`_CrtSetDumpClient`

Article
02/07/2023

Installs an application-defined function to dump _CLIENT_BLOCK type memory blocks (debug version only).

Syntax

_CRT_DUMP_CLIENT _CrtSetDumpClient( _CRT_DUMP_CLIENT dumpClient );

Parameters

dumpClient
New client-defined memory dump function to hook.

Return value

Returns the previously defined client block dump function.

Remarks

The _CrtSetDumpClient function allows the application to hook its own function to dump objects stored in _CLIENT_BLOCK memory blocks. As a result, every time a debug dump function such as _CrtMemDumpAllObjectsSince or _CrtDumpMemoryLeaks dumps a _CLIENT_BLOCK memory block, the application's dump function is called as well. _CrtSetDumpClient provides an application with an easy method for detecting memory leaks and validating or reporting the contents of data stored in _CLIENT_BLOCK blocks. When _DEBUG isn't defined, calls to _CrtSetDumpClient are removed during preprocessing.

The _CrtSetDumpClient function installs the new application-defined dump function specified in dumpClient and returns the previously defined dump function. An example of a client block dump function is as follows:

void DumpClientFunction( void *userPortion, size_t blockSize );

The userPortion argument is a pointer to the beginning of the user data portion of the memory block and blockSize specifies the size of the allocated memory block in bytes. The client block dump function must return void. The pointer to the client dump function that is passed to _CrtSetDumpClient is of type _CRT_DUMP_CLIENT, as defined in Crtdbg.h:

typedef void (__cdecl *_CRT_DUMP_CLIENT)( void *, size_t );

For more information about functions that operate on _CLIENT_BLOCK type memory blocks, see Client block hook functions. The _CrtReportBlockType function can be used to return information about block types and subtypes.

Requirements

Routine	Required header
`_CrtSetDumpClient`	<crtdbg.h>

For more compatibility information, see Compatibility.

Libraries

Debug versions of C run-time libraries only.