From c733d18fe10ed24858046fe184facfe8efe9b81a Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Fri, 28 Oct 2011 17:12:05 +0200 Subject: [PATCH] session doc: Document state transitions --- doc/session-overview.txt | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/doc/session-overview.txt b/doc/session-overview.txt index a297800..05e4a8d 100644 --- a/doc/session-overview.txt +++ b/doc/session-overview.txt @@ -69,3 +69,50 @@ Disconnect algorithm: |No | | | Service.Disconnect() Do nothing + + +Session States and Transitions +============================== + +There are three main strategies for state changes. + + - Free Ride + - Connect + - Disconnect + +The initial state for all new sessions is Free Ride. + +The Free Ride state means that a session will go online if a matching +service goes online without calling Service.Connect() itself. The idea +behind this is that a session doesn't request a connection for itself +instead waits until another session actively requires to go online. +This is comparable to piggy-backing. + +When a session is in the Connect state ConnMan tries to find a +matching service (see Connect algorithm) and then decides either to +connect the service or delay the request. ConnMan is allowed to +connect to the service or to delay it, e.g. group PeriodicConnects +together. The session will leave the Connect state when the service +goes offline unless StayConnected is True. It will enter the Free Ride +mode again. + +When the application calls Disconnect() the session enters the +Disconnect state and stays there until the application calls Connect() +again. + + + State Change to offline & StayConnected = True + +------+ + | v ++-----------+ +---------+ -- Disconnect() --> +------------+ +| Free Ride |-- Connect() -->| Connect | | Disconnect | ++-----------+ +---------+ <-- Connect() --- +------------+ + | ^ | ^ + | +------------------------ + | + | State Change to offline & StayConnected = False | + | | + | | + +----------------------- Disconnect() -----------------------+ + +Note: this documents the current behavior it is likely to change in near +future. -- 2.7.4