Date: Fri, 4 Jun 2004 00:04:19 EST-10EDT,10,-1,0,7200,3,-1,0,7200,3600
Subject: [UnixOS2_Archive] No. 392

**************************************************
Thursday 03 June 2004
 Number  392
**************************************************

Subjects for today
 
1   Os/2 Thread classes : Dave Webster <Dave.Webster at bhmi.com>
2  RE:  Os/2 Thread classes : Dave Webster <Dave.Webster at bhmi.com>
3  Re:  Os/2 Thread classes : Dave Yeo" <dave_yeo at paralynx.com>
4  Re:  Os/2 Thread classes : Stefan.Neis at t-online.de
1  Re:  Os/2 Thread classes : Stefan.Neis at t-online.de


**= Email   1 ==========================**

Date:  Wed, 2 Jun 2004 10:44:14 -0500
From:  Dave Webster <Dave.Webster at bhmi.com>
Subject:   Os/2 Thread classes

Stefan?  Have you tested wxOS2's Thread class lately with Innotek GCC?  I am
continuing to have great trouble getting threads to work using _beginthread
inside a Thread class (wxOS2's or my own).

Everything works quite nicely in a straight 'C' program as below:

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#define INCL_BASE
#include <os2.h>

extern "C" void CntThreadProc (void* pParam);

typedef struct counter_tag
{
    ULONG   ulThreadCnt;
    ULONG   ulCurCnt;
} SCounter;

int main (
  int                                   vArgc
, char*                                 ppzArgv[]
, char*                                 ppzEnvp[]
)
{
    SCounter                            vCounter;
    int                                 nThreadId;

    vCounter.ulThreadCnt = 75000;
    vCounter.ulCurCnt    = 0;

    nThreadId = _beginthread( CntThreadProc
                             ,NULL
                             ,32768
                             ,(void*)&vCounter
                            );
    ::DosSleep(100);
    ::DosSuspendThread(nThreadId);
    std::cout << "Thread: " << nThreadId << " Suspended for 3 seconds on
count of: " << vCounter.ulCurCnt << "." << std::endl;
    ::DosSleep(3000);
    std::cout << "Thread: " << nThreadId << " Resuming now for 2 seconds."
<< std::endl;
    ::DosResumeThread(nThreadId);
    while (vCounter.ulCurCnt < 25000)
    {
        ::DosSleep(2000);
        ::DosSuspendThread(nThreadId);
        std::cout << "Thread: " << nThreadId << " Suspended for 2 more
seconds on count of: " << vCounter.ulCurCnt << "." << std::endl;
        ::DosSleep(2000);
        std::cout << "Thread: " << nThreadId << " Resuming now for 2
seconds." << std::endl;
        ::DosResumeThread(nThreadId);
    }
    std::cout << "Thread: " << nThreadId << " Resuming now and waiting until
done." << std::endl;
    ::DosWaitThread((PULONG)&nThreadId, DCWW_WAIT);
    ::DosSleep(2000);
    std::cout << "Program has finished!" << std::endl;
    return 0;
} // end of main

extern "C" void CntThreadProc (
  void*                             pParam
)
{
    SCounter*                       pCounter = (SCounter*)pParam;
    ULONG                           ulSomething = 0;

    for (pCounter->ulCurCnt = 0;
         pCounter->ulCurCnt < pCounter->ulThreadCnt;
         pCounter->ulCurCnt++
        )
    {
        // so we have something to do
        while (ulSomething < 10000)
            ulSomething++;
        ulSomething = 0;
    }
    std::cout << "2nd Thread has finished!" << std::endl;
    _endthread();
}



However, when buried inside a thread class, the initialization function
passed to _begin thread does never gets called.  The thread gets created but
it never calls the proc???  Below is a snippet:

thread.h

class CThread
{
public:
	<Ctor, Dtor and Usual Thread stuff here>

	bool ThreadCreate();

	static void StartThread(void* pParam);

	.
	.
	.
private:
	int				m_nThreadId;
}



thread.cpp



void StartThread(void* pParam)
{
	do some initialization here.... 
	.
	.
	.
}

bool CThread::ThreadCreate()
{
    SStartup				vStartup; // contains a pointer to
this thread and other useful stuff
   
    m_nThreadId = ::_beginthread( CThread::StartThread
                                 ,NULL
                                 ,32768
                                 ,(void*)vStartup
                                );

    if (m_nThreadId == -1)
    {
		Some sort of error reporting here...
		return false;
	
    }
    ::DosSleep(100); // let thread initialize	
    return true;
}

Call to StartThread then posts a ::DosWaitThread(...) waiting for this
second thread to complete and just hangs forever....

Breakpoint on the if (m_nThreadId == -1) line indicates m_nThreadId is a
valid threadid.  IPMD (debugger) reports that there are two threads running.
But StartThread never gets called!!!  It is as if _beginthread cannot find
the address???  

I have tried this using an extern "C" initialization proc instead of a
static member proc with has the exact same results.  A new thread but init
function called.  Anyone with any idea???  Threads via classes appear to be
completely brokein with Innotek GCC at this time....  Must be missing
something basic but cannot figure it out.


**= Email   2 ==========================**

Date:  Wed, 2 Jun 2004 13:30:28 -0500
From:  Dave Webster <Dave.Webster at bhmi.com>
Subject:  RE:  Os/2 Thread classes

Actually, wxOS2's works fine now.  In my class however somehow my main
thread has entered a critical section.  So no problem related to Innotek's
_beginthread implementation.....

And for wxWidgets---

And this is confusing to me.  The wxThreadModule (I have something very
similar in my class as well) has the static global CritsecGui which gets
entered OnInit and does not get exitted until OnExit.  This should cause the
same problem in wxOS2's threads but it doesn't????  Entering a critical
section stops processing in all other threads until exitting, but the wxOS2
threads do not block when this Critsec is entered???  Must have something to
do with when and how the code in wxThreadModule get executed when using
wxThread.  I'm really missing something here.....


-----Original Message-----
From: Dave Webster [mailto:Dave.Webster at bhmi.com]
Sent: Wednesday, June 02, 2004 10:44 AM
To: WxDiscuss (E-mail); Unix-OS2 (E-mail 2)
Subject:  Os/2 Thread classes


Stefan?  Have you tested wxOS2's Thread class lately with Innotek GCC?  I am
continuing to have great trouble getting threads to work using _beginthread
inside a Thread class (wxOS2's or my own).

Everything works quite nicely in a straight 'C' program as below:

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#define INCL_BASE
#include <os2.h>

extern "C" void CntThreadProc (void* pParam);

typedef struct counter_tag
{
    ULONG   ulThreadCnt;
    ULONG   ulCurCnt;
} SCounter;

int main (
  int                                   vArgc
, char*                                 ppzArgv[]
, char*                                 ppzEnvp[]
)
{
    SCounter                            vCounter;
    int                                 nThreadId;

    vCounter.ulThreadCnt = 75000;
    vCounter.ulCurCnt    = 0;

    nThreadId = _beginthread( CntThreadProc
                             ,NULL
                             ,32768
                             ,(void*)&vCounter
                            );
    ::DosSleep(100);
    ::DosSuspendThread(nThreadId);
    std::cout << "Thread: " << nThreadId << " Suspended for 3 seconds on
count of: " << vCounter.ulCurCnt << "." << std::endl;
    ::DosSleep(3000);
    std::cout << "Thread: " << nThreadId << " Resuming now for 2 seconds."
<< std::endl;
    ::DosResumeThread(nThreadId);
    while (vCounter.ulCurCnt < 25000)
    {
        ::DosSleep(2000);
        ::DosSuspendThread(nThreadId);
        std::cout << "Thread: " << nThreadId << " Suspended for 2 more
seconds on count of: " << vCounter.ulCurCnt << "." << std::endl;
        ::DosSleep(2000);
        std::cout << "Thread: " << nThreadId << " Resuming now for 2
seconds." << std::endl;
        ::DosResumeThread(nThreadId);
    }
    std::cout << "Thread: " << nThreadId << " Resuming now and waiting until
done." << std::endl;
    ::DosWaitThread((PULONG)&nThreadId, DCWW_WAIT);
    ::DosSleep(2000);
    std::cout << "Program has finished!" << std::endl;
    return 0;
} // end of main

extern "C" void CntThreadProc (
  void*                             pParam
)
{
    SCounter*                       pCounter = (SCounter*)pParam;
    ULONG                           ulSomething = 0;

    for (pCounter->ulCurCnt = 0;
         pCounter->ulCurCnt < pCounter->ulThreadCnt;
         pCounter->ulCurCnt++
        )
    {
        // so we have something to do
        while (ulSomething < 10000)
            ulSomething++;
        ulSomething = 0;
    }
    std::cout << "2nd Thread has finished!" << std::endl;
    _endthread();
}



However, when buried inside a thread class, the initialization function
passed to _begin thread does never gets called.  The thread gets created but
it never calls the proc???  Below is a snippet:

thread.h

class CThread
{
public:
	<Ctor, Dtor and Usual Thread stuff here>

	bool ThreadCreate();

	static void StartThread(void* pParam);

	.
	.
	.
private:
	int				m_nThreadId;
}



thread.cpp



void StartThread(void* pParam)
{
	do some initialization here.... 
	.
	.
	.
}

bool CThread::ThreadCreate()
{
    SStartup				vStartup; // contains a pointer to
this thread and other useful stuff
   
    m_nThreadId = ::_beginthread( CThread::StartThread
                                 ,NULL
                                 ,32768
                                 ,(void*)vStartup
                                );

    if (m_nThreadId == -1)
    {
		Some sort of error reporting here...
		return false;
	
    }
    ::DosSleep(100); // let thread initialize	
    return true;
}

Call to StartThread then posts a ::DosWaitThread(...) waiting for this
second thread to complete and just hangs forever....

Breakpoint on the if (m_nThreadId == -1) line indicates m_nThreadId is a
valid threadid.  IPMD (debugger) reports that there are two threads running.
But StartThread never gets called!!!  It is as if _beginthread cannot find
the address???  

I have tried this using an extern "C" initialization proc instead of a
static member proc with has the exact same results.  A new thread but init
function called.  Anyone with any idea???  Threads via classes appear to be
completely brokein with Innotek GCC at this time....  Must be missing
something basic but cannot figure it out.


**= Email   3 ==========================**

Date:  Wed, 02 Jun 2004 23:11:48 -0800
From:  "Dave Yeo" <dave_yeo at paralynx.com>
Subject:  Re:  Os/2 Thread classes

On Wed, 2 Jun 2004 10:44:14 -0500, Dave Webster wrote:

>Anyone with any idea???  Threads via classes appear to be
>completely brokein with Innotek GCC at this time....  Must be missing
>something basic but cannot figure it out.

You might want to look at Mozilla's threading code, seems to be C++ but I can't find where its encapsalated 
as a class but it must be as Mozilla supports threading on quite a few architectures. I don't know enough to 
really tell exactly whats happening and Mozilla is big. Anyways in mozilla\nsprpub\pr\src\md\os2\os2thred.c 
theres some interesting code and comments.
Dave



**= Email   4 ==========================**

Date:  Thu, 03 Jun 2004 10:28:56 +0200 (CEST)
From:  Stefan.Neis at t-online.de
Subject:  Re:  Os/2 Thread classes

Dave Webster schrieb:

> And for wxWidgets---
> 
> And this is confusing to me.  The  wxThreadModule (I have
> something very
> similar in my class as well) has the static global
> CritsecGui which gets
> entered OnInit and does not get exitted until OnExit. 
> This should cause the
> same problem in wxOS2's threads but it doesn't???? 
> Entering a critical
> section stops processing in all other threads until
> exitting, but the wxOS2
> threads do not block when this Critsec is entered??? 

Probably a problem with naming conventions...
Note that a critical section on OS/2 and a critical
section on Windows are completely different things.
wxCriticalSection on OS/2 is implemented by _not_
using OS/2's critical sections (instead it's using
wxMutex which is using OS/2's mutex semaphores),
trying to achieve the behaviour seen on Windows
and expected by wxWindows thread class.

        HTH,
              Stefan


**= Email   1 ==========================**

Date:  Thu, 03 Jun 2004 10:28:56 +0200 (CEST)
From:  Stefan.Neis at t-online.de
Subject:  Re:  Os/2 Thread classes

Dave Webster schrieb:

> And for wxWidgets---
> 
> And this is confusing to me.  The  wxThreadModule (I have
> something very
> similar in my class as well) has the static global
> CritsecGui which gets
> entered OnInit and does not get exitted until OnExit. 
> This should cause the
> same problem in wxOS2's threads but it doesn't???? 
> Entering a critical
> section stops processing in all other threads until
> exitting, but the wxOS2
> threads do not block when this Critsec is entered??? 

Probably a problem with naming conventions...
Note that a critical section on OS/2 and a critical
section on Windows are completely different things.
wxCriticalSection on OS/2 is implemented by _not_
using OS/2's critical sections (instead it's using
wxMutex which is using OS/2's mutex semaphores),
trying to achieve the behaviour seen on Windows
and expected by wxWindows thread class.

        HTH,
              Stefan