This allows us to disable Unix sockets cleanly on Windows. Replaces some
read/write calls with recv/send counterparts, as Winsock does not like
read/writes.
While it really would be desirable to allow stream destruction during on_read()
callbacks, this does not work anymore since e49b2998. Until we have a proper
solution for this issue, use asynchronous disconnects for the only user doing
so.
Fixes#518.
When changing async callbacks on streams, we have to make sure the watcher
callback is not currently active and has temporarily disabled callbacks. This
could have been the case, as we didn't explicitly removed any pending
watcher registration if both callbacks are NULL.
By enforcing the watcher unregistration, we are sure the watcher callback is
not active and currently is not mangling the callback hooks. This should make
sure we avoid any races for the callback variables.
Due to the previous negation the high bits of the mask were set, which
at least some versions of the Android build system prevent with a compile-time
check.
It does not make much sense to reference running services in the manager,
especially as unregistration would need the URI (which a user would have to
store instead of the service reference).
While this will complicate the implementation of streams not based on a fd,
it allows us to unleash the full power of FILE based convenience functions.
Martin Willi