On Wed, 24 Apr 2002 10:18:01 -0400 (EDT), John Baldwin <[EMAIL PROTECTED]> said:
jhb> On 24-Apr-2002 Seigo Tanimura wrote: >> I am now working on locking down a socket. (I have heard that Jeffrey >> Hsu is also doing that, but I have never seen his patch. Has anyone >> seen that?) My first milestone patch is now available at: >> >> >> http://people.FreeBSD.org/~tanimura/patches/socket_milestone1.diff.gz >> >> >> The works I have done so far are: >> >> >> - Determine the lock required to protect each of the members in struct >> socket. >> >> - Add mutexes to each of the sockbufs in a socket as BSD/OS does. >> >> - Lock down so_count, so_options, so_linger and so_state. >> >> - Add a global mutex socq_lock to protect the connection queues of a >> listening socket. Lock socq_lock to lock two sockets at once, >> followed by enqueuing or dequeuing a socket, or moving a socket across >> queues. socq_lock is not an sx lock because we usually have to lock >> two sockets to modify them. jhb> Do you actually lock two sockets at once or do you lock one at a time while jhb> holding socq_lock. If you do lock two at once, what is the defined locking jhb> order? At the moment, I lock two sockets at once. This is required, eg in soisconnected() to move an accepting socket across the connection queues of a listening socket. The lock order is: 1. socq_lock 2. an accepting socket 3. a listening socket (in so_head of the accepting socket) -- Seigo Tanimura <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
