Quoting Dwight Engen (dwight.en...@oracle.com): > On Mon, 6 May 2013 13:06:43 -0400 > Dwight Engen <dwight.en...@oracle.com> wrote: > > > Hi Çağlar, > > > > Thanks for the test program, I can sort of recreate it here with that, > > although once I lxc-stop them all, lxc-monitord does go away. I put a > > debug in lxc_wait() to see that the client always close the fd to the > > monitord and they all were closed so I'm not sure why lxc-monitord > > isn't seeing the accepted fd coming back from epoll to close. Still > > investigating... > > Okay, so I debugged this and the problem is basically down to lxc not > being thread aware. With your test program we get multiple threads in > lxcapi_start() simultaneously in the daemonize case. One of them forks > while another one has the client fd to the monitor open and thus the fd > gets duped by the fork and that is the client fd that holds lxc-monitord > open until the container shuts down. > > Çağlar you could try out the following patch, it essentially serializes > container startup from a thread perspective. I haven't tested it > thoroughly, but it did fix the problem here. Right now lxc doesn't > support threaded use, so you may run into other things as well. > Depending on our stance on thread support in lxc, you may need to do > the serialization in the threaded app. I guess another > alternative is that initially we could just thread serialize at the API > (big lxc lock).
It sounds like lxcapi_start should be locking c->slock? The priv_lock is to protect the struct lxccontainer in memory (for when you do c = lxc_container_new(); then clone a new thread), while the slock is to protect the container data. It's being taken at create, info, destroy, etc, but not at start. ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. This 200-page book is written by three acclaimed leaders in the field. The early access version is available now. Download your free book today! http://p.sf.net/sfu/neotech_d2d_may _______________________________________________ Lxc-devel mailing list Lxc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lxc-devel
