Display Power Off Utility Code

#include "stdafx.h"

#include "LaunchGuard.h"
#include "Options.h"

namespace
{
	HANDLE hAppMutex;

	[[nodiscard]] auto GetMutexName()
	{
		constexpr auto cszMutexGuid = TEXT("{58E5128B-B829-4B61-B3EA-41DCF6A4B5D1}");

		CharBuffer<64, ClearBuffer::First> szMutexName;

		if (Options::NotificationAreaIcon())
		{
			VERIFY_STR(StringCchCat(szMutexName, szMutexName, TEXT("NotificationAreaIcon")));
		}

		VERIFY_STR(StringCchCat(szMutexName, szMutexName, cszMutexGuid));

		return szMutexName;
	}
}

bool LaunchGuard::TryEnter()
{
	const auto cszMutexName = GetMutexName();

	hAppMutex = CreateMutex(nullptr, FALSE, cszMutexName);
	ASSERT(hAppMutex);
	if (!hAppMutex || GetLastError() == ERROR_ALREADY_EXISTS)
	{
		TRACE(hAppMutex ? TEXT("Mutex already exists") : TEXT("Error creating mutex"));
		return false;
	}

	return true;
}

void LaunchGuard::Exit()
{
	if (hAppMutex)
	{
		TRACE(TEXT("Closing mutex..."));
		VERIFY(CloseHandle(hAppMutex));
	}
}