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.

[e-mail] 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/ou...
> ==============================================================================
> --- 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 */