[[!meta copyright="Copyright © 2010, 2013 Free Software Foundation, Inc."]] [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable id="license" text="Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU Free Documentation License|/fdl]]."]]"""]] [[!meta title="ext2fs.static: thread-cancel.c:55: hurd_thread_cancel: Assertion '! __spin_lock_locked (&ss->critical_section_lock)'"]] [[!tag open_issue_hurd]] [[!debbug 46859]], [[!debbug 195360]] IRC, unknown channel, unknown date: azeem, marcus: ext2fs.static: thread-cancel.c:55: hurd_thread_cancel: Assertion '! __spin_lock_locked (&ss->critical_section_lock)' failed I actually don't understand this assertion it's just before __spin_lock (&ss->critical_section_lock); why should one check that a lock is free before taking it ? just the same in hurdexec.c (no, ss is not our own sigstate, so it's not safe to assume no other path can take it) there's another one in sysdeps/mach/hurd/spawni.c and jmp-unwind.c youpi: why do you think it's nonsense?... the fact that we take the lock (so we can't be interrupted) doesn't mean we are willing to wait for others to release the lock... maybe the code path should never be reached while others have a lock, or something then it's useless to take the lock "we take the lock (so we can't be interrupted)": no, it's not _our_ lock here, it's the lock of the thread we want to cancel what exactly is cancelling a thread?... (sorry, I don't really have experience with thread programming) ~= killing it well, we take the lock so nobody can mess with the thread while we are cancelling it, no?... yes that is fine but checking that the lock is free before taking it doesn't make sense why nobody should be able to take the lock ? and if nobody is, why do we take it ? (since nobody would be able to take it) well, maybe after taking the lock, we do some action that might result in others trying to take it... nope: look at the code :) or maybe the cancel_hook, but I really doubt it See discussion about *`critical_section_lock`* on [[glibc]].