/*
* Copyright (c) 1996, 2005, 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 sun.misc;
import java.util.Properties;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
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;
}
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;
// Invoked by 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() {
booted = true;
}
public static boolean isBooted() {
return booted;
}
// 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.maxDirectMemory().
//
private static long directMemory = 64 * 1024 * 1024;
// If this method is invoked during VM initialization, it initializes the
// maximum amount of allocatable direct buffer memory (in bytes) from the
// system property sun.nio.MaxDirectMemorySize. The system property will
// be removed when it is accessed.
//
// If this method is invoked after the VM is booted, it returns the
// maximum amount of allocatable direct buffer memory.
//
public static long maxDirectMemory() {
if (booted)
return directMemory;
Properties p = System.getProperties();
String s = (String)p.remove("sun.nio.MaxDirectMemorySize");
System.setProperties(p);
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;
}
}
return directMemory;
}
// A user-settable boolean to determine whether ClassLoader.loadClass should
// accept array syntax. This value may be changed during VM initialization
// via the system property "sun.lang.ClassLoader.allowArraySyntax".
//
// The default for 1.5 is "true", array syntax is allowed. In 1.6, the
// default will be "false". The presence of this system property to
// control array syntax allows applications the ability to preview this new
// behaviour.
//
private static boolean defaultAllowArraySyntax = false;
private static boolean allowArraySyntax = defaultAllowArraySyntax;
// If this method is invoked during VM initialization, it initializes the
// allowArraySyntax boolean based on the value of the system property
// "sun.lang.ClassLoader.allowArraySyntax". If the system property is not
// provided, the default for 1.5 is "true". In 1.6, the default will be
// "false". If the system property is provided, then the value of
// allowArraySyntax will be equal to "true" if Boolean.parseBoolean()
// returns "true". Otherwise, the field will be set to "false".
//
// If this method is invoked after the VM is booted, it returns the
// allowArraySyntax boolean set during initialization.
//
public static boolean allowArraySyntax() {
if (!booted) {
String s
= System.getProperty("sun.lang.ClassLoader.allowArraySyntax");
allowArraySyntax = (s == null
? defaultAllowArraySyntax
: Boolean.parseBoolean(s));
}
return allowArraySyntax;
}
// 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 = 0;
/* Peak count of objects pending for finalization */
private static volatile int peakFinalRefCount = 0;
/*
* 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 <tt>n</tt> 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;
}
}
public static Thread.State toThreadState(int threadStatus) {
// Initialize the threadStateMap
initThreadStateMap();
Thread.State s = threadStateMap.get(threadStatus);
if (s == null) {
// default to RUNNABLE if the threadStatus value is unknown
s = Thread.State.RUNNABLE;
}
return s;
}
// a map of threadStatus values to the corresponding Thread.State
private static Map<Integer, Thread.State> threadStateMap = null;
private static Map<Integer, String> threadStateNames = null;
private synchronized static void initThreadStateMap() {
if (threadStateMap != null) {
return;
}
final Thread.State[] ts = Thread.State.values();
final int[][] vmThreadStateValues = new int[ts.length][];
final String[][] vmThreadStateNames = new String[ts.length][];
getThreadStateValues(vmThreadStateValues, vmThreadStateNames);
threadStateMap = new HashMap<Integer, Thread.State>();
threadStateNames = new HashMap<Integer, String>();
for (int i = 0; i < ts.length; i++) {
String state = ts[i].name();
int[] values = null;
String[] names = null;
for (int j = 0; j < ts.length; j++) {
if (vmThreadStateNames[j][0].startsWith(state)) {
values = vmThreadStateValues[j];
names = vmThreadStateNames[j];
}
}
if (values == null) {
throw new InternalError("No VM thread state mapped to " +
state);
}
if (values.length != names.length) {
throw new InternalError("VM thread state values and names " +
" mapped to " + state + ": length not matched" );
}
for (int k = 0; k < values.length; k++) {
threadStateMap.put(values[k], ts[i]);
threadStateNames.put(values[k], names[k]);
}
}
}
// Fill in vmThreadStateValues with int arrays, each of which contains
// the threadStatus values mapping to the Thread.State enum constant.
// Fill in vmThreadStateNames with String arrays, each of which contains
// the name of each threadStatus value of the format:
// <Thread.State.name()>[.<Substate name>]
// e.g. WAITING.OBJECT_WAIT
//
private native static void getThreadStateValues(int[][] vmThreadStateValues,
String[][] vmThreadStateNames);
static {
initialize();
}
private native static void initialize();
}