Allow custom restart pollInterval and quietPeriod

Allow the pollInterval and the quietPeriod of the filewatcher to be
configured.

Fixes gh-3139

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/autoconfigure/DevToolsProperties.java

@@ -29,6 +29,10 @@ public class DevToolsProperties {
 
 	private static final String DEFAULT_RESTART_EXCLUDES = "META-INF/resources/**,resource/**,static/**,public/**,templates/**";
 
+	private static final long DEFAULT_RESTART_POLL_INTERVAL = 1000;
+
+	private static final long DEFAULT_RESTART_QUIET_PERIOD = 400;
+
 	private Restart restart = new Restart();
 
 	private Livereload livereload = new Livereload();
@@ -62,6 +66,17 @@ public class DevToolsProperties {
 		 */
 		private String exclude = DEFAULT_RESTART_EXCLUDES;
 
+		/**
+		 * Amount of time (in milliseconds) to wait between polling for classpath changes.
+		 */
+		private long pollInterval = DEFAULT_RESTART_POLL_INTERVAL;
+
+		/**
+		 * Amount of quiet time (in milliseconds) requited without any classpath changes
+		 * before a restart is triggered.
+		 */
+		private long quietPeriod = DEFAULT_RESTART_QUIET_PERIOD;
+
 		/**
 		 * The name of specific that that when changed will will trigger the restart. If
 		 * not specified any classpath file change will trigger the restart.
@@ -84,6 +99,22 @@ public class DevToolsProperties {
 			this.exclude = exclude;
 		}
 
+		public long getPollInterval() {
+			return this.pollInterval;
+		}
+
+		public void setPollInterval(long pollInterval) {
+			this.pollInterval = pollInterval;
+		}
+
+		public long getQuietPeriod() {
+			return this.quietPeriod;
+		}
+
+		public void setQuietPeriod(long quietPeriod) {
+			this.quietPeriod = quietPeriod;
+		}
+
 		public String getTriggerFile() {
 			return this.triggerFile;
 		}

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/autoconfigure/LocalDevToolsAutoConfiguration.java

@@ -23,6 +23,7 @@ import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.devtools.autoconfigure.DevToolsProperties.Restart;
 import org.springframework.boot.devtools.classpath.ClassPathChangedEvent;
 import org.springframework.boot.devtools.classpath.ClassPathFileSystemWatcher;
 import org.springframework.boot.devtools.classpath.ClassPathRestartStrategy;
@@ -130,8 +131,11 @@ public class LocalDevToolsAutoConfiguration {
 
 		@Bean
 		public FileSystemWatcher getFileSystemWatcher() {
-			FileSystemWatcher watcher = new FileSystemWatcher();
-			String triggerFile = this.properties.getRestart().getTriggerFile();
+			Restart restartProperties = this.properties.getRestart();
+			FileSystemWatcher watcher = new FileSystemWatcher(true,
+					restartProperties.getPollInterval(),
+					restartProperties.getQuietPeriod());
+			String triggerFile = restartProperties.getTriggerFile();
 			if (StringUtils.hasLength(triggerFile)) {
 				watcher.setTriggerFilter(new TriggerFileFilter(triggerFile));
 			}

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/filewatch/FileSystemWatcher.java

@@ -40,17 +40,17 @@ import org.springframework.util.Assert;
  */
 public class FileSystemWatcher {
 
-	private static final long DEFAULT_IDLE_TIME = 400;
+	private static final long DEFAULT_POLL_INTERVAL = 1000;
 
-	private static final long DEFAULT_QUIET_TIME = 200;
+	private static final long DEFAULT_QUIET_PERIOD = 400;
 
 	private List<FileChangeListener> listeners = new ArrayList<FileChangeListener>();
 
 	private final boolean daemon;
 
-	private final long idleTime;
+	private final long pollInterval;
 
-	private final long quietTime;
+	private final long quietPeriod;
 
 	private Thread watchThread;
 
@@ -64,20 +64,24 @@ public class FileSystemWatcher {
 	 * Create a new {@link FileSystemWatcher} instance.
 	 */
 	public FileSystemWatcher() {
-		this(true, DEFAULT_IDLE_TIME, DEFAULT_QUIET_TIME);
+		this(true, DEFAULT_POLL_INTERVAL, DEFAULT_QUIET_PERIOD);
 	}
 
 	/**
 	 * Create a new {@link FileSystemWatcher} instance.
 	 * @param daemon if a daemon thread used to monitor changes
-	 * @param idleTime the amount of time to wait between checking for changes
-	 * @param quietTime the amount of time required after a change has been detected to
+	 * @param pollInterval the amount of time to wait between checking for changes
+	 * @param quietPeriod the amount of time required after a change has been detected to
 	 * ensure that updates have completed
 	 */
-	public FileSystemWatcher(boolean daemon, long idleTime, long quietTime) {
+	public FileSystemWatcher(boolean daemon, long pollInterval, long quietPeriod) {
+		Assert.isTrue(pollInterval > 0, "PollInterval must be positive");
+		Assert.isTrue(quietPeriod > 0, "QuietPeriod must be positive");
+		Assert.isTrue(pollInterval > quietPeriod,
+				"PollInterval must be greater than QuietPeriod");
 		this.daemon = daemon;
-		this.idleTime = idleTime;
-		this.quietTime = quietTime;
+		this.pollInterval = pollInterval;
+		this.quietPeriod = quietPeriod;
 	}
 
 	/**
@@ -131,10 +135,10 @@ public class FileSystemWatcher {
 								FileSystemWatcher.this.remainingScans.decrementAndGet();
 							}
 							scan();
-							remainingScans = FileSystemWatcher.this.remainingScans.get();
 						}
 						catch (InterruptedException ex) {
 						}
+						remainingScans = FileSystemWatcher.this.remainingScans.get();
 					}
 				};
 			};
@@ -152,13 +156,13 @@ public class FileSystemWatcher {
 	}
 
 	private void scan() throws InterruptedException {
-		Thread.sleep(this.idleTime - this.quietTime);
+		Thread.sleep(this.pollInterval - this.quietPeriod);
 		Map<File, FolderSnapshot> previous;
 		Map<File, FolderSnapshot> current = this.folders;
 		do {
 			previous = current;
 			current = getCurrentSnapshots();
-			Thread.sleep(this.quietTime);
+			Thread.sleep(this.quietPeriod);
 		}
 		while (isDifferent(previous, current));
 		if (isDifferent(this.folders, current)) {
@@ -228,6 +232,7 @@ public class FileSystemWatcher {
 		Thread thread = this.watchThread;
 		if (thread != null) {
 			this.remainingScans.set(remainingScans);
+			thread.interrupt();
 			if (Thread.currentThread() != thread) {
 				try {
 					thread.join();

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/remote/client/RemoteClientConfiguration.java

@@ -34,6 +34,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.devtools.autoconfigure.DevToolsProperties;
+import org.springframework.boot.devtools.autoconfigure.DevToolsProperties.Restart;
 import org.springframework.boot.devtools.autoconfigure.OptionalLiveReloadServer;
 import org.springframework.boot.devtools.autoconfigure.RemoteDevToolsProperties;
 import org.springframework.boot.devtools.autoconfigure.TriggerFileFilter;
@@ -187,8 +188,11 @@ public class RemoteClientConfiguration {
 
 		@Bean
 		public FileSystemWatcher getFileSystemWather() {
-			FileSystemWatcher watcher = new FileSystemWatcher();
-			String triggerFile = this.properties.getRestart().getTriggerFile();
+			Restart restartProperties = this.properties.getRestart();
+			FileSystemWatcher watcher = new FileSystemWatcher(true,
+					restartProperties.getPollInterval(),
+					restartProperties.getQuietPeriod());
+			String triggerFile = restartProperties.getTriggerFile();
 			if (StringUtils.hasLength(triggerFile)) {
 				watcher.setTriggerFilter(new TriggerFileFilter(triggerFile));
 			}

spring-boot-devtools/src/test/java/org/springframework/boot/devtools/filewatch/FileSystemWatcherTests.java

@@ -64,6 +64,27 @@ public class FileSystemWatcherTests {
 		setupWatcher(20, 10);
 	}
 
+	@Test
+	public void pollIntervalMustBePositive() throws Exception {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("PollInterval must be positive");
+		new FileSystemWatcher(true, 0, 1);
+	}
+
+	@Test
+	public void quietPeriodMustBePositive() throws Exception {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("QuietPeriod must be positive");
+		new FileSystemWatcher(true, 1, 0);
+	}
+
+	@Test
+	public void pollIntervalMustBeGreaterThanQuietPeriod() throws Exception {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("PollInterval must be greater than QuietPeriod");
+		new FileSystemWatcher(true, 1, 1);
+	}
+
 	@Test
 	public void listenerMustNotBeNull() throws Exception {
 		this.thrown.expect(IllegalArgumentException.class);
@@ -117,7 +138,7 @@ public class FileSystemWatcherTests {
 	@Test
 	public void waitsForIdleTime() throws Exception {
 		this.changes.clear();
-		setupWatcher(100, 0);
+		setupWatcher(100, 1);
 		File folder = startWithNewFolder();
 		touch(new File(folder, "test1.txt"));
 		Thread.sleep(200);

spring-boot-samples/spring-boot-sample-devtools/src/main/java/demo/SampleDevToolsApplication.java

@@ -26,5 +26,4 @@ public class SampleDevToolsApplication extends WebMvcAutoConfigurationAdapter {
 	public static void main(String[] args) {
 		SpringApplication.run(SampleDevToolsApplication.class, args);
 	}
-
 }

spring-boot-samples/spring-boot-sample-devtools/src/main/resources/application.properties

 spring.devtools.remote.secret=secret
+# spring.devtools.restart.poll-interval=10000
 # spring.devtools.restart.trigger-file=.reloadtrigger