-- This file is part of a Liberty Eiffel library.
-- See the full copyright at the end.
--
deferred class PERIODIC_JOB
   -- Pseudo periodic job. The timing is not exact : the time between
   -- two executions may be longer than the given period depending on
   -- time needed to execute the ready tasks. There is no try to recover the
   -- time lost each time.

inherit
   JOB

feature {ANY}
   period: REAL -- unit is seconds

   next_time: MICROSECOND_TIME

feature {LOOP_ITEM}
   prepare (events: EVENTS_SET)
      local
         t: TIME_EVENTS
      do
         events.expect(t.at_date(next_time))
      end

   is_ready (events: EVENTS_SET): BOOLEAN
      do
         Result := next_time <= events.current_time
         if Result then
            next_time := events.current_time + period
         end
      end

invariant
   period > 0

end -- class PERIODIC_JOB
--
-- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
--
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-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:
--
-- The above copyright notice and this permission notice shall be included in
-- all copies or substantial portions of the Software.
--
-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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-- THE SOFTWARE.