Hi!
> >I have a question about locking and releasing handles to memory. The
> >Palm OS Reference states I should release locked memory as soon as
> >possible, whereas some posts on this forum suggest locking/releasing
> >will take up valuable CPU cycles and not releasing as soon as possible
> >might not be that harmful after all.
>
> The reason to unlock handles is to allow the memory manager to shuffle things around
>to make room. If you're doing something that requires speed, you probably want to
>avoid allocating memory during the operation, which means there is no need to unlock
>handles during the operation either. I'd suggest using a debugger to isolate the 10%
>of the code that runs 90% of the time, and if lock/unlock or memory allocation is a
>significant portion of that 90%, keep the handle locked for the entire duration of
>the operation. Unless you've done profiling and found that it's a problem, I wouldn't
>worry about it.
Oops, I asked the wrong question (I shouldn't write e-mails early in the morning). I
really wanted to ask about locking and releasing database records in resource
databases.
Like in this typical piece of code:
MemHandle resH = DmGetResource( bitmapRsc, maskID );
ErrNonFatalDisplayIf( !resH, "Missing mask" );
BitmapType* resP = (BitmapPtr)MemHandleLock(resH);
WinDrawBitmap (resP, 0,0);
MemPtrUnlock(resP);
DmReleaseResource( resH );
Will there be any adverse side-effects to keeping the Resource locked if I need it a
lot of times? The DmGetResource method does eat up a considerable amount of CPU
cycles, according to the profiler log.
Cheers,
Tilo
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