CODEWITHSUNDEEP
delphi
Mawg
Mawg

Reputation: 40140

How can I track down an Out of Memory exception?

The stack looks like this 

:7576b9bc KERNELBASE.RaiseException + 0x58
:671c57ad ; F:\invariant data - not DropBox\3rd_party_vcl\MAD collection\madExcept\Dlls\madExcept32.dll
:671c953f ; F:\invariant data - not DropBox\3rd_party_vcl\MAD collection\madExcept\Dlls\madExcept32.dll
:71a80013 
System._ReallocMem(???,???)
:0040497d @ReallocMem + $45
System._DynArraySetLength
IdIOHandler.TIdIOHandler.ReadFromSource(True,-2,True)
IdIOHandler.TIdIOHandler.ReadLn(#$A,-1,16384,$D3B6FF0)
IdIOHandler.TIdIOHandler.ReadLn(nil)
IdCmdTCPServer.TIdCmdTCPServer.ReadCommandLine($7CC1AFB4)
IdCmdTCPServer.TIdCmdTCPServer.DoExecute($7CC1AFB4)
IdContext.TIdContext.Run
IdTask.TIdTask.DoRun
IdThread.TIdThreadWithTask.Run
IdThread.TIdThread.Execute
:004ccf91 HookedTThreadExecute + $2D
System.Classes.ThreadProc($7A486F84)
System.ThreadWrapper($7BFBEFF8)
:004cce73 CallThreadProcSafe + $F
:004ccee0 ThreadExceptFrame + $3C
:7559339a kernel32.BaseThreadInitThunk + 0x12
:76f39ef2 ntdll.RtlInitializeExceptionChain + 0x63
:76f39ec5 ntdll.RtlInitializeExceptionChain + 0x36

none of which is my code. It loks like INDY code, but I realize that if my code is buggy then the exception can still be thrown somewhere elase as a result of me taking all the memory.

I am running MAD Except with leak detection on. If I run for w hile and close the program, it reports no leak. If I leave the program running for a few hours I get the out of memory exception.

I only have two calls to Create(), both are in timer handlers and I have set the timer duration to one second in order to stres stest. The handlers are pretty simple and always Free() the created object.

Is there anything else I can look at, apart from the code of the timer handlers?

Here's the code if anyone really needs to see it ... these are the only two palces where I Create() an object ...

procedure TMainForm.ServerAliveTimerTimer(Sender: TObject);

   var timestamp : LongInt;
       ADConnection: TADConnection;
       theDialogForm : TDialogFormForm;
begin
   ServerAliveTimer.Enabled := False;
   TraceInfo('ServerAliveTimer expired after ' + IntToStr(ServerAliveTimer.Interval div 1000) + ' seconds');

   try
      ADConnection := TADConnection.Create(Self);
      ADConnection.DriverName := 'mysql';
      ADConnection.Params.Add('Server=' + MAIN_STOREROOM_IP_ADDRESS);
      ADConnection.Params.Add('Database=XXX');
      ADConnection.Params.Add('User_Name=XXX');
      ADConnection.Params.Add('Password=XXX');
      ADConnection.Params.Add('Port=3306');
      ADConnection.Connected := True;

   except
      on E : Exception do
      begin
         StopAllTimers();

         TraceError('Database error. Failed to create ADO connection');

         ADConnection.Free();

         theDialogForm := TDialogFormForm.Create(Nil);
         theDialogForm.ShowTheForm('Database problem'+#13+#10+''+#13+#10+
                                   E.ClassName+#13+#10+
                                   E.Message);

         StopTheApplication();
         Exit;
      end;
   end;

   if isMainStoreRoom then
   begin
      CheckIfStoreRoomIsAlive(SECONDARY_STOREROOM_IP_ADDRESS);
   end
   else
   begin
      CheckIfStoreRoomIsAlive(MAIN_STOREROOM_IP_ADDRESS);
   end;

   // Now, update our own timestamp
   try
      timestamp  := GetCurrentUnixTimeStamp();
      ADConnection.ExecSQL('UPDATE server_status SET alive_timestamp="' + IntToStr(timestamp) + '" WHERE ip_address="' + ipAddress + '"');

   except
      on E : Exception do
      begin
         TraceError('Database error. Failed to upate timestamp for ip_address = "' +
                        ipAddress + ' in table "server_status"' + #13#10#13#10 +
                        E.ClassName+#13+#10+
                        E.Message);
         ADConnection.Free();
         Exit;
      end;
   end;

   ADConnection.Free();
   ServerAliveTimer.Enabled := True;
end;     // ServerAliveTimerTimer()

and 

procedure TMainForm.CheckEndOfScheduleTimerTimer(Sender: TObject);
   var ADConnection : TADConnection;
       ADQuery : TADQuery;
       secondsSinceMidnight : LongInt;
       timeNow : LongInt;
       today : LongInt;
       checkoutDay : LongInt;
       checkoutExpireTime : LongInt;
       theDialogForm : TDialogFormForm;
       rfidTag : String;
       i : integer;
begin
   CheckEndOfScheduleTimer.Enabled := False;

   ADConnection := Nil;
   ADQuery := Nil;

   try
      TraceInfo('CheckEndOfScheduleTimer expired after ' + IntToStr(CheckEndOfScheduleTimer.Interval div 1000) + ' seconds');

      secondsSinceMidnight := GetSecondsSinceMidnight();
      timeNow := GetCurrentUnixTimeStamp();
      today := timeNow - secondsSinceMidnight;

      ADConnection := TADConnection.Create(nil);
      ADConnection.DriverName := 'mysql';
      ADConnection.Params.Add('Server=' + MAIN_STOREROOM_IP_ADDRESS);
      ADConnection.Params.Add('Database=XXX');
      ADConnection.Params.Add('User_Name=XXX');
      ADConnection.Params.Add('Password=XXX');
      ADConnection.Params.Add('Port=3306');
      ADConnection.Connected := True;

      ADQuery := TADQuery.Create(ADConnection);
      ADQuery.Connection := ADConnection;
      ADQuery.Open('SELECT * FROM tagged_chemicals');
      ADQuery.FetchAll();

      for i := 0 to Pred(ADQuery.Table.Rows.Count) do
      begin
         if ADQuery.Table.Rows[i].GetData('checked_out') = 'N' then
            Continue;

         checkoutDay        := ADQuery.Table.Rows[i].GetData('checkout_day');
         checkoutExpireTime := ADQuery.Table.Rows[i].GetData('checkout_expire_time');

         if (today + secondsSinceMidnight) > (checkoutDay + checkoutExpireTime) then
         begin
            rfidTag := ADQuery.Table.Rows[i].GetData('rfid_tag');

            TraceInfo('End of pouring time for RFID tag (' + IntToStr(secondsSinceMidnight) + ' seconds after midnight');

            ADConnection.ExecSQL('UPDATE tagged_chemicals ' +
                                    'SET checked_out="N", ' +
                                        'checkout_day="0", ' +
                                        'checkout_expire_time="0" ' +
                                 ' WHERE  rfid_tag="' + rfidTag + '"');
         end;
      end;

      ADQuery.Free();
      ADConnection.Free();

   except
      On E: Exception do
      begin
         ADQuery.Free();
         ADConnection.Free();
         TraceError('Databse exception (' + E.ClassName + ') : "' + E.Message + '"');

         theDialogForm := TDialogFormForm.Create(Nil);
         theDialogForm.ShowTheForm('Database error when checking end of pouring time'+#13+#10+''+#13+#10+
                    E.ClassName+#13+#10+
                    E.Message);
      end;
   end;

   CheckEndOfScheduleTimer.Enabled := True;
end;     // CheckEndOfScheduleTimerTimer()

Upvotes: 3

Views: 2020

Answers (1)

Mike Taylor
Mike Taylor

Reputation: 2524

Try using the Sysinternals tools VMMap and Process Explorer this should tell you where the memory is going.

Upvotes: 2

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