--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/jdk/internal/misc/VM.java Wed Jan 06 10:01:44 2016 +0000
@@ -0,0 +1,433 @@
+/*
+ * Copyright (c) 1996, 2015, 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.internal.misc;
+
+import static java.lang.Thread.State.*;
+import java.util.Properties;
+
+public class VM {
+
+ /* The following methods used to be native methods that instruct
+ * the VM to selectively suspend certain threads in low-memory
+ * situations. They are inherently dangerous and not implementable
+ * on native threads. We removed them in JDK 1.2. The skeletons
+ * remain so that existing applications that use these methods
+ * will still work.
+ */
+ private static boolean suspended = false;
+
+ /** @deprecated */
+ @Deprecated
+ public static boolean threadsSuspended() {
+ return suspended;
+ }
+
+ @SuppressWarnings("deprecation")
+ public static boolean allowThreadSuspension(ThreadGroup g, boolean b) {
+ return g.allowThreadSuspension(b);
+ }
+
+ /** @deprecated */
+ @Deprecated
+ public static boolean suspendThreads() {
+ suspended = true;
+ return true;
+ }
+
+ // Causes any suspended threadgroups to be resumed.
+ /** @deprecated */
+ @Deprecated
+ public static void unsuspendThreads() {
+ suspended = false;
+ }
+
+ // Causes threadgroups no longer marked suspendable to be resumed.
+ /** @deprecated */
+ @Deprecated
+ public static void unsuspendSomeThreads() {
+ }
+
+ /* Deprecated fields and methods -- Memory advice not supported in 1.2 */
+
+ /** @deprecated */
+ @Deprecated
+ public static final int STATE_GREEN = 1;
+
+ /** @deprecated */
+ @Deprecated
+ public static final int STATE_YELLOW = 2;
+
+ /** @deprecated */
+ @Deprecated
+ public static final int STATE_RED = 3;
+
+ /** @deprecated */
+ @Deprecated
+ public static final int getState() {
+ return STATE_GREEN;
+ }
+
+ /** @deprecated */
+ @Deprecated
+ public static void registerVMNotification(VMNotification n) { }
+
+ /** @deprecated */
+ @Deprecated
+ public static void asChange(int as_old, int as_new) { }
+
+ /** @deprecated */
+ @Deprecated
+ public static void asChange_otherthread(int as_old, int as_new) { }
+
+ /*
+ * Not supported in 1.2 because these will have to be exported as
+ * JVM functions, and we are not sure we want do that. Leaving
+ * here so it can be easily resurrected -- just remove the //
+ * comments.
+ */
+
+ /**
+ * Resume Java profiling. All profiling data is added to any
+ * earlier profiling, unless <code>resetJavaProfiler</code> is
+ * called in between. If profiling was not started from the
+ * command line, <code>resumeJavaProfiler</code> will start it.
+ * <p>
+ *
+ * NOTE: Profiling must be enabled from the command line for a
+ * java.prof report to be automatically generated on exit; if not,
+ * writeJavaProfilerReport must be invoked to write a report.
+ *
+ * @see resetJavaProfiler
+ * @see writeJavaProfilerReport
+ */
+
+ // public native static void resumeJavaProfiler();
+
+ /**
+ * Suspend Java profiling.
+ */
+ // public native static void suspendJavaProfiler();
+
+ /**
+ * Initialize Java profiling. Any accumulated profiling
+ * information is discarded.
+ */
+ // public native static void resetJavaProfiler();
+
+ /**
+ * Write the current profiling contents to the file "java.prof".
+ * If the file already exists, it will be overwritten.
+ */
+ // public native static void writeJavaProfilerReport();
+
+
+ private static volatile boolean booted = false;
+ private static final Object lock = new Object();
+
+ // Invoked by System.initializeSystemClass just before returning.
+ // Subsystems that are invoked during initialization can check this
+ // property in order to avoid doing things that should wait until the
+ // application class loader has been set up.
+ //
+ public static void booted() {
+ synchronized (lock) {
+ booted = true;
+ lock.notifyAll();
+ }
+ }
+
+ public static boolean isBooted() {
+ return booted;
+ }
+
+ // Waits until VM completes initialization
+ //
+ // This method is invoked by the Finalizer thread
+ public static void awaitBooted() throws InterruptedException {
+ synchronized (lock) {
+ while (!booted) {
+ lock.wait();
+ }
+ }
+ }
+
+ // A user-settable upper limit on the maximum amount of allocatable direct
+ // buffer memory. This value may be changed during VM initialization if
+ // "java" is launched with "-XX:MaxDirectMemorySize=<size>".
+ //
+ // The initial value of this field is arbitrary; during JRE initialization
+ // it will be reset to the value specified on the command line, if any,
+ // otherwise to Runtime.getRuntime().maxMemory().
+ //
+ private static long directMemory = 64 * 1024 * 1024;
+
+ // Returns the maximum amount of allocatable direct buffer memory.
+ // The directMemory variable is initialized during system initialization
+ // in the saveAndRemoveProperties method.
+ //
+ public static long maxDirectMemory() {
+ return directMemory;
+ }
+
+ // User-controllable flag that determines if direct buffers should be page
+ // aligned. The "-XX:+PageAlignDirectMemory" option can be used to force
+ // buffers, allocated by ByteBuffer.allocateDirect, to be page aligned.
+ private static boolean pageAlignDirectMemory;
+
+ // Returns {@code true} if the direct buffers should be page aligned. This
+ // variable is initialized by saveAndRemoveProperties.
+ public static boolean isDirectMemoryPageAligned() {
+ return pageAlignDirectMemory;
+ }
+
+ /**
+ * Returns true if the given class loader is in the system domain
+ * in which all permissions are granted.
+ */
+ public static boolean isSystemDomainLoader(ClassLoader loader) {
+ return loader == null;
+ }
+
+ /**
+ * Returns the system property of the specified key saved at
+ * system initialization time. This method should only be used
+ * for the system properties that are not changed during runtime.
+ * It accesses a private copy of the system properties so
+ * that user's locking of the system properties object will not
+ * cause the library to deadlock.
+ *
+ * Note that the saved system properties do not include
+ * the ones set by sun.misc.Version.init().
+ *
+ */
+ public static String getSavedProperty(String key) {
+ if (savedProps.isEmpty())
+ throw new IllegalStateException("Should be non-empty if initialized");
+
+ return savedProps.getProperty(key);
+ }
+
+ // TODO: the Property Management needs to be refactored and
+ // the appropriate prop keys need to be accessible to the
+ // calling classes to avoid duplication of keys.
+ private static final Properties savedProps = new Properties();
+
+ // Save a private copy of the system properties and remove
+ // the system properties that are not intended for public access.
+ //
+ // This method can only be invoked during system initialization.
+ public static void saveAndRemoveProperties(Properties props) {
+ if (booted)
+ throw new IllegalStateException("System initialization has completed");
+
+ savedProps.putAll(props);
+
+ // Set the maximum amount of direct memory. This value is controlled
+ // by the vm option -XX:MaxDirectMemorySize=<size>.
+ // The maximum amount of allocatable direct buffer memory (in bytes)
+ // from the system property sun.nio.MaxDirectMemorySize set by the VM.
+ // The system property will be removed.
+ String s = (String)props.remove("sun.nio.MaxDirectMemorySize");
+ if (s != null) {
+ if (s.equals("-1")) {
+ // -XX:MaxDirectMemorySize not given, take default
+ directMemory = Runtime.getRuntime().maxMemory();
+ } else {
+ long l = Long.parseLong(s);
+ if (l > -1)
+ directMemory = l;
+ }
+ }
+
+ // Check if direct buffers should be page aligned
+ s = (String)props.remove("sun.nio.PageAlignDirectMemory");
+ if ("true".equals(s))
+ pageAlignDirectMemory = true;
+
+ // Remove other private system properties
+ // used by java.lang.Integer.IntegerCache
+ props.remove("java.lang.Integer.IntegerCache.high");
+
+ // used by sun.launcher.LauncherHelper
+ props.remove("sun.java.launcher.diag");
+ }
+
+ // Initialize any miscellenous operating system settings that need to be
+ // set for the class libraries.
+ //
+ public static void initializeOSEnvironment() {
+ if (!booted) {
+ OSEnvironment.initialize();
+ }
+ }
+
+ /* Current count of objects pending for finalization */
+ private static volatile int finalRefCount;
+
+ /* Peak count of objects pending for finalization */
+ private static volatile int peakFinalRefCount;
+
+ /*
+ * Gets the number of objects pending for finalization.
+ *
+ * @return the number of objects pending for finalization.
+ */
+ public static int getFinalRefCount() {
+ return finalRefCount;
+ }
+
+ /*
+ * Gets the peak number of objects pending for finalization.
+ *
+ * @return the peak number of objects pending for finalization.
+ */
+ public static int getPeakFinalRefCount() {
+ return peakFinalRefCount;
+ }
+
+ /*
+ * Add {@code n} to the objects pending for finalization count.
+ *
+ * @param n an integer value to be added to the objects pending
+ * for finalization count
+ */
+ public static void addFinalRefCount(int n) {
+ // The caller must hold lock to synchronize the update.
+
+ finalRefCount += n;
+ if (finalRefCount > peakFinalRefCount) {
+ peakFinalRefCount = finalRefCount;
+ }
+ }
+
+ /**
+ * Returns Thread.State for the given threadStatus
+ */
+ public static Thread.State toThreadState(int threadStatus) {
+ if ((threadStatus & JVMTI_THREAD_STATE_RUNNABLE) != 0) {
+ return RUNNABLE;
+ } else if ((threadStatus & JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER) != 0) {
+ return BLOCKED;
+ } else if ((threadStatus & JVMTI_THREAD_STATE_WAITING_INDEFINITELY) != 0) {
+ return WAITING;
+ } else if ((threadStatus & JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT) != 0) {
+ return TIMED_WAITING;
+ } else if ((threadStatus & JVMTI_THREAD_STATE_TERMINATED) != 0) {
+ return TERMINATED;
+ } else if ((threadStatus & JVMTI_THREAD_STATE_ALIVE) == 0) {
+ return NEW;
+ } else {
+ return RUNNABLE;
+ }
+ }
+
+ /* The threadStatus field is set by the VM at state transition
+ * in the hotspot implementation. Its value is set according to
+ * the JVM TI specification GetThreadState function.
+ */
+ private static final int JVMTI_THREAD_STATE_ALIVE = 0x0001;
+ private static final int JVMTI_THREAD_STATE_TERMINATED = 0x0002;
+ private static final int JVMTI_THREAD_STATE_RUNNABLE = 0x0004;
+ private static final int JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER = 0x0400;
+ private static final int JVMTI_THREAD_STATE_WAITING_INDEFINITELY = 0x0010;
+ private static final int JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT = 0x0020;
+
+ /*
+ * Returns the first non-null class loader up the execution stack,
+ * or null if only code from the null class loader is on the stack.
+ */
+ public static native ClassLoader latestUserDefinedLoader();
+
+ /**
+ * Returns {@code true} if we are in a set UID program.
+ */
+ public static boolean isSetUID() {
+ long uid = getuid();
+ long euid = geteuid();
+ long gid = getgid();
+ long egid = getegid();
+ return uid != euid || gid != egid;
+ }
+
+ /**
+ * Returns the real user ID of the calling process,
+ * or -1 if the value is not available.
+ */
+ public static native long getuid();
+
+ /**
+ * Returns the effective user ID of the calling process,
+ * or -1 if the value is not available.
+ */
+ public static native long geteuid();
+
+ /**
+ * Returns the real group ID of the calling process,
+ * or -1 if the value is not available.
+ */
+ public static native long getgid();
+
+ /**
+ * Returns the effective group ID of the calling process,
+ * or -1 if the value is not available.
+ */
+ public static native long getegid();
+
+ /**
+ * Get a nanosecond time stamp adjustment in the form of a single long.
+ *
+ * This value can be used to create an instant using
+ * {@link java.time.Instant#ofEpochSecond(long, long)
+ * java.time.Instant.ofEpochSecond(offsetInSeconds,
+ * getNanoTimeAdjustment(offsetInSeconds))}.
+ * <p>
+ * The value returned has the best resolution available to the JVM on
+ * the current system.
+ * This is usually down to microseconds - or tenth of microseconds -
+ * depending on the OS/Hardware and the JVM implementation.
+ *
+ * @param offsetInSeconds The offset in seconds from which the nanosecond
+ * time stamp should be computed.
+ *
+ * @apiNote The offset should be recent enough - so that
+ * {@code offsetInSeconds} is within {@code +/- 2^32} seconds of the
+ * current UTC time. If the offset is too far off, {@code -1} will be
+ * returned. As such, {@code -1} must not be considered as a valid
+ * nano time adjustment, but as an exception value indicating
+ * that an offset closer to the current time should be used.
+ *
+ * @return A nanosecond time stamp adjustment in the form of a single long.
+ * If the offset is too far off the current time, this method returns -1.
+ * In that case, the caller should call this method again, passing a
+ * more accurate offset.
+ */
+ public static native long getNanoTimeAdjustment(long offsetInSeconds);
+
+ static {
+ initialize();
+ }
+ private static native void initialize();
+}