The Memory Validator API

 

There are some features of Memory Validator that are useful to call directly from your program, including tracking of memory in custom heap managers.

 

Memory Validator has an API that makes this possible; just include svlMPAPI.c and svlMPAPI.h to your codebase. There is no library to link to, dlls to copy.

 

 

Source files

 

The source files can be found in the API directory in the Memory Validator install directory.

 

 svlMVAPI.h

 svlMVAPI.c

 

Just add these files to your project and build.
 
If you are using precompiled headers you will need to disable them for svlMVAPI.c.

 

 

Working with services?

 

If you are working with services you to attach Memory Validator to a service and to start Memory Validator, you should use the NT Service API, not the functions in this API.

 

All the other functions in this API can be used with applications and with services.

 

 

Unicode or ANSI?

 

All the API functions are provided in Unicode and ANSI variants where strings are used. We've also provided a character width neutral #define in the same fashion that the Windows.h header files do.

 

For example the function for naming a heap is provided as mvSetHeapNameA(), mvSetHeapNameW() with the character width neutral mvSetHeapName() mapping to mvSetHeapNameW() for unicode and mvSetHeapNameA() for ANSI.

 

In this document we're going to use TCHAR like the Window.h header files do.

 

 

Loading the Profiler

 

For most use cases won't need to load the profiler, as the profiler will have been loaded when your launched your program from Memory Validator, or when you injected into your program using Inject or Wait For Application.

 

However if you're running your program from outside of Memory Validator and want to load the profiler from inside your program you can use mvLoadProfiler() to do that. You'll then need to call mvStartProfiler() to start it.

 

Function Definition:

 

 extern "C" void mvLoadProfiler();

 

 

If you are using services, you should use the NT Service API to attach Memory Validator to your service, not the functions in this API.

 

 

Starting the Profiler

 

To start the profiler from your API code you need to call the function "startProfiler" from your code before you call any API functions. Ideally you should call this function as early in your program as possible.

 

Function Definition:

 

 extern "C" void mvStartProfiler();

 

If you prefer to start the profiler from the user interface or command line you can omit the startProfiler() call. You can leave it present if you wish to start Memory Validator from your program.

 

All the API functions are declared as extern "C", so C as well as  C++ users can use them.

 

 

If you are using services, you should use the NT Service API to start Memory Validator, not the functions in this API.

 

 

Calling API functions using GetProcAddress

 

If you don't want to use the svlMVAPI.c/h files you can use GetProcAddress to find the interface functions in the Memory Validator DLL.

 

The interface functions have different names and do not use C++ name mangling, but have identical parameters to the API functions.

 

To determine the function name take any native API name, replace the leading mv with api. For example mvSetWatermarkEx() becomes apiSetWatermarkEx();

 

 

Example usage

 

HMODULE getValidatorModule()
{
   HMODULE   hModule;
 
   hModule = GetModuleHandle("svlMemoryValidatorStub6432.dll");                // 32 bit DLL with 64 bit Memory Validator GUI
   if (hModule == NULL)
      hModule = GetModuleHandle("svlMemoryValidatorStub_x64.dll");        // 64 bit DLL with 64 bit Memory Validator GUI
   if (hModule == NULL)
      hModule = GetModuleHandle("svlMemoryValidatorStub.dll");                // 32 bit DLL with 32 bit Memory Validator GUI
 
   return hModule;
}
 

HMODULE   hMod;
 
// get module, will only succeed if Memory Validator launched this app or is injected into this app
 
hMod = getValidatorModule();
if (hMod != NULL)
{
    // MV is present, lookup the function and call it to set a watermark for this location in the code
 
    mvSetWatermark_FUNC   pFunc;
 
    // "apiSetWatermark" is equivalent to linking against "mvSetWatermark"
 
    pFunc = (mvSetWatermark_FUNC)GetProcAddress(hMod, "apiSetWatermark");
    if (pFunc != NULL)
    {
        (*pFunc)(watermarkName);
    }
}

 

 

API functions and their GetProcAddress names

 

For any API functions not listed, try looking up the name in svlMemoryValidatorStub.dll using depends.exe

 

 

 

Other exported functions

 

You may see some other functions exported from svlMemoryValidatorStub.dll(_x64).dll.

 

These other functions are for Memory Validator's use. Using them may damage memory locations and/or crash your code. Best not to use them!