Introducing VirtualMM debugging memory manager

We will talk about the VirtualMM debugging memory manager. What it is, when to use it, when not to use it, how to use it, where to download it, how to configure it, and so on.

This article assumes that you are familiar (at least in general terms) with the concepts of address space, memory page, RESERVE, and COMMIT.

How to read bug reports

We were contacted by a customer who used a previous major version of EurekaLog and upgraded to the EurekaLog 7 recently. He said his application crashes on exit. He attached a bug report file produced by EurekaLog. The bug report was about access violation exception.

The customer did not actually ask any question. He just stated his app crashes. It was unclear if the customer is seeking help fixing a bug in his application, asking why there was no bug reported previosly, or he thinks it is some sort of "false-positive" bug report.

What can you do with the "Assember" tab in bug reports? Is it even useful?

We were contacted by a customer that claimed that his application worked fine until he added EurekaLog to it. Specifically, his application starts to raise an EAccessViolation exception with the following message:
Access violation at address 03DB472F in module 'Sample.exe'. Read of address 5653E4CC

EurekaLog helps not only you, but also developers of libraries that you are using

We were contacted by a customer that claimed that his application worked fine until he added EurekaLog to it. Specifically, his application starts to raise an EAccessViolation exception in his event handler's code.

Why it is recommended to restart the application after a crash

We were contacted by a client complaining that EurekaLog was hiding his application.

Even empty applications have bugs

We were contacted by a person who claimed to have found a bug in EurekaLog. He justified this statement as follows: if you create a new DataSnap application and add EurekaLog to it, the application will crash with Access Violation on exit.

EurekaLog causes AccessViolation?

We were contacted by a person who complained that his application was working fine until he added EurekaLog to it. An AccessViolation exception was raised after adding EurekaLog to project. The message was: "Access violation at address 00E15025 in module 'Project.exe'. Read of address 83EC8B69". And the stack was:

• Contoso.pas TContosoEventMessage.BasePerform
• Vcl.Forms.pas TApplication.WndProc
• System.Classes.pas StdWndProc
• Vcl.Forms.pas TApplication.HandleMessage
• Vcl.Forms.pas TApplication.Run
• Project.dpr Initialization

(all names have been replaced; Contoso represents some well-known library for Delphi).

How to read bug-reports

Well, recently I’ve noticed that there are many people, who have certain difficulties with reading and/or understanding bug-reports. There are many related questions both on support and forums. While it is quite surprising for me, it looks like there is a problem, which need to be solved.

Catching memory leaks

Before return to discussion of other ways to catch "bad" pointers - I wanted to talk about memory leaks and tools for its diagnostics. As we'll see later, this topic is very close related to our previous talk.

Access Violation in details

Exception of class EAccessViolation is most common error in Delphi applications. Today I want to discuss it, its reasons and how to deal with it. This article is mostly for beginners, so it can contain not very accurate phrases.

Why should you always use FreeAndNil instead of Free

Today I want to discuss the idea of using FreeAndNil routine instead of Obj.Free.