path: root/sys/sys/sockbuf.h
diff options
authorJohn Baldwin <jhb@FreeBSD.org>2009-06-01 21:17:03 +0000
committerJohn Baldwin <jhb@FreeBSD.org>2009-06-01 21:17:03 +0000
commit74fb0ba732c0470e4cae21d0a7af01715bd77bc3 (patch)
tree13628b6be10af95db7dc7d8ef88b3291d48583ab /sys/sys/sockbuf.h
parentb2bc85365907ed05547af9b400576928866915b9 (diff)
Rework socket upcalls to close some races with setup/teardown of upcalls.
- Each socket upcall is now invoked with the appropriate socket buffer locked. It is not permissible to call soisconnected() with this lock held; however, so socket upcalls now return an integer value. The two possible values are SU_OK and SU_ISCONNECTED. If an upcall returns SU_ISCONNECTED, then the soisconnected() will be invoked on the socket after the socket buffer lock is dropped. - A new API is provided for setting and clearing socket upcalls. The API consists of soupcall_set() and soupcall_clear(). - To simplify locking, each socket buffer now has a separate upcall. - When a socket upcall returns SU_ISCONNECTED, the upcall is cleared from the receive socket buffer automatically. Note that a SO_SND upcall should never return SU_ISCONNECTED. - All this means that accept filters should now return SU_ISCONNECTED instead of calling soisconnected() directly. They also no longer need to explicitly clear the upcall on the new socket. - The HTTP accept filter still uses soupcall_set() to manage its internal state machine, but other accept filters no longer have any explicit knowlege of socket upcall internals aside from their return value. - The various RPC client upcalls currently drop the socket buffer lock while invoking soreceive() as a temporary band-aid. The plan for the future is to add a new flag to allow soreceive() to be called with the socket buffer locked. - The AIO callback for socket I/O is now also invoked with the socket buffer locked. Previously sowakeup() would drop the socket buffer lock only to call aio_swake() which immediately re-acquired the socket buffer lock for the duration of the function call. Discussed with: rwatson, rmacklem
Notes: svn path=/head/; revision=193272
Diffstat (limited to 'sys/sys/sockbuf.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/sys/sys/sockbuf.h b/sys/sys/sockbuf.h
index b081114a4327..b8e669990289 100644
--- a/sys/sys/sockbuf.h
+++ b/sys/sys/sockbuf.h
@@ -99,6 +99,8 @@ struct sockbuf {
int sb_lowat; /* (c/d) low water mark */
int sb_timeo; /* (c/d) timeout for read/write */
short sb_flags; /* (c/d) flags, see below */
+ int (*sb_upcall)(struct socket *, void *, int); /* (c/d) */
+ void *sb_upcallarg; /* (c/d) */
#ifdef _KERNEL