[Sbcl-devel] Repeated read on empty stream fails on Windows

[Elliott S. <ell...@gm...>]

This is somewhat related to my previous inquiry about
read-char-no-hang. In the project I am working on, after reading the
available input from the keyboard, I push it into a string stream and
try to parse it with read. For some reason my code just randomly
failed if I let it run too long. I managed to distil the offending
code into the case below. The expression evaluated in the loop works
fine if executed once or a couple of times, but somehow fails when
called several thousand times in a row.

* (loop repeat 100000 do (with-input-from-string (is "") (read is nil)))
fatal error encountered in SBCL pid 2776:
GC invariant lost, file "gencgc.c", line 3920

LDB monitor
ldb>

This is on Windows with SBCL 1.0.9. The problem did not occur on Linux
(SBCL 1.0.6).

-- 
Elliott Slaughter

"Any road followed precisely to its end leads precisely nowhere." -
Frank Herbert