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From: "palves at redhat dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug nptl/17705] nptl_db: stale thread create/death events if debugger detaches
Date: Fri, 12 Dec 2014 17:44:00 -0000	[thread overview]
Message-ID: <bug-17705-131-We9GhKT6cK@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-17705-131@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=17705

--- Comment #1 from Pedro Alves <palves at redhat dot com> ---
Created attachment 8010
  --> https://sourceware.org/bugzilla/attachment.cgi?id=8010&action=edit
WIP fix

WIP fix.  The main idea is that whenever a __nptl_*_event event function is
called, the debugger is expected to consume the event (see
nptl_db/td_ta_event_getmsg.c).  If the event wasn't consumed, then it must be
the debugger is either gone, or misbehaved.  The death event is to reason about
-- clearly we shouldn't hang on the event forever, as the thread is about to be
wiped out.  So right after calling the event function, we remove the thread
from the event queue.  The complication is that a new debugger may manage to
reattach just while we're doing that, and the code must be written in a way
that works without any locking/synchronization between the debugger and the
inferior.

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  reply	other threads:[~2014-12-12 17:44 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-12 17:28 [Bug nptl/17705] New: " palves at redhat dot com
2014-12-12 17:44 ` palves at redhat dot com [this message]
2014-12-12 17:50 ` [Bug nptl/17705] " palves at redhat dot com

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