[jboss-cvs] JBossAS SVN: r92094 - projects/jboss-threads/trunk/main/src/main/java/org/jboss/threads.

[jboss-cvs-commits at lists.jboss.org]

Author: david.lloyd at jboss.com
Date: 2009-08-06 19:18:24 -0400 (Thu, 06 Aug 2009)
New Revision: 92094

Added:
   projects/jboss-threads/trunk/main/src/main/java/org/jboss/threads/SimpleLock.java
Log:
maybe this will work, maybe not

Added: projects/jboss-threads/trunk/main/src/main/java/org/jboss/threads/SimpleLock.java
===================================================================
--- projects/jboss-threads/trunk/main/src/main/java/org/jboss/threads/SimpleLock.java	                        (rev 0)
+++ projects/jboss-threads/trunk/main/src/main/java/org/jboss/threads/SimpleLock.java	2009-08-06 23:18:24 UTC (rev 92094)
@@ -0,0 +1,181 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2009, Red Hat Middleware LLC, and individual contributors
+ * as indicated by the @author tags. See the copyright.txt file in the
+ * distribution for a full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+
+package org.jboss.threads;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.TimeUnit;
+import java.util.Date;
+
+/**
+ * A simple lock impl which does no deadlock detection, no fairness, no reentrancy protection, no error checking,
+ * and has basically no frills whatsoever.  Non-public due to its highly experimental nature.  This probably won't work;
+ * in fact the only reason I'm even trying this is because I'm an obsessive moron.
+ */
+final class SimpleLock implements Lock {
+    private boolean locked;
+
+    public void lock() {
+        boolean intr = Thread.interrupted();
+        try {
+            synchronized (this) {
+                while (locked) {
+                    try {
+                        wait();
+                    } catch (InterruptedException e) {
+                        intr = true;
+                    }
+                }
+                locked = true;
+            }
+        } finally {
+            if (intr) Thread.currentThread().interrupt();
+        }
+    }
+
+    public void lockInterruptibly() throws InterruptedException {
+        synchronized (this) {
+            while (locked) {
+                wait();
+            }
+            locked = true;
+        }
+    }
+
+    public boolean tryLock() {
+        synchronized (this) {
+            if (locked) {
+                return false;
+            } else {
+                locked = true;
+                return true;
+            }
+        }
+    }
+
+    private static long clipHigh(long value) {
+        return value < 0 ? Long.MAX_VALUE : value;
+    }
+
+    public boolean tryLock(final long time, final TimeUnit unit) throws InterruptedException {
+        if (time < 0) {
+            return tryLock();
+        }
+        long now = System.currentTimeMillis();
+        long deadline = clipHigh(now + unit.toMillis(time));
+        synchronized (this) {
+            if (! locked) {
+                return locked = true;
+            }
+            for (;;) {
+                final long remaining = deadline - now;
+                if (remaining <= 0) {
+                    return false;
+                }
+                wait(remaining);
+                if (! locked) {
+                    return locked = true;
+                }
+                now = System.currentTimeMillis();
+            }
+        }
+    }
+
+    public void unlock() {
+        synchronized (this) {
+            locked = false;
+        }
+    }
+
+    public Condition newCondition() {
+        return new SimpleCondition();
+    }
+
+    public final class SimpleCondition implements Condition {
+
+        SimpleCondition() {
+        }
+
+        public void await() throws InterruptedException {
+            synchronized (this) {
+                unlock();
+                try {
+                    wait();
+                } finally {
+                    lock();
+                }
+            }
+        }
+
+        public void awaitUninterruptibly() {
+            boolean intr = Thread.interrupted();
+            try {
+                synchronized (this) {
+                    unlock();
+                    try {
+                        wait();
+                    } catch (InterruptedException e) {
+                        intr = true;
+                    } finally {
+                        lock();
+                    }
+                }
+            } finally {
+                if (intr) Thread.currentThread().interrupt();
+            }
+        }
+
+        public long awaitNanos(final long nanosTimeout) throws InterruptedException {
+            unlock();
+            try {
+                final long start = System.nanoTime();
+                synchronized (this) {
+                    wait(nanosTimeout / 1000000L, (int) (nanosTimeout % 1000000L));
+                }
+                return nanosTimeout - (System.nanoTime() - start);
+            } finally {
+                lock();
+            }
+        }
+
+        public boolean await(final long time, final TimeUnit unit) throws InterruptedException {
+            throw new UnsupportedOperationException("not implemented yet");
+        }
+
+        public boolean awaitUntil(final Date deadline) throws InterruptedException {
+            throw new UnsupportedOperationException("not implemented yet");
+        }
+
+        public void signal() {
+            synchronized (this) {
+                notify();
+            }
+        }
+
+        public void signalAll() {
+            synchronized (this) {
+                notifyAll();
+            }
+        }
+    }
+}