parallel_pipeline没有终止

Question

我在我的代码中使用了parallel_pipeline函数。有时当我的条件满足时它会停止管道，有时它不会。当流量控制调用停止后，即使它不会终止而是调用它的下一部分并打印控制台然后控制台输出变得像是一直停留在无限循环中而什么都不做。

代码是：

#include <iostream> 
#include <sstream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <tbb/pipeline.h>
#include <tbb/atomic.h>
#include <tbb/concurrent_queue.h>
#include <tbb/compat/thread>
#include <tbb/tbbmalloc_proxy.h>    
#include <tbb/tick_count.h>
using namespace std;
using namespace tbb;

#define pi 3.141593
#define FILTER_LEN  265

double coeffs[ FILTER_LEN ] =
{
  0.0033473431384214393,0.000032074683390218124,0.0033131082058404943,0.0024777666109278788,
  -0.0008968429179843104,-0.0031973449396977684,-0.003430943381749411,-0.0029796565504781646,
  -0.002770673157048994,-0.0022783059845596586,-0.0008531818129514857,0.001115432556294998,
  0.0026079871108133294,0.003012423848769931,0.002461420635709332,0.0014154004589753215,
  0.00025190669718400967,-0.0007608257014963959,-0.0013703600874774068,-0.0014133823230551277,
  -0.0009759556503342884,-0.00039687498737139273,-0.00007527524701314324,-0.00024181463305012626,
  -0.0008521761947454302,-0.00162618205097997,-0.002170446498273018,-0.002129903305507943,
  -0.001333859049002249,0.00010700092934983156,0.0018039564602637683,0.0032107930896349583,
  0.0038325849735515363,0.003416201274366522,0.002060848732332109,0.00017954815260431595,
  -0.0016358832300944531,-0.0028402136847527387,-0.0031256650498727384,-0.0025374271571154713,
  -0.001438370315670195,-0.00035115295209013755,0.0002606730012030533,0.0001969569787142967,
  -0.00039635535951198597,-0.0010886127490608972,-0.0013530057243606405,-0.0008123200399262436,
  0.0005730271959526784,0.0024419465938120906,0.004133717273258681,0.0049402122577746265,
  0.0043879285604252714,0.002449549610687005,-0.00040283102645093463,-0.003337730734820209,
  -0.0054508346511294775,-0.006093057767824609,-0.005117609782189977,-0.0029293645861970417,
  -0.0003251033117661085,0.0018074390555649442,0.0028351284091668164,0.002623563404428517,
  0.0015692864792199496,0.0004127664681096788,-0.00009249878881824428,0.0004690173244168184,
  0.001964334172374759,0.0037256715492873485,0.004809640399145206,0.004395274594482053,
  0.0021650921193604,-0.0014888595443799124,-0.005534807968511709,-0.008642334104607624,
  -0.009668950651149259,-0.008104732391434574,-0.004299972815463919,0.0006184612821881392,
  0.005136551428636121,0.007907786753766152,0.008241212326068366,0.00634786595941524,
  0.003235610213062744,0.00028882736660937287,-0.001320994685952108,-0.0011237433853145615,
  0.00044213409507615003,0.0022057106517524255,0.00277593527678719,0.0011909915058737617,
  -0.0025807757230413447,-0.007497632882437637,-0.011739520895818884,-0.013377018279057393,
  -0.011166543231844196,-0.005133056165990026,0.0032948631959114935,0.011673660427968408,
  0.017376415708412904,0.018548938130314566,0.014811760899506572,0.007450782505155853,
  -0.001019540069785369,-0.007805775815783898,-0.010898333714715424,-0.00985364043415772,
  -0.005988406030111452,-0.001818560524968024,0.000028552677472614846,-0.0019938756495376363,
  -0.007477684025727061,-0.013989430449615033,-0.017870518868849213,-0.015639422062597726,
  -0.005624959109456065,0.010993528170353541,0.03001263681283932,0.04527492462846608,
  0.050581340787164114,0.041949186532860346,0.019360612460662185,-0.012644336735920483,
  -0.0458782599058412,-0.07073838953156347,-0.0791205623455818,-0.06709535677423759,
  -0.03644544574795176,0.005505370370858695,0.04780486657828151,0.07898800597378192,
  0.0904453420042807,0.07898800597378192,0.04780486657828151,0.005505370370858695,
  -0.03644544574795176,-0.06709535677423759,-0.0791205623455818,-0.07073838953156347,
  -0.0458782599058412,-0.012644336735920483,0.019360612460662185,0.041949186532860346,
  0.050581340787164114,0.04527492462846608,0.03001263681283932,0.010993528170353541,
  -0.005624959109456065,-0.015639422062597726,-0.017870518868849213,-0.013989430449615033,
  -0.007477684025727061,-0.0019938756495376363,0.000028552677472614846,-0.001818560524968024,
  -0.005988406030111452,-0.00985364043415772,-0.010898333714715424,-0.007805775815783898,
  -0.001019540069785369,0.007450782505155853,0.014811760899506572,0.018548938130314566,
  0.017376415708412904,0.011673660427968408,0.0032948631959114935,-0.005133056165990026,
  -0.011166543231844196,-0.013377018279057393,-0.011739520895818884,-0.007497632882437637,
  -0.0025807757230413447,0.0011909915058737617,0.00277593527678719,0.0022057106517524255,
  0.00044213409507615003,-0.0011237433853145615,-0.001320994685952108,0.00028882736660937287,
  0.003235610213062744,0.00634786595941524,0.008241212326068366,0.007907786753766152,
  0.005136551428636121,0.0006184612821881392,-0.004299972815463919,-0.008104732391434574,
  -0.009668950651149259,-0.008642334104607624,-0.005534807968511709,-0.0014888595443799124,
  0.0021650921193604,0.004395274594482053,0.004809640399145206,0.0037256715492873485,
  0.001964334172374759,0.0004690173244168184,-0.00009249878881824428,0.0004127664681096788,
  0.0015692864792199496,0.002623563404428517,0.0028351284091668164,0.0018074390555649442,
  -0.0003251033117661085,-0.0029293645861970417,-0.005117609782189977,-0.006093057767824609,
  -0.0054508346511294775,-0.003337730734820209,-0.00040283102645093463,0.002449549610687005,
  0.0043879285604252714,0.0049402122577746265,0.004133717273258681,0.0024419465938120906,
  0.0005730271959526784,-0.0008123200399262436,-0.0013530057243606405,-0.0010886127490608972,
  -0.00039635535951198597,0.0001969569787142967,0.0002606730012030533,-0.00035115295209013755,
  -0.001438370315670195,-0.0025374271571154713,-0.0031256650498727384,-0.0028402136847527387,
  -0.0016358832300944531,0.00017954815260431595,0.002060848732332109,0.003416201274366522,
  0.0038325849735515363,0.0032107930896349583,0.0018039564602637683,0.00010700092934983156,
  -0.001333859049002249,-0.002129903305507943,-0.002170446498273018,-0.00162618205097997,
  -0.0008521761947454302,-0.00024181463305012626,-0.00007527524701314324,-0.00039687498737139273,
  -0.0009759556503342884,-0.0014133823230551277,-0.0013703600874774068,-0.0007608257014963959,
  0.00025190669718400967,0.0014154004589753215,0.002461420635709332,0.003012423848769931,
  0.0026079871108133294,0.001115432556294998,-0.0008531818129514857,-0.0022783059845596586,
  -0.002770673157048994,-0.0029796565504781646,-0.003430943381749411,-0.0031973449396977684,
  -0.0008968429179843104,0.0024777666109278788,0.0033131082058404943,0.000032074683390218124,
  0.0033473431384214393
};

class MyBuffer 
{
    public:
    double *acc;
    double *buffer;
    int start,end;
    static int j;

    MyBuffer()
    {
        start=0;
        end=0;

       buffer=new double[150264];
       acc=new double[150000];
       fill_n(buffer,150264,0);

    }

    ~MyBuffer()
    {
        delete[] buffer;
        delete[] acc;
    }

    int startnumber()
    {
        return start;
    }

    int endnumber()
    {
        return end;
    }

};

typedef concurrent_bounded_queue<MyBuffer>  QueueMyBufferType;
QueueMyBufferType chunk_queue;

atomic<bool> stop_flag;
atomic<bool> stop_filter;

int MyBuffer::j=0;
int queueloopcount=30;

void input_function()                               
{   
   stop_flag = false;     

   cout<<"thread reached to call input function " <<endl;
   ofstream o("testing sinewave.csv");

   int counter=0;
   while(counter<150000)    
  { 
    //  cout<<"value of counter is \t" <<counter << endl;

        MyBuffer *b=new MyBuffer;                                                       
        b->start=(FILTER_LEN-1+(counter));
        b->end=(5264+(counter));

    //  cout<<"value of b.start is and b.end is "<<b->start<<"\t" <<b->end<<endl;

        for(int i =b->startnumber(); i <b->endnumber(); i++)
         {
               b->buffer[i] = sin(700 * (2 * pi) * (i / 5000.0));
               o<<b->buffer[i]<<endl;   
         }
         chunk_queue.push(*b);

         counter+=5000;
        // cout<<"value of queueloopcount is "<< queueloopcount << endl;
     }

     cout<<"all data is perfectly generated" <<endl;
}

int main()
{

    int ntokens = 8;

    thread inputfunc(input_function);
    tick_count t1,t2;
    ofstream o("filter700Hz.csv");
    t1=tick_count::now();

     bool stop_pipeline = false;    
     stop_filter=false;


     inputfunc.join();

     parallel_pipeline(ntokens,make_filter<void,MyBuffer*>
     ( 
             filter::parallel,[&](flow_control& fc)->MyBuffer*
         {
             if(queueloopcount==0)
             {
                 fc.stop();
                 cout<<"pipeline stopped"<<endl;
             }
             else
             {
                  MyBuffer *b=new MyBuffer;
                  chunk_queue.pop(*b);
                 {
                     cout<<"value of start and end popped is "<<b->startnumber()<<"\t"<<b->endnumber()<<endl;
                     queueloopcount--;
                 }
                 return b;
             }
         }
     )&

    make_filter<MyBuffer*, void>
    (
        filter::serial,[&](MyBuffer* b)
        {
             cout<<"value of second filter start is and end is \t "<< b->startnumber() << "\t" << b->endnumber() <<endl;
        }
     )
    );

        cout<<"now i am out" <<endl;
    o.close();
    t2=tick_count::now();

    cout << "\n Time elapsed is \n\n" <<(t2-t1).seconds()<<endl;        

    return 0;
}

请帮助找出代码错误的位置。

Answer 1

此代码中的问题是使用过滤器，即在第一阶段并行导致出现问题的flow_control对象尝试弹出，并且它是一个阻塞调用，因为它阻塞并解决这个问题，你应该首先进行序列化过滤器只创建一个空MyBuffer *并在没有更多工作到期时停止管道。然后有一个并行的第二个过滤器，它执行实际工作，最后是一个串行（按顺序）输出阶段。