ExecuteSQL() somewhat async?

[Eric Forget]

> on 1/30/03 6:26 AM, Eric Forget at forgete at cafederic.com wrote:
> 
>> Hi,
>> 
>> After looking for a crash, I found that calling VDK_Cursor::ExecuteSQL()
>> finish by calling OBL_JoinSet_Builder::DoInnerJoinFirstForLink(OBL_Link*,
>> OBL_Object*, OBL_Object*, FBL_BitSet*, FBL_BitSet*) which calls
>> EventAvail(). Is there any reason for this?
>> 
>> The problem is that gives the control back to Cocoa who calls me back and
>> now I'm questioning the same VDK_Cursor of the ExecuteSQL() which cause my
>> crash.
>> 
>> I know how to go around it but it is cumbersome. Should all my code be
>> reentrant when I use the VSDK? I means which methods of the VSDK calls
>> EventAvail(), WaitNextEvent(), etc. directly or indirectly?
> 
> Hi Eric,
> 
> In file FBL_ThreadNative.h
> I have function as:
> 
> //-------------------------------------------------------
> inline void FBL_ModalYield( void )
> {
> #if !__MACH__
>   // Give time to other applications
>   EventRecord macEvent;
>   ::EventAvail( everyEvent, &macEvent );
> #endif
> 
>   // Yield to any other thread of this appliation
>   FBL_Yield();
> }
> //-------------------------------------------------------
> 
> 
> As you see I have wrap call ::EventAvail() by macro
>   __MACH__
> 
> So am I right that for GCC this macro not works ?
> 
> I think for now I can simply add
> 
> 
> #if !__MACH__ && !__CNUC__
> 
> 
> Agree?

For GCC as for most defines outside Universal Headers and Metrowerks always
assumes that all macros are defined like this:

#define __MACH__

Without any value (so it is always false!).

Your code should look like:

#ifndef __MACH__
   // Give time to other applications
   EventRecord macEvent;
   ::EventAvail( everyEvent, &macEvent );
#endif


But this resolve the problem of Mach-O target, not Mac OS X CFM ones. The
problem is that Cocoa is installing timers which are fired when you call
EventAvail(). The same thing may happen with Carbon Events. So it would be
better:

#ifndef __MACH__
    if (gVSDKIsNotRunningMacOSX) {  // Initialized in ValentinaInit()
    
        // Give time to other applications
        EventRecord macEvent;
        ::EventAvail( everyEvent, &macEvent );
    }
#endif


BTW, I suppose you know this about Mac OS X:

"Synchronous File Manager and OT calls on an MP thread yield better
performance than Async calls on Mac OS X" - from
<http://developer.apple.com/carbon/tipsandtricks.html>

Éric

___________________________________________________________________

 Eric Forget                       Cafederic
 ForgetE at cafederic.com             <http://www.cafederic.com/>

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