299987 : Removal of p2 services in favor of always using an agent.

12 files changed, 175 insertions, 150 deletions

diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/md5/MD5Verifier.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/md5/MD5Verifier.java
index d79f88394..49aa609a2 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/md5/MD5Verifier.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/md5/MD5Verifier.java
@@ -11,8 +11,6 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.artifact.processors.md5;
 
-import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
-
 import java.io.IOException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
@@ -20,7 +18,9 @@ import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.equinox.internal.p2.artifact.repository.Activator;
 import org.eclipse.equinox.internal.provisional.p2.artifact.repository.processing.ProcessingStep;
+import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactDescriptor;
+import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
 import org.eclipse.osgi.util.NLS;
 
 public class MD5Verifier extends ProcessingStep {
@@ -39,8 +39,8 @@ public class MD5Verifier extends ProcessingStep {
 	}
 
 	//This handle the case where the MD5 verification is initiated by a processing step
-	public void initialize(IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
-		super.initialize(descriptor, context);
+	public void initialize(IProvisioningAgent agent, IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
+		super.initialize(agent, descriptor, context);
 		String data = descriptor.getData();
 		if (IArtifactDescriptor.DOWNLOAD_MD5.equals(data))
 			expectedMD5 = context.getProperty(IArtifactDescriptor.DOWNLOAD_MD5);
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/pack200/Pack200ProcessorStep.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/pack200/Pack200ProcessorStep.java
index cf5778e67..8bf32b705 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/pack200/Pack200ProcessorStep.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/processors/pack200/Pack200ProcessorStep.java
@@ -11,8 +11,6 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.artifact.processors.pack200;
 
-import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
-
 import java.io.*;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
@@ -20,7 +18,9 @@ import org.eclipse.equinox.internal.p2.artifact.processing.AbstractBufferingStep
 import org.eclipse.equinox.internal.p2.artifact.repository.Activator;
 import org.eclipse.equinox.internal.p2.core.helpers.FileUtils;
 import org.eclipse.equinox.internal.p2.jarprocessor.UnpackStep;
+import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactDescriptor;
+import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
 import org.eclipse.internal.provisional.equinox.p2.jarprocessor.JarProcessorExecutor;
 import org.eclipse.internal.provisional.equinox.p2.jarprocessor.JarProcessorExecutor.Options;
 
@@ -37,8 +37,8 @@ public class Pack200ProcessorStep extends AbstractBufferingStep {
 		return new BufferedOutputStream(new FileOutputStream(incoming));
 	}
 
-	public void initialize(IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
-		super.initialize(descriptor, context);
+	public void initialize(IProvisioningAgent agent, IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
+		super.initialize(agent, descriptor, context);
 		if (!UnpackStep.canUnpack())
 			setStatus(new Status(IStatus.ERROR, Activator.ID, "Unpack facility not configured")); //$NON-NLS-1$
 	}
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/Activator.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/Activator.java
index 6a41d2d38..043ba761d 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/Activator.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/Activator.java
@@ -10,76 +10,24 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.artifact.repository;
 
-import java.util.HashMap;
-import java.util.Map;
-import org.eclipse.equinox.p2.core.IProvisioningAgent;
-import org.eclipse.equinox.p2.repository.artifact.IArtifactRepositoryManager;
-import org.osgi.framework.*;
-import org.osgi.util.tracker.ServiceTracker;
-import org.osgi.util.tracker.ServiceTrackerCustomizer;
+import org.osgi.framework.BundleActivator;
+import org.osgi.framework.BundleContext;
 
-public class Activator implements BundleActivator, ServiceTrackerCustomizer {
+public class Activator implements BundleActivator {
 	public static final String ID = "org.eclipse.equinox.p2.artifact.repository"; //$NON-NLS-1$
 	public static final String REPO_PROVIDER_XPT = ID + '.' + "artifactRepositories"; //$NON-NLS-1$
 
 	private static BundleContext context;
-	private ServiceRegistration repositoryManagerRegistration;
-	private static final Map<ArtifactRepositoryManager, IProvisioningAgent> createdManagers = new HashMap<ArtifactRepositoryManager, IProvisioningAgent>();
-	private ServiceTracker agentTracker;
 
 	public static BundleContext getContext() {
 		return Activator.context;
 	}
 
-	/**
-	 * Remember an artifact repository manager so we can shut it down when the bundle stops
-	 */
-	static void addManager(ArtifactRepositoryManager manager, IProvisioningAgent agent) {
-		synchronized (createdManagers) {
-			createdManagers.put(manager, agent);
-		}
-	}
-
 	public void start(BundleContext aContext) throws Exception {
 		Activator.context = aContext;
-		// need to track agent so we can register global artifact repository manager
-		String filter = "(&(objectClass=" + IProvisioningAgent.SERVICE_NAME + ")(agent.current=true))"; //$NON-NLS-1$ //$NON-NLS-2$
-		agentTracker = new ServiceTracker(context, aContext.createFilter(filter), this);
-		agentTracker.open();
 	}
 
 	public void stop(BundleContext aContext) throws Exception {
 		Activator.context = null;
-		if (repositoryManagerRegistration != null)
-			repositoryManagerRegistration.unregister();
-		repositoryManagerRegistration = null;
-		synchronized (createdManagers) {
-			for (ArtifactRepositoryManager manager : createdManagers.keySet()) {
-				manager.shutdown();
-				IProvisioningAgent agent = createdManagers.get(manager);
-				agent.unregisterService(IArtifactRepositoryManager.SERVICE_NAME, manager);
-			}
-			createdManagers.clear();
-		}
-		agentTracker.close();
-	}
-
-	public Object addingService(ServiceReference reference) {
-		//when someone registers the agent service, register a repository manager service
-		IProvisioningAgent agent = (IProvisioningAgent) context.getService(reference);
-		repositoryManagerRegistration = context.registerService(IArtifactRepositoryManager.SERVICE_NAME, agent.getService(IArtifactRepositoryManager.SERVICE_NAME), null);
-		return agent;
-	}
-
-	public void modifiedService(ServiceReference reference, Object service) {
-		// ignored
-	}
-
-	public void removedService(ServiceReference reference, Object service) {
-		//the agent is going away so withdraw our service
-		if (repositoryManagerRegistration != null) {
-			repositoryManagerRegistration.unregister();
-			repositoryManagerRegistration = null;
-		}
 	}
 }
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryComponent.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryComponent.java
index 901457a8e..6a0a01505 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryComponent.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryComponent.java
@@ -10,8 +10,6 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.artifact.repository;
 
-import org.eclipse.equinox.internal.provisional.p2.core.eventbus.IProvisioningEventBus;
-import org.eclipse.equinox.p2.core.IAgentLocation;
 import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.core.spi.IAgentServiceFactory;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactRepositoryManager;
@@ -22,11 +20,6 @@ import org.eclipse.equinox.p2.repository.artifact.IArtifactRepositoryManager;
 public class ArtifactRepositoryComponent implements IAgentServiceFactory {
 
 	public Object createService(IProvisioningAgent agent) {
-		final ArtifactRepositoryManager manager = new ArtifactRepositoryManager();
-		manager.setEventBus((IProvisioningEventBus) agent.getService(IProvisioningEventBus.SERVICE_NAME));
-		manager.setAgentLocation((IAgentLocation) agent.getService(IAgentLocation.SERVICE_NAME));
-		manager.setAgent(agent);
-		Activator.addManager(manager, agent);
-		return manager;
+		return new ArtifactRepositoryManager(agent);
 	}
 }
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryManager.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryManager.java
index 21e54aa6f..9b6cfdb01 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryManager.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/ArtifactRepositoryManager.java
@@ -16,10 +16,8 @@ import java.util.HashMap;
 import java.util.Map;
 import org.eclipse.core.runtime.*;
 import org.eclipse.equinox.internal.p2.core.helpers.LogHelper;
-import org.eclipse.equinox.internal.p2.core.helpers.ServiceHelper;
 import org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager;
-import org.eclipse.equinox.p2.core.IAgentLocation;
-import org.eclipse.equinox.p2.core.ProvisionException;
+import org.eclipse.equinox.p2.core.*;
 import org.eclipse.equinox.p2.metadata.IArtifactKey;
 import org.eclipse.equinox.p2.repository.IRepository;
 import org.eclipse.equinox.p2.repository.artifact.*;
@@ -33,8 +31,8 @@ import org.eclipse.equinox.p2.repository.artifact.spi.ArtifactRepositoryFactory;
  */
 public class ArtifactRepositoryManager extends AbstractRepositoryManager<IArtifactKey> implements IArtifactRepositoryManager {
 
-	public ArtifactRepositoryManager() {
-		super();
+	public ArtifactRepositoryManager(IProvisioningAgent agent) {
+		super(agent);
 	}
 
 	public void addRepository(IArtifactRepository repository) {
@@ -109,7 +107,7 @@ public class ArtifactRepositoryManager extends AbstractRepositoryManager<IArtifa
 	 */
 	protected void restoreSpecialRepositories() {
 		// TODO while recreating, we may want to have proxies on repo instead of the real repo object to limit what is activated.
-		IAgentLocation location = (IAgentLocation) ServiceHelper.getService(Activator.getContext(), IAgentLocation.class.getName());
+		IAgentLocation location = (IAgentLocation) getAgent().getService(IAgentLocation.SERVICE_NAME);
 		if (location == null)
 			// TODO should do something here since we are failing to restore.
 			return;
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/CompositeArtifactRepository.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/CompositeArtifactRepository.java
index e1fb37a64..7e2820a80 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/CompositeArtifactRepository.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/CompositeArtifactRepository.java
@@ -84,7 +84,7 @@ public class CompositeArtifactRepository extends AbstractArtifactRepository impl
 	 * This is only called by the parser when loading a repository.
 	 */
 	CompositeArtifactRepository(IArtifactRepositoryManager manager, CompositeRepositoryState state) {
-		super(state.getName(), state.getType(), state.getVersion(), state.getLocation(), state.getDescription(), state.getProvider(), state.getProperties());
+		super(manager.getAgent(), state.getName(), state.getType(), state.getVersion(), state.getLocation(), state.getDescription(), state.getProvider(), state.getProperties());
 		this.manager = manager;
 		for (int i = 0; i < state.getChildren().length; i++)
 			addChild(state.getChildren()[i], false);
@@ -94,7 +94,7 @@ public class CompositeArtifactRepository extends AbstractArtifactRepository impl
 	 * @noreference This constructor is not intended to be referenced by clients.
 	 */
 	protected CompositeArtifactRepository(IArtifactRepositoryManager manager, URI location, String repositoryName, Map<String, String> properties) {
-		super(repositoryName, REPOSITORY_TYPE, REPOSITORY_VERSION.toString(), location, null, null, properties);
+		super(manager.getAgent(), repositoryName, REPOSITORY_TYPE, REPOSITORY_VERSION.toString(), location, null, null, properties);
 		this.manager = manager;
 		save();
 	}
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/MirrorSelector.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/MirrorSelector.java
index 6fb6259de..1fbd11df8 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/MirrorSelector.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/MirrorSelector.java
@@ -11,6 +11,7 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.artifact.repository;
 
+import java.io.FileNotFoundException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.*;
@@ -40,8 +41,15 @@ public class MirrorSelector {
 	 * Encapsulates information about a single mirror
 	 */
 	public static class MirrorInfo implements Comparable<MirrorInfo> {
+		private static final long PRIMARY_FAILURE_LINGER_TIME = 30000; // Retry again after 30 seconds
+		private static final long SECONDARY_FAILURE_LINGER_TIME = 300000; // Wait 5 minutes
+		private static final int ACCEPTABLE_FILE_NOT_FOUND_COUNT = 5; // Given an established connection, those are generally quick
+		private static final Timer resetFailure = new Timer("Mirror failure timer", true); //$NON-NLS-1$
+
 		long bytesPerSecond;
 		int failureCount;
+		int fileNotFoundCount;
+		int totalFailureCount;
 		private final int initialRank;
 		String locationString;
 
@@ -51,33 +59,86 @@ public class MirrorSelector {
 			if (!locationString.endsWith("/")) //$NON-NLS-1$
 				locationString = locationString + "/"; //$NON-NLS-1$
 			failureCount = 0;
+			totalFailureCount = 0;
 			bytesPerSecond = DownloadStatus.UNKNOWN_RATE;
 		}
 
 		/**
 		 * Comparison used to sort mirrors.
 		 */
-		public int compareTo(MirrorInfo that) {
-			//less failures is better
-			if (this.failureCount != that.failureCount)
-				return this.failureCount - that.failureCount;
-			//faster is better
-			if (this.bytesPerSecond != that.bytesPerSecond)
-				return (int) (that.bytesPerSecond - this.bytesPerSecond);
-			//trust that initial rank indicates geographical proximity
-			return this.initialRank - that.initialRank;
+		public synchronized int compareTo(MirrorInfo that) {
+			synchronized (that) {
+				double rank = 0.0;
+				if (bytesPerSecond != that.bytesPerSecond) {
+					if (bytesPerSecond != DownloadStatus.UNKNOWN_RATE && that.bytesPerSecond != DownloadStatus.UNKNOWN_RATE) {
+						if (bytesPerSecond > that.bytesPerSecond)
+							rank -= (double) bytesPerSecond / (double) that.bytesPerSecond;
+						else
+							rank += (double) that.bytesPerSecond / (double) bytesPerSecond;
+					}
+				}
+
+				//less failures is better
+				if (failureCount != that.failureCount) {
+					if (failureCount > that.failureCount)
+						rank += ((double) (failureCount + 1) / (double) (that.failureCount + 1)) * 2.0;
+					else
+						rank -= ((double) (that.failureCount + 1) / (double) (failureCount + 1)) * 2.0;
+				}
+
+				if (rank == 0.0)
+					//trust that initial rank indicates geographical proximity
+					rank = initialRank - that.initialRank;
+
+				if (rank == 0.0)
+					return 0;
+
+				int intRank;
+				intRank = (int) rank;
+				if (intRank == 0)
+					intRank = rank > 0 ? 1 : -1;
+				return intRank;
+			}
 		}
 
-		public void incrementFailureCount() {
-			this.failureCount++;
+		public synchronized String toString() {
+			return "Mirror(" + locationString + ',' + failureCount + ',' + bytesPerSecond + ')'; //$NON-NLS-1$
 		}
 
-		public void setBytesPerSecond(long newValue) {
-			this.bytesPerSecond = newValue;
+		public synchronized void decrementFailureCount() {
+			if (failureCount > 0)
+				failureCount--;
 		}
 
-		public String toString() {
-			return "Mirror(" + locationString + ',' + failureCount + ',' + bytesPerSecond + ')'; //$NON-NLS-1$
+		public synchronized void incrementFailureCount() {
+			++failureCount;
+			++totalFailureCount;
+			if (totalFailureCount < 3) {
+				resetFailure.schedule(new TimerTask() {
+					@Override
+					public void run() {
+						decrementFailureCount();
+					}
+				}, totalFailureCount == 1 ? PRIMARY_FAILURE_LINGER_TIME : SECONDARY_FAILURE_LINGER_TIME);
+			}
+		}
+
+		public synchronized void setBytesPerSecond(long newValue) {
+			// Any non-positive value is treated as an unknown rate
+			if (newValue <= 0)
+				newValue = DownloadStatus.UNKNOWN_RATE;
+
+			if (newValue > 0)
+				// Back in commission
+				failureCount = 0;
+			bytesPerSecond = newValue;
+		}
+
+		public synchronized void incrementFileNotFoundCount() {
+			if (++fileNotFoundCount > ACCEPTABLE_FILE_NOT_FOUND_COUNT) {
+				incrementFailureCount();
+				fileNotFoundCount = 0;
+			}
 		}
 	}
 
@@ -220,8 +281,16 @@ public class MirrorSelector {
 		for (int i = 0; i < mirrors.length; i++) {
 			MirrorInfo mirror = mirrors[i];
 			if (toDownload.startsWith(mirror.locationString)) {
-				if (!result.isOK() && result.getSeverity() != IStatus.CANCEL)
-					mirror.incrementFailureCount();
+				if (!result.isOK() && result.getSeverity() != IStatus.CANCEL) {
+					// Punishing a mirror harshly for a FileNotFoundException can be very wrong.
+					// Some artifacts are not found on any mirror. When that's the case,
+					// the best mirrors will be the first to receive that kind of punishment.
+					//
+					if (result.getException() instanceof FileNotFoundException)
+						mirror.incrementFileNotFoundCount();
+					else
+						mirror.incrementFailureCount();
+				}
 				if (result instanceof DownloadStatus) {
 					long oldRate = mirror.bytesPerSecond;
 					long newRate = ((DownloadStatus) result).getTransferRate();
@@ -232,7 +301,6 @@ public class MirrorSelector {
 				}
 				if (Tracing.DEBUG_MIRRORS)
 					Tracing.debug("Updated mirror " + mirror); //$NON-NLS-1$
-				Arrays.sort(mirrors);
 				return;
 			}
 		}
@@ -243,9 +311,11 @@ public class MirrorSelector {
 	 * @return whether or not there is a valid mirror in this selector.
 	 */
 	public synchronized boolean hasValidMirror() {
-		// return true if there is a mirror and it has not failed.  Since the mirrors
-		// list is sorted with failures last, we only have to test the first element for failure.
-		return mirrors != null && mirrors.length > 0 && mirrors[0].failureCount == 0;
+		// return true if there is a mirror and it doesn't have multiple failures.
+		if (mirrors == null || mirrors.length == 0)
+			return false;
+		Arrays.sort(mirrors);
+		return mirrors[0].failureCount < 2;
 	}
 
 	/**
@@ -257,22 +327,37 @@ public class MirrorSelector {
 		int mirrorCount;
 		if (mirrors == null || (mirrorCount = mirrors.length) == 0)
 			return null;
-		//this is a function that randomly selects a mirror based on a logarithmic
-		//distribution. Mirror 0 has a 1/2 chance of being selected, mirror 1 has a 1/4 chance, 
-		// mirror 2 has a 1/8 chance, etc. This introduces some variation in the mirror 
-		//selection, while still heavily favoring better mirrors
-		//the algorithm computes the most significant digit in a binary number by computing the base 2 logarithm
-		//if the first digit is most significant, mirror 0 is selected, if the second is most significant, mirror 1 is selected, etc
-		int highestMirror = Math.min(15, mirrorCount);
-		int result = (int) (Math.log(random.nextInt(1 << highestMirror) + 1) / LOG2);
-		if (result >= highestMirror || result < 0)
-			result = highestMirror - 1;
-		MirrorInfo selected = mirrors[highestMirror - 1 - result];
-		//if we selected a mirror that has failed in the past, revert to best available mirror
-		if (selected.failureCount > 0)
+
+		MirrorInfo selected;
+		if (mirrorCount == 1)
 			selected = mirrors[0];
-		//for now, don't tolerate failing mirrors
-		if (selected.failureCount > 0)
+		else {
+			Arrays.sort(mirrors);
+			for (;;) {
+				//this is a function that randomly selects a mirror based on a logarithmic
+				//distribution. Mirror 0 has a 1/2 chance of being selected, mirror 1 has a 1/4 chance, 
+				// mirror 2 has a 1/8 chance, etc. This introduces some variation in the mirror 
+				//selection, while still heavily favoring better mirrors
+				//the algorithm computes the most significant digit in a binary number by computing the base 2 logarithm
+				//if the first digit is most significant, mirror 0 is selected, if the second is most significant, mirror 1 is selected, etc
+				int highestMirror = Math.min(15, mirrorCount);
+				int result = (int) (Math.log(random.nextInt(1 << highestMirror) + 1) / LOG2);
+				if (result >= highestMirror || result < 0)
+					result = highestMirror - 1;
+
+				int mirrorIndex = highestMirror - 1 - result;
+				selected = mirrors[mirrorIndex];
+
+				// If the ranking of the selected mirror is significantly worse then the top ranked
+				// mirror, then we consider this a bad choice and reiterate.
+				if (mirrorIndex == 0 || mirrors[0].compareTo(selected) < 4)
+					// This is good enough
+					break;
+			}
+		}
+
+		//for now, don't tolerate mirrors with multiple failures
+		if (selected.failureCount > 1)
 			return null;
 		return selected;
 	}
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepository.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepository.java
index 4f9a0c33c..674df3b9d 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepository.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepository.java
@@ -24,11 +24,11 @@ import org.eclipse.equinox.internal.p2.artifact.processors.md5.MD5Verifier;
 import org.eclipse.equinox.internal.p2.artifact.repository.*;
 import org.eclipse.equinox.internal.p2.artifact.repository.Messages;
 import org.eclipse.equinox.internal.p2.core.helpers.FileUtils;
-import org.eclipse.equinox.internal.p2.core.helpers.ServiceHelper;
 import org.eclipse.equinox.internal.p2.repository.RepositoryTransport;
 import org.eclipse.equinox.internal.p2.repository.Transport;
 import org.eclipse.equinox.internal.provisional.p2.artifact.repository.processing.*;
 import org.eclipse.equinox.internal.provisional.p2.repository.IStateful;
+import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.core.ProvisionException;
 import org.eclipse.equinox.p2.metadata.IArtifactKey;
 import org.eclipse.equinox.p2.query.*;
@@ -257,8 +257,8 @@ public class SimpleArtifactRepository extends AbstractArtifactRepository impleme
 	/*
 	 * This is only called by the parser when loading a repository.
 	 */
-	SimpleArtifactRepository(String name, String type, String version, String description, String provider, Set<SimpleArtifactDescriptor> artifacts, String[][] mappingRules, Map<String, String> properties) {
-		super(name, type, version, null, description, provider, properties);
+	SimpleArtifactRepository(IProvisioningAgent agent, String name, String type, String version, String description, String provider, Set<SimpleArtifactDescriptor> artifacts, String[][] mappingRules, Map<String, String> properties) {
+		super(agent, name, type, version, null, description, provider, properties);
 		this.artifactDescriptors.addAll(artifacts);
 		this.mappingRules = mappingRules;
 		for (SimpleArtifactDescriptor desc : artifactDescriptors)
@@ -286,8 +286,8 @@ public class SimpleArtifactRepository extends AbstractArtifactRepository impleme
 			artifactMap.remove(key);
 	}
 
-	public SimpleArtifactRepository(String repositoryName, URI location, Map<String, String> properties) {
-		super(repositoryName, REPOSITORY_TYPE, REPOSITORY_VERSION.toString(), location, null, null, properties);
+	public SimpleArtifactRepository(IProvisioningAgent agent, String repositoryName, URI location, Map<String, String> properties) {
+		super(agent, repositoryName, REPOSITORY_TYPE, REPOSITORY_VERSION.toString(), location, null, null, properties);
 		initializeAfterLoad(location);
 		if (properties != null) {
 			if (properties.containsKey(PUBLISH_PACK_FILES_AS_SIBLINGS)) {
@@ -834,7 +834,7 @@ public class SimpleArtifactRepository extends AbstractArtifactRepository impleme
 
 	public OutputStream processDestination(ProcessingStepHandler handler, IArtifactDescriptor descriptor, OutputStream destination, IProgressMonitor monitor) {
 		destination = addPostSteps(handler, descriptor, destination, monitor);
-		destination = handler.createAndLink(descriptor.getProcessingSteps(), descriptor, destination, monitor);
+		destination = handler.createAndLink(agent, descriptor.getProcessingSteps(), descriptor, destination, monitor);
 		destination = addPreSteps(handler, descriptor, destination, monitor);
 		return destination;
 	}
@@ -940,7 +940,7 @@ public class SimpleArtifactRepository extends AbstractArtifactRepository impleme
 					os = jOs;
 				}
 				super.setProperty(IRepository.PROP_TIMESTAMP, Long.toString(System.currentTimeMillis()));
-				new SimpleArtifactRepositoryIO().write(this, os);
+				new SimpleArtifactRepositoryIO(agent).write(this, os);
 			} catch (IOException e) {
 				// TODO proper exception handling
 				e.printStackTrace();
@@ -969,7 +969,7 @@ public class SimpleArtifactRepository extends AbstractArtifactRepository impleme
 		}
 		save();
 		//force repository manager to reload this repository because it caches properties
-		ArtifactRepositoryManager manager = (ArtifactRepositoryManager) ServiceHelper.getService(Activator.getContext(), IArtifactRepositoryManager.SERVICE_NAME);
+		ArtifactRepositoryManager manager = (ArtifactRepositoryManager) agent.getService(IArtifactRepositoryManager.SERVICE_NAME);
 		if (manager.removeRepository(getLocation()))
 			manager.addRepository(this);
 		return oldValue;
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryFactory.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryFactory.java
index a3aec4822..d9cd59a79 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryFactory.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryFactory.java
@@ -10,10 +10,6 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.artifact.repository.simple;
 
-import org.eclipse.equinox.p2.repository.artifact.spi.ArtifactRepositoryFactory;
-
-import org.eclipse.equinox.p2.core.ProvisionException;
-
 import java.io.*;
 import java.net.URI;
 import java.util.Map;
@@ -25,8 +21,10 @@ import org.eclipse.equinox.internal.p2.artifact.repository.Messages;
 import org.eclipse.equinox.internal.p2.core.helpers.Tracing;
 import org.eclipse.equinox.internal.p2.repository.RepositoryTransport;
 import org.eclipse.equinox.internal.p2.repository.Transport;
+import org.eclipse.equinox.p2.core.ProvisionException;
 import org.eclipse.equinox.p2.repository.IRepositoryManager;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactRepository;
+import org.eclipse.equinox.p2.repository.artifact.spi.ArtifactRepositoryFactory;
 import org.eclipse.osgi.util.NLS;
 
 public class SimpleArtifactRepositoryFactory extends ArtifactRepositoryFactory {
@@ -99,7 +97,7 @@ public class SimpleArtifactRepositoryFactory extends ArtifactRepositoryFactory {
 					}
 					descriptorStream = jInStream;
 				}
-				SimpleArtifactRepositoryIO io = new SimpleArtifactRepositoryIO();
+				SimpleArtifactRepositoryIO io = new SimpleArtifactRepositoryIO(getAgent());
 				SimpleArtifactRepository result = (SimpleArtifactRepository) io.read(localFile.toURL(), descriptorStream, sub.newChild(100));
 				result.initializeAfterLoad(location);
 				if (Tracing.DEBUG_METADATA_PARSING) {
@@ -124,7 +122,7 @@ public class SimpleArtifactRepositoryFactory extends ArtifactRepositoryFactory {
 	}
 
 	public IArtifactRepository create(URI location, String name, String type, Map<String, String> properties) {
-		return new SimpleArtifactRepository(name, location, properties);
+		return new SimpleArtifactRepository(getAgent(), name, location, properties);
 	}
 
 	private Transport getTransport() {
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryIO.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryIO.java
index 477aac105..06df4e3e6 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryIO.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/p2/artifact/repository/simple/SimpleArtifactRepositoryIO.java
@@ -10,13 +10,6 @@
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.artifact.repository.simple;
 
-import org.eclipse.equinox.p2.metadata.Version;
-import org.eclipse.equinox.p2.metadata.VersionRange;
-
-import org.eclipse.equinox.p2.core.ProvisionException;
-
-import org.eclipse.equinox.p2.repository.artifact.spi.ProcessingStepDescriptor;
-
 import java.io.*;
 import java.net.URL;
 import java.util.*;
@@ -29,8 +22,12 @@ import org.eclipse.equinox.internal.p2.core.helpers.OrderedProperties;
 import org.eclipse.equinox.internal.p2.metadata.ArtifactKey;
 import org.eclipse.equinox.internal.p2.persistence.XMLParser;
 import org.eclipse.equinox.internal.p2.persistence.XMLWriter;
-import org.eclipse.equinox.p2.metadata.IArtifactKey;
-import org.eclipse.equinox.p2.repository.artifact.*;
+import org.eclipse.equinox.p2.core.IProvisioningAgent;
+import org.eclipse.equinox.p2.core.ProvisionException;
+import org.eclipse.equinox.p2.metadata.*;
+import org.eclipse.equinox.p2.repository.artifact.IArtifactRepository;
+import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
+import org.eclipse.equinox.p2.repository.artifact.spi.ProcessingStepDescriptor;
 import org.eclipse.osgi.util.NLS;
 import org.osgi.framework.BundleContext;
 import org.xml.sax.*;
@@ -46,6 +43,12 @@ import org.xml.sax.*;
 //		 for getting a repository reader/writer given a repository type
 public class SimpleArtifactRepositoryIO {
 
+	private final IProvisioningAgent agent;
+
+	public SimpleArtifactRepositoryIO(IProvisioningAgent agent) {
+		this.agent = agent;
+	}
+
 	/**
 	 * Writes the given artifact repository to the stream.
 	 * This method performs buffering, and closes the stream when finished.
@@ -330,7 +333,7 @@ public class SimpleArtifactRepositoryIO {
 							: propertiesHandler.getProperties());
 					Set<SimpleArtifactDescriptor> artifacts = (artifactsHandler == null ? new HashSet<SimpleArtifactDescriptor>(0) //
 							: artifactsHandler.getArtifacts());
-					repository = new SimpleArtifactRepository(attrValues[0], attrValues[1], attrValues[2], attrValues[3], //
+					repository = new SimpleArtifactRepository(agent, attrValues[0], attrValues[1], attrValues[2], attrValues[3], //
 							attrValues[4], artifacts, mappingRules, properties);
 				}
 			}
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStep.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStep.java
index 403670e1a..c0e4858ec 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStep.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStep.java
@@ -11,13 +11,13 @@
 *******************************************************************************/
 package org.eclipse.equinox.internal.provisional.p2.artifact.repository.processing;
 
-import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
-
 import java.io.IOException;
 import java.io.OutputStream;
 import org.eclipse.core.runtime.*;
 import org.eclipse.equinox.internal.provisional.p2.repository.IStateful;
+import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactDescriptor;
+import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
 
 /**
  * ProcessingSteps process the data written to them and pass the resultant data on
@@ -41,7 +41,7 @@ public abstract class ProcessingStep extends OutputStream implements IStateful {
 	 * @param descriptor description of the step
 	 * @param context the context in which the step is being used
 	 */
-	public void initialize(IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
+	public void initialize(IProvisioningAgent agent, IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
 		// nothing to do here!
 	}
 
diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStepHandler.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStepHandler.java
index 0387fcd28..e5530e937 100644
--- a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStepHandler.java
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/processing/ProcessingStepHandler.java
@@ -11,15 +11,15 @@
 *******************************************************************************/
 package org.eclipse.equinox.internal.provisional.p2.artifact.repository.processing;
 
-import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
-
 import java.io.OutputStream;
 import java.util.ArrayList;
 import org.eclipse.core.runtime.*;
 import org.eclipse.equinox.internal.p2.artifact.repository.Activator;
 import org.eclipse.equinox.internal.p2.artifact.repository.simple.SimpleArtifactRepository.ArtifactOutputStream;
 import org.eclipse.equinox.internal.provisional.p2.repository.IStateful;
+import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactDescriptor;
+import org.eclipse.equinox.p2.repository.artifact.IProcessingStepDescriptor;
 import org.eclipse.osgi.util.NLS;
 
 /**
@@ -127,14 +127,14 @@ public class ProcessingStepHandler {
 		return null;
 	}
 
-	public ProcessingStep[] create(IProcessingStepDescriptor[] descriptors, IArtifactDescriptor context) {
+	public ProcessingStep[] create(IProvisioningAgent agent, IProcessingStepDescriptor[] descriptors, IArtifactDescriptor context) {
 		ProcessingStep[] result = new ProcessingStep[descriptors.length];
 		for (int i = 0; i < descriptors.length; i++)
-			result[i] = create(descriptors[i], context);
+			result[i] = create(agent, descriptors[i], context);
 		return result;
 	}
 
-	public ProcessingStep create(IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
+	public ProcessingStep create(IProvisioningAgent agent, IProcessingStepDescriptor descriptor, IArtifactDescriptor context) {
 		IExtensionRegistry registry = RegistryFactory.getRegistry();
 		IExtension extension = registry.getExtension(PROCESSING_STEPS_EXTENSION_ID, descriptor.getProcessorId());
 		Exception error;
@@ -143,7 +143,7 @@ public class ProcessingStepHandler {
 			try {
 				Object object = config[0].createExecutableExtension("class"); //$NON-NLS-1$
 				ProcessingStep step = (ProcessingStep) object;
-				step.initialize(descriptor, context);
+				step.initialize(agent, descriptor, context);
 				return step;
 			} catch (Exception e) {
 				error = e;
@@ -157,10 +157,10 @@ public class ProcessingStepHandler {
 		return result;
 	}
 
-	public OutputStream createAndLink(IProcessingStepDescriptor[] descriptors, IArtifactDescriptor context, OutputStream output, IProgressMonitor monitor) {
+	public OutputStream createAndLink(IProvisioningAgent agent, IProcessingStepDescriptor[] descriptors, IArtifactDescriptor context, OutputStream output, IProgressMonitor monitor) {
 		if (descriptors == null)
 			return output;
-		ProcessingStep[] steps = create(descriptors, context);
+		ProcessingStep[] steps = create(agent, descriptors, context);
 		return link(steps, output, monitor);
 	}