lib/sequencer

BACKGROUND_JOB
 Describe job to be executed in the background, when there nothing
 more important to do. Such job is ready to run at any time.

INPUT_WATCHED_FILE
 File which may be used by some `JOB' as waiting condition.
 May be useful to wait data from socket without locking the process
 and/or with timeout capability.

JOB
The job life will looks like :
   do
      prepare
      if is_ready then
         continue
   repeat while not done

If the same job as to live again, restart is called.

 Note: never change priority after job inserted in loop_item.
       Priority should only be set at creation time.

LOOP_ITEM
 One loop level with related jobs to run

LOOP_STACK
 Manage `LOOP_ITEM'. When new loop is pushed, all jobs in current
 running loop suspend until the new loop end (all jobs end or break).

OUTPUT_WATCHED_FILE
 File which may be used by some `JOB' as waiting condition.
 May be useful to wait socket ready to send more data without locking
 the process and/or with timeout capability.

PERIODIC_JOB
 Pseudo periodic job. The timing is not exact : the time between
 two execution may be longer than the given period depending on
 time needed to execute ready tasks. There is no try to recover the
 time lost each time.

READY_DESCRIPTION
 Mainly used by loop_item and jobs.
 May be useful for time/date waiting.
 May be useful to check if data are available in files without locking.
 Have a look at `queryable' for the two states.

SIMPLE_BACKGROUND_JOB
 Describe job to be executed in the background, when there nothing
 more important to do. Such job is ready to run at any time.

SIMPLE_PERIODIC_JOB
 Pseudo periodic job. The timing is not exact : the time between
 two execution may be longer than the given period depending on
 time needed to execute ready tasks. There is no try to recover the
 time lost each time.