Query the Value of a Semaphore

Well, Win32 does not give you the possibilty to get the value, but there is a call in ntdll.dll which allows to query the semaphore. So the 'QuerySemaphore.lib' simply provides a small static lib, which wraps the NtQuerySemaphore call in ntdll.dll.

QuerySemaphore.lib is selfcontained, so your program does not need ntdll.lib to resolve the call to NtQuerySemaphore.

A simple example

	#include "QuerySemaphore.h"

	LONG	Value, v1;

	// Create a semaphore
	HANDLE	Handle = CreateSemaphore(NULL, 4, 10, NULL);

	// Query the content of a semaphore
	QuerySemaphore(Handle, &Value);

	// Acquire Semaphore
	WaitForSingleObject(Handle, INFINITE);
	
	// Query again
	QuerySemaphore(Handle, &Value);

So all you need is to include 'QuerySemaphore.h' in your sourcecode and add 'QuerySemaphore.lib' to the libraries you are linking against.

Download demo project - 2 KB

Download source - 8 KB