Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1R0zvs-0004cx-PU for bitcoin-development@lists.sourceforge.net; Tue, 06 Sep 2011 17:59:36 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.161.47 as permitted sender) client-ip=209.85.161.47; envelope-from=gavinandresen@gmail.com; helo=mail-fx0-f47.google.com; Received: from mail-fx0-f47.google.com ([209.85.161.47]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1R0zvr-0000SA-Pw for bitcoin-development@lists.sourceforge.net; Tue, 06 Sep 2011 17:59:36 +0000 Received: by fxg11 with SMTP id 11so29127fxg.34 for ; Tue, 06 Sep 2011 10:59:29 -0700 (PDT) MIME-Version: 1.0 Received: by 10.223.47.156 with SMTP id n28mr126798faf.7.1315331969478; Tue, 06 Sep 2011 10:59:29 -0700 (PDT) Received: by 10.152.22.130 with HTTP; Tue, 6 Sep 2011 10:59:29 -0700 (PDT) In-Reply-To: References: <20110904115926.GA16476@ulyssis.org> Date: Tue, 6 Sep 2011 13:59:29 -0400 Message-ID: From: Gavin Andresen To: Bitcoin Dev Content-Type: text/plain; charset=ISO-8859-1 X-Spam-Score: -1.6 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (gavinandresen[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1R0zvr-0000SA-Pw Subject: Re: [Bitcoin-development] 0.4rc1 known bugs X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 06 Sep 2011 17:59:36 -0000 Nice work, Detective Wuille! Patch for the deadlock issue: https://github.com/bitcoin/bitcoin/pull/500 I took a different approach to fix from the one Pieter suggested, performing the database operation after the cs_mapaddresses deadlock is released. Please review to check my logic, it did survive my start/stop/restart... stress test. And I did review every place in the code that starts a database transaction, to look for similar issues, and they are all OK. RE: improving DEBUG_LOCKORDER: requires some thought. Deadlocks are still possible with TRY_CRITICAL_SECTION, if some codepaths TRY and some don't. On Tue, Sep 6, 2011 at 7:55 AM, Pieter Wuille wrote: > My mistake: these are not actual potential deadlocks, as all locking > of cs_vRecv/cs_vSend > happens inside TRY_CRITICAL_SECTION blocks. Gavin, maybe you can add the rule to > your debug code that ignores critical sections which are only locked > through TRY_...? > >>> + sipa found what looks like a deadlock between the addr-handling and >>> IRC-join-handling code. > > Regarding the actual deadlock between IRC seeding and AddAddress: > > Internally, DB also uses pthreads to implement the txn_begin()/commit() scheme, > though I'm not sure with which granularity. These need to be taken into account > when searching for deadlocks, but are obviously not detected by > DEBUG_LOCKORDER. -- -- Gavin Andresen