feat(jdk8): move files to new folder to avoid resources compiled.

jdkSrc/jdk8/com/sun/tools/jdi/VMState.java

@@ -0,0 +1,250 @@
+/*
+ * Copyright (c) 1999, 2020, 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 com.sun.tools.jdi;
+
+import com.sun.jdi.*;
+
+import java.lang.ref.WeakReference;
+import java.util.*;
+
+class VMState {
+    private final VirtualMachineImpl vm;
+
+    // Listeners
+    private final List<WeakReference<VMListener>> listeners = new ArrayList<WeakReference<VMListener>>(); // synchronized (this)
+    private boolean notifyingListeners = false;  // synchronized (this)
+
+    /*
+     * Certain information can be cached only when the entire VM is
+     * suspended and there are no pending resumes. The field below
+     * is used to track whether there are pending resumes.
+     */
+    private final Set<Integer> pendingResumeCommands = Collections.synchronizedSet(new HashSet<>());
+
+    // This is cached only while the VM is suspended
+    private static class Cache {
+        List<ThreadGroupReference> groups = null;  // cached Top Level ThreadGroups
+        List<ThreadReference> threads = null; // cached Threads
+    }
+
+    private Cache cache = null;               // synchronized (this)
+    private static final Cache markerCache = new Cache();
+
+    private void disableCache() {
+        synchronized (this) {
+            cache = null;
+        }
+    }
+
+    private void enableCache() {
+        synchronized (this) {
+            cache = markerCache;
+        }
+    }
+
+    private Cache getCache() {
+        synchronized (this) {
+            if (cache == markerCache) {
+                cache = new Cache();
+            }
+            return cache;
+        }
+    }
+
+    VMState(VirtualMachineImpl vm) {
+        this.vm = vm;
+    }
+
+    /**
+     * Is the VM currently suspended, for the purpose of caching?
+     * Must be called synchronized on vm.state()
+     */
+    boolean isSuspended() {
+        return cache != null;
+    }
+
+    /*
+     * A JDWP command has been completed (reply has been received).
+     * Update data that tracks pending resume commands.
+     */
+    void notifyCommandComplete(int id) {
+        pendingResumeCommands.remove(id);
+    }
+
+    synchronized void freeze() {
+        if (cache == null && (pendingResumeCommands.isEmpty())) {
+            /*
+             * No pending resumes to worry about. The VM is suspended
+             * and additional state can be cached. Notify all
+             * interested listeners.
+             */
+            processVMAction(new VMAction(vm, VMAction.VM_SUSPENDED));
+            enableCache();
+        }
+    }
+
+    synchronized PacketStream thawCommand(CommandSender sender) {
+        PacketStream stream = sender.send();
+        pendingResumeCommands.add(stream.id());
+        thaw();
+        return stream;
+    }
+
+    /**
+     * All threads are resuming
+     */
+    void thaw() {
+        thaw(null);
+    }
+
+    /**
+     * Tell listeners to invalidate suspend-sensitive caches.
+     * If resumingThread != null, then only that thread is being
+     * resumed.
+     */
+    synchronized void thaw(ThreadReference resumingThread) {
+        if (cache != null) {
+            if ((vm.traceFlags & VirtualMachine.TRACE_OBJREFS) != 0) {
+                vm.printTrace("Clearing VM suspended cache");
+            }
+            disableCache();
+        }
+        processVMAction(new VMAction(vm, resumingThread, VMAction.VM_NOT_SUSPENDED));
+    }
+
+    private synchronized void processVMAction(VMAction action) {
+        if (!notifyingListeners) {
+            // Prevent recursion
+            notifyingListeners = true;
+
+            Iterator<WeakReference<VMListener>> iter = listeners.iterator();
+            while (iter.hasNext()) {
+                WeakReference<VMListener> ref = iter.next();
+                VMListener listener = ref.get();
+                if (listener != null) {
+                    boolean keep = true;
+                    switch (action.id()) {
+                        case VMAction.VM_SUSPENDED:
+                            keep = listener.vmSuspended(action);
+                            break;
+                        case VMAction.VM_NOT_SUSPENDED:
+                            keep = listener.vmNotSuspended(action);
+                            break;
+                    }
+                    if (!keep) {
+                        iter.remove();
+                    }
+                } else {
+                    // Listener is unreachable; clean up
+                    iter.remove();
+                }
+            }
+
+            notifyingListeners = false;
+        }
+    }
+
+    synchronized void addListener(VMListener listener) {
+        listeners.add(new WeakReference<VMListener>(listener));
+    }
+
+    synchronized boolean hasListener(VMListener listener) {
+        Iterator<WeakReference<VMListener>> iter = listeners.iterator();
+        while (iter.hasNext()) {
+            WeakReference<VMListener> ref = iter.next();
+            if (listener.equals(ref.get())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    synchronized void removeListener(VMListener listener) {
+        Iterator<WeakReference<VMListener>> iter = listeners.iterator();
+        while (iter.hasNext()) {
+            WeakReference<VMListener> ref = iter.next();
+            if (listener.equals(ref.get())) {
+                iter.remove();
+                break;
+            }
+        }
+    }
+
+    List<ThreadReference> allThreads() {
+        List<ThreadReference> threads = null;
+        try {
+            Cache local = getCache();
+
+            if (local != null) {
+                // may be stale when returned, but not provably so
+                threads = local.threads;
+            }
+            if (threads == null) {
+                threads = Arrays.asList((ThreadReference[])JDWP.VirtualMachine.AllThreads.
+                                        process(vm).threads);
+                if (local != null) {
+                    local.threads = threads;
+                    if ((vm.traceFlags & VirtualMachine.TRACE_OBJREFS) != 0) {
+                        vm.printTrace("Caching all threads (count = " +
+                                      threads.size() + ") while VM suspended");
+                    }
+                }
+            }
+        } catch (JDWPException exc) {
+            throw exc.toJDIException();
+        }
+        return threads;
+    }
+
+
+    List<ThreadGroupReference> topLevelThreadGroups() {
+        List<ThreadGroupReference> groups = null;
+        try {
+            Cache local = getCache();
+
+            if (local != null) {
+                groups = local.groups;
+            }
+            if (groups == null) {
+                groups = Arrays.asList(
+                                (ThreadGroupReference[])JDWP.VirtualMachine.TopLevelThreadGroups.
+                                       process(vm).groups);
+                if (local != null) {
+                    local.groups = groups;
+                    if ((vm.traceFlags & VirtualMachine.TRACE_OBJREFS) != 0) {
+                        vm.printTrace(
+                          "Caching top level thread groups (count = " +
+                          groups.size() + ") while VM suspended");
+                    }
+                }
+            }
+        } catch (JDWPException exc) {
+            throw exc.toJDIException();
+        }
+        return groups;
+    }
+
+}