如何使用fastMM追踪棘手的内存泄漏？

Question

将项目从Delphi 2007升级到Delphi 2009后,我收到了一个未知的内存泄漏,到目前为止我一直在尝试使用fastMM来跟踪它,这是fastMM堆栈跟踪报告:

A memory block has been leaked. The size is: 20

This block was allocated by thread 0x111C, and the stack trace (return addresses) 
  at the time was:
40339E [System.pas][System][@GetMem][3412] 534873 [crtl][_malloc]
56D1C4 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3918]
56D316 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3961]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
562D48 [DBCommon.pas][DBCommon][TFilterExpr.PutExprNode][1583]
408E46 [System.pas][System][DynArraySetLength][20464]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
408E92 [System.pas][System][@DynArraySetLength][20486]
528C1B [Forms.pas][Forms][TCustomForm.DoCreate][3260]
171A1A [GetRawStackTrace]

The block is currently used for an object of class: Unknown

The allocation number is: 302844

有时我得到这个:

A memory block has been leaked. The size is: 20

This block was allocated by thread 0x111C, and the stack trace (return addresses) 
  at the time was:
40339E [System.pas][System][@GetMem][3412]
534873 [crtl][_malloc]
56D1C4 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3918]
56D316 [canex.cpp][MidasLib][DllGetDataSnapClassObject][3961]
77DC921A [RtlAnsiStringToUnicodeString]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
7726B8F5 [GetProcAddress]
7726B907 [GetProcAddress]
589B1E [ossrv.cpp][MidasLib][DllGetDataSnapClassObject][3163]
56D5EE [canex.cpp][MidasLib][DllGetDataSnapClassObject][4085]
408E92 [System.pas][System][@DynArraySetLength][20486]

The block is currently used for an object of class: Unknown

有没有更好的方法来弄清楚究竟是什么导致内存泄漏？

Answer 1

这个内存泄漏是由Delphi bug引起的,QC #67709

它是由最后一次Delphi 2009更新修复的,难怪我无法修复它.

Answer 2

只要泄漏的内存块的大小没有增长,你的程序使用的时间越长越长,那么它就不是问题了.如果你有一个长期存在的对象,只有在你终止应用程序时才会释放它,就像你泄漏它们一样 - 所有内存都在终止时被回收(当然除非它们处理超出内存的资源).

您想要关注的内存泄漏是随着时间或使用而累积的内存泄漏.如果每次都是20个字节,那么就不要冒汗了.