Your message dated Sat, 06 Jun 2026 06:04:15 +0000
with message-id <[email protected]>
and subject line Bug#862594: fixed in libasyncns 0.8-8
has caused the Debian Bug report #862594,
regarding libasyncns0: libasyncns using pthreads blocks until workers die on
free()
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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--
862594: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=862594
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: libasyncns0
Severity: normal
Tags: patch upstream
Hello,
Forwarding here this bug, since there's no any action from upstream:
https://bugs.freedesktop.org/show_bug.cgi?id=94849
When using libasyncns with pthreads support, it freezes entire
application, when you try to asyncns_free() instance, that have one of
its workers blocked by getaddrinfo() (worker may be blocked eg. because
of some problem with resolver servers).
An easy way to reproduce this bug is to set your nameserver in
resolv.conf to something non-existent (like 1.2.3.4), then create
asyncns resolver, make a request, and then immediately asyncns_free()
resolver. It will block the application, until worker gets network
timeout.
The problem, as I see it, lies in this code (in asyncns_free()):
/* Now terminate them and wait until they are gone. */
for (p = 0; p < asyncns->valid_workers; p++) {
#ifndef HAVE_PTHREAD
kill(asyncns->workers[p], SIGTERM);
for (;;) {
if (waitpid(asyncns->workers[p], NULL, 0) >= 0 || errno != EINTR)
break;
}
#else
for (;;) {
if (pthread_join(asyncns->workers[p], NULL) != EINTR)
break;
}
#endif
}
So, when pthreads are not in use, it kill()'s worker, then wait()'s for
it. When they are used - it just pthread_join()'s them, which, AFAICS,
is equal to just wait(). I'm no expert on threading, but I've found,
that pthread_cancel() just before waiting cycle solves this problem.
Please, consider including this fix (or any other, that resolves the
problem) into the upstream.
Patch, that fixes the problem for me (not sure, how to attach the file
in reportbug, thus inserting plaintext):
--- a/libasyncns/asyncns.c 2016-03-19 19:13:00.774406379 +0200
+++ b/libasyncns/asyncns.c 2016-03-19 19:13:02.378415461 +0200
@@ -865,6 +865,7 @@
break;
}
#else
+ pthread_cancel(asyncns->workers[p]);
for (;;) {
if (pthread_join(asyncns->workers[p], NULL) != EINTR)
break;
-- System Information:
Debian Release: 9.0
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64
(x86_64)
Foreign Architectures: i386
Kernel: Linux 4.9.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=uk_UA.UTF-8, LC_CTYPE=uk_UA.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
--- End Message ---
--- Begin Message ---
Source: libasyncns
Source-Version: 0.8-8
Done: Jayen Ashar <[email protected]>
We believe that the bug you reported is fixed in the latest version of
libasyncns, which is due to be installed in the Debian FTP archive.
A summary of the changes between this version and the previous one is
attached.
Thank you for reporting the bug, which will now be closed. If you
have further comments please address them to [email protected],
and the maintainer will reopen the bug report if appropriate.
Debian distribution maintenance software
pp.
Jayen Ashar <[email protected]> (supplier of updated libasyncns package)
(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing [email protected])
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
Format: 1.8
Date: Sat, 06 Jun 2026 09:33:47 +1000
Source: libasyncns
Architecture: source
Version: 0.8-8
Distribution: unstable
Urgency: medium
Maintainer: Jayen Ashar <[email protected]>
Changed-By: Jayen Ashar <[email protected]>
Closes: 862594 862596 1123614
Changes:
libasyncns (0.8-8) unstable; urgency=medium
.
[ Jayen Ashar ]
* New maintainer (Closes: #1123614).
* Apply equality_in_assert.patch — fixes assignment-instead-of-comparison
in two asserts (Closes: #862596).
* Apply pthreads.patch — pthread_cancel before pthread_join so a blocked
worker no longer freezes asyncns_free() (Closes: #862594).
* Add Forwarded: header to both new patches (point at the upstream
freedesktop bugs cited in Origin).
* d/watch: switch URL to https.
* d/upstream/metadata: add DEP-12 stub.
* Standards-Version: 4.7.4. (Removed Priority field)
* d/watch: match upstream's absolute http:// tarball links and
downloadurlmangle the fetch to https. The https-only pattern matched
nothing on the index page, which failed the Salsa CI test-uscan job.
.
[ Andreas Tille ]
* d/watch: version=5
* lintian-overrides for false positive debian-watch-uses-insecure-uri
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