001/*-
002 * #%L
003 * HAPI FHIR - Core Library
004 * %%
005 * Copyright (C) 2014 - 2024 Smile CDR, Inc.
006 * %%
007 * Licensed under the Apache License, Version 2.0 (the "License");
008 * you may not use this file except in compliance with the License.
009 * You may obtain a copy of the License at
010 *
011 *      http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 * #L%
019 */
020package ca.uhn.fhir.util;
021
022/**
023 * A utility class for thread sleeps.
024 * Uses non-static methods for easier mocking and unnecessary waits in unit tests
025 */
026public class SleepUtil {
027        private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(SleepUtil.class);
028
029        public void sleepAtLeast(long theMillis) {
030                sleepAtLeast(theMillis, true);
031        }
032
033        @SuppressWarnings("BusyWait")
034        public void sleepAtLeast(long theMillis, boolean theLogProgress) {
035                long start = System.currentTimeMillis();
036                while (System.currentTimeMillis() < start + theMillis) {
037                        try {
038                                long timeSinceStarted = System.currentTimeMillis() - start;
039                                long timeToSleep = Math.max(0, theMillis - timeSinceStarted);
040                                if (theLogProgress) {
041                                        ourLog.info("Sleeping for {}ms", timeToSleep);
042                                }
043                                Thread.sleep(timeToSleep);
044                        } catch (InterruptedException e) {
045                                Thread.currentThread().interrupt();
046                                ourLog.error("Interrupted", e);
047                        }
048                }
049        }
050}