MT5 Freezes randomly

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Hi

i'm currently trying to debug a MT5 indicator that randomly freezes the platform. I have to force the close then reopen it (i tried to wait for a long time to see if it gets its hand back but it didn't happen)

it freezes when i click "ok" after modifying some parameters. It doesn't matter which parameter i change.

To debug it, i have to be able to reproduce the error consistently, which i have not been able to do.

i tried starting from a smaller code and adding some parts but sometimes i click and change parameters for 20 minutes and nothing happens. Then another change and it freezes

this is really frustrating and i don't know how to go from there.

some help would be welcome

thanks a lot

Jeff

 
Jean Francois Le Bas:

Hi

i'm currently trying to debug a MT5 indicator that randomly freezes the platform. I have to force the close then reopen it (i tried to wait for a long time to see if it gets its hand back but it didn't happen)

it freezes when i click "ok" after modifying some parameters. It doesn't matter which parameter i change.

To debug it, i have to be able to reproduce the error consistently, which i have not been able to do.

i tried starting from a smaller code and adding some parts but sometimes i click and change parameters for 20 minutes and nothing happens. Then another change and it freezes

this is really frustrating and i don't know how to go from there.

some help would be welcome

thanks a lot

Jeff

Your indicator is bugged. It's hard to help you without the code.

 
Alain Verleyen:

Your indicator is bugged. It's hard to help you without the code.

well that could be one reason, but i'm quite an experienced programmer and this is the first time i see something like that. granted i know MT5 a little bit less than MT4 but it is quite similar.


unfortunately the code is too big to share it here.


But is there a way to debug random events ?

i tried logging the Init function, but the logging mechanism is delayed so nothing is written on screen before the crash

i think writing on disk would be the same ? i need to find where the error comes from but as it is random i'm not sure i can.


thanks for help

 

ok so i wrote data to file to see where the problem is coming, hoping it is not delayed.

the log filed and DeInited correctly the previous set i used before it crashed.

but before the crash nothing was written on disk, not even the start of the Init() function.


so to summarize, the crash happened before the init function and after the previous (working) set was DeInited.


this is becoming really weird.

 
Jean Francois Le Bas:

well that could be one reason, but i'm quite an experienced programmer and this is the first time i see something like that. granted i know MT5 a little bit less than MT4 but it is quite similar.


unfortunately the code is too big to share it here.


But is there a way to debug random events ?

i tried logging the Init function, but the logging mechanism is delayed so nothing is written on screen before the crash

i think writing on disk would be the same ? i need to find where the error comes from but as it is random i'm not sure i can.


thanks for help

Well the API is very similar (mql), though MT5 has a completely different architecture, and I would not say its "quite similar". Anyway...

Usually when MT5 freeze that's because either you have an infinite loop or it is doing heavy calculation. You can also try to change "Max bars in chart" to a small value to see if it's related. I can't help more without code, sorry.

EDIT: What build are you using ?
 
Alain Verleyen:

Well the API is very similar (mql), though MT5 has a completely different architecture, and I would not say its "quite similar". Anyway...

Usually when MT5 freeze that's because either you have an infinite loop or it is doing heavy calculation. You can also try to change "Max bars in chart" to a small value to see if it's related. I can't help more without code, sorry.

EDIT: What build are you using ?

thanks. 


also i'm using AlgLib so if any pointer was going rogue, i would get a message i think.

i agree that if MT5 freezes it is that there is a long computation of some kind, but i could not pinpoint the culprit

i use latest build btw

 

Two ideas: (without knowing your code):

(1) insert

Comment(__FUNCTION__,", line ",__LINE__);

at some strategic points in your code and therefore narrow down the last line that definitely has been executed before the freezing

(2) run the profiler and wait for some time after freezing, then stop and check for lines with extreme processing time

 
Chris70:

Two ideas: (without knowing your code):

(1) insert

at some strategic points in your code and therefore narrow down the last line that definitely has been executed before the freezing

(2) run the profiler and wait for some time after freezing, then stop and check for lines with extreme processing time

good ideas i'll remember that.


i kinda pinpointed where the error comes from though (i removed most of the code until it didn't crash anymore)


and it comes down to labels that i create at the beginning of the processing of the last "maxBars"

if i remove the label creation, then no more freezes. If i put it back it eventually freezes.


here is the code i used:

int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
//---
   

   /*if (maxlogs >= 0)      
   if(file_handle!=INVALID_HANDLE)
   {
      FileWrite(file_handle,"d");
   }*/
   if (maxBars > 0)
   {
      if (i < rates_total - maxBars-npoints-reserve) 
      { 
        if i remove this next comments then it frezes again
         /*LabelDelete("compute time");
         LabelDelete("time left");
         LabelInit("compute time", InpX, InpY, InpFont, InpFontSize, InpColor, InpAngle, InpAnchor, InpBack, InpSelection, InpHidden, InpZOrder);
         LabelInit("time left", InpX, InpY+20, InpFont, InpFontSize, InpColor, InpAngle, InpAnchor, InpBack, InpSelection, InpHidden, InpZOrder);*/
                  
         /*LabelUpdate(0);
         LabelTime(maxComputeTime);*/

         i = rates_total - maxBars-npoints-reserve;
       
         for (int j = 0; j < rates_total && !_StopFlag; j++)
         {
            MASHC[j] = EMPTY_VALUE; 
         }
         
         timCompute = TimeLocal();
      }
   }
   else if (i == 0)
   {   
      if i remove this next comments then it frezes again
      /*LabelDelete("compute time");
      LabelDelete("time left");
      LabelInit("compute time", InpX, InpY, InpFont, InpFontSize, InpColor, InpAngle, InpAnchor, InpBack, InpSelection, InpHidden, InpZOrder);
      LabelInit("time left", InpX, InpY+20, InpFont, InpFontSize, InpColor, InpAngle, InpAnchor, InpBack, InpSelection, InpHidden, InpZOrder);*/
      
      /*LabelUpdate(0);
      LabelTime(maxComputeTime);*/
      
      for (int j = 0; j < rates_total && !_StopFlag; j++)
      {
         MASHC[j] = EMPTY_VALUE; 
      }
                  
      timCompute = TimeLocal();
   }
   else i = rates_total-1;
   
   
     
   
   for (; i < rates_total && !_StopFlag; i++)
   {

...........
rest of the code
...........

and here is the code i use for the label creation (standard code from Metaquotes)

void LabelInit(string name, int x, int y, string InpFont, int InpFontSize, color InpColor, double InpAngle, ENUM_ANCHOR_POINT InpAnchor, bool InpBack, bool InpSelection, bool InpHidden,long InpZOrder)
{
//--- store the label's coordinates in the local variables

//--- chart window size
   long x_distance;
//--- set window size
   if(!ChartGetInteger(0,CHART_WIDTH_IN_PIXELS,0,x_distance))
     {
      Print("Failed to get the chart width! Error code = ",GetLastError());
      return;
     }

//--- prepare initial text for the label
//--- create a text label on the chart
   if(!LabelCreate(0,name,0,x,y,CORNER_RIGHT_UPPER,"Compute completion",InpFont,InpFontSize,
      InpColor,InpAngle,InpAnchor,InpBack,InpSelection,InpHidden,InpZOrder))
     {
      return;
     }
//--- redraw the chart and wait for half a second
   ChartRedraw();
  // Sleep(500);
}

i still don't understand why this code is an issue.


Would it be better to create the label only once and hide the text when i don't want it to show ? i might try that.

thanks for the help guys

Jeff

 

hmm i just noticed, i commented the "Sleep(500);" line at the end of label creation. could it be the reason it freezes ? i'll investigate


Jeff

 

it seems MT5 freezes even with the Label creation only in the OnInit() function...


so the trick to show and hide labels didn't solve the problem


Jeff

 

ok i've tested the indicator for several hours now (without the Labels creation) and it doesn't freeze

so i'm confident to say that this is the reason of the freezes


i think it may be a bug, but i don't understand why it happens on my MT5 and probably not in other people MT5? or is it a global bug?


it's a problem if i can't use Labels in my indicator... any ideas?


Jeff

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