[releng] Try project deletion multiple times

We sometimes see test failures in the master build caused by not being
able to delete a test project. See builds 173, 170, 165... for examples.

Therefore repeat project deletion in case of error, as it may be locked
by some other concurrent processing.

Change-Id: I3dbeba99a4d5bf5a6e0c9e960c5abb2277c057a1
Signed-off-by: Michael Keppler <Michael.Keppler@gmx.de>

3 files changed, 55 insertions, 43 deletions

diff --git a/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestProject.java b/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestProject.java
index acef0d0408..c27eb0fc64 100644
--- a/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestProject.java
+++ b/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestProject.java
@@ -92,8 +92,9 @@ public class TestProject {
 		IProjectDescription description = createDescription(path, insidews,
 				root);
 		project = root.getProject(description.getName());
-		if (remove)
-			project.delete(true, null);
+		if (remove) {
+			TestUtils.deleteProject(project);
+		}
 		IPath locationBefore = null;
 		URI locationURI = description.getLocationURI();
 		if (locationURI != null) {
@@ -204,9 +205,9 @@ public class TestProject {
 
 	public void dispose() throws CoreException, IOException {
 		waitForIndexer();
-		if (project.exists())
-			project.delete(true, true, null);
-		else {
+		if (project.exists()) {
+			TestUtils.deleteProject(project);
+		} else {
 			File f = new File(location);
 			if (f.exists())
 				FileUtils.delete(f, FileUtils.RECURSIVE | FileUtils.RETRY);
diff --git a/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestUtils.java b/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestUtils.java
index a18cd8935b..207269e618 100644
--- a/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestUtils.java
+++ b/org.eclipse.egit.core.junit/src/org/eclipse/egit/core/test/TestUtils.java
@@ -35,8 +35,10 @@ import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IProjectDescription;
+import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.ICoreRunnable;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.jobs.IJobManager;
@@ -55,6 +57,10 @@ public class TestUtils {
 
 	private final static File rootDir = customTestDirectory();
 
+	private static final int MAX_DELETE_RETRY = 5;
+
+	private static final int DELETE_RETRY_DELAY = 1000; // ms
+
 	/**
 	 * Allow to set a custom directory for running tests
 	 *
@@ -412,4 +418,45 @@ public class TestUtils {
 		return dump.toString();
 	}
 
+	/**
+	 * Delete a project and repeat multiple times in case of resource deletion
+	 * errors. A {@link ICoreRunnable} is used to avoid concurrent activities
+	 * disturbing the deletion.
+	 *
+	 * @param project
+	 *
+	 * @throws CoreException
+	 */
+	public static void deleteProject(IProject project) throws CoreException {
+		ResourcesPlugin.getWorkspace().run(monitor -> {
+			// Following code inspired by {@link
+			// org.eclipse.jdt.testplugin.JavaProjectHelper#delete(IResource)}.
+			// Sometimes resource deletion may fail due to concurrently held
+			// locks.
+			for (int i = 0; i < MAX_DELETE_RETRY; i++) {
+				try {
+					project.delete(
+							IResource.FORCE
+									| IResource.ALWAYS_DELETE_PROJECT_CONTENT,
+							null);
+					break;
+				} catch (CoreException e) {
+					if (i == MAX_DELETE_RETRY - 1) {
+						throw e;
+					}
+					try {
+						org.eclipse.egit.core.Activator.logInfo(
+								"Sleep before retrying to delete project "
+										+ project.getLocationURI());
+						// Give other threads the time to close and release
+						// the resource.
+						Thread.sleep(DELETE_RETRY_DELAY);
+					} catch (InterruptedException e1) {
+						// Ignore and retry to delete
+					}
+				}
+			}
+		}, null);
+	}
+
 }
diff --git a/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/common/JavaProjectTester.java b/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/common/JavaProjectTester.java
index eb602c628a..4013f75da3 100644
--- a/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/common/JavaProjectTester.java
+++ b/org.eclipse.egit.ui.test/src/org/eclipse/egit/ui/common/JavaProjectTester.java
@@ -32,6 +32,7 @@ import org.eclipse.egit.core.Activator;
 import org.eclipse.egit.core.internal.indexdiff.IndexDiffCache;
 import org.eclipse.egit.core.op.CommitOperation;
 import org.eclipse.egit.core.op.ConnectProviderOperation;
+import org.eclipse.egit.core.test.TestUtils;
 import org.eclipse.egit.ui.test.TestUtil;
 import org.eclipse.jdt.core.IClasspathEntry;
 import org.eclipse.jdt.core.IJavaProject;
@@ -61,10 +62,6 @@ public class JavaProjectTester {
 	public static final String INITIAL_FILE_CONTENT = "package " + PACKAGE_NAME
 			+ ";\nclass " + JAVA_CLASS_NAME + " {\n\n}";
 
-	private static final int MAX_DELETE_RETRY = 5;
-
-	private static final int DELETE_RETRY_DELAY = 1000; // ms
-
 	private final LocalRepositoryTestCase testCase;
 
 	public JavaProjectTester(LocalRepositoryTestCase testCase) {
@@ -190,40 +187,7 @@ public class JavaProjectTester {
 			return;
 		}
 		final IProject project = javaProject.getProject();
-		IWorkspaceRunnable runnable = new IWorkspaceRunnable() {
-			@Override
-			public void run(IProgressMonitor monitor) throws CoreException {
-				// Following code inspired by {@link
-				// org.eclipse.jdt.testplugin.JavaProjectHelper#delete(IResource)}.
-				// I don't like all this sleeping at all, but apparently it's
-				// needed because the Java indexer might still run and hold on
-				// to some resources.
-				for (int i = 0; i < MAX_DELETE_RETRY; i++) {
-					try {
-						project.delete(IResource.FORCE
-								| IResource.ALWAYS_DELETE_PROJECT_CONTENT,
-								null);
-						break;
-					} catch (CoreException e) {
-						if (i == MAX_DELETE_RETRY - 1) {
-							throw e;
-						}
-						try {
-							Activator.logInfo(
-									"Sleep before retrying to delete project "
-											+ project.getLocationURI());
-							// Give other threads the time to close and release
-							// the resource.
-							Thread.sleep(DELETE_RETRY_DELAY);
-						} catch (InterruptedException e1) {
-							// Ignore and retry to delete
-						}
-					}
-				}
-
-			}
-		};
-		ResourcesPlugin.getWorkspace().run(runnable, null);
+		TestUtils.deleteProject(project);
 	}
 
 }