| /******************************************************************************* |
| * Copyright (c) 2000, 2011 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.core.search.processing; |
| |
| import org.eclipse.core.runtime.*; |
| import org.eclipse.core.runtime.jobs.Job; |
| import org.eclipse.jdt.internal.core.util.Messages; |
| import org.eclipse.jdt.internal.core.util.Util; |
| |
| public abstract class JobManager implements Runnable { |
| |
| /* queue of jobs to execute */ |
| protected IJob[] awaitingJobs = new IJob[10]; |
| protected int jobStart = 0; |
| protected int jobEnd = -1; |
| protected boolean executing = false; |
| |
| /* background processing */ |
| protected Thread processingThread; |
| protected Job progressJob; |
| |
| /* counter indicating whether job execution is enabled or not, disabled if <= 0 |
| it cannot go beyond 1 */ |
| private int enableCount = 1; |
| |
| public static boolean VERBOSE = false; |
| /* flag indicating that the activation has completed */ |
| public boolean activated = false; |
| |
| private int awaitingClients = 0; |
| |
| /** |
| * Invoked exactly once, in background, before starting processing any job |
| */ |
| public void activateProcessing() { |
| this.activated = true; |
| } |
| /** |
| * Answer the amount of awaiting jobs. |
| */ |
| public synchronized int awaitingJobsCount() { |
| // pretend busy in case concurrent job attempts performing before activated |
| return this.activated ? this.jobEnd - this.jobStart + 1 : 1; |
| } |
| /** |
| * Answers the first job in the queue, or null if there is no job available |
| * Until the job has completed, the job manager will keep answering the same job. |
| */ |
| public synchronized IJob currentJob() { |
| if (this.enableCount > 0 && this.jobStart <= this.jobEnd) |
| return this.awaitingJobs[this.jobStart]; |
| return null; |
| } |
| public synchronized void disable() { |
| this.enableCount--; |
| if (VERBOSE) |
| Util.verbose("DISABLING background indexing"); //$NON-NLS-1$ |
| } |
| /** |
| * Remove the index from cache for a given project. |
| * Passing null as a job family discards them all. |
| */ |
| public void discardJobs(String jobFamily) { |
| |
| if (VERBOSE) |
| Util.verbose("DISCARD background job family - " + jobFamily); //$NON-NLS-1$ |
| |
| try { |
| IJob currentJob; |
| // cancel current job if it belongs to the given family |
| synchronized(this){ |
| currentJob = currentJob(); |
| disable(); |
| } |
| if (currentJob != null && (jobFamily == null || currentJob.belongsTo(jobFamily))) { |
| currentJob.cancel(); |
| |
| // wait until current active job has finished |
| while (this.processingThread != null && this.executing){ |
| try { |
| if (VERBOSE) |
| Util.verbose("-> waiting end of current background job - " + currentJob); //$NON-NLS-1$ |
| Thread.sleep(50); |
| } catch(InterruptedException e){ |
| // ignore |
| } |
| } |
| } |
| |
| // flush and compact awaiting jobs |
| int loc = -1; |
| synchronized(this) { |
| for (int i = this.jobStart; i <= this.jobEnd; i++) { |
| currentJob = this.awaitingJobs[i]; |
| if (currentJob != null) { // sanity check |
| this.awaitingJobs[i] = null; |
| if (!(jobFamily == null || currentJob.belongsTo(jobFamily))) { // copy down, compacting |
| this.awaitingJobs[++loc] = currentJob; |
| } else { |
| if (VERBOSE) |
| Util.verbose("-> discarding background job - " + currentJob); //$NON-NLS-1$ |
| currentJob.cancel(); |
| } |
| } |
| } |
| this.jobStart = 0; |
| this.jobEnd = loc; |
| } |
| } finally { |
| enable(); |
| } |
| if (VERBOSE) |
| Util.verbose("DISCARD DONE with background job family - " + jobFamily); //$NON-NLS-1$ |
| } |
| public synchronized void enable() { |
| this.enableCount++; |
| if (VERBOSE) |
| Util.verbose("ENABLING background indexing"); //$NON-NLS-1$ |
| notifyAll(); // wake up the background thread if it is waiting (context must be synchronized) |
| } |
| protected synchronized boolean isJobWaiting(IJob request) { |
| for (int i = this.jobEnd; i > this.jobStart; i--) // don't check job at jobStart, as it may have already started |
| if (request.equals(this.awaitingJobs[i])) return true; |
| return false; |
| } |
| /** |
| * Advance to the next available job, once the current one has been completed. |
| * Note: clients awaiting until the job count is zero are still waiting at this point. |
| */ |
| protected synchronized void moveToNextJob() { |
| //if (!enabled) return; |
| |
| if (this.jobStart <= this.jobEnd) { |
| this.awaitingJobs[this.jobStart++] = null; |
| if (this.jobStart > this.jobEnd) { |
| this.jobStart = 0; |
| this.jobEnd = -1; |
| } |
| } |
| } |
| /** |
| * When idle, give chance to do something |
| */ |
| protected void notifyIdle(long idlingTime) { |
| // do nothing |
| } |
| /** |
| * This API is allowing to run one job in concurrence with background processing. |
| * Indeed since other jobs are performed in background, resource sharing might be |
| * an issue.Therefore, this functionality allows a given job to be run without |
| * colliding with background ones. |
| * Note: multiple thread might attempt to perform concurrent jobs at the same time, |
| * and should synchronize (it is deliberately left to clients to decide whether |
| * concurrent jobs might interfere or not. In general, multiple read jobs are ok). |
| * |
| * Waiting policy can be: |
| * IJobConstants.ForceImmediateSearch |
| * IJobConstants.CancelIfNotReadyToSearch |
| * IJobConstants.WaitUntilReadyToSearch |
| * |
| */ |
| public boolean performConcurrentJob(IJob searchJob, int waitingPolicy, IProgressMonitor monitor) { |
| if (VERBOSE) |
| Util.verbose("STARTING concurrent job - " + searchJob); //$NON-NLS-1$ |
| |
| searchJob.ensureReadyToRun(); |
| |
| boolean status = IJob.FAILED; |
| try { |
| SubMonitor subMonitor = SubMonitor.convert(monitor); |
| if (awaitingJobsCount() > 0) { |
| switch (waitingPolicy) { |
| |
| case IJob.ForceImmediate : |
| if (VERBOSE) |
| Util.verbose("-> NOT READY - forcing immediate - " + searchJob);//$NON-NLS-1$ |
| try { |
| disable(); // pause indexing |
| status = searchJob.execute(subMonitor); |
| } finally { |
| enable(); |
| } |
| if (VERBOSE) |
| Util.verbose("FINISHED concurrent job - " + searchJob); //$NON-NLS-1$ |
| return status; |
| |
| case IJob.CancelIfNotReady : |
| if (VERBOSE) |
| Util.verbose("-> NOT READY - cancelling - " + searchJob); //$NON-NLS-1$ |
| if (VERBOSE) |
| Util.verbose("CANCELED concurrent job - " + searchJob); //$NON-NLS-1$ |
| throw new OperationCanceledException(); |
| |
| case IJob.WaitUntilReady : |
| int totalWork = 1000; |
| SubMonitor subProgress = subMonitor.setWorkRemaining(10).split(8).setWorkRemaining(totalWork); |
| // use local variable to avoid potential NPE (see bug 20435 NPE when searching java method |
| // and bug 42760 NullPointerException in JobManager when searching) |
| Thread t = this.processingThread; |
| int originalPriority = t == null ? -1 : t.getPriority(); |
| try { |
| if (t != null) |
| t.setPriority(Thread.currentThread().getPriority()); |
| synchronized(this) { |
| this.awaitingClients++; |
| } |
| IJob previousJob = null; |
| int awaitingJobsCount; |
| int lastJobsCount = totalWork; |
| float lastWorked = 0; |
| float totalWorked = 0; |
| while ((awaitingJobsCount = awaitingJobsCount()) > 0) { |
| if (subProgress.isCanceled() || this.processingThread == null) |
| throw new OperationCanceledException(); |
| IJob currentJob = currentJob(); |
| // currentJob can be null when jobs have been added to the queue but job manager is not enabled |
| if (currentJob != null && currentJob != previousJob) { |
| if (VERBOSE) |
| Util.verbose("-> NOT READY - waiting until ready - " + searchJob);//$NON-NLS-1$ |
| if (subProgress != null) { |
| String indexing = Messages.bind(Messages.jobmanager_filesToIndex, currentJob.getJobFamily(), Integer.toString(awaitingJobsCount)); |
| subProgress.subTask(indexing); |
| // ratio of the amount of work relative to the total work |
| float ratio = awaitingJobsCount < totalWork ? 1 : ((float) totalWork) / awaitingJobsCount; |
| if (lastJobsCount > awaitingJobsCount) { |
| totalWorked += (lastJobsCount - awaitingJobsCount) * ratio; |
| } else { |
| // more jobs were added, just increment by the ratio |
| totalWorked += ratio; |
| } |
| if (totalWorked - lastWorked >= 1) { |
| subProgress.worked((int) (totalWorked - lastWorked)); |
| lastWorked = totalWorked; |
| } |
| lastJobsCount = awaitingJobsCount; |
| } |
| previousJob = currentJob; |
| } |
| try { |
| if (VERBOSE) |
| Util.verbose("-> GOING TO SLEEP - " + searchJob);//$NON-NLS-1$ |
| Thread.sleep(50); |
| } catch (InterruptedException e) { |
| // ignore |
| } |
| } |
| } finally { |
| synchronized(this) { |
| this.awaitingClients--; |
| } |
| if (t != null && originalPriority > -1 && t.isAlive()) |
| t.setPriority(originalPriority); |
| } |
| } |
| } |
| status = searchJob.execute(subMonitor); |
| } finally { |
| SubMonitor.done(monitor); |
| if (VERBOSE) |
| Util.verbose("FINISHED concurrent job - " + searchJob); //$NON-NLS-1$ |
| } |
| return status; |
| } |
| public abstract String processName(); |
| |
| public synchronized void request(IJob job) { |
| |
| job.ensureReadyToRun(); |
| |
| // append the job to the list of ones to process later on |
| int size = this.awaitingJobs.length; |
| if (++this.jobEnd == size) { // when growing, relocate jobs starting at position 0 |
| this.jobEnd -= this.jobStart; // jobEnd now equals the number of jobs |
| if (this.jobEnd < 50 && this.jobEnd < this.jobStart) { |
| // plenty of free space in the queue so shift the remaining jobs to the beginning instead of growing it |
| System.arraycopy(this.awaitingJobs, this.jobStart, this.awaitingJobs, 0, this.jobEnd); |
| for (int i = this.jobStart; i < size; i++) |
| this.awaitingJobs[i] = null; |
| } else { |
| System.arraycopy(this.awaitingJobs, this.jobStart, this.awaitingJobs = new IJob[size * 2], 0, this.jobEnd); |
| } |
| this.jobStart = 0; |
| } |
| this.awaitingJobs[this.jobEnd] = job; |
| if (VERBOSE) { |
| Util.verbose("REQUEST background job - " + job); //$NON-NLS-1$ |
| Util.verbose("AWAITING JOBS count: " + awaitingJobsCount()); //$NON-NLS-1$ |
| } |
| notifyAll(); // wake up the background thread if it is waiting |
| } |
| /** |
| * Flush current state |
| */ |
| public synchronized void reset() { |
| if (VERBOSE) |
| Util.verbose("Reset"); //$NON-NLS-1$ |
| |
| if (this.processingThread != null) { |
| discardJobs(null); // discard all jobs |
| } else { |
| /* initiate background processing */ |
| this.processingThread = new Thread(this, processName()); |
| this.processingThread.setDaemon(true); |
| // less prioritary by default, priority is raised if clients are actively waiting on it |
| this.processingThread.setPriority(Thread.NORM_PRIORITY-1); |
| // https://bugs.eclipse.org/bugs/show_bug.cgi?id=296343 |
| // set the context loader to avoid leaking the current context loader |
| this.processingThread.setContextClassLoader(this.getClass().getClassLoader()); |
| this.processingThread.start(); |
| } |
| } |
| /** |
| * Infinite loop performing resource indexing |
| */ |
| public void run() { |
| |
| long idlingStart = -1; |
| activateProcessing(); |
| try { |
| class ProgressJob extends Job { |
| ProgressJob(String name) { |
| super(name); |
| } |
| protected IStatus run(IProgressMonitor monitor) { |
| IJob job = currentJob(); |
| while (!monitor.isCanceled() && job != null) { |
| String taskName = new StringBuffer(Messages.jobmanager_indexing) |
| .append(Messages.bind(Messages.jobmanager_filesToIndex, job.getJobFamily(), Integer.toString(awaitingJobsCount()))) |
| .toString(); |
| monitor.subTask(taskName); |
| setName(taskName); |
| try { |
| Thread.sleep(500); |
| } catch (InterruptedException e) { |
| // ignore |
| } |
| job = currentJob(); |
| } |
| return Status.OK_STATUS; |
| } |
| } |
| this.progressJob = null; |
| while (this.processingThread != null) { |
| try { |
| IJob job; |
| synchronized (this) { |
| // handle shutdown case when notifyAll came before the wait but after the while loop was entered |
| if (this.processingThread == null) continue; |
| |
| // must check for new job inside this sync block to avoid timing hole |
| if ((job = currentJob()) == null) { |
| if (this.progressJob != null) { |
| this.progressJob.cancel(); |
| this.progressJob = null; |
| } |
| if (idlingStart < 0) |
| idlingStart = System.currentTimeMillis(); |
| else |
| notifyIdle(System.currentTimeMillis() - idlingStart); |
| this.wait(); // wait until a new job is posted (or reenabled:38901) |
| } else { |
| idlingStart = -1; |
| } |
| } |
| if (job == null) { |
| notifyIdle(System.currentTimeMillis() - idlingStart); |
| // just woke up, delay before processing any new jobs, allow some time for the active thread to finish |
| Thread.sleep(500); |
| continue; |
| } |
| if (VERBOSE) { |
| Util.verbose(awaitingJobsCount() + " awaiting jobs"); //$NON-NLS-1$ |
| Util.verbose("STARTING background job - " + job); //$NON-NLS-1$ |
| } |
| try { |
| this.executing = true; |
| if (this.progressJob == null) { |
| this.progressJob = new ProgressJob(Messages.bind(Messages.jobmanager_indexing, "", "")); //$NON-NLS-1$ //$NON-NLS-2$ |
| this.progressJob.setPriority(Job.LONG); |
| this.progressJob.setSystem(true); |
| this.progressJob.schedule(); |
| } |
| /*boolean status = */job.execute(null); |
| //if (status == FAILED) request(job); |
| } finally { |
| this.executing = false; |
| if (VERBOSE) |
| Util.verbose("FINISHED background job - " + job); //$NON-NLS-1$ |
| moveToNextJob(); |
| if (this.awaitingClients == 0) |
| Thread.sleep(50); |
| } |
| } catch (InterruptedException e) { // background indexing was interrupted |
| } |
| } |
| } catch (RuntimeException e) { |
| if (this.processingThread != null) { // if not shutting down |
| // log exception |
| Util.log(e, "Background Indexer Crash Recovery"); //$NON-NLS-1$ |
| |
| // keep job manager alive |
| discardJobs(null); |
| this.processingThread = null; |
| reset(); // this will fork a new thread with no waiting jobs, some indexes will be inconsistent |
| } |
| throw e; |
| } catch (Error e) { |
| if (this.processingThread != null && !(e instanceof ThreadDeath)) { |
| // log exception |
| Util.log(e, "Background Indexer Crash Recovery"); //$NON-NLS-1$ |
| |
| // keep job manager alive |
| discardJobs(null); |
| this.processingThread = null; |
| reset(); // this will fork a new thread with no waiting jobs, some indexes will be inconsistent |
| } |
| throw e; |
| } |
| } |
| /** |
| * Stop background processing, and wait until the current job is completed before returning |
| */ |
| public void shutdown() { |
| |
| if (VERBOSE) |
| Util.verbose("Shutdown"); //$NON-NLS-1$ |
| |
| disable(); |
| discardJobs(null); // will wait until current executing job has completed |
| Thread thread = this.processingThread; |
| try { |
| if (thread != null) { // see http://bugs.eclipse.org/bugs/show_bug.cgi?id=31858 |
| synchronized (this) { |
| this.processingThread = null; // mark the job manager as shutting down so that the thread will stop by itself |
| notifyAll(); // ensure its awake so it can be shutdown |
| } |
| // in case processing thread is handling a job |
| thread.join(); |
| } |
| Job job = this.progressJob; |
| if (job != null) { |
| job.cancel(); |
| job.join(); |
| } |
| } catch (InterruptedException e) { |
| // ignore |
| } |
| } |
| public String toString() { |
| StringBuffer buffer = new StringBuffer(10); |
| buffer.append("Enable count:").append(this.enableCount).append('\n'); //$NON-NLS-1$ |
| int numJobs = this.jobEnd - this.jobStart + 1; |
| buffer.append("Jobs in queue:").append(numJobs).append('\n'); //$NON-NLS-1$ |
| for (int i = 0; i < numJobs && i < 15; i++) { |
| buffer.append(i).append(" - job["+i+"]: ").append(this.awaitingJobs[this.jobStart+i]).append('\n'); //$NON-NLS-1$ //$NON-NLS-2$ |
| } |
| return buffer.toString(); |
| } |
| } |