什么有用的东西可以用Visual C ++调试CRT分配钩子，除了找到可重现的内存泄漏？ [英] What useful things can I do with Visual C++ Debug CRT allocation hooks except finding reproduceable memory leaks?

问题描述

Visual C ++调试运行时库功能所谓的分配钩子以这种方式工作：您定义回调并调用 _CrtSetAllocHook（）设置该回调。现在每次内存分配/重新分配/重新分配完成CRT调用，回调并传递一些参数。

Visual C++ debug runtime library features so-called allocation hooks. Works this way: you define a callback and call _CrtSetAllocHook() to set that callback. Now every time a memory allocation/deallocation/reallocation is done CRT calls that callback and passes a handful of parameters.

我成功地使用了一个分配钩来找到一个可重现的内存泄漏 - 基本上CRT报告说，在程序中有一个未分配的块，分配号为N（每个程序运行都是相同的）终止，所以我写了以下内容：

I successfully used an allocation hook to find a reproduceable memory leak - basically CRT reported that there was an unfreed block with allocation number N (N was the same on every program run) at program termination and so I wrote the following in my hook:

int MyAllocHook( int allocType, void* userData, size_t size, int blockType, 
    long requestNumber, const unsigned char* filename, int lineNumber)
{
     if( requestNumber == TheNumberReported ) {
         Sleep( 0 );// a line to put breakpoint on
     }
     return TRUE;
}

由于每次只能报告泄漏量与相同的分配号码在if语句中放置一个断点，等待它被击中，然后检查调用堆栈。

since the leak was reported with the very same allocation number every time I could just put a breakpoint inside the if-statement and wait until it was hit and then inspect the call stack.

使用分配钩可以使用什么其他有用的东西？

What other useful things can I do using allocation hooks?

推荐答案

您还可以使用它来查找不可重复的内存泄漏：

You could also use it to find unreproducible memory leaks:

• 创建一个数据结构，将分配的指针映射到附加信息


• 在分配钩子中，您可以查询当前的调用堆栈（StackWalk函数）并将调用堆栈存储在数据结构


• 在解除分配挂钩中，删除该分配的调用堆栈信息


• 在应用程序结束时，循环数据结构并报告所有调用堆栈。这些是分配内存但未被释放的地方。

• Make a data structure where you map the allocated pointer to additional information
• In the allocation hook you could query the current call stack (StackWalk function) and store the call stack in the data structure
• In the de-allocation hook, remove the call stack information for that allocation
• At the end of your application, loop over the data structure and report all call stacks. These are the places where memory was allocated but not freed.

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