001// Copyright 2011 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry5.ioc.services.cron; 016 017/** 018 * Used with {@link PeriodicExecutor} to control the schedule for when jobs execute. 019 */ 020public interface Schedule 021{ 022 /** 023 * For a newly created job, what is the start time for the job. Often, the current clock time is returned, to start 024 * a job as soon as possible. 025 * 026 * @return start time for new job, in system clock millis 027 */ 028 long firstExecution(); 029 030 /** 031 * Computes the next execution time for a job. 032 * 033 * @param previousExecution time of previous execution (in system clock millis) 034 * @return time of next execution (in system clock millis) 035 */ 036 long nextExecution(long previousExecution); 037}