C / C++ / MFC

ForNow9-Jan-17 18:57

9-Jan-17 18:57

I am a MainFrame Assembler programmer by trade

this is the emulator

The Hercules System/370, ESA/390, and z/Architecture Emulator[^]

I overlay two bytes of code (causing it to pause) right before I overlay the code I do a ResetEvent which will cause a manual Event to be NON-signaled the threads right behind this will stop on the WaitForSingleObject

I have code to determine the Work unit executing code in CSA (common storage) it is only for that code that I do a ResetEvent and then memcpy

Once the emulated code that I overlayed (cuasing it to interrupt and pause)

I put back the legal opcode via memcpy right after I do a SetEvent for the other workunits executing the common storage to proceed (as it is now okay) and bypass the overlaying logic

I will paste the relevant code shortly as it is late (have to get to sleep)

I wanted to give you a feel (of what I doing) as you have been so verrrrrry helpful

leon de boer10-Jan-17 23:23

leon de boer

10-Jan-17 23:23

Make sure you are using manual reset events there is a trap for young players with Auto-Reset Events

Read the documentation
SetEvent function (Windows)[^]
Quote => The state of an auto-reset event object remains signaled until a single waiting thread is released, at which time the system automatically sets the state to nonsignaled. If no threads are waiting, the event object's state remains signaled.

In vino veritas

ForNow11-Jan-17 12:29

11-Jan-17 12:29

Hi
before pasting the code let me Clarify NON-signaled would mean a thread executing WaitForSingleObject is suspended

I am still running into problems where other threads are executing the overlayed code

here is the code Initiallly the event is created signaled

C++

sysblk.single_thread = CreateEvent(NULL,TRUE,FALSE,"WaitThread");

/* this block of code checks if the address where the code is executing is within the address looking to be traced and is the address space correct the GET_WU function checks the the task or thread within the address space so GET_WU returns a 64 bit value 32 bits for a address space 32 for the task this is UNIQUE */

C++

 if(sysblk.debug_init == 0)
 {

    if (sysblk.asid != 0)
{
 if((shouldstep == 1)  && (regs->CR_LHL(4) == sysblk.asid))
 {
     sysblk.debug_init = 1;
     regs->should_step = 1;
         sysblk.hercgui_break = 1;
     sysblk.hercgui_initbreak = 0;  // TEMPORARY
     sysblk.debug_wu.D = ARCH_DEP(GET_WU)(regs);
      if(IsDebuggerPresent())
      {
       sprintf(buf,"CPU%4.4X: WU Being Debugged ASCB=%4X,TCB/SRB=%4X \n",regs->cpuad,sysblk.debug_wu.F.H.F,sysblk.debug_wu.F.L.F);
        OutputDebugString(buf);
      }
 }
 else
     shouldstep = 0;

    }

/* the next piece of code checks after the user has examined the code and I have restored the correct instruction I want to let it execute and not over lay stop ia is the instruction address */
// Hercmd is a from end Windows MFC/C++ I have written to display the information

C++

// this should oly happens if hercmd hit <enter>
  if(regs->psw.ia.D == sysblk.debug_ia.D)
  {
      wu_ptr.D = ARCH_DEP(GET_WU)(regs);
   if(wu_ptr.D == sysblk.debug_wu.D)
   {
       sysblk.debug_ia.D =0;
       if(IsDebuggerPresent())
      {
       ARCH_DEP(vfetchc)(buf1,5,regs->psw.ia.D,0X00,regs);
       sprintf(buf,"CPU%4.4X: inst being executed=%s At address %8X\n",buf1,regs->psw.ia.D);
        OutputDebugString(buf);
      }

       return;
   }
  }

/* this is the code where I check if other threads are execting the same code and the address or instruction has been overlayed to genarate a pause so I WaitForSingleObject */

C++

    if(regs->psw.ia.D == sysblk.debug_ia.D)
    {
        wu_ptr.D = ARCH_DEP(GET_WU)(regs);
    if (wu_ptr.D != sysblk.debug_wu.D)
    {
        regs->cpustate = CPUSTATE_STOPPED;
        dwWaitResult =  WaitForSingleObject(sysblk.single_thread,INFINITE);
           if(dwWaitResult == -1)
                    errcd = GetLastError();
           // regs->cpustate = CPUSTATE_STARTED;
            if(IsDebuggerPresent())
            {
                ARCH_DEP(vfetchc)(buf1,4,regs->psw.ia.D,0X00,regs);
                FETCH_FW(INST,buf1);
       sprintf(buf,"CPU%4.4X: WU Was Held ASCB=%4X TCB/SRB=%4X, AT instruction address %8X inst=%04X\n",regs->cpuad,wu_ptr.F.H.F,wu_ptr.F.L.F,regs->psw.ia.D,INST);
       OutputDebugString(buf);
            }
           return;
       }
    else
        return;
}

// this where I overlay the insruction to stop the CORRECT task

C++

  if ((wu_ptr.D = ARCH_DEP(GET_WU)(regs)) == sysblk.debug_wu.D &&  shouldstep == 1)
	   
  
    {
 ResetEvent(sysblk.single_thread);   // Turn to NON-signal any thread executing the WaitForSingleObject will stop   
        ip = regs->ip < regs->aip ? regs->inst : regs->ip;
        ARCH_DEP(display_inst) (regs, ip);
  
   sysblk.debug_inst_count++;

	
// debug2:
	 
	
	  

  sysblk.stop_ip = regs->ip < regs->aip ? regs->inst : regs->ip;
 
   if(sysblk.debug_overlay[0] == 0x00)
		{
			  ip = regs->ip < regs->aip ? regs->inst : regs->ip;
			sysblk.debug_ip = ip;
		    memcpy((void *)&sysblk.debug_overlay[0],(void *)ip,2);
			memcpy((char *)&sysblk.savereg15,(char *)®s->gr[15],8);
	    	memcpy((char *)&sysblk.savereg14,(char *)®s->gr[14],8);
			sysblk.debug_ia.D = regs->psw.ia.D;
			  memcpy((void *)®s->gr[15].F.L.F,(void *)&sysblk.pause_rtn,4);  /* point IEAVPSE2 */
			   
			 memcpy((void *)ip,(void *)&BASSM,2);  // Overlay the istruction 
			sysblk.hercgui_debug = 1;
		}

     regs->is_debugging = 1;
	 
	  if(IsDebuggerPresent())
	  {
	 sprintf(buf,"CPU%4.4X: Inst Modified For ASCB=%4X TCB/SRB=%4X \n",regs->cpuad,wu_ptr.F.H.F,wu_ptr.F.L.F);
        OutputDebugString(buf);
	  }
	}

// This the code after the emulated instruction that I overlayed has executed I put back the 1st two bytes of the instruction and do a SetEvent as now other threads can proceed

if((regs->gr[15].F.L.F == sysblk.pause_rtn) && ((void *)sysblk.pause_rtn != NULL))
  {
      memcpy(sysblk.stop_ip,&sysblk.debug_overlay[0],2);
      memcpy((char *)®s->gr[15],(char *)&sysblk.savereg15,8);
          memcpy((char *)®s->gr[14],(char *)&sysblk.savereg14,8);
      sysblk.debug_overlay[0] = 0x00;
      sysblk.debug_overlay[1] = 0x00;
      sysblk.hercgui_is_debugging = 0;
  //  SetEvent(sysblk.single_thread2);
      regs->bypass_debug = 1;
      regs->is_debugging = 0;
      regs->should_step = 0;
      SetEvent(sysblk.single_thread);  // let other threads go
      wu_ptr.D = ARCH_DEP(GET_WU)(regs);
       if(IsDebuggerPresent())
       {
      sprintf(buf,"CPU%4.4X: SetEvent for ASCB=%4X TBC/SRB=%4X\n",regs->cpuad,wu_ptr.F.H.F,wu_ptr.F.L.F);
       OutputDebugString(buf);
       }
  }

leon de boer12-Jan-17 14:38

leon de boer

12-Jan-17 14:38

I will need time to look at this and see if I can spot it.

This is one of those situations it would be nice to have a .NET managed thread so you can pull a threadstate enumeration on all the threads, something we can't do on raw win32 threads Smile | :)

In vino veritas

ForNow13-Jan-17 3:28

13-Jan-17 3:28

Do you have an-email address I can e-mail you offline

Thanks

leon de boer14-Jan-17 22:47

leon de boer

14-Jan-17 22:47

It's on my bio

In vino veritas

ForNow8-Jan-17 22:56

8-Jan-17 22:56

thanks
The Visual Studio Thread windows I know has the ability to freeze threads

Regardless I'll download the extension

Let me explain the nature of the problem

I'll writing an a debugger for another platform (working with an emulator )

I am modifying the emulated "C" code

the way interrupt the "debugged" code/program

is by overlaying the instruction which gives me control and shows the user the code

I quickly put back the over laid instruction

this works well when the user is debugging a Single Threaded program

however in a multiThreaded programs other threads or tasks executing the same code

get a operation exception before I put the code back

The way I coded this was as soon as I overlay the instruction I do a

ResetEvent which cause a Event to be non-signaled and stop the other threads/tasks

from executing this code until I have a chance

to put back the instruction I then do a SetEvent

to let the other threads/tasks execute the code

Something is obviously not working out right in this timing

In Visual Studio I can observe how QUICKLY The Windows dispatcher

Switches from thread to thread

Thanks for your help

MFC ribbon designer (gallery button)

Munchies_Matt23-Jan-17 6:32

Munchies_Matt

23-Jan-17 6:32

If you get this then you need to use thread synchronisaiton so that WHATEVER happens, and it will, one day, your threads process data and events in a coordinated fashion.

Maximilien6-Jan-17 9:43

Maximilien

6-Jan-17 9:43

(I still must be in the spirit of Christmas)

Q: How do I add gallery buttons items to a gallery button with the resource editor ?

I created a default application with the ribbon UI.

In the resource editor, I added a "Gallery Button" and into that I added a few button items in the collection
I manually added event handlers for each item.

When I start the application, the gallery button just looks like a button and when I click on it, no "menu" is displayed.

I looked at the samples projects ( RibbonGadgets and RibbonMDI) and they just code the ribbon manually.

Q: Am I missing something? The properties for the gallery button does not show anything useful.

Q: Should I just give up on the ribbon designer and code everything manually ?

Thanks.

Max.

I'd rather be phishing!

Re: MFC ribbon designer (gallery button)

DeeEllEll30-Mar-17 4:55

DeeEllEll

30-Mar-17 4:55

Did you ever find an answer here? I have the same issue.

Is function prototyping dead?

Vaclav_6-Jan-17 5:43

Vaclav_

6-Jan-17 5:43

A semi-popular IDE compiles my C++ code without declaring function prototype.
Did I missed the newsflash or just an compiler option?
Seems odd.

Richard MacCutchan6-Jan-17 5:49

Richard MacCutchan

6-Jan-17 5:49

You only need prototypes for forward declarations. And IDEs do not do the compiling, that's the compiler's job.

Vaclav_6-Jan-17 16:19

Vaclav_

6-Jan-17 16:19

True, but I have been using IDE whose authors are very fond of their "beginners feature " which actually builds prototypes "for you". So they claim.

I am now test driving another IDE, still based on GCC and the first test function I used compiled without prototype, that is why I made this post.

Next function failed without prototype, so I am not sure what is going on.

So what is the difference between prototype and forward declaration?
Or is there a difference?

Richard MacCutchan6-Jan-17 21:55

Richard MacCutchan

6-Jan-17 21:55

When the compiler comes across a function call it checks its tables for a declared prototype. If it cannot find one then it will infer a definition from the parameters of the function call. When it then finds the actual function it will check that the definition matches the stored declaration. If it does, then all well and good. If it does not then it will throw out an error message.

As to your last question, a prototype is a forward declaration. It just tells the compiler the type of the parameters and return value of the function, so it can check on any calls made to the function before it is found in the source. The same applies to external functions whose prototypes are in .h files.

Jochen Arndt6-Jan-17 22:17

6-Jan-17 22:17

A declaration (prototype) describes an object (function, class, variable).

C++

int some_function(int some_arg);

A definition (implementation) implements an object.

C++

int some_function(int some_arg)
{
    int result = 0;
    // some code
    return result;
}

If there is no declaration for an object, the definition implies the declaration.

The compiler needs a declaration when an object is used the first time (accessing a variable, calling a function). So there is no need for a declaration if the first usage is located after the definition in the source code.

While strictly speaking all declarations are forward declarations, the term is mainly used with function declarations in header files where a pointer or reference to another class is passed as function argument. An example:

C++

// Header file for MyClass

// Forward declaration for OtherClass.
class OtherClass;

class MyClass
{
    MyClass();
    SomeFunction(OtherClass &otherClass);
};

The implementation file of MyClass must still include the header file containing the OtherClass declaration. But the above header file must not do so which reduces the compile time. More important, this must be used when both classes use the other which would normally require that both header files include each other which would lock the compiler (recursive inclusion).

See also this SO thread: c++ - What is the difference between a definition and a declaration? - Stack Overflow[^]

Vaclav_7-Jan-17 4:29

Vaclav_

7-Jan-17 4:29

The compiler needs a declaration when an object is used the first time (accessing a variable, calling a function). So there is no need for a declaration if the first usage is located after the definition in the source code.

Perfect answer - that is exactly why my test function - first one in header file - did not need declaration.

Jochen,
I really appreciate your help - always right to the point. Thanks

PS
Are you by any chance teacher / instructor ? You sure know how to explain stuff.

Cheers
Vaclav

Jochen Arndt8-Jan-17 20:58

8-Jan-17 20:58

Thank you.

I'm not a teacher. I'm an R&D engineer (hardware and software).

Jochen Arndt6-Jan-17 6:49

6-Jan-17 6:49

A function definition is also a declaration if there was none so far. The compiler (not the IDE) will add it to it's internal declaration list when processing such a function.

Multi Core question

ForNow4-Jan-17 4:11

4-Jan-17 4:11

Hi
I have C/C++ solution/project
The parent process is C the child process is MFC C++.
Each in its own project

The C project has a number of threads.

I have a quad core laptop.

Is there any way of knowing how many cores the .exe(s) is/are using. Don't know if task manager is the answer.

More so can I have an affinity of a thread to a core ?

Thanks

Jochen Arndt4-Jan-17 4:39

4-Jan-17 4:39

It is all handled by the operation system. Don't care about. While it is possible to set a thread affinity it is usually not necessary and often counterproductive.

If a process has multiple threads it will use multiple cores when available. But there is no single core assigned to a specific thread. The OS assigns the cores so that a thread runs on different cores.

ForNow4-Jan-17 4:50

4-Jan-17 4:50

Is there anything in task manager or VS debugger or maybe the Kernal debugger that would show me any information about this

Thanks

Jochen Arndt4-Jan-17 5:01

4-Jan-17 5:01

Showing information about the core that runs a specific thread makes no sense due to the fast switching between the cores.

For process information have a look at the Sysinternals Suite[^].

ForNow4-Jan-17 5:06