gen_timer

v0.0.2

gen_timer v0.0.2 GenTimer

A GenServer for asynchronously running a function after some duration.

Usage

Register a function and a duration. The function will be called after the duration. If using start_repeated/4 or start_link_repeated/4 it will continue for the specified amount of times.

Link to this section Summary

Functions

child_spec(arg)

Returns a specification to start this module under a supervisor

init(state)

Invoked when the server is started. start_link/3 or start/3 will block until it returns

last_returned_value(pid)

Synchronously calls the GenServer at pid to receive the last value returned by the registered function. All previous returned values will not be kept

start(function, args, duration)

Starts a GenServer process without links (outside of a supervision tree). The function is registered. After the duration the function will be called using specified args

start_link(function, args, duration)

Starts a GenServer process linked to the current process. The function is registered. After the duration the function will be called using specified args

start_link_repeated(function, args, duration, times \\ :infinite)

The same as start_link/3 but allows to specify an amount of times to repeat, defaulting to :infinite

start_repeated(function, args, duration, times \\ :infinite)

The same as start/3 but allows to specify an amount of times to repeat, defaulting to :infinite

Link to this section Functions

Link to this function child_spec(arg)

Returns a specification to start this module under a supervisor.

See Supervisor.

Link to this function init(state)

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

args 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 handle_info(:timeout, state) will be called after timeout milliseconds if no messages are received within the timeout.

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 :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 (re)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:

  • The GenServer is disabled by configuration but might be enabled later.
  • An error occurred and it will be handled by a different mechanism than the 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.

Link to this function last_returned_value(pid) 
last_returned_value(pid()) :: any()

Synchronously calls the GenServer at pid to receive the last value returned by the registered function. All previous returned values will not be kept.

Link to this function start(function, args, duration) 
start((... -> any()), list(), non_neg_integer()) :: GenServer.on_start()

Starts a GenServer process without links (outside of a supervision tree). The function is registered. After the duration the function will be called using specified args.

Link to this function start_link(function, args, duration) 
start_link((... -> any()), list(), non_neg_integer()) :: GenServer.on_start()

Starts a GenServer process linked to the current process. The function is registered. After the duration the function will be called using specified args.

Link to this function start_repeated(function, args, duration, times \\ :infinite) 
start_repeated(
  (... -> any()),
  list(),
  non_neg_integer(),
  non_neg_integer() | :infinite
) :: GenServer.on_start()

The same as start/3 but allows to specify an amount of times to repeat, defaulting to :infinite.