Запрос на простую реализацию пула потоков C++

Stackoverflow оказал мне огромную помощь, и я хотел бы отблагодарить сообщество. Я реализовал простой пул потоков, используя веб-сайт TinyThread++ переносимую библиотеку потоков C++, используя то, что я узнал из Stackoverflow. Я новичок в программировании потоков, поэтому мне не очень удобно работать с мьютексами и т. д. У меня есть вопрос, который лучше всего задать после представления кода (, который довольно хорошо работает под Linux ):

// ThreadPool.h

class ThreadPool
{
 public:

 ThreadPool();
~ThreadPool();

// Creates a pool of threads and gets them ready to be used
void CreateThreads(int numOfThreads);

// Assigns a job to a thread in the pool, but doesn't start the job
// Each SubmitJob call will use up one thread of the pool.
// This operation can only be undone by calling StartJobs and
// then waiting for the jobs to complete. On completion,
// new jobs may be submitted.
void SubmitJob( void (*workFunc)(void *), void *workData );

// Begins execution of all the jobs in the pool.
void StartJobs();

// Waits until all jobs have completed.
// The wait will block the caller.
// On completion, new jobs may be submitted.
void WaitForJobsToComplete();

private:

enum typeOfWorkEnum { e_work, e_quit };

 class ThreadData
 {
   public:

    bool ready;  // thread has been created and is ready for work  
    bool haveWorkToDo;
    typeOfWorkEnum  typeOfWork;

    // Pointer to the work function each thread has to call.
    void (*workFunc)(void *);

    // Pointer to work data
    void *workData;

    ThreadData() : ready(false), haveWorkToDo(false) {  };
 };

struct ThreadArgStruct
{
    ThreadPool *threadPoolInstance;
    int         threadId;
};

// Data for each thread
ThreadData  *m_ThreadData;

ThreadPool(ThreadPool const&); // copy ctor hidden
ThreadPool& operator=(ThreadPool const&); // assign op. hidden

// Static function that provides the function pointer that a thread can call
// By including the ThreadPool instance in the void * parameter,
// we can use it to access other data and methods in the ThreadPool instance.
static void ThreadFuncWrapper(void *arg)
{
    ThreadArgStruct *threadArg = static_cast(arg);
    threadArg->threadPoolInstance->ThreadFunc(threadArg->threadId);
}

// The function each thread calls    
void ThreadFunc( int threadId );

// Called by the thread pool destructor
void DestroyThreadPool();

// Total number of threads available
// (fixed on creation of thread pool)
int m_numOfThreads;
int m_NumOfThreadsDoingWork;
int m_NumOfThreadsGivenJobs;

// List of threads
std::vector m_ThreadList;

// Condition variable to signal each thread has been created and executing
tthread::mutex              m_ThreadReady_mutex;
tthread::condition_variable m_ThreadReady_condvar;

 // Condition variable to signal each thread to start work
tthread::mutex              m_WorkToDo_mutex;
tthread::condition_variable m_WorkToDo_condvar;

// Condition variable to signal the main thread that 
// all threads in the pool have completed their work
tthread::mutex              m_WorkCompleted_mutex;
tthread::condition_variable m_WorkCompleted_condvar;
};

. cpp-файл:

//
//  ThreadPool.cpp
//

#include "ThreadPool.h"    

// This is the thread function for each thread.
// All threads remain in this function until
// they are asked to quit, which only happens
// when terminating the thread pool.
void ThreadPool::ThreadFunc( int threadId )
{
 ThreadData *myThreadData = &m_ThreadData[threadId]; 
 std::cout << "Hello world: Thread " << threadId << std::endl;

 // Signal that this thread is ready
 m_ThreadReady_mutex.lock();
       myThreadData->ready = true;
       m_ThreadReady_condvar.notify_one(); // notify the main thread
 m_ThreadReady_mutex.unlock();       

 while(true)
 {
    //tthread::lock_guard guard(m);
    m_WorkToDo_mutex.lock();

    while(!myThreadData->haveWorkToDo) // check for work to do
         m_WorkToDo_condvar.wait(m_WorkToDo_mutex); // if no work, wait here 
    myThreadData->haveWorkToDo = false; // need to do this before unlocking the mutex

    m_WorkToDo_mutex.unlock();

    // Do the work
    switch(myThreadData->typeOfWork)
    {
        case e_work:
            std::cout << "Thread " << threadId << ": Woken with work to do\n";

            // Do work
            myThreadData->workFunc(myThreadData->workData);

            std::cout << "#Thread " << threadId  << ": Work is completed\n";
            break;

         case e_quit:
             std::cout << "Thread " << threadId << ": Asked to quit\n";
             return; // ends the thread
    }

    // Now to signal the main thread that my work is completed
    m_WorkCompleted_mutex.lock();
       m_NumOfThreadsDoingWork--;

      // Unsure if this 'if' would make the program more efficient
      // if(m_NumOfThreadsDoingWork == 0)
           m_WorkCompleted_condvar.notify_one(); // notify the main thread
    m_WorkCompleted_mutex.unlock();       
  }

}


ThreadPool::ThreadPool() 
{ 
   m_numOfThreads = 0;  m_NumOfThreadsDoingWork = 0; m_NumOfThreadsGivenJobs = 0;
}


ThreadPool::~ThreadPool()
{
    if(m_numOfThreads)
    {
    DestroyThreadPool(); 
    delete [] m_ThreadData;
    }
}


void ThreadPool::CreateThreads(int numOfThreads)
{
// Check if a thread pool has already been created
if(m_numOfThreads > 0) 
   return;

m_NumOfThreadsGivenJobs = 0;
m_NumOfThreadsDoingWork = 0;
m_numOfThreads = numOfThreads;
m_ThreadData = new ThreadData[m_numOfThreads];
ThreadArgStruct threadArg;

for(int i=0; i= m_numOfThreads)
    return;

 m_ThreadData[m_NumOfThreadsGivenJobs].workFunc = workFunc;
 m_ThreadData[m_NumOfThreadsGivenJobs].workData = workData;  

 std::cout << "Submitted job " << m_NumOfThreadsGivenJobs << std::endl;

 m_NumOfThreadsGivenJobs++;  
}

void ThreadPool::StartJobs()
{
// Check that the thread pool has been created
// and some jobs have been assigned
if(!m_numOfThreads || !m_NumOfThreadsGivenJobs) 
   return;

// Set 'haveworkToDo' flag for all threads 
m_WorkToDo_mutex.lock();
   for(int i=0; i 0)  // Check if all threads have completed their work
   m_WorkCompleted_condvar.wait(m_WorkCompleted_mutex); // If not, wait here
 m_WorkCompleted_mutex.unlock();    
}


void ThreadPool::DestroyThreadPool()
{
std::cout << "Ask threads to quit\n";
m_WorkToDo_mutex.lock();
   for(int i=0; ijoin();
 }
 m_numOfThreads = 0;
}

Пример использования: (это вычисляет число пи -в квадрате/6 путем суммирования обратных величин квадратов )Фактически, этот пример использования выполняет одно и то же вычисление 10 раз параллельно. Более практичным использованием было бы вычисление каждым потоком другого набора суммируемых членов. Затем окончательный результат получается путем добавления всех результатов потока после завершения задания пула.

struct CalculationDataStruct
{
int inputVal;
double outputVal;
};

void LongCalculation( void *theSums )
{
CalculationDataStruct *sums = (CalculationDataStruct *)theSums;

int terms = sums->inputVal;
double sum;
for(int i=1; ioutputVal = sum;
}


int main(int argc, char** argv)
{ 
int numThreads = 10;

// Create pool
ThreadPool threadPool;
threadPool.CreateThreads(numThreads);

// Create thread workspace
CalculationDataStruct sums[numThreads];

// Set up jobs
for(int i=0; i

Вопрос :В методе ThreadPool ::ThreadFunc будет ли получена лучшая производительность, если следующий оператор if

if(NumOfThreadsDoingWork == 0)

был включен? Кроме того, я был бы признателен за критику и способы улучшения кода. В то же время, я надеюсь, что код будет полезен другим.