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authorAlex Elder <elder@inktank.com>2012-06-20 21:53:53 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-26 11:38:28 -0800
commitdb90f992eb77188ce3e2b95d36f99ba194e04e66 (patch)
tree9f3e121e70ae6fb8260db9c64b29b0f077b60465
parenta8651271bb5d77402251bf35554d1f320463c949 (diff)
libceph: add some fine ASCII art
(cherry picked from commit bc18f4b1c850ab355e38373fbb60fd28568d84b5) Sage liked the state diagram I put in my commit description so I'm putting it in with the code. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/ceph/messenger.c42
1 files changed, 41 insertions, 1 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 73e2ee847be..c40d1d5b304 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -29,7 +29,47 @@
* the sender.
*/
-/* State values for ceph_connection->sock_state; NEW is assumed to be 0 */
+/*
+ * We track the state of the socket on a given connection using
+ * values defined below. The transition to a new socket state is
+ * handled by a function which verifies we aren't coming from an
+ * unexpected state.
+ *
+ * --------
+ * | NEW* | transient initial state
+ * --------
+ * | con_sock_state_init()
+ * v
+ * ----------
+ * | CLOSED | initialized, but no socket (and no
+ * ---------- TCP connection)
+ * ^ \
+ * | \ con_sock_state_connecting()
+ * | ----------------------
+ * | \
+ * + con_sock_state_closed() \
+ * |\ \
+ * | \ \
+ * | ----------- \
+ * | | CLOSING | socket event; \
+ * | ----------- await close \
+ * | ^ |
+ * | | |
+ * | + con_sock_state_closing() |
+ * | / \ |
+ * | / --------------- |
+ * | / \ v
+ * | / --------------
+ * | / -----------------| CONNECTING | socket created, TCP
+ * | | / -------------- connect initiated
+ * | | | con_sock_state_connected()
+ * | | v
+ * -------------
+ * | CONNECTED | TCP connection established
+ * -------------
+ *
+ * State values for ceph_connection->sock_state; NEW is assumed to be 0.
+ */
#define CON_SOCK_STATE_NEW 0 /* -> CLOSED */
#define CON_SOCK_STATE_CLOSED 1 /* -> CONNECTING */