Adding Function and FunctionTask extending RunnableTask functionality

Function allows passing arguments and having a return value in contrast to Runnable,
where FunctionTask allows a Function to be invoked and waited for.

1 files changed, 160 insertions, 0 deletions

diff --git a/src/java/com/jogamp/common/util/FunctionTask.java b/src/java/com/jogamp/common/util/FunctionTask.java
new file mode 100644
index 0000000..8a1ef44
--- /dev/null
+++ b/src/java/com/jogamp/common/util/FunctionTask.java
@@ -0,0 +1,160 @@
+/**
+ * Copyright 2013 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ * 
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+ 
+package com.jogamp.common.util;
+
+/**
+ * Helper class to provide a Runnable queue implementation with a Runnable wrapper
+ * which notifies after execution for the <code>invokeAndWait()</code> semantics.
+ */
+public class FunctionTask<R,A> extends TaskBase implements Function<R,A> {
+    protected Function<R,A> runnable;
+    protected R result;
+    protected A[] args;
+
+    /**
+     * Invokes <code>func</code>.
+     * @param waitUntilDone if <code>true</code>, waits until <code>func</code> execution is completed, otherwise returns immediately. 
+     * @param func the {@link Function} to execute.
+     * @param args the {@link Function} arguments
+     * @return the {@link Function} return value
+     */
+    public static <U,V> U invoke(boolean waitUntilDone, Function<U,V> func, V... args) {
+        Throwable throwable = null;
+        final Object sync = new Object();
+        final FunctionTask<U,V> rt = new FunctionTask<U,V>( func, waitUntilDone ? sync : null, true );
+        final U res;
+        synchronized(sync) {
+            res = rt.eval(args);
+            if( waitUntilDone ) {
+                try {
+                    sync.wait();
+                } catch (InterruptedException ie) {
+                    throwable = ie;
+                }
+                if(null==throwable) {
+                    throwable = rt.getThrowable();
+                }
+                if(null!=throwable) {
+                    throw new RuntimeException(throwable);
+                }
+            }
+        }
+        return res;
+    }
+    
+    /**
+     * Create a RunnableTask object w/ synchronization,
+     * ie. suitable for <code>invokeAndWait()</code>. 
+     * 
+     * @param runnable the user action
+     * @param syncObject the synchronization object the caller shall wait until <code>runnable</code> execution is completed,
+     *                   or <code>null</code> if waiting is not desired. 
+     * @param catchExceptions if true, exception during <code>runnable</code> execution are catched, otherwise not.
+     *                        Use {@link #getThrowable()} to determine whether an exception has been catched. 
+     */
+    public FunctionTask(Function<R,A> runnable, Object syncObject, boolean catchExceptions) {
+        super(syncObject, catchExceptions);
+        this.runnable = runnable ;
+        result = null;
+        args = null;
+    }
+
+    /** Return the user action */
+    public Function<R,A> getRunnable() {
+        return runnable;
+    }
+
+    /**
+     * Sets the arguments for {@link #run()}.
+     * They will be cleared afterwards.
+     */
+    public void setArgs(A... args) {
+        this.args = args;
+    }
+    
+    /**
+     * Retrieves the cached result of {@link #run()}
+     * and clears it afterwards.
+     */
+    public R getResult() {
+        final R res = result;
+        result = null;
+        return res;
+    }
+    
+    /**
+     * {@inheritDoc}
+     * <p>
+     * Calls {@link #eval(Object...)}.
+     * </p>
+     * <p>
+     * You may set the {@link #eval(Object...)} arguments via {@link #setArgs(Object...)}
+     * and retrieve the result via {@link #getResult()}.
+     * </p>
+     */
+    @Override
+    public void run() {
+        result = eval(args);
+        args = null;
+    }
+
+    @Override
+    public R eval(A... args) {
+        R res = null;
+        tStarted = System.currentTimeMillis();
+        if(null == syncObject) {
+            try {
+                res = runnable.eval(args);
+            } catch (Throwable t) {
+                runnableException = t;
+                if(!catchExceptions) {
+                    throw new RuntimeException(runnableException);
+                }
+            } finally {
+                tExecuted = System.currentTimeMillis();
+            }
+        } else {
+            synchronized (syncObject) {
+                try {
+                    res = runnable.eval(args);
+                } catch (Throwable t) {
+                    runnableException = t;
+                    if(!catchExceptions) {
+                        throw new RuntimeException(runnableException);
+                    }
+                } finally {
+                    tExecuted = System.currentTimeMillis();
+                    syncObject.notifyAll();
+                }
+            }
+        }        
+        return res;
+    }    
+}
+