/* * Copyright (c) 2008, 2009, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.nio.ch; import java.nio.channels.*;import java.util.concurrent.*;import java.security.AccessController;import sun.security.action.GetIntegerAction; /** * Defines static methods to invoke a completion handler or arbitrary task. */ class Invoker { private Invoker() { } // maximum number of completion handlers that may be invoked on the current // thread before it re-directs invocations to the thread pool. This helps // avoid stack overflow and lessens the risk of starvation. private static final int maxHandlerInvokeCount = AccessController.doPrivileged( new GetIntegerAction("sun.nio.ch.maxCompletionHandlersOnStack", 16)); // Per-thread object with reference to channel group and a counter for // the number of completion handlers invoked. This should be reset to 0 // when all completion handlers have completed. static class GroupAndInvokeCount { private final AsynchronousChannelGroupImpl group; private int handlerInvokeCount; GroupAndInvokeCount(AsynchronousChannelGroupImpl group) { this.group = group; } AsynchronousChannelGroupImpl group() { return group; } int invokeCount() { return handlerInvokeCount; } void setInvokeCount(int value) { handlerInvokeCount = value; } void resetInvokeCount() { handlerInvokeCount = 0; } void incrementInvokeCount() { handlerInvokeCount++; } } private static final ThreadLocal<GroupAndInvokeCount> myGroupAndInvokeCount = new ThreadLocal<GroupAndInvokeCount>() { @Override protected GroupAndInvokeCount initialValue() { return null; } }; /** * Binds this thread to the given group */ static void bindToGroup(AsynchronousChannelGroupImpl group) { myGroupAndInvokeCount.set(new GroupAndInvokeCount(group)); } /** * Returns the GroupAndInvokeCount object for this thread. */ static GroupAndInvokeCount getGroupAndInvokeCount() { return myGroupAndInvokeCount.get(); } /** * Returns true if the current thread is in a channel group's thread pool */ static boolean isBoundToAnyGroup() { return myGroupAndInvokeCount.get() != null; } /** * Returns true if the current thread is in the given channel's thread * pool and we haven't exceeded the maximum number of handler frames on * the stack. */ static boolean mayInvokeDirect(GroupAndInvokeCount myGroupAndInvokeCount, AsynchronousChannelGroupImpl group) { if ((myGroupAndInvokeCount != null) && (myGroupAndInvokeCount.group() == group) && (myGroupAndInvokeCount.invokeCount() < maxHandlerInvokeCount)) { return true; } return false; } /** * Invoke handler without checking the thread identity or number of handlers * on the thread stack. */ static <V,A> void invokeUnchecked(CompletionHandler<V,? super A> handler, A attachment, V value, Throwable exc) { if (exc == null) { handler.completed(value, attachment); } else { handler.failed(exc, attachment); } // clear interrupt Thread.interrupted(); } /** * Invoke handler assuming thread identity already checked */ static <V,A> void invokeDirect(GroupAndInvokeCount myGroupAndInvokeCount, CompletionHandler<V,? super A> handler, A attachment, V result, Throwable exc) { myGroupAndInvokeCount.incrementInvokeCount(); Invoker.invokeUnchecked(handler, attachment, result, exc); } /** * Invokes the handler. If the current thread is in the channel group's * thread pool then the handler is invoked directly, otherwise it is * invoked indirectly. */ static <V,A> void invoke(AsynchronousChannel channel, CompletionHandler<V,? super A> handler, A attachment, V result, Throwable exc) { boolean invokeDirect = false; boolean identityOkay = false; GroupAndInvokeCount thisGroupAndInvokeCount = myGroupAndInvokeCount.get(); if (thisGroupAndInvokeCount != null) { if ((thisGroupAndInvokeCount.group() == ((Groupable)channel).group())) identityOkay = true; if (identityOkay && (thisGroupAndInvokeCount.invokeCount() < maxHandlerInvokeCount)) { // group match invokeDirect = true; } } if (invokeDirect) { invokeDirect(thisGroupAndInvokeCount, handler, attachment, result, exc); } else { try { invokeIndirectly(channel, handler, attachment, result, exc); } catch (RejectedExecutionException ree) { // channel group shutdown; fallback to invoking directly // if the current thread has the right identity. if (identityOkay) { invokeDirect(thisGroupAndInvokeCount, handler, attachment, result, exc); } else { throw new ShutdownChannelGroupException(); } } } } /** * Invokes the handler indirectly via the channel group's thread pool. */ static <V,A> void invokeIndirectly(AsynchronousChannel channel, final CompletionHandler<V,? super A> handler, final A attachment, final V result, final Throwable exc) { try { ((Groupable)channel).group().executeOnPooledThread(new Runnable() { public void run() { GroupAndInvokeCount thisGroupAndInvokeCount = myGroupAndInvokeCount.get(); if (thisGroupAndInvokeCount != null) thisGroupAndInvokeCount.setInvokeCount(1); invokeUnchecked(handler, attachment, result, exc); } }); } catch (RejectedExecutionException ree) { throw new ShutdownChannelGroupException(); } } /** * Invokes the handler "indirectly" in the given Executor */ static <V,A> void invokeIndirectly(final CompletionHandler<V,? super A> handler, final A attachment, final V value, final Throwable exc, Executor executor) { try { executor.execute(new Runnable() { public void run() { invokeUnchecked(handler, attachment, value, exc); } }); } catch (RejectedExecutionException ree) { throw new ShutdownChannelGroupException(); } } /** * Invokes the given task on the thread pool associated with the given * channel. If the current thread is in the thread pool then the task is * invoked directly. */ static void invokeOnThreadInThreadPool(Groupable channel, Runnable task) { boolean invokeDirect; GroupAndInvokeCount thisGroupAndInvokeCount = myGroupAndInvokeCount.get(); AsynchronousChannelGroupImpl targetGroup = channel.group(); if (thisGroupAndInvokeCount == null) { invokeDirect = false; } else { invokeDirect = (thisGroupAndInvokeCount.group == targetGroup); } try { if (invokeDirect) { task.run(); } else { targetGroup.executeOnPooledThread(task); } } catch (RejectedExecutionException ree) { throw new ShutdownChannelGroupException(); } } /** * Invoke handler with completed result. This method does not check the * thread identity or the number of handlers on the thread stack. */ static <V,A> void invokeUnchecked(PendingFuture<V,A> future) { assert future.isDone(); CompletionHandler<V,? super A> handler = future.handler(); if (handler != null) { invokeUnchecked(handler, future.attachment(), future.value(), future.exception()); } } /** * Invoke handler with completed result. If the current thread is in the * channel group's thread pool then the handler is invoked directly, * otherwise it is invoked indirectly. */ static <V,A> void invoke(PendingFuture<V,A> future) { assert future.isDone(); CompletionHandler<V,? super A> handler = future.handler(); if (handler != null) { invoke(future.channel(), handler, future.attachment(), future.value(), future.exception()); } } /** * Invoke handler with completed result. The handler is invoked indirectly, * via the channel group's thread pool. */ static <V,A> void invokeIndirectly(PendingFuture<V,A> future) { assert future.isDone(); CompletionHandler<V,? super A> handler = future.handler(); if (handler != null) { invokeIndirectly(future.channel(), handler, future.attachment(), future.value(), future.exception()); } }}
/*
* Copyright (c) 2008, 2009, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.nio.ch;
import java.nio.channels.*;
import java.util.concurrent.*;
import java.security.AccessController;
import sun.security.action.GetIntegerAction;
/**
* Defines static methods to invoke a completion handler or arbitrary task.
*/
class Invoker {
private Invoker() { }
// maximum number of completion handlers that may be invoked on the current
// thread before it re-directs invocations to the thread pool. This helps
// avoid stack overflow and lessens the risk of starvation.
private static final int maxHandlerInvokeCount = AccessController.doPrivileged(
new GetIntegerAction("sun.nio.ch.maxCompletionHandlersOnStack", 16));
// Per-thread object with reference to channel group and a counter for
// the number of completion handlers invoked. This should be reset to 0
// when all completion handlers have completed.
static class GroupAndInvokeCount {
private final AsynchronousChannelGroupImpl group;
private int handlerInvokeCount;
GroupAndInvokeCount(AsynchronousChannelGroupImpl group) {
this.group = group;
}
AsynchronousChannelGroupImpl group() {
return group;
}
int invokeCount() {
return handlerInvokeCount;
}
void setInvokeCount(int value) {
handlerInvokeCount = value;
}
void resetInvokeCount() {
handlerInvokeCount = 0;
}
void incrementInvokeCount() {
handlerInvokeCount++;
}
}
private static final ThreadLocal<GroupAndInvokeCount> myGroupAndInvokeCount =
new ThreadLocal<GroupAndInvokeCount>() {
@Override protected GroupAndInvokeCount initialValue() {
return null;
}
};
/**
* Binds this thread to the given group
*/
static void bindToGroup(AsynchronousChannelGroupImpl group) {
myGroupAndInvokeCount.set(new GroupAndInvokeCount(group));
}
/**
* Returns the GroupAndInvokeCount object for this thread.
*/
static GroupAndInvokeCount getGroupAndInvokeCount() {
return myGroupAndInvokeCount.get();
}
/**
* Returns true if the current thread is in a channel group's thread pool
*/
static boolean isBoundToAnyGroup() {
return myGroupAndInvokeCount.get() != null;
}
/**
* Returns true if the current thread is in the given channel's thread
* pool and we haven't exceeded the maximum number of handler frames on
* the stack.
*/
static boolean mayInvokeDirect(GroupAndInvokeCount myGroupAndInvokeCount,
AsynchronousChannelGroupImpl group)
{
if ((myGroupAndInvokeCount != null) &&
(myGroupAndInvokeCount.group() == group) &&
(myGroupAndInvokeCount.invokeCount() < maxHandlerInvokeCount))
{
return true;
}
return false;
}
/**
* Invoke handler without checking the thread identity or number of handlers
* on the thread stack.
*/
static <V,A> void invokeUnchecked(CompletionHandler<V,? super A> handler,
A attachment,
V value,
Throwable exc)
{
if (exc == null) {
handler.completed(value, attachment);
} else {
handler.failed(exc, attachment);
}
// clear interrupt
Thread.interrupted();
}
/**
* Invoke handler assuming thread identity already checked
*/
static <V,A> void invokeDirect(GroupAndInvokeCount myGroupAndInvokeCount,
CompletionHandler<V,? super A> handler,
A attachment,
V result,
Throwable exc)
{
myGroupAndInvokeCount.incrementInvokeCount();
Invoker.invokeUnchecked(handler, attachment, result, exc);
}
/**
* Invokes the handler. If the current thread is in the channel group's
* thread pool then the handler is invoked directly, otherwise it is
* invoked indirectly.
*/
static <V,A> void invoke(AsynchronousChannel channel,
CompletionHandler<V,? super A> handler,
A attachment,
V result,
Throwable exc)
{
boolean invokeDirect = false;
boolean identityOkay = false;
GroupAndInvokeCount thisGroupAndInvokeCount = myGroupAndInvokeCount.get();
if (thisGroupAndInvokeCount != null) {
if ((thisGroupAndInvokeCount.group() == ((Groupable)channel).group()))
identityOkay = true;
if (identityOkay &&
(thisGroupAndInvokeCount.invokeCount() < maxHandlerInvokeCount))
{
// group match
invokeDirect = true;
}
}
if (invokeDirect) {
invokeDirect(thisGroupAndInvokeCount, handler, attachment, result, exc);
} else {
try {
invokeIndirectly(channel, handler, attachment, result, exc);
} catch (RejectedExecutionException ree) {
// channel group shutdown; fallback to invoking directly
// if the current thread has the right identity.
if (identityOkay) {
invokeDirect(thisGroupAndInvokeCount,
handler, attachment, result, exc);
} else {
throw new ShutdownChannelGroupException();
}
}
}
}
/**
* Invokes the handler indirectly via the channel group's thread pool.
*/
static <V,A> void invokeIndirectly(AsynchronousChannel channel,
final CompletionHandler<V,? super A> handler,
final A attachment,
final V result,
final Throwable exc)
{
try {
((Groupable)channel).group().executeOnPooledThread(new Runnable() {
public void run() {
GroupAndInvokeCount thisGroupAndInvokeCount =
myGroupAndInvokeCount.get();
if (thisGroupAndInvokeCount != null)
thisGroupAndInvokeCount.setInvokeCount(1);
invokeUnchecked(handler, attachment, result, exc);
}
});
} catch (RejectedExecutionException ree) {
throw new ShutdownChannelGroupException();
}
}
/**
* Invokes the handler "indirectly" in the given Executor
*/
static <V,A> void invokeIndirectly(final CompletionHandler<V,? super A> handler,
final A attachment,
final V value,
final Throwable exc,
Executor executor)
{
try {
executor.execute(new Runnable() {
public void run() {
invokeUnchecked(handler, attachment, value, exc);
}
});
} catch (RejectedExecutionException ree) {
throw new ShutdownChannelGroupException();
}
}
/**
* Invokes the given task on the thread pool associated with the given
* channel. If the current thread is in the thread pool then the task is
* invoked directly.
*/
static void invokeOnThreadInThreadPool(Groupable channel,
Runnable task)
{
boolean invokeDirect;
GroupAndInvokeCount thisGroupAndInvokeCount = myGroupAndInvokeCount.get();
AsynchronousChannelGroupImpl targetGroup = channel.group();
if (thisGroupAndInvokeCount == null) {
invokeDirect = false;
} else {
invokeDirect = (thisGroupAndInvokeCount.group == targetGroup);
}
try {
if (invokeDirect) {
task.run();
} else {
targetGroup.executeOnPooledThread(task);
}
} catch (RejectedExecutionException ree) {
throw new ShutdownChannelGroupException();
}
}
/**
* Invoke handler with completed result. This method does not check the
* thread identity or the number of handlers on the thread stack.
*/
static <V,A> void invokeUnchecked(PendingFuture<V,A> future) {
assert future.isDone();
CompletionHandler<V,? super A> handler = future.handler();
if (handler != null) {
invokeUnchecked(handler,
future.attachment(),
future.value(),
future.exception());
}
}
/**
* Invoke handler with completed result. If the current thread is in the
* channel group's thread pool then the handler is invoked directly,
* otherwise it is invoked indirectly.
*/
static <V,A> void invoke(PendingFuture<V,A> future) {
assert future.isDone();
CompletionHandler<V,? super A> handler = future.handler();
if (handler != null) {
invoke(future.channel(),
handler,
future.attachment(),
future.value(),
future.exception());
}
}
/**
* Invoke handler with completed result. The handler is invoked indirectly,
* via the channel group's thread pool.
*/
static <V,A> void invokeIndirectly(PendingFuture<V,A> future) {
assert future.isDone();
CompletionHandler<V,? super A> handler = future.handler();
if (handler != null) {
invokeIndirectly(future.channel(),
handler,
future.attachment(),
future.value(),
future.exception());
}
}
}