🚀 go-pugleaf

The following appears to work - it also restricts to a single instance
system-wide
on machines running citrix derived systems like WinDD.

Return is true if it succeeded in creating the mutex, FALSE if failed
because it's
already running

PMac

--

BOOL	CheckandCreateMutex(const char * mutexName)
{
	BOOL	ret = FALSE;

	// The nastiness here is because of multi-user NT derivatives ala Citrix.
	// To make a global resource on these, \SYSTEM must be appended -- but
this
	// fails on vanilla NT, so I try both (\SYSTEM first) ... because I cannot
	// determine portably if the system is multi-user !!!
	HANDLE hMutex1 = OpenMutex(MUTEX_ALL_ACCESS, FALSE, mutexName);
	HANDLE hMutex2 = OpenMutex(MUTEX_ALL_ACCESS, FALSE, CString(mutexName) +
"\\SYSTEM");
	if (hMutex1 == NULL && hMutex2 == NULL)
	{
		HANDLE hMutex = CreateMutex(0, TRUE, CString(mutexName) + "\\SYSTEM");
		if (hMutex == NULL)
			hMutex = CreateMutex(0, TRUE, mutexName);

		DWORD err = GetLastError();
		ret = !(hMutex == NULL || err == ERROR_ALREADY_EXISTS);
		ASSERT(ret);
	}
	else
	{
		if (hMutex1)
			CloseHandle(hMutex1);
		if (hMutex2)
			CloseHandle(hMutex2);
	}

	return ret;
}


-- 
________________________________________________________________
All Opinions are my own ... not necessarily those of my employer
________________________________________________________________
Peter MacLiesh                *      Email:  pmac@synopsys.com
Synopsys Inc.                 *      Phone:  (415)694-4423
700A E. Middlefield Rd.       *      Fax:    (415)694-1626
Mountain View, CA 94043       *