I've written too much mails to the lyx list ;)
Peter Kümmel wrote:
> Timothy Vismor wrote:
>> On 11/17/06, Havoc Pennington <[EMAIL PROTECTED]> wrote:
>>>
>>>
>>> Timothy Vismor wrote:
>>>> A common way to guarantee a unique instance of a Windows application
>>>> is to use a well known mutex name. A simple example is:
>>>>
>>> Thanks, that looks pretty good. We'd need to solve one more problem
>>> also, which is how to get the address of the existing process... any
>>> typical pattern for that? ;-)
>>>
>>> Havoc
>>
>> Never needed to do that specific operation, but it seems that a simple
>> solution could be to use named shared memory. When a process grabs
>> the DBus mutex, it could write relevant address information to a well
>> known block of named shared memory. When you release the
>> mutex, you also release the shared memory block. If a process
>> fails to grab the mutex, it could read the required information from
>> shared memory.
>>
>> DURING STARTUP, AFTER YOU CREATE THE MUTEX
>>
>> SECURITY_ATTRIBUTES sa;
>> sa.nLength = sizeof( sa );
>> sa.lpSecurityDescriptor = m_pMemSD;
>> sa.bInheritHandle = TRUE;
>>
>> // Create shared virual memory in the page file.
>> m_hSharedMem = CreateFileMapping( (HANDLE)0xFFFFFFFF, &sa,
>> PAGE_READWRITE,
>> ZERO, nBytes, "DBusAddressInfo"
>> );
>> if( m_hSharedMem == NULL )
>> {
>> // Unable to allocate shared memory.
>> return( FALSE );
>> }
>>
>> // Map shared memory into process address space.
>> if( m_hSharedMem != NULL )
>> {
>> m_pSharedMem = MapViewOfFile( m_hSharedMem, FILE_MAP_WRITE, ZERO,
>> ZERO, ZERO );
>> if( m_pSharedMem == NULL )
>> {
>> // Unable to map shared memory.
>> ::CloseHandle( m_hSharedMem );
>> m_hSharedMem = NULL;
>> return( FALSE );
>> }
>> }
>> // Write process information to shared memory.
>> ...
>>
>> DURING SHUTDOWN
>>
>> if( m_pSharedMem != NULL )
>> {
>> ::UnmapViewOfFile( m_pSharedMem );
>> m_pSharedMem = NULL;
>> }
>> if( m_hNetDevMem != NULL )
>> {
>> ::CloseHandle( m_hSharedMem );
>> m_hSharedMem = NULL;
>> }
>>
>>
>> IF CAN'T GET MUTEX
>>
>> // Connect to the memory mapped file (actually the paging file).
>> m_hSharedMem = OpenFileMapping(FILE_MAP_READ, FALSE, "DBusAddressInfo");
>>
>> if( m_hSharedMem == NULL )
>> {
>> // Unable to link to shared memory.
>> // Process is no longer running.
>> return( FALSE );
>> }
>>
>> // Map shared memory into our address space.
>> m_pSharedMem = MapViewOfFile( m_hSharedMem, FILE_MAP_READ,ZERO, ZERO,
>> ZERO );
>> if( m_pSharedMem == NULL )
>> {
>> // Unable to map shared memory.
>> CloseHandle( m_hSharedMem );
>> m_hSharedMem = NULL;
>> return( FALSE );
>> }
>> // Read process info from shared mem
>> ....
>
> Great! I'll give it a try.
>
> Peter
>
--
Peter Kümmel
