[sre] Add configuration property for specifying the max number of thr…

…eads.

Signed-off-by: Stéphane Galland <galland@arakhne.org>

sre/io.janusproject/io.janusproject.plugin/src/io/janusproject/JanusConfig.java

@@ -184,11 +184,25 @@ public final class JanusConfig {
     public static final String MAX_NUMBER_OF_THREADS_IN_EXECUTOR_NAME = "janus.executors.threads.max"; //$NON-NLS-1$
 
     /**
-     * Indicates the maximal number of threads to keep in the pool, even if they are idle, unless {@code allowCoreThreadTimeOut} is set.
+     * Indicates the maximal number of threads to keep in the pool.
      *
      * @see #MAX_NUMBER_OF_THREADS_IN_EXECUTOR_NAME
      */
-    public static final int MAX_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE = 50;
+    public static final int MAX_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE = 512;
+
+    /**
+     * Name of the property that contains the minimal number of threads in the pool.
+     *
+     * @see #MIN_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE
+     */
+    public static final String MIN_NUMBER_OF_THREADS_IN_EXECUTOR_NAME = "janus.executors.threads.min"; //$NON-NLS-1$
+
+    /**
+     * Indicates the minimal number of threads to keep in the pool, even if they are idle.
+     *
+     * @see #MIN_NUMBER_OF_THREADS_IN_EXECUTOR_NAME
+     */
+    public static final int MIN_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE = 16;
 
     /**
      * Name of the property that contains the numbers of seconds that the kernel is waiting for thread terminations before timeout.
@@ -259,6 +273,7 @@ public static void getDefaultValues(Properties defaultValues) {
         defaultValues.put(VERBOSE_LEVEL_NAME, VERBOSE_LEVEL_VALUE);
         defaultValues.put(LOGGING_PROPERTY_FILE_NAME, LOGGING_PROPERTY_FILE_VALUE);
         defaultValues.put(HAZELCAST_LOGGER_FACTORY_NAME, HAZELCAST_LOGGER_FACTORY_VALUE);
+        defaultValues.put(MIN_NUMBER_OF_THREADS_IN_EXECUTOR_NAME, Integer.toString(MIN_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE));
         defaultValues.put(MAX_NUMBER_OF_THREADS_IN_EXECUTOR_NAME, Integer.toString(MAX_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE));
         defaultValues.put(KERNEL_THREAD_TIMEOUT_NAME, Integer.toString(KERNEL_THREAD_TIMEOUT_VALUE));
         defaultValues.put(KERNEL_THREAD_PURGE_DELAY_NAME, Integer.toString(KERNEL_THREAD_PURGE_DELAY_VALUE));

sre/io.janusproject/io.janusproject.plugin/src/io/janusproject/kernel/services/jdk/executors/JdkScheduledThreadPoolExecutor.java

@@ -51,8 +51,8 @@ public class JdkScheduledThreadPoolExecutor extends ScheduledThreadPoolExecutor
 	 */
 	@Inject
 	public JdkScheduledThreadPoolExecutor(ThreadFactory factory) {
-		super(JanusConfig.getSystemPropertyAsInteger(JanusConfig.MAX_NUMBER_OF_THREADS_IN_EXECUTOR_NAME,
-				JanusConfig.MAX_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE), factory);
+		super(JanusConfig.getSystemPropertyAsInteger(JanusConfig.MIN_NUMBER_OF_THREADS_IN_EXECUTOR_NAME,
+				JanusConfig.MIN_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE), factory);
 	}
 
 	/**

sre/io.janusproject/io.janusproject.plugin/src/io/janusproject/kernel/services/jdk/executors/JdkThreadPoolExecutor.java

@@ -43,7 +43,7 @@
  */
 public class JdkThreadPoolExecutor extends ThreadPoolExecutor {
 
-	private static final long TIMEOUT = 60;
+	private static final long TIMEOUT = 120;
 
 	private ListenerCollection<JdkTaskListener> listeners;
 
@@ -61,7 +61,20 @@ public JdkThreadPoolExecutor(ThreadFactory factory) {
 	 * @param factory - thread factory.
 	 */
 	public JdkThreadPoolExecutor(int poolSize, ThreadFactory factory) {
-		super(poolSize, Integer.MAX_VALUE, TIMEOUT, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), factory);
+		this(JanusConfig.getSystemPropertyAsInteger(JanusConfig.MIN_NUMBER_OF_THREADS_IN_EXECUTOR_NAME,
+				JanusConfig.MIN_NUMBER_OF_THREADS_IN_EXECUTOR_VALUE),
+			poolSize, factory);
+	}
+
+	/**
+	 * @param minPoolSize - minimal number of threads in the pool.
+	 * @param maxPoolSize - maximal number of threads in the pool.
+	 * @param factory - thread factory.
+	 */
+	public JdkThreadPoolExecutor(int minPoolSize, int maxPoolSize, ThreadFactory factory) {
+		super(Math.max(0, Math.min(minPoolSize, maxPoolSize)),
+				Math.max(0, maxPoolSize),
+				TIMEOUT, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), factory);
 	}
 
 	/**