ecrn_agent (erlcron v1.3.8)

Per-job gen_server that manages the lifecycle of a single scheduled job.

When a job is added to the scheduler, one ecrn_agent process is started for it. The process calculates the duration until the job's next execution time and uses gen_server timeouts to sleep for exactly that long. To avoid accumulated drift from DST transitions or other system-clock changes, the sleep duration is capped at 30 minutes; the next execution time is then recalculated from scratch at each wake-up.

The module also exposes the schedule normalisation and next-run calculation logic through the public functions normalize/2, and until_next_time/2, which are used by the test suite.

Summary

Types

job()
normalized_period()
normalized_sched()

Functions

cancel(Pid)
code_change(OldVsn, State, Extra)
get_datetime(Pid)
get_datetime/2
handle_call/3
handle_cast/2
handle_info/2
info(Pid)
init/1
next_run(Pid)

Return the time (millisecond epoch) at which the job is next scheduled to run

normalize/2
recalculate(Pid)
run(Pid)

Run the job immediately, without affecting the next scheduled run time

set_datetime(Pid, DateTime, Actual)
set_datetime(Pid, DateTime, Actual, UTC)
start_link/3 deprecated
start_link/4

Start a job agent linked to the calling process

terminate(Reason, State)
until_next_time(NowEpochTime, Sched)

Calculate the duration in milliseconds until Sched next fires, relative to NowEpochTime.

validate/1

Validate a erlcron:schedule/0 spec without scheduling it.

Types

job()

-type job() :: #job{schedule :: term(), task :: term(), lambda :: term()}.

normalized_period()

-type normalized_period() :: [{integer(), integer(), integer()}].

normalized_sched()

-type normalized_sched() ::
          {once, {relative | absolute, integer()}} |
          {daily, normalized_period()} |
          {weekly, [integer()], normalized_period()} |
          {monthly, integer(), normalized_period()}.

Functions

cancel(Pid)

-spec cancel(pid()) -> ok.

code_change(OldVsn, State, Extra)

get_datetime(Pid)

-spec get_datetime(pid()) -> calendar:datetime().

get_datetime/2

-spec get_datetime(pid(), local | universal) -> calendar:datetime().

handle_call/3

handle_cast/2

handle_info/2

info(Pid)

-spec info(pid()) -> #job{schedule :: term(), task :: term(), lambda :: term()}.

init/1

next_run(Pid)

-spec next_run(pid()) -> erlang:timestamp().

Return the time (millisecond epoch) at which the job is next scheduled to run

normalize/2

-spec normalize(erlcron:schedule(), calendar:datetime()) -> normalized_sched().

recalculate(Pid)

-spec recalculate(pid()) -> ok.

run(Pid)

-spec run(pid()) -> ok.

Run the job immediately, without affecting the next scheduled run time

set_datetime(Pid, DateTime, Actual)

-spec set_datetime(pid(), calendar:datetime(), erlcron:milliseconds()) -> ok.

set_datetime(Pid, DateTime, Actual, UTC)

-spec set_datetime(pid(), calendar:datetime(), erlcron:milliseconds(), UTC :: local | universal) ->
                      ok | {error, term()}.

start_link/3

This function is deprecated. Use start_link/4 instead.. 
-spec start_link(erlcron:job_ref(), erlcron:job(), erlcron:job_opts()) ->
                    ignore | {error, Reason :: term()} | {ok, pid()}.

start_link/4

-spec start_link(erlcron:job_ref(),
                 erlcron:job(),
                 undefined | fun(() -> any()) | fun((erlcron:job_ref(), calendar:datetime()) -> any()),
                 erlcron:job_opts()) ->
                    ignore | {error, Reason :: term()} | {ok, pid()}.

Start a job agent linked to the calling process

terminate(Reason, State)

until_next_time(NowEpochTime, Sched)

-spec until_next_time(erlcron:milliseconds(), erlcron:schedule()) -> erlcron:milliseconds().

Calculate the duration in milliseconds until Sched next fires, relative to NowEpochTime.

This is the stateless public entry point used by the test suite.

validate/1

-spec validate(erlcron:schedule() | binary() | string()) -> ok | {error, term()}.

Validate a erlcron:schedule/0 spec without scheduling it.

Returns ok when the spec is syntactically and semantically valid, or {error, Reason} otherwise.