RecursiveThreadGroupLock: New recursive lock interface and impl, allowing 'spawn off' process to become the lock owner.

To avoid complicated synchronization via synchronized, wait and notify between one thread
and a 'spawn' off thread which temporarly requires the hold lock,
RecursiveThreadGroupLock allows to add and remove other threads to become owners of the lock
as if they were the original holder.

This simplifies some rare locking use cases, eg. in JOGL's GLProfile initialization sequence
where a SharedResourceRunner thread is taking over initialization of shared resources.

1 files changed, 327 insertions, 0 deletions

diff --git a/src/junit/com/jogamp/common/util/locks/TestRecursiveThreadGroupLock01.java b/src/junit/com/jogamp/common/util/locks/TestRecursiveThreadGroupLock01.java
new file mode 100644
index 0000000..2eecce1
--- /dev/null
+++ b/src/junit/com/jogamp/common/util/locks/TestRecursiveThreadGroupLock01.java
@@ -0,0 +1,327 @@
+/**
+ * Copyright 2010 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.locks;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.jogamp.common.os.Platform;
+import com.jogamp.junit.util.JunitTracer;
+
+public class TestRecursiveThreadGroupLock01 extends JunitTracer {
+
+    public enum YieldMode {
+        NONE(0), YIELD(1), SLEEP(2); 
+        
+        public final int id;
+
+        YieldMode(int id){
+            this.id = id;
+        }
+    }    
+    
+    static void yield(YieldMode mode) {
+        switch(mode) {
+            case YIELD:
+                Thread.yield();
+                break;
+            case SLEEP:
+                try {
+                    Thread.sleep(10);
+                } catch (InterruptedException ie) {
+                    ie.printStackTrace();
+                }
+                break;
+            default:
+                break;
+        }
+
+    }
+
+    static class LockedObject {
+        static final boolean DEBUG = false;
+        
+        private RecursiveThreadGroupLock locker; // post
+        private volatile int slaveCounter;
+
+        public LockedObject() {
+            locker = LockFactory.createRecursiveThreadGroupLock();
+            slaveCounter = 0;
+        }
+
+        public final void masterAction(String tab, String name, Thread[] slaves, int loops, int mark, final YieldMode yieldMode) {
+            locker.lock();
+            if(DEBUG) {
+                System.err.println(tab+"<"+name+" c "+slaveCounter);
+            }
+            Assert.assertTrue(mark>loops);
+            Assert.assertTrue(loops*loops>mark);
+            try {
+                if(slaveCounter<mark) {
+                    for(int i=0; i<slaves.length; i++) {
+                        locker.addOwner(slaves[i]);
+                        slaves[i].start();
+                    }
+                    while(slaveCounter<mark) {
+                        yield(yieldMode);
+                    }
+                }
+            } finally {
+                if(DEBUG) {
+                    System.err.println(tab+" "+name+" c "+slaveCounter+">");
+                }
+                // Implicit waits until all slaves got off the lock
+                locker.unlock();
+            }
+        }
+
+        public final void slaveAction(String tab, String name, int loops, int mark, YieldMode yieldMode) {
+            if(slaveCounter>=mark) {
+                if(DEBUG) {
+                    System.err.println(tab+"["+name+" c "+slaveCounter+" - NOP]");
+                }
+                return;                
+            }
+            locker.lock();
+            if(DEBUG) {
+                System.err.println(tab+"["+name+" c "+slaveCounter);
+            }
+            Assert.assertTrue(mark>loops);
+            Assert.assertTrue(loops*loops>mark);
+            try {
+                while(loops>0 && slaveCounter<mark) {
+                    slaveCounter++;
+                    loops--;
+                }
+                /**
+                while(slaveCounter<mark) {
+                    slaveCounter++;
+                } */
+                yield(yieldMode);
+            } finally {
+                if(DEBUG) {
+                    System.err.println(tab+" "+name+" c "+slaveCounter+"]");
+                }
+                locker.unlock();
+            }
+        }
+
+        public final boolean isLocked() {
+            return locker.isLocked();
+        }
+        
+    }
+
+    interface LockedObjectRunner extends Runnable {
+        void stop();
+        boolean isStarted();
+        boolean isStopped();
+        void waitUntilStopped();
+    }
+
+    class LockedObjectRunner1 implements LockedObjectRunner {
+        volatile boolean shouldStop;
+        volatile boolean stopped;
+        volatile boolean started;
+        String tab, name;
+        LockedObject lo;
+        Thread[] slaves;
+        int loops;
+        int mark;
+        YieldMode yieldMode;
+
+        /** master constructor */
+        public LockedObjectRunner1(String tab, String name, LockedObject lo, Thread[] slaves, int loops, int mark, YieldMode yieldMode) {
+            this.tab = tab;
+            this.name = name;
+            this.lo = lo;
+            this.slaves = slaves;
+            this.loops = loops;
+            this.mark = mark;
+            this.shouldStop = false;
+            this.stopped = false;
+            this.yieldMode = yieldMode;
+            Assert.assertTrue(mark>loops);
+            Assert.assertTrue(loops*loops>mark);
+        }
+
+        /** slave constructor */
+        public LockedObjectRunner1(String tab, String name, LockedObject lo, int loops, int mark, YieldMode yieldMode) {
+            this.tab = tab;
+            this.name = name;
+            this.lo = lo;
+            this.slaves = null; // slave
+            this.loops = loops;
+            this.mark = mark;
+            this.shouldStop = false;
+            this.stopped = false;
+            this.yieldMode = yieldMode;
+            Assert.assertTrue(mark>loops);
+            Assert.assertTrue(loops*loops>mark);
+        }
+        
+        public final void stop() {
+            shouldStop = true;
+        }
+
+        public final boolean isStarted() {
+            return started;
+        }
+        public final boolean isStopped() {
+            return stopped;
+        }
+        
+        public void waitUntilStopped() {
+            synchronized(this) {
+                while(!stopped) {
+                    try {
+                        this.wait();
+                    } catch (InterruptedException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+            
+        }
+
+        public void run() {
+            synchronized(this) {
+                started = true;
+                for(int i=0; !shouldStop && i<loops; i++) {
+                    if(null != slaves) {
+                        lo.masterAction(tab, name, slaves, loops, mark, yieldMode);
+                    } else {
+                        lo.slaveAction(tab, name, loops, mark, yieldMode);
+                    }
+                }
+                stopped = true;
+                this.notifyAll();
+            }
+        }
+    }
+
+    protected long testLockedObjectImpl(LockFactory.ImplType implType, boolean fair, 
+                                        int slaveThreadNum, int concurrentThreadNum, 
+                                        int loops, int mark, YieldMode yieldMode) throws InterruptedException {
+        final long t0 = System.currentTimeMillis();
+        LockedObject lo = new LockedObject();
+        LockedObjectRunner[] concurrentRunners = new LockedObjectRunner[concurrentThreadNum];
+        LockedObjectRunner[] slaveRunners = new LockedObjectRunner[slaveThreadNum];
+        Thread[] concurrentThreads = new Thread[concurrentThreadNum];
+        Thread[] slaveThreads = new Thread[slaveThreadNum];
+        Thread[] noCoOwnerThreads = new Thread[0];
+        int i;
+
+        for(i=0; i<slaveThreadNum; i++) {
+            slaveRunners[i] = new LockedObjectRunner1("    ", "s"+i, lo, loops, mark, yieldMode);
+            String name = "ActionThread-Slaves-"+i+"_of_"+slaveThreadNum;
+            slaveThreads[i] = new Thread( slaveRunners[i], name );
+        }
+        for(i=0; i<concurrentThreadNum; i++) {
+            String name;
+            if(i==0) {
+                concurrentRunners[i] = new LockedObjectRunner1("", "M0", lo, slaveThreads, loops, mark, yieldMode);
+                name = "ActionThread-Master-"+i+"_of_"+concurrentThreadNum;            
+            } else {
+                concurrentRunners[i] = new LockedObjectRunner1("  ", "O"+i, lo, noCoOwnerThreads, loops, mark, yieldMode);
+                name = "ActionThread-Others-"+i+"_of_"+concurrentThreadNum;
+            }
+            concurrentThreads[i] = new Thread( concurrentRunners[i], name );
+            concurrentThreads[i].start();
+            if(i==0) {
+                // master thread w/ slaves shall start first
+                while(!concurrentRunners[i].isStarted()) {
+                    Thread.sleep(100);
+                }
+            }
+        }
+
+        for( i=0; i<slaveThreadNum; i++ ) {
+            slaveRunners[i].waitUntilStopped();
+        }
+        for( i=0; i<concurrentThreadNum; i++ ) {
+            concurrentRunners[i].waitUntilStopped();
+        }
+        Assert.assertEquals(0, lo.locker.getHoldCount());
+        Assert.assertEquals(false, lo.locker.isLocked());
+        
+        final long dt = System.currentTimeMillis()-t0;
+        
+        System.err.println();
+        final String fair_S = fair ? "fair  " : "unfair" ;
+        System.err.printf("---- TestRecursiveLock01.testLockedObjectThreading: i %5s, %s, threads %2d, loops-outter %6d, loops-inner %6d, yield %5s - dt %6d ms", 
+                implType, fair_S, concurrentThreadNum, loops, mark, yieldMode, dt);
+        System.err.println();
+        return dt;
+    }
+    
+    @Test
+    public void testTwoThreadsInGroup() throws InterruptedException {
+        LockFactory.ImplType t = LockFactory.ImplType.Int02ThreadGroup; 
+        boolean fair=true;
+        int coOwnerThreadNum=2;
+        int threadNum=5; 
+        int loops=1000; 
+        int mark=10000; 
+        YieldMode yieldMode=YieldMode.YIELD;
+        
+        if( Platform.getCPUFamily() == Platform.CPUFamily.ARM ) {
+            loops=5; mark=10;
+        }
+        
+        testLockedObjectImpl(t, fair, coOwnerThreadNum, threadNum, loops, mark, yieldMode);
+    }
+
+    public static void main(String args[]) throws IOException, InterruptedException {
+        String tstname = TestRecursiveThreadGroupLock01.class.getName();
+        org.junit.runner.JUnitCore.main(tstname);
+        
+        /**
+        BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
+        System.err.println("Press enter to continue");
+        System.err.println(stdin.readLine()); 
+        TestRecursiveLock01 t = new TestRecursiveLock01();
+        t.testLockedObjectThreading5x1000x10000N_Int01_Unfair();
+        
+        t.testLockedObjectThreading5x1000x10000N_Int01_Fair();
+        t.testLockedObjectThreading5x1000x10000N_Java5_Fair();
+        t.testLockedObjectThreading5x1000x10000N_Int01_Unfair();
+        t.testLockedObjectThreading5x1000x10000N_Java5_Unfair();
+        */
+    }
+
+}