] to Queue index [22]
Assigning Worker[198] Address:[0x147c140] to Queue index [23]
Assigning Worker[199] Address:[0x147c0e0] to Queue index [24]
Work is still incomplete=50
Work is still incomplete=25
All Done!! Wow! That was a lot of work!
16 seconds elapsed