On Mon, 20 Dec 2004, Tomas Hajny wrote:
> Date sent: Mon, 20 Dec 2004 22:50:06 +0100 (CET) > From: [EMAIL PROTECTED] > To: [EMAIL PROTECTED], > "FPC developers' list" <[EMAIL PROTECTED]> > Subject: RE: [fpc-devel] THandle and 64bit platforms > Copies to: Send reply to: FPC developers' list > <[EMAIL PROTECTED]> > <mailto:[EMAIL PROTECTED]> > <mailto:[EMAIL PROTECTED]> > > . > . > > > > > > > In the LCL a THandle is used everywhere and in most cases it > > > > > > > represents a pointer. It is also part of the emulated > > > > > > > message records. All members of it are defined as PtrInt. On > > > > > > > placed where a handle is iused, it should map on a PtrInt. > > > . > > > . > > In principle, a windows handle is an 'opaque' type. > > You're not supposed to make any assumptions about it's size or > > internal structure. > > > > That Windows uses the same handle type for the I/O API and it's GUI > > subsystem is an unfortunate coincidence. > > Probably more design decision than "coincidence" - the same type is > used for everything, not just I/O and GUI, but processes, threads and > all kinds of system resources too. A matter of preference, I prefer the Unix way of pid_t, mode_t, size_t. Allows more freedom, in my opinion. The handles are not compatible anyway. It doesn't make much sense to send a windows message to a file handle ;-) > > Thinking about it some more I think the more 'correct' choice for > > Lazarus is to introduce a TLCLHandle type, which will be equal to a > > HANDLE (or THANDLE) type on Windows, but which probably will equal a > > pointer under e.g. GTK, and hence a 64-bit pointer on 64-bit > > platforms. > > > > This will take some work :-) > . > . > > Would THandle exist on non-Windows platforms under your concept then? Yes. But only for compatibility. > If so, what would it be on Linux x86-64 (by pure coincidence, of > course ;-) )? Whatever TFileHandle is, obviously :) Michael. _______________________________________________ fpc-devel maillist - [EMAIL PROTECTED] http://lists.freepascal.org/mailman/listinfo/fpc-devel
