Lock ChangeSet: Prepare RecursiveLock to be an implementation of it's new interface

1 files changed, 245 insertions, 0 deletions

diff --git a/src/java/jogamp/common/util/locks/RecursiveLockImpl01Unfairish.java b/src/java/jogamp/common/util/locks/RecursiveLockImpl01Unfairish.java
new file mode 100644
index 0000000..ad29f78
--- /dev/null
+++ b/src/java/jogamp/common/util/locks/RecursiveLockImpl01Unfairish.java
@@ -0,0 +1,245 @@
+/**
+ * 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 jogamp.common.Debug;
+import java.security.AccessController;
+
+import java.util.LinkedList;
+
+/**
+ * Reentrance locking toolkit, impl a complete fair FIFO scheduler
+ */
+public class RecursiveLock implements LockExt {
+
+    static class SyncData {
+        // owner of the lock
+        Thread owner = null; 
+        // lock recursion
+        int recursionCount = 0; 
+        // stack trace of the lock, only used if DEBUG
+        Throwable lockedStack = null;
+        // waiting thread queue
+        LinkedList threadQueue = new LinkedList(); 
+        // flag signaling unlock has woken up a waiting thread
+        boolean signaled = false; 
+    }
+    private final SyncData sdata = new SyncData(); // synchronized (flow/mem)  mutable access
+
+    private static final boolean TRACE_LOCK = Debug.isPropertyDefined("jogamp.debug.Lock.TraceLock", true, AccessController.getContext());
+
+    public RecursiveLock() {
+    }
+
+    /**
+     * Returns the Throwable instance generated when this lock was taken the 1st time
+     * and if {@link com.jogamp.common.util.locks.Lock#DEBUG} is turned on, otherwise it returns always <code>null</code>.
+     * @see com.jogamp.common.util.locks.Lock#DEBUG
+     */
+    public final Throwable getLockedStack() {
+        synchronized(sdata) {
+            return sdata.lockedStack;
+        }
+    }
+
+    public final Thread getOwner() {
+        synchronized(sdata) {
+            return sdata.owner;
+        }
+    }
+
+    public final boolean isOwner() {
+        return isOwner(Thread.currentThread());
+    }
+
+    public final boolean isOwner(Thread thread) {
+        synchronized(sdata) {
+            return sdata.owner == thread ;
+        }
+    }
+
+    public final boolean isLocked() {
+        synchronized(sdata) {
+            return null != sdata.owner;
+        }
+    }
+
+    public final boolean isLockedByOtherThread() {
+        synchronized(sdata) {
+            return null != sdata.owner && Thread.currentThread() != sdata.owner ;
+        }
+    }
+
+    public final int getRecursionCount() {
+        synchronized(sdata) {
+            return sdata.recursionCount;
+        }
+    }
+
+    public final void validateLocked() {
+        synchronized(sdata) {
+            if ( null == sdata.owner ) {
+                throw new RuntimeException(Thread.currentThread()+": Not locked");
+            }
+            if ( Thread.currentThread() != sdata.owner ) {
+                if(null!=sdata.lockedStack) {
+                    sdata.lockedStack.printStackTrace();
+                }
+                throw new RuntimeException(Thread.currentThread()+": Not owner, owner is "+sdata.owner);
+            }
+        }
+    }
+
+    public final void lock() {
+        synchronized(sdata) {
+            if(!tryLock(TIMEOUT)) {
+                if(null!=sdata.lockedStack) {
+                    sdata.lockedStack.printStackTrace();
+                }
+                throw new RuntimeException("Waited "+TIMEOUT+"ms for: "+sdata.owner+" - "+Thread.currentThread()+", with recursionCount "+sdata.recursionCount+", lock: "+this+", qsz "+sdata.threadQueue.size());
+            }
+        }
+    }
+
+    public boolean tryLock(long maxwait) {
+        synchronized(sdata) {
+            Thread cur = Thread.currentThread();
+            if(TRACE_LOCK) {
+                String msg = "LOCK 0 ["+this+"], recursions "+sdata.recursionCount+", cur "+cur+", owner "+sdata.owner;
+                System.err.println(msg);
+                //Throwable tt = new Throwable(msg);
+                //tt.printStackTrace();
+            }
+            if (sdata.owner == cur) {
+                ++sdata.recursionCount;
+                if(TRACE_LOCK) {
+                    System.err.println("+++ LOCK 2 ["+this+"], recursions "+sdata.recursionCount+", "+cur);
+                }
+                return true;
+            }
+
+            if ( sdata.owner != null || 
+                 0 < maxwait && ( sdata.signaled || sdata.threadQueue.size() > 0 ) ) {
+
+                if ( 0 >= maxwait ) {
+                    // implies 'sdata.owner != null': locked by other thread
+                    // no waiting requested, bail out right away
+                    return false;
+                }
+
+                boolean timedOut = false;
+                do {
+                    sdata.threadQueue.addFirst(cur); // should only happen once 
+                    try {
+                        sdata.wait(maxwait);
+                        timedOut = sdata.threadQueue.remove(cur); // TIMEOUT if not already removed by unlock
+                    } catch (InterruptedException e) {
+                        if(!sdata.signaled) {
+                            // theoretically we could stay in the loop,
+                            // in case the interrupt wasn't issued by unlock, 
+                            // hence the re-enqueue
+                            sdata.threadQueue.remove(cur);
+                            if(TRACE_LOCK) {
+                                System.err.println("XXX LOCK - ["+this+"], recursions "+sdata.recursionCount+", "+cur);
+                            }
+                        }
+                    }
+                } while (null != sdata.owner && !timedOut) ;
+
+                sdata.signaled = false;
+
+                if(timedOut || null != sdata.owner) {
+                    return false;
+                }
+
+                if(TRACE_LOCK) {
+                    System.err.println("+++ LOCK 3 ["+this+"], recursions "+sdata.recursionCount+", qsz "+sdata.threadQueue.size()+", "+cur);
+                }
+            } else if(TRACE_LOCK) {
+                System.err.println("+++ LOCK 1 ["+this+"], recursions "+sdata.recursionCount+", qsz "+sdata.threadQueue.size()+", "+cur);
+            }
+
+            sdata.owner = cur;
+            if(DEBUG) {
+                sdata.lockedStack = new Throwable("Previously locked by "+sdata.owner+", lock: "+this);
+            }
+            return true;
+        }
+    }
+    
+
+    public final void unlock() {
+        unlock(null);
+    }
+
+    public final void unlock(Runnable taskAfterUnlockBeforeNotify) {
+        synchronized(sdata) {
+            validateLocked();
+
+            if (sdata.recursionCount > 0) {
+                --sdata.recursionCount;
+                if(TRACE_LOCK) {
+                    System.err.println("--- LOCK 1 ["+this+"], recursions "+sdata.recursionCount+", "+Thread.currentThread());
+                }
+                return;
+            }
+            sdata.owner = null;
+            sdata.lockedStack = null;
+            if(null!=taskAfterUnlockBeforeNotify) {
+                taskAfterUnlockBeforeNotify.run();
+            }
+
+            int qsz = sdata.threadQueue.size();
+            if(qsz > 0) {
+                Thread parkedThread = (Thread) sdata.threadQueue.removeLast();
+                if(TRACE_LOCK) {
+                    System.err.println("--- LOCK X ["+this+"], recursions "+sdata.recursionCount+
+                                       ", "+Thread.currentThread()+", irq "+(qsz-1)+": "+parkedThread);
+                }
+                sdata.signaled = true;
+                if(qsz==1) {
+                    // fast path, just one waiting thread
+                    sdata.notify();
+                } else {
+                    // signal the oldest one ..
+                    parkedThread.interrupt(); // Propagate SecurityException if it happens
+                }
+            } else if(TRACE_LOCK) {
+                System.err.println("--- LOCK X ["+this+"], recursions "+sdata.recursionCount+", "+Thread.currentThread());
+            }
+        }
+    }
+    
+    public int getWaitingThreadQueueSize() {
+        synchronized(sdata) {
+            return sdata.threadQueue.size();
+        }
+    }
+}
+