Keeps track of presences in a single shard
Returns a specification to start this module under a supervisor.
Invoked when the server is started. start_link/3
or start/3
will block until it returns.
Returns a specification to start this module under a supervisor.
See Supervisor
.
Invoked when the server is started. start_link/3
or start/3
will block until it returns.
init_arg
is the argument term (second argument) passed to start_link/3
.
Returning {:ok, state}
will cause start_link/3
to return {:ok, pid}
and the process to enter its loop.
Returning {:ok, state, timeout}
is similar to {:ok, state}
, except that it also sets a timeout. See the "Timeouts" section in the module documentation for more information.
Returning {:ok, state, :hibernate}
is similar to {:ok, state}
except the process is hibernated before entering the loop. See c:handle_call/3
for more information on hibernation.
Returning {:ok, state, {:continue, continue}}
is similar to {:ok, state}
except that immediately after entering the loop the c:handle_continue/2
callback will be invoked with the value continue
as first argument.
Returning :ignore
will cause start_link/3
to return :ignore
and the process will exit normally without entering the loop or calling c:terminate/2
. If used when part of a supervision tree the parent supervisor will not fail to start nor immediately try to restart the GenServer
. The remainder of the supervision tree will be started and so the GenServer
should not be required by other processes. It can be started later with Supervisor.restart_child/2
as the child specification is saved in the parent supervisor. The main use cases for this are:
GenServer
is disabled by configuration but might be enabled later. Supervisor
. Likely this approach involves calling Supervisor.restart_child/2
after a delay to attempt a restart. Returning {:stop, reason}
will cause start_link/3
to return {:error, reason}
and the process to exit with reason reason
without entering the loop or calling c:terminate/2
.
Callback implementation for GenServer.init/1
.
© 2014 Chris McCord
Licensed under the MIT License.
https://hexdocs.pm/phoenix_pubsub/Phoenix.Tracker.Shard.html