// This is a part of the Microsoft Foundation Classes C++ library.
// Copyright (C) Microsoft Corporation
// All rights reserved.
//
// This source code is only intended as a supplement to the
// Microsoft Foundation Classes Reference and related
// electronic documentation provided with the library.
// See these sources for detailed information regarding the
// Microsoft Foundation Classes product.

#include "stdafx.h"



#pragma warning(disable: 4706) // assignment within conditional

/////////////////////////////////////////////////////////////////////////////
// global thread protection

#ifdef _MT

AFX_STATIC_DATA BOOL _afxCriticalInit = 0;   // set _afxGlobalLock, _afxTempLock init

// _afxResourceLock and _afxLockInit are used to lock each MFC global resource
AFX_STATIC_DATA CRITICAL_SECTION _afxResourceLock[CRIT_MAX] = { { 0 } };
AFX_STATIC_DATA CRITICAL_SECTION _afxLockInitLock = { 0 };
AFX_STATIC_DATA BOOL _afxLockInit[CRIT_MAX] = { 0 };
#ifdef _DEBUG
AFX_STATIC_DATA BOOL _afxResourceLocked[CRIT_MAX] = { 0 };
#endif

BOOL AFXAPI AfxCriticalInit()
{
	// Note: this must be initialized with only one thread running
	if (!_afxCriticalInit)
	{
		// now we are about to be initialized
		VERIFY(++_afxCriticalInit);
		InitializeCriticalSection(&_afxLockInitLock);
	}
	return _afxCriticalInit;
}

void AFXAPI AfxCriticalTerm()
{
	if (_afxCriticalInit)
	{
		VERIFY(!--_afxCriticalInit);

		// delete helper critical sections
		DeleteCriticalSection(&_afxLockInitLock);

		// delete specific resource critical sections
		for (int i = 0; i < CRIT_MAX; i++)
		{
#ifdef _DEBUG
			ASSERT(!_afxResourceLocked[i]);
#endif
			if (_afxLockInit[i])
			{
				DeleteCriticalSection(&_afxResourceLock[i]);
				VERIFY(!--_afxLockInit[i]);
			}
		}
	}
}

void AFXAPI AfxLockGlobals(int nLockType)
{
	ENSURE((UINT)nLockType < CRIT_MAX);

	// intialize global state, if necessary
	if (!_afxCriticalInit)
	{
		AfxCriticalInit();
		ASSERT(_afxCriticalInit);
	}

	// initialize specific resource if necessary
	if (!_afxLockInit[nLockType])
	{
		EnterCriticalSection(&_afxLockInitLock);
		if (!_afxLockInit[nLockType])
		{
			InitializeCriticalSection(&_afxResourceLock[nLockType]);
			VERIFY(++_afxLockInit[nLockType]);
		}
		LeaveCriticalSection(&_afxLockInitLock);
	}

	// lock specific resource
	EnterCriticalSection(&_afxResourceLock[nLockType]);
#ifdef _DEBUG
	ASSERT(++_afxResourceLocked[nLockType] > 0);
#endif
}

void AFXAPI AfxUnlockGlobals(int nLockType)
{
	ASSERT(_afxCriticalInit);
	ENSURE((UINT)nLockType < CRIT_MAX);

	// unlock specific resource
	ASSERT(_afxLockInit[nLockType]);
#ifdef _DEBUG
	ASSERT(--_afxResourceLocked[nLockType] >= 0);
#endif
	LeaveCriticalSection(&_afxResourceLock[nLockType]);
}

#endif

/////////////////////////////////////////////////////////////////////////////