From 5c157fcd7bc87de8d4c62f39c3953c6a7f30300e Mon Sep 17 00:00:00 2001
From: Tim Vernum <tim@adjective.org>
Date: Fri, 23 Jun 2017 11:45:09 +1000
Subject: [PATCH] [TESTS] Fix potential for negative sleep
 (elastic/x-pack-elasticsearch#1818)

Original commit: elastic/x-pack-elasticsearch@cb19908a61d4e9bff863a63891a1cbb13034b4e7
---
 .../CachingUsernamePasswordRealmTests.java    | 28 +++++++++++--------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/plugin/src/test/java/org/elasticsearch/xpack/security/authc/support/CachingUsernamePasswordRealmTests.java b/plugin/src/test/java/org/elasticsearch/xpack/security/authc/support/CachingUsernamePasswordRealmTests.java
index 9be5577c99b..18c1080e143 100644
--- a/plugin/src/test/java/org/elasticsearch/xpack/security/authc/support/CachingUsernamePasswordRealmTests.java
+++ b/plugin/src/test/java/org/elasticsearch/xpack/security/authc/support/CachingUsernamePasswordRealmTests.java
@@ -5,26 +5,23 @@
  */
 package org.elasticsearch.xpack.security.authc.support;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.PlainActionFuture;
 import org.elasticsearch.common.settings.SecureString;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.concurrent.ThreadContext;
+import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.security.authc.Realm;
 import org.elasticsearch.xpack.security.authc.RealmConfig;
 import org.elasticsearch.xpack.security.user.User;
-import org.elasticsearch.test.ESTestCase;
 import org.junit.Before;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicInteger;
-
 import static java.util.Collections.emptyMap;
 import static org.hamcrest.Matchers.arrayContaining;
 import static org.hamcrest.Matchers.containsString;
@@ -263,19 +260,19 @@ public class CachingUsernamePasswordRealmTests extends ESTestCase {
         assertThat(realm.authInvocationCounter.intValue(), is(1));
 
         // After 100 ms (from the original start time), authenticate (read from cache). We don't care about the result
-        Thread.sleep(start + 100 - System.currentTimeMillis());
+        sleepUntil(start + 100);
         future = new PlainActionFuture<>();
         realm.authenticate(authToken, future);
         future.actionGet();
 
         // After 200 ms (from the original start time), authenticate (read from cache). We don't care about the result
-        Thread.sleep(start + 200 - System.currentTimeMillis());
+        sleepUntil(start + 200);
         future = new PlainActionFuture<>();
         realm.authenticate(authToken, future);
         future.actionGet();
 
         // After 300 ms (from the original start time), authenticate again. The cache entry should have expired (despite the previous reads)
-        Thread.sleep(start + 300 - System.currentTimeMillis());
+        sleepUntil(start + 300);
         future = new PlainActionFuture<>();
         realm.authenticate(authToken, future);
         final User user2 = future.actionGet();
@@ -285,6 +282,13 @@ public class CachingUsernamePasswordRealmTests extends ESTestCase {
         assertThat(realm.authInvocationCounter.intValue(), greaterThan(1));
     }
 
+    private void sleepUntil(long until) throws InterruptedException {
+        final long sleep = until - System.currentTimeMillis();
+        if (sleep > 0) {
+            Thread.sleep(sleep);
+        }
+    }
+
     public void testAuthenticateContract() throws Exception {
         Realm realm = new FailingAuthenticationRealm(Settings.EMPTY, globalSettings);
         PlainActionFuture<User> future = new PlainActionFuture<>();