Since the CS/SI refactoring, the .release callback function may be called
twice. The first call when a shutdown for read or for write is performed.
The second one when the applet is detached from its conn-stream. The second
call must be guarded, just like the first one, to only be performed is the
stream-interface is not the in disconnected (SI_ST_DIS) or closed
(SI_ST_CLO) state.
To simplify the fix, we now always rely on si_applet_release() function.
It is 2.6-specific, no backport is needed.
In the same way a stream has always valid conn-streams, when a health-checks
is created, a conn-stream is now created and the health-check is attached on
it, as an app. This simplify a bit the connect part when a health-check is
running.
cs_detach_app() function is added to detach an app from a conn-stream. And
now, both cs_detach_app() and cs_detach_endp() release the conn-stream when
both the app and the endpoint are detached.
Thanks to all previous changes, it is now possible to move the
stream-interface into the conn-stream. To do so, some SI functions are
removed and their conn-stream counterparts are added. In addition, the
conn-stream is now responsible to create and release the
stream-interface. While the stream-interfaces were inlined in the stream
structure, there is now a pointer in the conn-stream. stream-interfaces are
now dynamically allocated. Thus a dedicated pool is added. It is a temporary
change because, at the end, the stream-interface structure will most
probably disappear.
In the same way the conn-stream has a pointer to the stream endpoint , this
patch adds a pointer to the application entity in the conn-stream
structure. For now, it is a stream or a health-check. It is mandatory to
merge the stream-interface with the conn-stream.
