--- /dev/null	2017-11-09 09:38:01.297999907 +0100
+++ new/src/jdk.jfr/share/classes/jdk/jfr/internal/Repository.java	2018-04-09 16:03:29.154993395 +0200
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2012, 2018, 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 jdk.jfr.internal;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.HashSet;
+import java.util.Set;
+
+import jdk.jfr.internal.SecuritySupport.SafePath;
+
+public final class Repository {
+
+    private static final int MAX_REPO_CREATION_RETRIES = 1000;
+    private static final JVM jvm = JVM.getJVM();
+    private static final Repository instance = new Repository();
+
+    static DateTimeFormatter REPO_DATE_FORMAT = DateTimeFormatter
+            .ofPattern("yyyy_MM_dd_HH_mm_ss");
+
+    private final Set<SafePath> cleanupDirectories = new HashSet<>();
+    private SafePath baseLocation;
+    private SafePath repository;
+
+    private Repository() {
+    }
+
+    public static Repository getRepository() {
+        return instance;
+    }
+
+    public synchronized void setBasePath(SafePath baseLocation) throws Exception {
+        // Probe to see if repository can be created, needed for fail fast
+        // during JVM startup or JFR.configure
+        this.repository = createRepository(baseLocation);
+        try {
+            // Remove so we don't "leak" repositories, if JFR is never started
+            // and shutdown hook not added.
+            SecuritySupport.delete(repository);
+        } catch (IOException ioe) {
+            Logger.log(LogTag.JFR, LogLevel.INFO, "Could not delete disk repository " + repository);
+        }
+        this.baseLocation = baseLocation;
+    }
+
+    synchronized void ensureRepository() throws Exception {
+        if (baseLocation == null) {
+            setBasePath(SecuritySupport.JAVA_IO_TMPDIR);
+        }
+    }
+
+    synchronized RepositoryChunk newChunk(Instant timestamp) {
+        try {
+            if (!SecuritySupport.existDirectory(repository)) {
+                this.repository = createRepository(baseLocation);
+                jvm.setRepositoryLocation(repository.toString());
+                cleanupDirectories.add(repository);
+            }
+            return new RepositoryChunk(repository, timestamp);
+        } catch (Exception e) {
+            String errorMsg = String.format("Could not create chunk in repository %s, %s", repository, e.getMessage());
+            Logger.log(LogTag.JFR, LogLevel.ERROR, errorMsg);
+            jvm.abort(errorMsg);
+            throw new InternalError("Could not abort after JFR disk creation error");
+        }
+    }
+
+    private static SafePath createRepository(SafePath basePath) throws Exception {
+        SafePath canonicalBaseRepositoryPath = createRealBasePath(basePath);
+        SafePath f = null;
+
+        String basename = REPO_DATE_FORMAT.format(LocalDateTime.now()) + "_" + JVM.getJVM().getPid();
+        String name = basename;
+
+        int i = 0;
+        for (; i < MAX_REPO_CREATION_RETRIES; i++) {
+            f = new SafePath(canonicalBaseRepositoryPath.toPath().resolve(name));
+            if (tryToUseAsRepository(f)) {
+                break;
+            }
+            name = basename + "_" + i;
+        }
+
+        if (i == MAX_REPO_CREATION_RETRIES) {
+            throw new Exception("Unable to create JFR repository directory using base location (" + basePath + ")");
+        }
+        SafePath canonicalRepositoryPath = SecuritySupport.toRealPath(f);
+        return canonicalRepositoryPath;
+    }
+
+    private static SafePath createRealBasePath(SafePath safePath) throws Exception {
+        if (SecuritySupport.exists(safePath)) {
+            if (!SecuritySupport.isWritable(safePath)) {
+                throw new IOException("JFR repository directory (" + safePath.toString() + ") exists, but isn't writable");
+            }
+            return SecuritySupport.toRealPath(safePath);
+        }
+        SafePath p = SecuritySupport.createDirectories(safePath);
+        return SecuritySupport.toRealPath(p);
+    }
+
+    private static boolean tryToUseAsRepository(final SafePath path) {
+        Path parent = path.toPath().getParent();
+        if (parent == null) {
+            return false;
+        }
+        try {
+            try {
+                SecuritySupport.createDirectories(path);
+            } catch (Exception e) {
+                // file already existed or some other problem occurred
+            }
+            if (!SecuritySupport.exists(path)) {
+                return false;
+            }
+            if (!SecuritySupport.isDirectory(path)) {
+                return false;
+            }
+            return true;
+        } catch (IOException io) {
+            return false;
+        }
+    }
+
+    synchronized void clear() {
+        for (SafePath p : cleanupDirectories) {
+            try {
+                SecuritySupport.clearDirectory(p);
+                Logger.log(LogTag.JFR, LogLevel.INFO, "Removed repository " + p);
+            } catch (IOException e) {
+                Logger.log(LogTag.JFR, LogLevel.ERROR, "Repository " + p + " could not be removed at shutdown: " + e.getMessage());
+            }
+        }
+    }
+
+    public synchronized SafePath getRepositoryPath() {
+        return repository;
+    }
+}