Serial and pread

[Mike McCormack]

Izak Burger wrote:

> Ok.  I had to set +comm to get that info, and modified the code to dump 
> the contents of the COMMTIMEOUTS structure:
> 
> trace:comm:SetCommTimeouts ReadIntervalTimeout=4294967295
> trace:comm:SetCommTimeouts ReadTotalTimeoutMultiplier=0
> trace:comm:SetCommTimeouts ReadTotalTimeoutConstant=0
> trace:comm:SetCommTimeouts WriteTotalTimeoutMultiplier=0
> trace:comm:SetCommTimeouts WriteTotalTimeoutConstant=5000
> 
> MSDN says this means to return immediately with whatever is there.
> 
>> ReadFile command may also be important - check whether it is being 
>> called with an overlapped structure or not.
> 
> 
> It is called with an overlapped structure:
> trace:file:ReadFile 0x88 0x42295ff1 1040 0x4081ace0 0x42295b5f

Hi Izak,

It appears we don't handle this case properly.  We only handle 
ReadIntervalTimeout=MAXDWORD in non-overlapped mode.  Can you try the 
following (untested) patch and see if it fixes the problem?

Mike
-------------- next part --------------
Index: server/serial.c
===================================================================
RCS file: /home/wine/wine/server/serial.c,v
retrieving revision 1.33
diff -u -r1.33 serial.c
--- server/serial.c	8 Apr 2004 19:09:04 -0000	1.33
+++ server/serial.c	14 Apr 2004 10:25:45 -0000
@@ -273,6 +273,28 @@
         if ( !async )
             return;
 
+        /*
+         * The following combination of timeout values means we're try to
+         * read as much data as is available, then return immediately.
+         */
+        if ( (serial->readinterval == MAXDWORD) &&
+              (serial->readmult == 0) && (serial->readconst == 0) )
+        {
+            struct pollfd pfd;
+
+            pfd.fd = get_unix_fd(fd);
+            pfd.events = POLLIN;
+            pfd.revents = 0;
+            poll( &pfd, 1, 0 );
+
+            if ( !(pfd.revents & POLLIN) )
+            {
+                async_notify( async, STATUS_SUCCESS);
+                destroy_async( async );
+                return;
+            }
+        }
+
         async->status = STATUS_PENDING;
         if(!async->q)
         {