diff options
Diffstat (limited to 'bundles/org.eclipse.team.cvs.core/src/org/eclipse/team/internal/ccvs/core/syncinfo/ReentrantLock.java')
| -rw-r--r-- | bundles/org.eclipse.team.cvs.core/src/org/eclipse/team/internal/ccvs/core/syncinfo/ReentrantLock.java | 328 |
1 files changed, 0 insertions, 328 deletions
diff --git a/bundles/org.eclipse.team.cvs.core/src/org/eclipse/team/internal/ccvs/core/syncinfo/ReentrantLock.java b/bundles/org.eclipse.team.cvs.core/src/org/eclipse/team/internal/ccvs/core/syncinfo/ReentrantLock.java deleted file mode 100644 index fbae8d65e..000000000 --- a/bundles/org.eclipse.team.cvs.core/src/org/eclipse/team/internal/ccvs/core/syncinfo/ReentrantLock.java +++ /dev/null @@ -1,328 +0,0 @@ -/******************************************************************************* - * Copyright (c) 2000, 2003 IBM Corporation and others. - * All rights reserved. This program and the accompanying materials - * are made available under the terms of the Common Public License v1.0 - * which accompanies this distribution, and is available at - * http://www.eclipse.org/legal/cpl-v10.html - * - * Contributors: - * IBM Corporation - initial API and implementation - *******************************************************************************/ -package org.eclipse.team.internal.ccvs.core.syncinfo; - -import java.util.ArrayList; -import java.util.HashMap; -import java.util.HashSet; -import java.util.Iterator; -import java.util.List; -import java.util.Map; -import java.util.Set; - -import org.eclipse.core.resources.IContainer; -import org.eclipse.core.resources.IResource; -import org.eclipse.core.runtime.IProgressMonitor; -import org.eclipse.core.runtime.IStatus; -import org.eclipse.core.runtime.OperationCanceledException; -import org.eclipse.core.runtime.Platform; -import org.eclipse.core.runtime.jobs.ISchedulingRule; -import org.eclipse.core.runtime.jobs.MultiRule; -import org.eclipse.team.internal.ccvs.core.CVSException; -import org.eclipse.team.internal.ccvs.core.CVSProviderPlugin; -import org.eclipse.team.internal.ccvs.core.CVSStatus; -import org.eclipse.team.internal.ccvs.core.Policy; -import org.eclipse.team.internal.ccvs.core.util.Assert; - -/** - * Provides a per-thread nested locking mechanism. A thread can acquire a - * lock on a specific resource by calling acquire(). Subsequently, acquire() can be called - * multiple times on the resource or any of its children from within the same thread - * without blocking. Other threads that try - * and acquire the lock on those same resources will be blocked until the first - * thread releases all it's nested locks. - * <p> - * The locking is managed by the platform via scheduling rules. This class simply - * provides the nesting mechnism in order to allow the client to determine when - * the lock for the thread has been released. Therefore, this lock will block if - * another thread already locks the same resource.</p> - */ -public class ReentrantLock { - - private final static boolean DEBUG = Policy.DEBUG_THREADING; - - // This is a placeholder rule used to indicate that no scheduling rule is needed - /* internal use only */ static final ISchedulingRule NULL_SCHEDULING_RULE= new ISchedulingRule() { - public boolean contains(ISchedulingRule rule) { - return false; - } - public boolean isConflicting(ISchedulingRule rule) { - return false; - } - }; - - public class ThreadInfo { - private Set changedResources = new HashSet(); - private Set changedFolders = new HashSet(); - private IFlushOperation operation; - private List rules = new ArrayList(); - public ThreadInfo(IFlushOperation operation) { - this.operation = operation; - } - /** - * Push a scheduling rule onto the stack for this thread and - * acquire the rule if it is not the workspace root. - * @param resource - */ - public ISchedulingRule pushRule(ISchedulingRule resource, IProgressMonitor monitor) { - // The scheduling rule is either the project or the resource's parent - ISchedulingRule rule = getRuleForResoure(resource); - if (rule != NULL_SCHEDULING_RULE) { - try { - Platform.getJobManager().beginRule(rule, monitor); - } catch (RuntimeException e) { - // The begin was cancelled (or some other problem occurred). - // Free the scheduling rule and throw the cancel - // so the clients of ReentrantLock don't need to - // do an endRule when the operation is cancelled. - Platform.getJobManager().endRule(rule); - throw e; - } - } - addRule(rule); - return rule; - } - /** - * Pop the scheduling rule from the stack and release it if it - * is not the workspace root. Flush any changed sync info to - * disk if necessary. A flush is necessary if the stack is empty - * or if the top-most non-null scheduling rule was popped as a result - * of this operation. - * @param monitor - * @throws CVSException - */ - public void popRule(ISchedulingRule rule, IProgressMonitor monitor) throws CVSException { - try { - if (isFlushRequired()) { - flush(monitor); - } - } finally { - ISchedulingRule stackedRule = removeRule(); - if (rule == null) { - rule = NULL_SCHEDULING_RULE; - } - Assert.isTrue(stackedRule.equals(rule), "end for resource '" + rule + "' does not match stacked rule '" + stackedRule + "'"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ - if (rule != NULL_SCHEDULING_RULE) { - Platform.getJobManager().endRule(rule); - } - } - } - private ISchedulingRule getRuleForResoure(ISchedulingRule resourceRule) { - ISchedulingRule rule; - if (resourceRule instanceof IResource) { - IResource resource = (IResource)resourceRule; - if (resource.getType() == IResource.ROOT) { - // Never lock the whole workspace - rule = NULL_SCHEDULING_RULE; - } else if (resource.getType() == IResource.PROJECT) { - rule = resource; - } else { - rule = resource.getParent(); - } - } else if (resourceRule instanceof MultiRule) { - // Create a MultiRule for all projects from the given rule - ISchedulingRule[] rules = ((MultiRule)resourceRule).getChildren(); - Set projects = new HashSet(); - for (int i = 0; i < rules.length; i++) { - ISchedulingRule childRule = rules[i]; - if (childRule instanceof IResource) { - projects.add(((IResource)childRule).getProject()); - } - } - if (projects.isEmpty()) { - rule = NULL_SCHEDULING_RULE; - } else if (projects.size() == 1) { - rule = (ISchedulingRule)projects.iterator().next(); - } else { - rule = new MultiRule((ISchedulingRule[]) projects.toArray(new ISchedulingRule[projects.size()])); - } - } else { - // Rule is not associated with resources so ignore it - rule = NULL_SCHEDULING_RULE; - } - return rule; - } - /** - * Return <code>true</code> if we are still nested in - * an acquire for this thread. - * - * @return - */ - public boolean isNested() { - return !rules.isEmpty(); - } - public void addChangedResource(IResource resource) { - changedResources.add(resource); - } - public void addChangedFolder(IContainer container) { - changedFolders.add(container); - } - public boolean isEmpty() { - return changedFolders.isEmpty() && changedResources.isEmpty(); - } - public IResource[] getChangedResources() { - return (IResource[]) changedResources.toArray(new IResource[changedResources.size()]); - } - public IContainer[] getChangedFolders() { - return (IContainer[]) changedFolders.toArray(new IContainer[changedFolders.size()]); - } - public void flush(IProgressMonitor monitor) throws CVSException { - try { - operation.flush(this, monitor); - } catch (OutOfMemoryError e) { - throw e; - } catch (Error e) { - handleAbortedFlush(e); - throw e; - } catch (RuntimeException e) { - handleAbortedFlush(e); - throw e; - } finally { - // We have to clear the resources no matter what since the next attempt - // to fluch may not have an appropriate scheduling rule - changedResources.clear(); - changedFolders.clear(); - } - } - private boolean isFlushRequired() { - return rules.size() == 1 || remainingRulesAreNull(); - } - /* - * Return true if all but the last rule in the stack is null - */ - private boolean remainingRulesAreNull() { - for (int i = 0; i < rules.size() - 1; i++) { - ISchedulingRule rule = (ISchedulingRule) rules.get(i); - if (rule != NULL_SCHEDULING_RULE) { - return false; - } - } - return true; - } - private void handleAbortedFlush(Throwable t) { - CVSProviderPlugin.log(new CVSStatus(IStatus.ERROR, Policy.bind("ReentrantLock.9"), t)); //$NON-NLS-1$ - } - private void addRule(ISchedulingRule rule) { - rules.add(rule); - } - private ISchedulingRule removeRule() { - return (ISchedulingRule)rules.remove(rules.size() - 1); - } - public boolean ruleContains(IResource resource) { - for (Iterator iter = rules.iterator(); iter.hasNext();) { - ISchedulingRule rule = (ISchedulingRule) iter.next(); - if (rule != NULL_SCHEDULING_RULE && rule.contains(resource)) { - return true; - } - } - return false; - } - } - - public interface IFlushOperation { - public void flush(ThreadInfo info, IProgressMonitor monitor) throws CVSException; - } - - private Map infos = new HashMap(); - - private ThreadInfo getThreadInfo() { - Thread thisThread = Thread.currentThread(); - synchronized (infos) { - ThreadInfo info = (ThreadInfo)infos.get(thisThread); - return info; - } - } - - private ThreadInfo getThreadInfo(IResource resource) { - synchronized (infos) { - for (Iterator iter = infos.values().iterator(); iter.hasNext();) { - ThreadInfo info = (ThreadInfo) iter.next(); - if (info.ruleContains(resource)) { - return info; - } - } - return null; - } - } - - public ISchedulingRule acquire(ISchedulingRule resourceRule, IFlushOperation operation, IProgressMonitor monitor) { - ThreadInfo info = getThreadInfo(); - boolean added = false; - synchronized (infos) { - if (info == null) { - info = new ThreadInfo(operation); - Thread thisThread = Thread.currentThread(); - infos.put(thisThread, info); - added = true; - if(DEBUG) System.out.println("[" + thisThread.getName() + "] acquired CVS lock on " + resourceRule); //$NON-NLS-1$ //$NON-NLS-2$ - } - } - try { - return info.pushRule(resourceRule, monitor); - } catch (OperationCanceledException e) { - // The operation was cancelled. - // If this is the outermost acquire then remove the info that was just added - if (added) { - synchronized (infos) { - infos.remove(Thread.currentThread()); - } - } - throw e; - } - } - - /** - * Release the lock held on any resources by this thread. The provided rule must - * be identical to the rule returned by the corresponding acquire(). If the rule - * for the release is non-null and all remaining rules held by the lock are null, - * the the flush operation provided in the acquire method will be executed. - */ - public void release(ISchedulingRule rule, IProgressMonitor monitor) throws CVSException { - ThreadInfo info = getThreadInfo(); - Assert.isNotNull(info, "Unmatched acquire/release."); //$NON-NLS-1$ - Assert.isTrue(info.isNested(), "Unmatched acquire/release."); //$NON-NLS-1$ - info.popRule(rule, monitor); - synchronized (infos) { - if (!info.isNested()) { - Thread thisThread = Thread.currentThread(); - if(DEBUG) System.out.println("[" + thisThread.getName() + "] released CVS lock"); //$NON-NLS-1$ //$NON-NLS-2$ - infos.remove(thisThread); - } - } - } - - public void folderChanged(IContainer folder) { - ThreadInfo info = getThreadInfo(); - Assert.isNotNull(info, "Folder changed outside of resource lock"); //$NON-NLS-1$ - info.addChangedFolder(folder); - } - - public void resourceChanged(IResource resource) { - ThreadInfo info = getThreadInfo(); - Assert.isNotNull(info, "Folder changed outside of resource lock"); //$NON-NLS-1$ - info.addChangedResource(resource); - } - - /** - * Flush any changes accumulated by the lock so far. - */ - public void flush(IProgressMonitor monitor) throws CVSException { - ThreadInfo info = getThreadInfo(); - Assert.isNotNull(info, "Flush requested outside of resource lock"); //$NON-NLS-1$ - info.flush(monitor); - } - - public boolean isWithinActiveOperationScope(IResource resource) { - synchronized (infos) { - return getThreadInfo(resource) != null; - } - } -} |