Go4ThreadManager/TGo4Thread.cxx

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// $Id: TGo4Thread.cxx 999 2013-07-25 11:58:59Z linev $
//-----------------------------------------------------------------------
//       The GSI Online Offline Object Oriented (Go4) Project
//         Experiment Data Processing at EE department, GSI
//-----------------------------------------------------------------------
// Copyright (C) 2000- GSI Helmholtzzentrum für Schwerionenforschung GmbH
//                     Planckstr. 1, 64291 Darmstadt, Germany
// Contact:            http://go4.gsi.de
//-----------------------------------------------------------------------
// This software can be used under the license agreements as stated
// in Go4License.txt file which is part of the distribution.
//-----------------------------------------------------------------------

#include "TGo4Thread.h"

#include "TThread.h"
#include "TSystem.h"
#include "TCondition.h"

#include "TGo4Runnable.h"
#include "TGo4Log.h"
#include "TGo4LockGuard.h"
#include "Go4Exceptions.h"

TGo4Thread::TGo4Thread(const TGo4Thread &right)
   :TNamed(right)
{
   GO4TRACE((14,"TGo4Thread::TGo4Thread() copy constructor",__LINE__, __FILE__));
   fxRunnable = right.fxRunnable;
   fbIsInternal = right.fbIsInternal;
   fxCondition = new TCondition();
}

TGo4Thread::TGo4Thread (const char* name, TGo4Runnable* runnable, Bool_t internal)
   :TNamed(name,"This is a TGo4Thread"),
   fbIsCreated(kFALSE),
   fbIsRunning(kFALSE),
   fiThreadPID(0),
   fiThreadSelfID(0),
   fbIsWaiting(kFALSE),
   fxThread(0)
{
   GO4TRACE((14,"TGo4Thread::TGo4Thread(const char*, TGo4Runnable*, Bool_t) constructor",__LINE__, __FILE__));

   TGo4Log::Debug(" New Go4Thread ``%s'' created ",name);
   fxRunnable = runnable;
   fbIsInternal = internal;
   fxCondition = new TCondition();
   fxRunnable->SetThread(this);
}


TGo4Thread::~TGo4Thread()
{
   GO4TRACE((14,"TGo4Thread::~TGo4Thread() destructor",__LINE__, __FILE__));

   Stop();
   Cancel();
   delete fxCondition;
   if(fbIsInternal)
      {
         GO4TRACE((14,"TGo4Thread::~TGo4Thread() internal mode",__LINE__, __FILE__));
         TGo4Log::Debug(" Go4Thread ``%s'' deleting runnable ``%s'' ",
                  GetName(),fxRunnable->GetName());
         delete fxRunnable; // internal mode: go4thread responsible for runnable
      }
   else
      {
         GO4TRACE((14,"TGo4Thread::~TGo4Thread() non internal mode",__LINE__, __FILE__));
         // do nothing
      }

}

void TGo4Thread::Threadfunc (void* arg)
{
   GO4TRACE((2,"TGo4Thread::Threadfunc(void*)",__LINE__, __FILE__));
   TGo4Thread* go4th= (TGo4Thread*) arg; // we need reference to calling class instance
   TGo4Runnable* runnable = go4th->GetRunnable();

  // this is the function running as pthread...
  // initializations:
   go4th->SetPID();
   go4th->SetSelfID();
//   fiThreadPID=gSystem->GetPid(); // set ids
//   fiThreadSelfID=TThread::SelfId();
   TGo4Log::Debug(" TThread %d (PID:%d) of Go4Thread ``%s''  started... \n",
            go4th->GetSelfID(), go4th->GetPID(), go4th->GetName());

for(;;) // loop keeps thread alive after exception has occured...
   {
   try
      {
      GO4TRACE((1,"TGo4Thread::Threadfunc(void*) try block",__LINE__, __FILE__));
      while(1)
         {
            TThread::CancelPoint();
            if( !(go4th->IsRunning()) )
               {
                  GO4TRACE((1,"TGo4Thread::Threadfunc(void*) waiting mode",__LINE__, __FILE__));
                  TGo4Log::Debug(" Go4Thread ``%s'' (PID:%d) waiting...\n",
                           go4th->GetName(), go4th->GetPID());
                   go4th->SetWaiting(kTRUE);
                   go4th->GetCondition()->Wait(); //wait for funcrun condition
                   go4th->SetWaiting(kFALSE);
                   TGo4Log::Debug(" Go4Thread ``%s'' (PID:%d) running...\n",
                           go4th->GetName(), go4th->GetPID() );
                }
            else
               {
               // Do Nothing, just continue
               }

            if(go4th->IsCreated())
               // normal  mode: enter runnable
               {
               GO4TRACE((1,"TGo4Thread::Threadfunc(void*) entering running mode",__LINE__, __FILE__));
                  // call runnable prerun method before running:
               runnable->PreRun((void*) 0); // we are runnable's friend, can call protected method...
               while(go4th->IsRunning())
                  {
                     TThread::CancelPoint();
                     runnable->Run((void*) 0); // we are runnable's friend, can call protected method...
                  }
                   // call runnable postrun method before stopping
               runnable->PostRun((void*) 0); // we are runnable's friend, can call protected method...

               }
            else
               // aborting mode after condition release: loop cancel point
               {
                  GO4TRACE((1,"TGo4Thread::Threadfunc(void*) entering Cancel loop",__LINE__, __FILE__));
                  TGo4Log::Debug(" Go4Thread ``%s''  entering Cancel loop\n ", go4th->GetName());
                  while(!(go4th->IsCreated()))
                     {
                        {
                        #ifdef WIN32
                           return; // cancel point does not work on windows; escape to root thread framework...
                        #endif
                        GO4TRACE((1,"TGo4Thread::Threadfunc(void*) in Cancel loop",__LINE__, __FILE__));
                        Sleep(500);
                        TThread::CancelPoint();
                        }
                     }
               }
        } // while(1)
    }// try
  catch(TGo4Exception& ex)
    {
      GO4TRACE((1,"TGo4Thread::Threadfunc(void*) Go4Exception Catch",__LINE__, __FILE__));
      runnable->ThreadCatch(ex);
      TThread::CancelPoint();
    }

  catch(...)
    {
      GO4TRACE((1,"TGo4Thread::Threadfunc(void*) Unexpected Catch",__LINE__, __FILE__));
      //runnable->UnexpectedCatch(); // do not handle alien exceptions!
      TThread::CancelPoint();
      throw; // otherwise, we have trouble with newer pthread
             // implementations that use one pid for all threads, e.g. Fedora2
    }

   } // for(;;) loop keeps thread alive
}

Bool_t TGo4Thread::Create ()
{
   GO4TRACE((14,"TGo4Thread::Create()",__LINE__, __FILE__));
   if(!fbIsCreated)
     // thread not existing, create it
     {
       fxThread= new TThread(GetName(),
                            (void(*) (void *)) &Threadfunc ,
                            (void*) this);
       fxThread->Run();
       fbIsCreated=kTRUE;
       return kTRUE;
     }
   else
     // thread instance already there...
     {
       return kFALSE;
     }
}

Bool_t TGo4Thread::Cancel ()
{
    GO4TRACE((14,"TGo4Thread::Cancel()",__LINE__, __FILE__));

    if(fbIsCreated)
    // thread existing, then cancel
   {
      TGo4Log::Debug(" Go4Thread ``%s'' --  Canceling TThread %d (PID:%d) ",
               GetName(), fiThreadSelfID, fiThreadPID);
      //std::cout << "canceling thread "<<fiThreadSelfID<< std::endl;
      if(fxThread)
         {
         GO4TRACE((13,"TGo4Thread::Cancel() -- canceling existing TThread",__LINE__, __FILE__));
         fbIsCreated=kFALSE;
         fbIsRunning=kTRUE; // these settings let Threadfunc enter Cancel loop
         fxCondition->Signal();  // unlock condition mutex before deleting it
         Sleep(500); // waitstate for Threadfunc to enter cancel loop after condition



// this does not work properly for ROOT versions < 5.17-04
// due to bug in static Delete() method (see root bug report 31085)
//         TThread::Delete(fxThread);
// use workaround, later with root version ifdefs:
        fxThread->Kill();
        delete fxThread;
// note: this will skip the thread Cleanup(), but we do not use this feature in Go4

//#ifndef WIN32
//            // the following cleanup might fail on win32, better not do it...
//         if(TThread::GetThread(fiThreadSelfID)!=0)
//            {
//               //std::cout <<"thread of "<<fiThreadSelfID<<" not yet deleted, do it now:" << std::endl;
//               delete fxThread; // only delete thread if Cleanup method of TThread::Delete not yet invoked
//            }
//#endif
         fxThread=0;
         fiThreadPID=0;
         fiThreadSelfID=0;

         }
      else
         {
            GO4TRACE((13,"TGo4Thread::Cancel() -- Error: TThread pointer is zero!",__LINE__, __FILE__));
            TGo4Log::Debug(" Go4Thread ``%s'' Cancel -- Internal inconsistency error! ",GetName());
            throw TGo4RuntimeException();
         }
      return kTRUE;
    }
  else
    // no such thread...
    {
      return kFALSE;
    }
}

Bool_t TGo4Thread::ReCreate ()
{
   GO4TRACE((14,"TGo4Thread::ReCreate()",__LINE__, __FILE__));

   TThread* oldthread;
   if(fbIsCreated)
    // thread existing, then recreate possible

    {
    GO4TRACE((13,"TGo4Thread::ReCreate() -- old TThread existing",__LINE__, __FILE__));
    TGo4Log::Debug(" Recreating Go4Thread ``%s'' --  old TThread %d (PID:%d) ",
               GetName(), fiThreadSelfID, fiThreadPID);
       //std::cout << "recreating thread "<<GetName()<< std::endl;
      if(fxThread)
         {
            GO4TRACE((13,"TGo4Thread::ReCreate() -- recreating existing TThread",__LINE__, __FILE__));
            Stop();// halt runnable
            oldthread=fxThread; // remember old TThread
            // first start new TThread of same Threadfunc and runnable:
            fxThread= new TThread(GetName(),
                               (void(*) (void *)) &Threadfunc ,
                               (void*) this);

            // then kill the old TThread, so Threadfunc may ReCreate() itself
            fbIsCreated=kFALSE;
            if(fbIsWaiting)
            {
               fxCondition->Signal();  // unlock condition mutex before deleting it
                                       // this will not start the runnable, fbIsRunning still false
               //fbIsWaiting=kFALSE;    // keep flag consistent with Threadfunc state..
            }
            TThread::Delete(oldthread);
            //delete oldthread;
            fbIsCreated=kTRUE;
            fxThread->Run(); // does this work if thread recreates itself?
            Start(); // start runnable in new TThread

         }
      else
         {
            GO4TRACE((13,"TGo4Thread::ReCreate() -- Error: old TThread pointer is zero!",__LINE__, __FILE__));
            TGo4Log::Debug(" Go4Thread ``%s'' ReCreate -- Internal inconsistency error! ",GetName());
            //std::cout << "TGo4Thread "<<GetName()<<" ReCreate inconsistency error!"<< std::endl;
            throw TGo4RuntimeException();
         }
      return kTRUE;
    }
  else //if(fbIsCreated)
    // no old thread, then create new one
    {
      GO4TRACE((13,"TGo4Thread::ReCreate() -- old TThread existing",__LINE__, __FILE__));
      Create();
      return kFALSE;
    }
}

Bool_t TGo4Thread::Start ()
{
   GO4TRACE((12,"TGo4Thread::Start()",__LINE__, __FILE__));
   if(!fbIsCreated)
      // check if thread is up
      {
         // not yet created, then do so
         GO4TRACE((11,"TGo4Thread::Start() -- creating new TThread",__LINE__, __FILE__));
         Create();
      }
   else
      {
         // do nothing, thread already there
         GO4TRACE((11,"TGo4Thread::Start() -- TThread already existing",__LINE__, __FILE__));
      }
   Bool_t old=fbIsRunning;
   fbIsRunning=kTRUE;
   fxCondition->Signal(); // wake up waiting threadfunction
   return old; // old status of workfunc requested by thread list
}

Bool_t TGo4Thread::Stop ()
{
   GO4TRACE((12,"TGo4Thread::Stop()",__LINE__, __FILE__));
   Bool_t old=fbIsRunning;
   fbIsRunning=kFALSE;
   return old; // old status of workfunc requested by thread list
}

void TGo4Thread::Sleep (UInt_t millisecs)
{
   GO4TRACE((12,"TGo4Thread::Sleep()",__LINE__, __FILE__));
   gSystem->Sleep(millisecs);
   TThread::CancelPoint();
}

void TGo4Thread::SetSelfID()
{
   fiThreadSelfID = TThread::SelfId();
}

void TGo4Thread::SetPID()
{
   fiThreadPID = gSystem->GetPid();
}