From b60f38f05ca966ce4559513b65b57be424d83925 Mon Sep 17 00:00:00 2001
From: refactormachine <39365897+refactormachine@users.noreply.github.com>
Date: Sun, 26 Aug 2018 20:49:35 +0300
Subject: [PATCH] Refactored BTraceEngine listeners to an appropriate class
 (#361)

---
 .../sun/btrace/api/impl/BTraceEngineImpl.java | 43 ++--------------
 .../api/impl/BTraceEngineListeners.java       | 51 +++++++++++++++++++
 2 files changed, 56 insertions(+), 38 deletions(-)
 create mode 100644 src/share/classes/com/sun/btrace/api/impl/BTraceEngineListeners.java

diff --git a/src/share/classes/com/sun/btrace/api/impl/BTraceEngineImpl.java b/src/share/classes/com/sun/btrace/api/impl/BTraceEngineImpl.java
index d9ce508e7..44e8a587e 100644
--- a/src/share/classes/com/sun/btrace/api/impl/BTraceEngineImpl.java
+++ b/src/share/classes/com/sun/btrace/api/impl/BTraceEngineImpl.java
@@ -32,9 +32,7 @@
 import java.io.IOException;
 import java.util.EventListener;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
@@ -51,7 +49,7 @@
 import com.sun.btrace.spi.impl.BTraceSettingsProviderImpl;
 import com.sun.btrace.spi.OutputProvider;
 import com.sun.btrace.spi.impl.PortLocatorImpl;
-import java.lang.ref.WeakReference;
+
 import java.util.EnumSet;
 import java.util.Iterator;
 import java.util.ServiceLoader;
@@ -64,6 +62,7 @@
  */
 public class BTraceEngineImpl extends BTraceEngine {
     final private static Logger LOGGER = Logger.getLogger(BTraceEngineImpl.class.getName());
+    private final BTraceEngineListeners listeners = new BTraceEngineListeners();
 
     /**
      * Basic state listener<br>
@@ -90,7 +89,6 @@ interface StateListener extends EventListener {
 
     private Map<BTraceTask, Client> clientMap = new HashMap<BTraceTask, Client>();
 
-    final private Set<WeakReference<StateListener>> listeners = new HashSet<WeakReference<StateListener>>();
     final private ExecutorService commQueue = Executors.newCachedThreadPool();
 
     public BTraceEngineImpl() {
@@ -163,21 +161,7 @@ public BTraceTask createTask(int pid) {
     }
 
     void addListener(StateListener listener) {
-        synchronized(listeners) {
-            listeners.add(new WeakReference<StateListener>(listener));
-        }
-    }
-
-    void removeListener(StateListener listener) {
-        synchronized(listeners) {
-            for(Iterator<WeakReference<StateListener>> iter=listeners.iterator();iter.hasNext();) {
-                WeakReference<StateListener> ref = iter.next();
-                StateListener l = ref.get();
-                if (l == null || l.equals(listener)) {
-                    iter.remove();
-                }
-            }
-        }
+        listeners.addListener(listener);
     }
 
     boolean start(final BTraceTask task) {
@@ -186,7 +170,7 @@ boolean start(final BTraceTask task) {
         boolean result = doStart(task);
         LOGGER.log(Level.FINEST, "BTrace task {0}", result ? "started successfuly" : "failed");
         if (result) {
-            fireOnTaskStart(task);
+            listeners.fireOnTaskStart(task);
         }
         return result;
     }
@@ -201,7 +185,7 @@ boolean stop(final BTraceTask task) {
                 boolean result = doStop(task);
                 LOGGER.log(Level.FINEST, "BTrace task {0}", result ? "stopped successfuly" : "not stopped");
                 if (result) {
-                    fireOnTaskStop(task);
+                    listeners.fireOnTaskStop(task);
                 }
                 return result;
             }
@@ -340,21 +324,4 @@ ClasspathProvider getClasspathProvider() {
         return cpProvider;
     }
 
-    private void fireOnTaskStart(BTraceTask task) {
-        synchronized(listeners) {
-            for(WeakReference<StateListener> ref : listeners) {
-                StateListener l = ref.get();
-                if (l != null) l.onTaskStart(task);
-            }
-        }
-    }
-
-    private void fireOnTaskStop(BTraceTask task) {
-        synchronized(listeners) {
-            for(WeakReference<StateListener> ref : listeners) {
-                StateListener l = ref.get();
-                if (l != null) l.onTaskStop(task);
-            }
-        }
-    }
 }
diff --git a/src/share/classes/com/sun/btrace/api/impl/BTraceEngineListeners.java b/src/share/classes/com/sun/btrace/api/impl/BTraceEngineListeners.java
new file mode 100644
index 000000000..c228f9777
--- /dev/null
+++ b/src/share/classes/com/sun/btrace/api/impl/BTraceEngineListeners.java
@@ -0,0 +1,51 @@
+package com.sun.btrace.api.impl;
+
+import com.sun.btrace.api.BTraceTask;
+
+import java.lang.ref.WeakReference;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+
+class BTraceEngineListeners {
+    private final Set<WeakReference<BTraceEngineImpl.StateListener>> listeners = new HashSet<WeakReference<BTraceEngineImpl.StateListener>>();
+
+    BTraceEngineListeners() {
+    }
+
+    void addListener(BTraceEngineImpl.StateListener listener) {
+        synchronized (listeners) {
+            listeners.add(new WeakReference<BTraceEngineImpl.StateListener>(listener));
+        }
+    }
+
+    void removeListener(BTraceEngineImpl.StateListener listener) {
+        synchronized (listeners) {
+            for (Iterator<WeakReference<BTraceEngineImpl.StateListener>> iter = listeners.iterator(); iter.hasNext(); ) {
+                WeakReference<BTraceEngineImpl.StateListener> ref = iter.next();
+                BTraceEngineImpl.StateListener l = ref.get();
+                if (l == null || l.equals(listener)) {
+                    iter.remove();
+                }
+            }
+        }
+    }
+
+    void fireOnTaskStart(BTraceTask task) {
+        synchronized (listeners) {
+            for (WeakReference<BTraceEngineImpl.StateListener> ref : listeners) {
+                BTraceEngineImpl.StateListener l = ref.get();
+                if (l != null) l.onTaskStart(task);
+            }
+        }
+    }
+
+    void fireOnTaskStop(BTraceTask task) {
+        synchronized (listeners) {
+            for (WeakReference<BTraceEngineImpl.StateListener> ref : listeners) {
+                BTraceEngineImpl.StateListener l = ref.get();
+                if (l != null) l.onTaskStop(task);
+            }
+        }
+    }
+}
\ No newline at end of file