[comp.sys.amiga.programmer] Memory Alloc during Duplicate

breemen@rulcvx.LeidenUniv.nl (E. van Breemen) (06/18/91)

Normally I am using a SHELL instead of the WB to do things on my Amiga. A
friend of mine said something strange about the Duplicate function of
the WB. He said that during a duplicate of an empty(!) directory the WB
allocates all the memory available in the Amiga (only +- 10K chip left).
He has an Amiga with 1Mb. I have checked this on my Amiga with 3Mb. The
same thing happened on my machine. Appearantly, the WB needs 2.8 Mb to
duplicate an empty directory. Why is that? Commodore does know of the
fact that intuition crashes under low memory conditions. I have been
able to crash my Amiga relativly easy. I hope this has been fixed under
2.0 for more stability.

Erwin van Breemen

mks@cbmvax.commodore.com (Michael Sinz) (06/18/91)

In article <1991Jun18.084313.25813@rulway.LeidenUniv.nl> breemen@rulcvx.LeidenUniv.nl (E. van Breemen) writes:
>
>Normally I am using a SHELL instead of the WB to do things on my Amiga. A
>friend of mine said something strange about the Duplicate function of
>the WB. He said that during a duplicate of an empty(!) directory the WB
>allocates all the memory available in the Amiga (only +- 10K chip left).
>He has an Amiga with 1Mb. I have checked this on my Amiga with 3Mb. The
>same thing happened on my machine. Appearantly, the WB needs 2.8 Mb to
>duplicate an empty directory. Why is that? Commodore does know of the
>fact that intuition crashes under low memory conditions. I have been
>able to crash my Amiga relativly easy. I hope this has been fixed under
>2.0 for more stability.

Oh, you did not know of the "Eat all memory" function that workbench
calls whenever it does something like copy a file?  ;^)

Yes, I know that was a problem in 1.x of workbench.  2.04 does not have
this problem.  In fact, it should work rather well in the copy area as
I had completely redone it.  Copies on a single floppy will only take one
swap (assuming you have the memory) but it will only use the memory it needs
to do the copy.  It also copies a bit faster than before.

In addition to this, the system is now completely stable under low memory
conditions in 2.04.  You can bring the system down to 0 bytes free and it
will not crash.  You may not be able to do anything usefull, but it will
not crash.

/----------------------------------------------------------------------\
|      /// Michael Sinz  -  Amiga Software Engineer                    |
|     ///                   Operating System Development Group         |
|    ///   BIX:  msinz      UUNET:  rutgers!cbmvax!mks                 |
|\\\///                                                                |
| \XX/     "I don't think so" said Ren'e Descartes, then he vanished.  |
\----------------------------------------------------------------------/