Hi,
I had sent the following to the user forum and did not receive any
comments. I am reposting it in the bug forum with the hope that one of the
experts may be able to comment...
Thanks,
Anand
---------- Forwarded message ----------
From: Anand Mohanadoss <anand...@gmail.com>
Date: Wed, Feb 25, 2015 at 9:35 PM
Subject: Memory leak from seek/ftell with files larger than 2GB
To: guile-u...@gnu.org
Hi,
We are seeing an issue with seek and ftell leaking memory with files larger
than 2GB.
We are using 2.0.11 guile built as a 32-bit application with large file
support enabled (guile was built using gcc 4.4.0 for Linux with flags
_FILE_OFFSET_BITS=64, _LARGEFILE_SOURCE and _LARGEFILE64_SOURCE). The
issue also appears to happen with guile 2.2.
The memory leaks start only after the offset exceeds maximum positive value
for a 32-bit signed integer. ftell and seek do work as expected (given how
lseek should work with large file support).
Appended is a program that illustrates the problem. The first seek simply
skips the part of the file where you won't see a memory leak. If you
comment out ftell and the second seek lines and un-comment the lines that
follow them, there is no memory leak.
Is this a bug in guile or should we be doing things differently? If this
is a known issue, is there a recommended work around?
Thanks,
Anand
(define MAX_SIGNED_INT 2147483647)
(define BYTES_TO_READ 10)
(define file "/tmp/test.pcap") ;sample file greater than 2.5GB
(define (traverse file)
(let* ((port (open-input-file file #:binary #t))
(file-sz (stat:size (stat port)))
(ua (make-bytevector BYTES_TO_READ 0))
(cur-offset 0))
(seek port (- MAX_UNSIGNED_INT 1000) SEEK_CUR)
(while (< (ftell port) (- file-sz BYTES_TO_READ))
;(while (< cur-offset (- file-sz BYTES_TO_READ))
(seek port BYTES_TO_READ SEEK_CUR)
;(get-bytevector-n! port ua 0 BYTES_TO_READ)
(set! cur-offset (+ BYTES_TO_READ cur-offset)))
(close-port port)))
(traverse file)
