Number: 2014

Date: 29-Aug-84 13':55':23

Submitter: Woody.pasa

Source: Woody.pasa

Subject: RAND crashing with bad call to \SLOWIDIFFERENCE

Assigned To: 

Attn: 

Status: Incomplete

In/By: 

Problem Type: Bug

Impact: Annoying

Difficulty: Easy

Frequency: Once

Priority: Perhaps

System: Language Support

Subsystem: Arithmetic

Machine: 1108

Disk: SA1000 (10MB)

Lisp Version: 21-Jun-84 10':50':28

Source Files: 

Microcode Version: 5124

Memory Size: 7168

File Server: IFS

Server Software Version: 

Disposition: Subject': AR#2014'
To': Woody.pasa'
cc': JonL'
'
Hi --'
'
I''m completely unable to reproduce your problem with RAND. It looks like something that happened previously just caused the RANDSTATE values to get smashed.'
'
On the AR fields': one main thing is to leave the AR status as New rather than Open, so that we can make sure its been assigned correctly, OK?'
'
put the stuff you put under Test Case into Description; we''re gonna keep Test Case for the file names of files required to reproduce the AR.'
["Masinter" " 1-Sep-84 14':25':54" Attn': Status':(Open->Incomplete) Disposition': Description': Workaround': Test% Case':]

Description: The random number generator crashed with a bad call to the function \SLOWIDIFFERENCE.  Since this is the only case of it ever happening to me, I''ll use my bad experience as the test case':'
'
The call was to (RAND 0 808)'
'
Error (forming a break window) was':'
'
(29511 ARGUMENT.PROBLEM SCOPE.TYPE) - Non-numeric arg.'
'
A back-trace and the relavent information surrounding it':'
'
RAND'
   *Lower* = 0'
   *Upper* = 808'
\SLOWIDIFFERENCE'
   *X* = 22012'
   *Y* = (29511 ARGUMENT.PROBLEM SCOPE.TYPE)'
\LISPERROR'
   *X* = (29511 ARGUMENT.PROBLEM SCOPE.TYPE)'
   *N* = 10'
   *CONTINUEOKFLG* = NIL'
  ------'
'
(RANDSET NIL) after the crash returns the value'
  (22021 27978 12281 8372 750 40708 46242 37675 13112 59756 50651 48812 57500 17589 23754 35255 53712 6693 8812 15827 35640 51433 62123 55055 19251 56446 61850 52581 39114 64625 WINDOWPROP {WINDOW}#6,50062 (QUOTE PROCESS) NIL)'
'
The value of RANDSTATE is'
  ( (... [the value of (RANDSET)] ...)  WINDOWPROP {WINDOW}#6,50062 (QUOTE PROCESS) NIL)'
'
'
And now, because the random number generator is dead, any subsequent calls to RAND are unsuccessful.

Workaround: 

Test Case: '


Edit-By: Masinter

Edit-Date:  1-Sep-84 14':25':55