Re: [ros-dev] [ros-diffs] [mjmartin] 40557: - Add volatile to variables in OutputDebugStringA. Fix #1 of ? for 3424.

[Timo Kreuzer]

Can you explain, why the variables need to be volatile? This looks like
a SEH problem.

mjmartin(a)svn.reactos.org schrieb:
>   Author: mjmartin
>  Date: Fri Apr 17 13:59:03 2009
>  New Revision: 40557
>
>  URL: http://svn.reactos.org/svn/reactos?rev=40557&view=rev
>  Log:
>  - Add volatile to variables in OutputDebugStringA. Fix #1 of ? for 3424.
>
>  Modified:
>      trunk/reactos/dll/win32/kernel32/debug/output.c
>
>  Modified: trunk/reactos/dll/win32/kernel32/debug/output.c
>  URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/kernel32/debug/o…
>  ==============================================================================
>  --- trunk/reactos/dll/win32/kernel32/debug/output.c [iso-8859-1] (original)
>  +++ trunk/reactos/dll/win32/kernel32/debug/output.c [iso-8859-1] Fri Apr 17 13:59:03
> 2009
>  @@ -219,9 +219,9 @@
>   		static BOOL s_bDBMonMutexTriedOpen = FALSE;
>   
>   		/* local copy of the mutex handle */
>  -		HANDLE hDBMonMutex = s_hDBMonMutex;
>  +		volatile HANDLE hDBMonMutex = s_hDBMonMutex;
>   		/* handle to the Section of the shared buffer */
>  -		HANDLE hDBMonBuffer = NULL;
>  +		volatile HANDLE hDBMonBuffer = NULL;
>   
>   		/* pointer to the mapped view of the shared buffer. It consist of the current
>   		   process id followed by the message string */
>  @@ -229,11 +229,11 @@
>   
>   		/* event: signaled by the debug message monitor when OutputDebugString can write
>   		   to the shared buffer */
>  -		HANDLE hDBMonBufferReady = NULL;
>  +		volatile HANDLE hDBMonBufferReady = NULL;
>   
>   		/* event: to be signaled by OutputDebugString when it's done writing to the
>   		   shared buffer */
>  -		HANDLE hDBMonDataReady = NULL;
>  +		volatile HANDLE hDBMonDataReady = NULL;
>   
>   		/* mutex not opened, and no previous attempts to open/create it */
>   		if(hDBMonMutex == NULL && !s_bDBMonMutexTriedOpen)
>  @@ -295,10 +295,10 @@
>   			_SEH2_TRY
>   			{
>   				/* size of the current output block */
>  -				SIZE_T nRoundLen;
>  +				volatile SIZE_T nRoundLen;
>   
>   				/* size of the remainder of the string */
>  -				SIZE_T nOutputStringLen;
>  +				volatile SIZE_T nOutputStringLen;
>   
>   				/* output the whole string */
>   				nOutputStringLen = strlen(_OutputString);
>  @@ -339,11 +339,12 @@
>   					else
>   					{
>   						/* output in blocks of 512 characters */
>  -						CHAR a_cBuffer[512];
>  +						volatile PCHAR a_cBuffer;
>  +						a_cBuffer = (CHAR*)HeapAlloc(GetProcessHeap(), 0, 512);
>   
>   						/* write a maximum of 511 bytes */
>  -						if(nOutputStringLen > (sizeof(a_cBuffer) - 2))
>  -							nRoundLen = sizeof(a_cBuffer) - 2;
>  +						if(nOutputStringLen > 510)
>  +							nRoundLen = 510;
>   						else
>   							nRoundLen = nOutputStringLen;
>   
>  @@ -355,6 +356,8 @@
>   
>   						/* send the current block to the kernel debugger */
>   						DbgPrint("%s", a_cBuffer);
>  +
>  +						HeapFree(GetProcessHeap(), 0, a_cBuffer);
>   					}
>   
>   					/* move to the next block */
>
>
>