RE: [ROOT] 1st go with threads

From: Lisanne Canal (lcanal@enteract.com)
Date: Fri Jun 28 2002 - 23:53:13 MEST 

Hi,

This might be a silly question ... but did you link against the thread
library? (I.e. added -lThread).

The message 

undefined reference to `TThread::TThread(char const *, void (*)(void *),
void *, TThread::EPriority)'

sounds like a linker error.  The method TThread::TThread is implemented
in TThread.cxx which is compiled in libThread.so (same of TThread
type_info).

> is there anything special I have to have in my linkdef file for a 
> static member funtion?

No there is not.  The error you mentioned are unrelated.

Cheers,
Philippe.

-----Original Message-----
From: owner-roottalk@pcroot.cern.ch
[mailto:owner-roottalk@pcroot.cern.ch] On Behalf Of P.Dixon
Sent: Friday, June 28, 2002 10:02 AM
To: roottalk@pcroot.cern.ch
Subject: Re: [ROOT] 1st go with threads

>    SurfMainFrame::fExternTest should be a static class method and not
a
> member function.
> 
Cheers... one step closer... however...

is there anything special I have to have in my linkdef file for a 
static member funtion?

I'm getting some compile messages I don't understand:

Compiling canvasgui.cxx ...
SurfMainFrame.o: In function `SurfMainFrame::fThreadTest(void)':
SurfMainFrame.o(.text+0x3133): undefined reference to 
`TThread::TThread(char const *, void (*)(void *), void *, 
TThread::EPriority)'
SurfMainFrameDict.o: In function `TBuffer & operator>><TThread>(TBuffer
&, 
TThread *&)':
SurfMainFrameDict.o(.gnu.linkonce.t.__rs__H1Z7TThread_R7TBufferRPX01_R7T
Buffer+0xd): 
undefined reference to `TThread type_info function'
collect2: ld returned 1 exit status
make: *** [canvasgui] Error 1

my linkdef is:

#ifdef __CINT__

#pragma link off all globals;
#pragma link off all classes;
#pragma link off all functions;
#pragma link C++ class SurfMainFrame;
#pragma link C++ global gSurfMainFrame;
#endif


I've been trying to follow the examples from:

http://www-linux.gsi.de/~go4/HOWTOthreads/howtoframe.html

And now I have 

.h file:
static void fExternalTest(void *fTarg);
void fThreadTest(void);
TThread *fEthread;

.cxx file:
void SurfMainFrame::fExternalTest(void *fTarg){
  char fReadLineText[1000];  
  FILE* in = gSystem->OpenPipe("./run.sh", "r");
  while (!feof(in)){
    fgets(fReadLineText, 1000, in);
    printf(fReadLineText);
    //fScaleTextView->AddLine(fReadLineText);
  }
  fclose(in);
}

void SurfMainFrame::fThreadTest(void){
     fEthread = new TThread("t1", &SurfMainFrame::fExternalTest, (void
*)"0");
     //    fEthread->Run();
}

Cheers,
					Paul

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