Path: news.cs.au.dk!not-for-mail
From: "Sascha Kimmel \(tricos Mediaservice\)" <kimmel@tricos.com>
Newsgroups: comp.lang.beta
Subject: Severe bug in array implementation (nti) - extendBlock: VirtualAlloc failed - Out of memory
Date: 20 Feb 2000 10:38:58 -0000
Organization: University of Aarhus, Department of Computer Science (DAIMI)
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Hello,

I found a severe bug in the array implementation.
The following program gives an access violation during execution on Windows
(other platforms not tested):

>>>>>
ORIGIN '~beta/basiclib/betaenv';
-- program: descriptor --

(** BETA CRASH TEST **)

(#
	a:[0]@char;
	do
	(for i:32768 repeat (** might also be a value smaller than 2^15 with at
east about 23850 for chars **)
		'Array@char has is set to a length of '->putText; i->putInt; '
bytes.'->putLine;
		1->a.extend;
		'@'->a[a.range];
	for);

	'Ready.'->putLine;
	stop;
#)
<<<<<

The same problem also occurs when using an array of integer and probably
every time a STATIC OBJECT is used instead of a REFERENCE as an array
object.
It works well with an array of ^text.

After running the program shown above the following output is displayed
after some time:

[...]
Array@char has is set to a length of 23844 bytes.
Array@char has is set to a length of 23845 bytes.
Array@char has is set to a length of 23846 bytes.
extendBlock: VirtualAlloc failed with GetLastError 8
Array@char has is set to a length of 23847 bytes.
Array@char has is set to a length of 23848 bytes.


During execution it seems that a vast amount of memory is used because of
heavy harddisk access (swap file?)
Afterwards a BETA execution "Access violation" occurs, the dump file says:

>>>>>
Beta execution aborted: Access violation.

Call chain: (nti_ms)

Current object is zero!
  [ EXTERNAL ACTIVATION PART (address 0x4143e9
<_AOAAllocateFromFreeList+0x329>) ]

# Beta execution aborted: Access violation
# Error during dump: Reference is none. Aborting.
<<<<<


The WINAPI function GetLastError returns 8 which is defined in winerror.h as

>>>>>
// MessageId: ERROR_NOT_ENOUGH_MEMORY
//
// MessageText:
//
//  Not enough storage is available to process this command.
//
#define ERROR_NOT_ENOUGH_MEMORY          8L    // dderror
<<<<<


A workaround is to use REFERENCES instead of OBJECTS.
The error "extendBlock: VirtualAlloc failed..." originates from betarun.lib
and betarun_v.lib, making it impossible for any BETA programmer to trace the
problem.

I hope that an updated version of betarun.lib and betarun_v.lib will be
available soon - it is normal to use e.g. integer OBJECTS instead of
references.

Any feedback especially from MJOLNER is welcome.

Regards,
Sascha Kimmel