Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdahl!oliveb!tymix!antares!jms From: jms@antares.UUCP (Joe Smith) Newsgroups: comp.sys.amiga.tech Subject: Re: ReallocMem Message-ID: <432@antares.UUCP> Date: 1 Apr 89 10:42:15 GMT References: <6406@cbmvax.UUCP> <6464@cbmvax.UUCP> Reply-To: jms@antares.UUCP (Joe Smith) Organization: Tymnet QSATS, San Jose CA Lines: 22 In article shadow@pawl.rpi.edu (Deven T. Corzine) writes: >... Now, if C-A will add a ReallocMem to Exec V1.4+, it won't be a problem. I don't understand how ReallocMem could ever work under AmigaDOS unless the caller always does a Forbid before the FreeMem and a Permit after the ReallocMem. As soon as you free memory on the Amiga, some other task may get a chance to run and get the block you just freed. (Memory blocks are either in use, or completely free - available to anyone. There are no other possiblilities.) With Unix, each process gets its own private virtual address space so that the other guy's alloc won't interfere with your alloc. And sbrk provides contiguous blocks of virtual memory, something which cannot be done with AmigaDOS. You keep saying that it is trivial to add ReallocMem to the OS. Given the fact that all tasks on the Amiga share the same virtual=physical address space (currently), I believe it is very difficult. I would venture to say that it is impossible in version 1.x - you will have to wait for 2.0 or 3.0. -- Joe Smith (408)922-6220 | jms@antares.Tymnet.COM or jms@opus.Tymnet.COM McDonnell Douglas FSCO | UUCP: ...!{ames,pyramid}!oliveb!tymix!antares!jms PO Box 49019, MS-D21 | PDP-10:JMS@F74.Tymnet.COM CA license plate:"POPJ P," San Jose, CA 95161-9019 | narrator.device: "I didn't say that, my Amiga did!"