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script-astra/Android/Sdk/sources/android-35/java/lang/System.java

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/*
* Copyright (C) 2014 The Android Open Source Project
* Copyright (c) 1994, 2013, 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 java.lang;
import dalvik.annotation.optimization.CriticalNative;
import dalvik.annotation.optimization.FastNative;
import android.system.ErrnoException;
import android.system.StructUtsname;
import dalvik.system.VMRuntime;
import java.io.*;
import java.nio.channels.Channel;
import java.nio.channels.spi.SelectorProvider;
import java.util.Locale;
import java.util.Map;
import java.util.Properties;
import java.util.PropertyPermission;
import java.util.function.BiFunction;
import java.util.function.Function;
import libcore.icu.ICU;
import libcore.io.Libcore;
import sun.reflect.CallerSensitive;
import sun.reflect.Reflection;
import sun.security.util.SecurityConstants;
/**
* The <code>System</code> class contains several useful class fields
* and methods. It cannot be instantiated.
*
* <p>Among the facilities provided by the <code>System</code> class
* are standard input, standard output, and error output streams;
* access to externally defined properties and environment
* variables; a means of loading files and libraries; and a utility
* method for quickly copying a portion of an array.
*
* @author unascribed
* @since JDK1.0
*/
public final class System {
/** Don't let anyone instantiate this class */
private System() {
}
/**
* The "standard" input stream. This stream is already
* open and ready to supply input data. Typically this stream
* corresponds to keyboard input or another input source specified by
* the host environment or user.
*/
public final static InputStream in;
/**
* The "standard" output stream. This stream is already
* open and ready to accept output data. Typically this stream
* corresponds to display output or another output destination
* specified by the host environment or user.
* <p>
* For simple stand-alone Java applications, a typical way to write
* a line of output data is:
* <blockquote><pre>
* System.out.println(data)
* </pre></blockquote>
* <p>
* See the <code>println</code> methods in class <code>PrintStream</code>.
*
* @see java.io.PrintStream#println()
* @see java.io.PrintStream#println(boolean)
* @see java.io.PrintStream#println(char)
* @see java.io.PrintStream#println(char[])
* @see java.io.PrintStream#println(double)
* @see java.io.PrintStream#println(float)
* @see java.io.PrintStream#println(int)
* @see java.io.PrintStream#println(long)
* @see java.io.PrintStream#println(java.lang.Object)
* @see java.io.PrintStream#println(java.lang.String)
*/
public final static PrintStream out;
/**
* The "standard" error output stream. This stream is already
* open and ready to accept output data.
* <p>
* Typically this stream corresponds to display output or another
* output destination specified by the host environment or user. By
* convention, this output stream is used to display error messages
* or other information that should come to the immediate attention
* of a user even if the principal output stream, the value of the
* variable <code>out</code>, has been redirected to a file or other
* destination that is typically not continuously monitored.
*/
public final static PrintStream err;
/**
* Dedicated lock for GC / Finalization logic.
*/
private static final Object LOCK = new Object();
/**
* Whether or not we need to do a GC before running the finalizers.
*/
private static boolean runGC;
/**
* If we just ran finalization, we might want to do a GC to free the finalized objects.
* This lets us do gc/runFinlization/gc sequences but prevents back to back System.gc().
*/
private static boolean justRanFinalization;
/**
* Reassigns the "standard" input stream.
*
* <p>First, if there is a security manager, its <code>checkPermission</code>
* method is called with a <code>RuntimePermission("setIO")</code> permission
* to see if it's ok to reassign the "standard" input stream.
* <p>
*
* @param in the new standard input stream.
*
* @throws SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* reassigning of the standard input stream.
*
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*
* @since JDK1.1
*/
public static void setIn(InputStream in) {
setIn0(in);
}
/**
* Reassigns the "standard" output stream.
*
* <p>First, if there is a security manager, its <code>checkPermission</code>
* method is called with a <code>RuntimePermission("setIO")</code> permission
* to see if it's ok to reassign the "standard" output stream.
*
* @param out the new standard output stream
*
* @throws SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* reassigning of the standard output stream.
*
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*
* @since JDK1.1
*/
public static void setOut(PrintStream out) {
setOut0(out);
}
/**
* Reassigns the "standard" error output stream.
*
* <p>First, if there is a security manager, its <code>checkPermission</code>
* method is called with a <code>RuntimePermission("setIO")</code> permission
* to see if it's ok to reassign the "standard" error output stream.
*
* @param err the new standard error output stream.
*
* @throws SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* reassigning of the standard error output stream.
*
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*
* @since JDK1.1
*/
public static void setErr(PrintStream err) {
setErr0(err);
}
private static volatile Console cons = null;
/**
* Returns the unique {@link java.io.Console Console} object associated
* with the current Java virtual machine, if any.
*
* @return The system console, if any, otherwise <tt>null</tt>.
*
* @since 1.6
*/
public static Console console() {
// Android-changed: Added proper double checked locking for cons access
if (cons == null) {
synchronized (System.class) {
if (cons == null) {
cons = Console.console();
}
}
}
return cons;
}
/**
* Returns the channel inherited from the entity that created this
* Java virtual machine.
*
* <p> This method returns the channel obtained by invoking the
* {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
* inheritedChannel} method of the system-wide default
* {@link java.nio.channels.spi.SelectorProvider} object. </p>
*
* <p> In addition to the network-oriented channels described in
* {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
* inheritedChannel}, this method may return other kinds of
* channels in the future.
*
* @return The inherited channel, if any, otherwise <tt>null</tt>.
*
* @throws IOException
* If an I/O error occurs
*
* @throws SecurityException
* If a security manager is present and it does not
* permit access to the channel.
*
* @since 1.5
*/
public static Channel inheritedChannel() throws IOException {
return SelectorProvider.provider().inheritedChannel();
}
private static native void setIn0(InputStream in);
private static native void setOut0(PrintStream out);
private static native void setErr0(PrintStream err);
/**
* Throws {@code SecurityException} (except in case {@code sm == null}).
*
* <p>Security managers do <i>not</i> provide a secure environment for
* executing untrusted code and are unsupported on Android. Untrusted code
* cannot be safely isolated within a single VM on Android, so this method
* <i>always</i> throws a {@code SecurityException} when passed a non-null SecurityManager
*
* @param s a security manager
* @throws SecurityException always, unless {@code sm == null}
*/
public static
void setSecurityManager(final SecurityManager s) {
if (s != null) {
throw new SecurityException();
}
}
/**
* Always returns {@code null} in Android
*
* @return {@code null} in Android
*/
public static SecurityManager getSecurityManager() {
// No-op on android.
return null;
}
/**
* Returns the current time in milliseconds. Note that
* while the unit of time of the return value is a millisecond,
* the granularity of the value depends on the underlying
* operating system and may be larger. For example, many
* operating systems measure time in units of tens of
* milliseconds.
*
* <p> See the description of the class <code>Date</code> for
* a discussion of slight discrepancies that may arise between
* "computer time" and coordinated universal time (UTC).
*
* @return the difference, measured in milliseconds, between
* the current time and midnight, January 1, 1970 UTC.
* @see java.util.Date
*/
@CriticalNative
public static native long currentTimeMillis();
// Android-added: Note on elapse time and deep sleep.
/**
* Returns the current value of the running Java Virtual Machine's
* high-resolution time source, in nanoseconds.
*
* <p>This method can only be used to measure elapsed time and is
* not related to any other notion of system or wall-clock time.
* The value returned represents nanoseconds since some fixed but
* arbitrary <i>origin</i> time (perhaps in the future, so values
* may be negative). The same origin is used by all invocations of
* this method in an instance of a Java virtual machine; other
* virtual machine instances are likely to use a different origin.
*
* <p>This method provides nanosecond precision, but not necessarily
* nanosecond resolution (that is, how frequently the value changes)
* - no guarantees are made except that the resolution is at least as
* good as that of {@link #currentTimeMillis()}.
*
* <p>Differences in successive calls that span greater than
* approximately 292 years (2<sup>63</sup> nanoseconds) will not
* correctly compute elapsed time due to numerical overflow.
*
* <p>The values returned by this method become meaningful only when
* the difference between two such values, obtained within the same
* instance of a Java virtual machine, is computed.
*
* <p> For example, to measure how long some code takes to execute:
* <pre> {@code
* long startTime = System.nanoTime();
* // ... the code being measured ...
* long estimatedTime = System.nanoTime() - startTime;}</pre>
*
* <p>To compare two nanoTime values
* <pre> {@code
* long t0 = System.nanoTime();
* ...
* long t1 = System.nanoTime();}</pre>
*
* one should use {@code t1 - t0 < 0}, not {@code t1 < t0},
* because of the possibility of numerical overflow.
*
* <p>The value returned by this method does not account for elapsed
* time during deep sleep. For timekeeping facilities available on
* Android see {@link android.os.SystemClock}.
*
* @return the current value of the running Java Virtual Machine's
* high-resolution time source, in nanoseconds
* @since 1.5
*/
@CriticalNative
public static native long nanoTime();
/**
* Copies an array from the specified source array, beginning at the
* specified position, to the specified position of the destination array.
* A subsequence of array components are copied from the source
* array referenced by <code>src</code> to the destination array
* referenced by <code>dest</code>. The number of components copied is
* equal to the <code>length</code> argument. The components at
* positions <code>srcPos</code> through
* <code>srcPos+length-1</code> in the source array are copied into
* positions <code>destPos</code> through
* <code>destPos+length-1</code>, respectively, of the destination
* array.
* <p>
* If the <code>src</code> and <code>dest</code> arguments refer to the
* same array object, then the copying is performed as if the
* components at positions <code>srcPos</code> through
* <code>srcPos+length-1</code> were first copied to a temporary
* array with <code>length</code> components and then the contents of
* the temporary array were copied into positions
* <code>destPos</code> through <code>destPos+length-1</code> of the
* destination array.
* <p>
* If <code>dest</code> is <code>null</code>, then a
* <code>NullPointerException</code> is thrown.
* <p>
* If <code>src</code> is <code>null</code>, then a
* <code>NullPointerException</code> is thrown and the destination
* array is not modified.
* <p>
* Otherwise, if any of the following is true, an
* <code>ArrayStoreException</code> is thrown and the destination is
* not modified:
* <ul>
* <li>The <code>src</code> argument refers to an object that is not an
* array.
* <li>The <code>dest</code> argument refers to an object that is not an
* array.
* <li>The <code>src</code> argument and <code>dest</code> argument refer
* to arrays whose component types are different primitive types.
* <li>The <code>src</code> argument refers to an array with a primitive
* component type and the <code>dest</code> argument refers to an array
* with a reference component type.
* <li>The <code>src</code> argument refers to an array with a reference
* component type and the <code>dest</code> argument refers to an array
* with a primitive component type.
* </ul>
* <p>
* Otherwise, if any of the following is true, an
* <code>IndexOutOfBoundsException</code> is
* thrown and the destination is not modified:
* <ul>
* <li>The <code>srcPos</code> argument is negative.
* <li>The <code>destPos</code> argument is negative.
* <li>The <code>length</code> argument is negative.
* <li><code>srcPos+length</code> is greater than
* <code>src.length</code>, the length of the source array.
* <li><code>destPos+length</code> is greater than
* <code>dest.length</code>, the length of the destination array.
* </ul>
* <p>
* Otherwise, if any actual component of the source array from
* position <code>srcPos</code> through
* <code>srcPos+length-1</code> cannot be converted to the component
* type of the destination array by assignment conversion, an
* <code>ArrayStoreException</code> is thrown. In this case, let
* <b><i>k</i></b> be the smallest nonnegative integer less than
* length such that <code>src[srcPos+</code><i>k</i><code>]</code>
* cannot be converted to the component type of the destination
* array; when the exception is thrown, source array components from
* positions <code>srcPos</code> through
* <code>srcPos+</code><i>k</i><code>-1</code>
* will already have been copied to destination array positions
* <code>destPos</code> through
* <code>destPos+</code><i>k</I><code>-1</code> and no other
* positions of the destination array will have been modified.
* (Because of the restrictions already itemized, this
* paragraph effectively applies only to the situation where both
* arrays have component types that are reference types.)
*
* @param src the source array.
* @param srcPos starting position in the source array.
* @param dest the destination array.
* @param destPos starting position in the destination data.
* @param length the number of array elements to be copied.
* @exception IndexOutOfBoundsException if copying would cause
* access of data outside array bounds.
* @exception ArrayStoreException if an element in the <code>src</code>
* array could not be stored into the <code>dest</code> array
* because of a type mismatch.
* @exception NullPointerException if either <code>src</code> or
* <code>dest</code> is <code>null</code>.
*/
@FastNative
public static native void arraycopy(Object src, int srcPos,
Object dest, int destPos,
int length);
// BEGIN Android-changed
/**
* The char array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_CHAR_ARRAY_THRESHOLD = 32;
/**
* The char[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(char[] src, int srcPos, char[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_CHAR_ARRAY_THRESHOLD) {
// Copy char by char for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for longer arrays.
arraycopyCharUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The char[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyCharUnchecked(char[] src, int srcPos,
char[] dst, int dstPos, int length);
/**
* The byte array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_BYTE_ARRAY_THRESHOLD = 32;
/**
* The byte[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(byte[] src, int srcPos, byte[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_BYTE_ARRAY_THRESHOLD) {
// Copy byte by byte for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for longer arrays.
arraycopyByteUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The byte[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyByteUnchecked(byte[] src, int srcPos,
byte[] dst, int dstPos, int length);
/**
* The short array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_SHORT_ARRAY_THRESHOLD = 32;
/**
* The short[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(short[] src, int srcPos, short[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_SHORT_ARRAY_THRESHOLD) {
// Copy short by short for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for longer arrays.
arraycopyShortUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The short[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyShortUnchecked(short[] src, int srcPos,
short[] dst, int dstPos, int length);
/**
* The short array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_INT_ARRAY_THRESHOLD = 32;
/**
* The int[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(int[] src, int srcPos, int[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_INT_ARRAY_THRESHOLD) {
// Copy int by int for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for longer arrays.
arraycopyIntUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The int[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyIntUnchecked(int[] src, int srcPos,
int[] dst, int dstPos, int length);
/**
* The short array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_LONG_ARRAY_THRESHOLD = 32;
/**
* The long[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(long[] src, int srcPos, long[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_LONG_ARRAY_THRESHOLD) {
// Copy long by long for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for longer arrays.
arraycopyLongUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The long[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyLongUnchecked(long[] src, int srcPos,
long[] dst, int dstPos, int length);
/**
* The short array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_FLOAT_ARRAY_THRESHOLD = 32;
/**
* The float[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(float[] src, int srcPos, float[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_FLOAT_ARRAY_THRESHOLD) {
// Copy float by float for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for floater arrays.
arraycopyFloatUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The float[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyFloatUnchecked(float[] src, int srcPos,
float[] dst, int dstPos, int length);
/**
* The short array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_DOUBLE_ARRAY_THRESHOLD = 32;
/**
* The double[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(double[] src, int srcPos, double[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_DOUBLE_ARRAY_THRESHOLD) {
// Copy double by double for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for floater arrays.
arraycopyDoubleUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The double[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyDoubleUnchecked(double[] src, int srcPos,
double[] dst, int dstPos, int length);
/**
* The short array length threshold below which to use a Java
* (non-native) version of arraycopy() instead of the native
* version. See b/7103825.
*/
private static final int ARRAYCOPY_SHORT_BOOLEAN_ARRAY_THRESHOLD = 32;
/**
* The boolean[] specialized version of arraycopy().
* Note: This method is required for runtime ART compiler optimizations.
* Do not remove or change the signature.
*/
@SuppressWarnings("unused")
private static void arraycopy(boolean[] src, int srcPos, boolean[] dst, int dstPos, int length) {
if (src == null) {
throw new NullPointerException("src == null");
}
if (dst == null) {
throw new NullPointerException("dst == null");
}
if (srcPos < 0 || dstPos < 0 || length < 0 ||
srcPos > src.length - length || dstPos > dst.length - length) {
throw new ArrayIndexOutOfBoundsException(
"src.length=" + src.length + " srcPos=" + srcPos +
" dst.length=" + dst.length + " dstPos=" + dstPos + " length=" + length);
}
if (length <= ARRAYCOPY_SHORT_BOOLEAN_ARRAY_THRESHOLD) {
// Copy boolean by boolean for shorter arrays.
if (src == dst && srcPos < dstPos && dstPos < srcPos + length) {
// Copy backward (to avoid overwriting elements before
// they are copied in case of an overlap on the same
// array.)
for (int i = length - 1; i >= 0; --i) {
dst[dstPos + i] = src[srcPos + i];
}
} else {
// Copy forward.
for (int i = 0; i < length; ++i) {
dst[dstPos + i] = src[srcPos + i];
}
}
} else {
// Call the native version for floater arrays.
arraycopyBooleanUnchecked(src, srcPos, dst, dstPos, length);
}
}
/**
* The boolean[] specialized, unchecked, native version of
* arraycopy(). This assumes error checking has been done.
*/
@FastNative
private static native void arraycopyBooleanUnchecked(boolean[] src, int srcPos,
boolean[] dst, int dstPos, int length);
// END Android-changed
/**
* Returns the same hash code for the given object as
* would be returned by the default method hashCode(),
* whether or not the given object's class overrides
* hashCode().
* The hash code for the null reference is zero.
*
* @param x object for which the hashCode is to be calculated
* @return the hashCode
* @since JDK1.1
*/
public static int identityHashCode(Object x) {
if (x == null) {
return 0;
}
return Object.identityHashCode(x);
}
/**
* System properties. The following properties are guaranteed to be defined:
* <dl>
* <dt>java.version <dd>Java version number
* <dt>java.vendor <dd>Java vendor specific string
* <dt>java.vendor.url <dd>Java vendor URL
* <dt>java.home <dd>Java installation directory
* <dt>java.class.version <dd>Java class version number
* <dt>java.class.path <dd>Java classpath
* <dt>os.name <dd>Operating System Name
* <dt>os.arch <dd>Operating System Architecture
* <dt>os.version <dd>Operating System Version
* <dt>file.separator <dd>File separator ("/" on Unix)
* <dt>path.separator <dd>Path separator (":" on Unix)
* <dt>line.separator <dd>Line separator ("\n" on Unix)
* <dt>user.name <dd>User account name
* <dt>user.home <dd>User home directory
* <dt>user.dir <dd>User's current working directory
* </dl>
*/
private static Properties props;
private static Properties unchangeableProps;
private static native String[] specialProperties();
static final class PropertiesWithNonOverrideableDefaults extends Properties {
PropertiesWithNonOverrideableDefaults(Properties defaults) {
super(defaults);
}
@Override
public synchronized Object compute(Object key,
BiFunction<? super Object, ? super Object, ?> remappingFunction) {
if (defaults == null || !defaults.containsKey(key)) {
return super.compute(key, remappingFunction);
} else {
logE("Ignoring attempt to modify property " + key);
// No new value is associated with the key, hence null.
return null;
}
}
@Override
public synchronized Object computeIfAbsent(Object key,
Function<? super Object, ?> mappingFunction) {
if (defaults == null || !defaults.containsKey(key)) {
return super.computeIfAbsent(key, mappingFunction);
} else {
logE("Ignoring attempt to modify property " + key);
return defaults.get(key);
}
}
@Override
public synchronized Object computeIfPresent(Object key,
BiFunction<? super Object, ? super Object, ?> remappingFunction) {
if (defaults == null || !defaults.containsKey(key)) {
return super.computeIfPresent(key, remappingFunction);
} else {
logE("Ignoring attempt to modify property " + key);
return defaults.get(key);
}
}
@Override
public synchronized Object merge(Object key, Object value,
BiFunction<? super Object, ? super Object, ?> remappingFunction) {
if (defaults == null || !defaults.containsKey(key)) {
return super.merge(key, value, remappingFunction);
} else {
logE("Ignoring attempt to modify property " + key);
// No new value is associated with the key, but
return defaults.get(key);
}
}
@Override
public Object put(Object key, Object value) {
if (defaults.containsKey(key)) {
logE("Ignoring attempt to set property \"" + key +
"\" to value \"" + value + "\".");
return defaults.get(key);
}
return super.put(key, value);
}
@Override
public synchronized void putAll(Map<?, ?> m) {
m.forEach(this::put);
}
@Override
public synchronized Object putIfAbsent(Object key, Object value) {
if (defaults == null || !defaults.containsKey(key)) {
return super.putIfAbsent(key, value);
} else {
logE("Ignoring attempt to modify property " + key);
// Returned values is in sync with put(Object, Object).
return defaults.get(key);
}
}
@Override
public Object remove(Object key) {
if (defaults.containsKey(key)) {
logE("Ignoring attempt to remove property \"" + key + "\".");
return null;
}
return super.remove(key);
}
@Override
public synchronized Object replace(Object key, Object value) {
if (defaults == null || !defaults.containsKey(key)) {
return super.replace(key, value);
} else {
logE("Ignoring attempt to replace property \"" + key + "\".");
return defaults.get(key);
}
}
@Override
public synchronized boolean replace(Object key, Object oldValue, Object newValue) {
if (defaults == null || !defaults.containsKey(key)) {
return super.replace(key, oldValue, newValue);
} else {
logE("Ignoring attempt to replace property \"" + key + "\".");
// As it was not changed.
return false;
}
}
}
private static void parsePropertyAssignments(Properties p, String[] assignments) {
for (String assignment : assignments) {
int split = assignment.indexOf('=');
String key = assignment.substring(0, split);
String value = assignment.substring(split + 1);
p.put(key, value);
}
}
private static Properties initUnchangeableSystemProperties() {
VMRuntime runtime = VMRuntime.getRuntime();
Properties p = new Properties();
// Set non-static properties.
p.put("java.boot.class.path", runtime.bootClassPath());
p.put("java.class.path", runtime.classPath());
// This is probably not useful, but it's documented as being present.
// ANDROID_ART_ROOT is defined in `system/core/rootdir/init.environ.rc.in`.
String javaHome = getenv("ANDROID_ART_ROOT");
if (javaHome == null) {
javaHome = "/apex/com.android.art";
}
p.put("java.home", javaHome);
p.put("java.vm.version", runtime.vmVersion());
String userName;
try {
userName = Libcore.os.getpwuid(Libcore.os.getuid()).pw_name;
} catch (ErrnoException exception) {
userName = "unknown";
}
p.put("user.name", userName);
StructUtsname info = Libcore.os.uname();
p.put("os.arch", info.machine);
// os.name was previously hardcoded to "Linux", but was reverted due to support
// for Fuchsia. b/121268567 shows initialization regressions.
p.put("os.name", info.sysname);
p.put("os.version", info.release);
// Android-added: Undocumented properties that exist only on Android.
p.put("android.icu.library.version", ICU.getIcuVersion());
p.put("android.icu.unicode.version", ICU.getUnicodeVersion());
p.put("android.icu.cldr.version", ICU.getCldrVersion());
parsePropertyAssignments(p, specialProperties());
// Override built-in properties with settings from the command line.
// Note: it is not possible to override hardcoded values.
parsePropertyAssignments(p, runtime.properties());
// Set static hardcoded properties.
// These come last, as they must be guaranteed to agree with what a backend compiler
// may assume when compiling the boot image on Android.
for (String[] pair : AndroidHardcodedSystemProperties.STATIC_PROPERTIES) {
if (p.containsKey(pair[0])) {
logE("Ignoring command line argument: -D" + pair[0]);
}
if (pair[1] == null) {
p.remove(pair[0]);
} else {
p.put(pair[0], pair[1]);
}
}
return p;
}
private static Properties initProperties() {
Properties p = new PropertiesWithNonOverrideableDefaults(unchangeableProps);
setDefaultChangeableProperties(p);
return p;
}
private static Properties setDefaultChangeableProperties(Properties p) {
// On Android, "java.io.tmpdir" is set in android.app.ActivityThread. Each app gets its
// own location, a typical value would be "/data/user/0/com.android.deskclock/cache.
// The value set here is just a fallback default for host.
// We check first if the property has not been set already: note that it
// can only be set from the command line through the '-Djava.io.tmpdir=' option.
if (!unchangeableProps.containsKey("java.io.tmpdir")) {
p.put("java.io.tmpdir", "/tmp");
}
// Android has always had an empty "user.home" (see docs for getProperty).
// This is not useful for normal android apps which need to use android specific
// APIs such as {@code Context.getFilesDir} and {@code Context.getCacheDir} but
// we make it changeable for backward compatibility, so that they can change it
// to a writeable location if required.
// We check first if the property has not been set already: note that it
// can only be set from the command line through the '-Duser.home=' option.
if (!unchangeableProps.containsKey("user.home")) {
p.put("user.home", "");
}
return p;
}
/**
* Inits an unchangeable system property with the given value.
*
* This is called from native code when the environment needs to change under native
* bridge emulation.
*
* @hide also visible for tests.
*/
public static void setUnchangeableSystemProperty(String key, String value) {
checkKey(key);
unchangeableProps.put(key, value);
}
private static void addLegacyLocaleSystemProperties() {
final String locale = getProperty("user.locale", "");
if (!locale.isEmpty()) {
Locale l = Locale.forLanguageTag(locale);
setUnchangeableSystemProperty("user.language", l.getLanguage());
setUnchangeableSystemProperty("user.region", l.getCountry());
setUnchangeableSystemProperty("user.variant", l.getVariant());
} else {
// If "user.locale" isn't set we fall back to our old defaults of
// language="en" and region="US" (if unset) and don't attempt to set it.
// The Locale class will fall back to using user.language and
// user.region if unset.
final String language = getProperty("user.language", "");
final String region = getProperty("user.region", "");
if (language.isEmpty()) {
setUnchangeableSystemProperty("user.language", "en");
}
if (region.isEmpty()) {
setUnchangeableSystemProperty("user.region", "US");
}
}
}
/**
* Determines the current system properties.
*
*
* <p>The following properties are always provided by the Dalvik VM:</p>
* <p><table BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
* <tr BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
* <td><b>Name</b></td> <td><b>Meaning</b></td> <td><b>Example</b></td></tr>
* <tr><td>file.separator</td> <td>{@link java.io.File#separator}</td> <td>{@code /}</td></tr>
*
* <tr><td>java.class.path</td> <td>System class path</td> <td>{@code .}</td></tr>
* <tr><td>java.class.version</td> <td>(Not useful on Android)</td> <td>{@code 50.0}</td></tr>
* <tr><td>java.compiler</td> <td>(Not useful on Android)</td> <td>Empty</td></tr>
* <tr><td>java.ext.dirs</td> <td>(Not useful on Android)</td> <td>Empty</td></tr>
* <tr><td>java.home</td> <td>Location of the VM on the file system</td> <td>{@code /apex/com.android.art/}</td></tr>
* <tr><td>java.io.tmpdir</td> <td>Location of a temporary directory.<br>The location varies by application.<br>See {@link java.io.File#createTempFile}</td> <td>{@code /data/user/0/com.android.app/cache}</td></tr>
* <tr><td>java.library.path</td> <td>Search path for JNI libraries</td> <td>{@code /vendor/lib:/system/lib}</td></tr>
* <tr><td>java.vendor</td> <td>Human-readable VM vendor</td> <td>{@code The Android Project}</td></tr>
* <tr><td>java.vendor.url</td> <td>URL for VM vendor's web site</td> <td>{@code http://www.android.com/}</td></tr>
* <tr><td>java.version</td> <td>(Not useful on Android)</td> <td>{@code 0}</td></tr>
*
* <tr><td>java.specification.version</td> <td>VM libraries version</td> <td>{@code 0.9}</td></tr>
* <tr><td>java.specification.vendor</td> <td>VM libraries vendor</td> <td>{@code The Android Project}</td></tr>
* <tr><td>java.specification.name</td> <td>VM libraries name</td> <td>{@code Dalvik Core Library}</td></tr>
* <tr><td>java.vm.version</td> <td>VM implementation version</td> <td>{@code 1.2.0}</td></tr>
* <tr><td>java.vm.vendor</td> <td>VM implementation vendor</td> <td>{@code The Android Project}</td></tr>
* <tr><td>java.vm.name</td> <td>VM implementation name</td> <td>{@code Dalvik}</td></tr>
* <tr><td>java.vm.specification.version</td> <td>VM specification version</td> <td>{@code 0.9}</td></tr>
* <tr><td>java.vm.specification.vendor</td> <td>VM specification vendor</td> <td>{@code The Android Project}</td></tr>
* <tr><td>java.vm.specification.name</td> <td>VM specification name</td> <td>{@code Dalvik Virtual Machine Specification}</td></tr>
*
* <tr><td>line.separator</td> <td>The system line separator</td> <td>{@code \n}</td></tr>
*
* <tr><td>os.arch</td> <td>OS architecture</td> <td>{@code aarch64}</td></tr>
* <tr><td>os.name</td> <td>OS (kernel) name</td> <td>{@code Linux}</td></tr>
* <tr><td>os.version</td> <td>OS (kernel) version</td> <td>{@code 5.10.98-g6ea688a79989}</td></tr>
*
* <tr><td>path.separator</td> <td>See {@link java.io.File#pathSeparator}</td> <td>{@code :}</td></tr>
*
* <tr><td>user.dir</td> <td>Base of non-absolute paths</td> <td>{@code /}</td></tr>
* <tr><td>user.home</td> <td>(Not useful on Android)</td> <td>Empty</td></tr>
* <tr><td>user.name</td> <td>(Not useful on Android)</td> <td>Empty</td></tr>
*
* </table>
* <p>
* Multiple paths in a system property value are separated by the path
* separator character of the platform.
* <p>
* Note that even if the security manager does not permit the
* <code>getProperties</code> operation, it may choose to permit the
* {@link #getProperty(String)} operation.
*
* @return the system properties
* @exception SecurityException if a security manager exists and its
* <code>checkPropertiesAccess</code> method doesn't allow access
* to the system properties.
* @see #setProperties
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkPropertiesAccess()
* @see java.util.Properties
*/
public static Properties getProperties() {
SecurityManager sm = getSecurityManager();
if (sm != null) {
sm.checkPropertiesAccess();
}
return props;
}
/**
* Returns the system-dependent line separator string. It always
* returns the same value - the initial value of the {@linkplain
* #getProperty(String) system property} {@code line.separator}.
*
* <p>On UNIX systems, it returns {@code "\n"}; on Microsoft
* Windows systems it returns {@code "\r\n"}.
*
* @return the system-dependent line separator string
* @since 1.7
*/
public static String lineSeparator() {
return lineSeparator;
}
private static String lineSeparator;
// Comment replaced with android one.
/**
* Attempts to set all system properties. Copies all properties from
* {@code p} and discards system properties that are read only and cannot
* be modified. See {@link #getProperty} for a list of such properties.
*/
public static void setProperties(Properties props) {
Properties baseProperties = new PropertiesWithNonOverrideableDefaults(unchangeableProps);
if (props != null) {
baseProperties.putAll(props);
} else {
setDefaultChangeableProperties(baseProperties);
}
System.props = baseProperties;
}
/**
* Gets the system property indicated by the specified key.
* <p>
* First, if there is a security manager, its
* <code>checkPropertyAccess</code> method is called with the key as
* its argument. This may result in a SecurityException.
* <p>
* If there is no current set of system properties, a set of system
* properties is first created and initialized in the same manner as
* for the <code>getProperties</code> method.
*
* @param key the name of the system property.
* @return the string value of the system property,
* or <code>null</code> if there is no property with that key.
*
* @exception SecurityException if a security manager exists and its
* <code>checkPropertyAccess</code> method doesn't allow
* access to the specified system property.
* @exception NullPointerException if <code>key</code> is
* <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
* @see #setProperty
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
* @see java.lang.System#getProperties()
*/
public static String getProperty(String key) {
checkKey(key);
SecurityManager sm = getSecurityManager();
if (sm != null) {
sm.checkPropertyAccess(key);
}
return props.getProperty(key);
}
/**
* Gets the system property indicated by the specified key.
* <p>
* First, if there is a security manager, its
* <code>checkPropertyAccess</code> method is called with the
* <code>key</code> as its argument.
* <p>
* If there is no current set of system properties, a set of system
* properties is first created and initialized in the same manner as
* for the <code>getProperties</code> method.
*
* @param key the name of the system property.
* @param def a default value.
* @return the string value of the system property,
* or the default value if there is no property with that key.
*
* @exception SecurityException if a security manager exists and its
* <code>checkPropertyAccess</code> method doesn't allow
* access to the specified system property.
* @exception NullPointerException if <code>key</code> is
* <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
* @see #setProperty
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
* @see java.lang.System#getProperties()
*/
public static String getProperty(String key, String def) {
checkKey(key);
SecurityManager sm = getSecurityManager();
if (sm != null) {
sm.checkPropertyAccess(key);
}
return props.getProperty(key, def);
}
/**
* Sets the system property indicated by the specified key.
* <p>
* First, if a security manager exists, its
* <code>SecurityManager.checkPermission</code> method
* is called with a <code>PropertyPermission(key, "write")</code>
* permission. This may result in a SecurityException being thrown.
* If no exception is thrown, the specified property is set to the given
* value.
* <p>
*
* @param key the name of the system property.
* @param value the value of the system property.
* @return the previous value of the system property,
* or <code>null</code> if it did not have one.
*
* @exception SecurityException if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* setting of the specified property.
* @exception NullPointerException if <code>key</code> or
* <code>value</code> is <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
* @see #getProperty
* @see java.lang.System#getProperty(java.lang.String)
* @see java.lang.System#getProperty(java.lang.String, java.lang.String)
* @see java.util.PropertyPermission
* @see SecurityManager#checkPermission
* @since 1.2
*/
public static String setProperty(String key, String value) {
checkKey(key);
SecurityManager sm = getSecurityManager();
if (sm != null) {
sm.checkPermission(new PropertyPermission(key,
SecurityConstants.PROPERTY_WRITE_ACTION));
}
return (String) props.setProperty(key, value);
}
/**
* Removes the system property indicated by the specified key.
* <p>
* First, if a security manager exists, its
* <code>SecurityManager.checkPermission</code> method
* is called with a <code>PropertyPermission(key, "write")</code>
* permission. This may result in a SecurityException being thrown.
* If no exception is thrown, the specified property is removed.
* <p>
*
* @param key the name of the system property to be removed.
* @return the previous string value of the system property,
* or <code>null</code> if there was no property with that key.
*
* @exception SecurityException if a security manager exists and its
* <code>checkPropertyAccess</code> method doesn't allow
* access to the specified system property.
* @exception NullPointerException if <code>key</code> is
* <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
* @see #getProperty
* @see #setProperty
* @see java.util.Properties
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkPropertiesAccess()
* @since 1.5
*/
public static String clearProperty(String key) {
checkKey(key);
SecurityManager sm = getSecurityManager();
if (sm != null) {
sm.checkPermission(new PropertyPermission(key, "write"));
}
return (String) props.remove(key);
}
private static void checkKey(String key) {
if (key == null) {
throw new NullPointerException("key can't be null");
}
if (key.equals("")) {
throw new IllegalArgumentException("key can't be empty");
}
}
/**
* Gets the value of the specified environment variable. An
* environment variable is a system-dependent external named
* value.
*
* <p>If a security manager exists, its
* {@link SecurityManager#checkPermission checkPermission}
* method is called with a
* <code>{@link RuntimePermission}("getenv."+name)</code>
* permission. This may result in a {@link SecurityException}
* being thrown. If no exception is thrown the value of the
* variable <code>name</code> is returned.
*
* <p><a name="EnvironmentVSSystemProperties"><i>System
* properties</i> and <i>environment variables</i></a> are both
* conceptually mappings between names and values. Both
* mechanisms can be used to pass user-defined information to a
* Java process. Environment variables have a more global effect,
* because they are visible to all descendants of the process
* which defines them, not just the immediate Java subprocess.
* They can have subtly different semantics, such as case
* insensitivity, on different operating systems. For these
* reasons, environment variables are more likely to have
* unintended side effects. It is best to use system properties
* where possible. Environment variables should be used when a
* global effect is desired, or when an external system interface
* requires an environment variable (such as <code>PATH</code>).
*
* <p>On UNIX systems the alphabetic case of <code>name</code> is
* typically significant, while on Microsoft Windows systems it is
* typically not. For example, the expression
* <code>System.getenv("FOO").equals(System.getenv("foo"))</code>
* is likely to be true on Microsoft Windows.
*
* @param name the name of the environment variable
* @return the string value of the variable, or <code>null</code>
* if the variable is not defined in the system environment
* @throws NullPointerException if <code>name</code> is <code>null</code>
* @throws SecurityException
* if a security manager exists and its
* {@link SecurityManager#checkPermission checkPermission}
* method doesn't allow access to the environment variable
* <code>name</code>
* @see #getenv()
* @see ProcessBuilder#environment()
*/
public static String getenv(String name) {
if (name == null) {
throw new NullPointerException("name == null");
}
return Libcore.os.getenv(name);
}
/**
* Returns an unmodifiable string map view of the current system environment.
* The environment is a system-dependent mapping from names to
* values which is passed from parent to child processes.
*
* <p>If the system does not support environment variables, an
* empty map is returned.
*
* <p>The returned map will never contain null keys or values.
* Attempting to query the presence of a null key or value will
* throw a {@link NullPointerException}. Attempting to query
* the presence of a key or value which is not of type
* {@link String} will throw a {@link ClassCastException}.
*
* <p>The returned map and its collection views may not obey the
* general contract of the {@link Object#equals} and
* {@link Object#hashCode} methods.
*
* <p>The returned map is typically case-sensitive on all platforms.
*
* <p>If a security manager exists, its
* {@link SecurityManager#checkPermission checkPermission}
* method is called with a
* <code>{@link RuntimePermission}("getenv.*")</code>
* permission. This may result in a {@link SecurityException} being
* thrown.
*
* <p>When passing information to a Java subprocess,
* <a href=#EnvironmentVSSystemProperties>system properties</a>
* are generally preferred over environment variables.
*
* @return the environment as a map of variable names to values
* @throws SecurityException
* if a security manager exists and its
* {@link SecurityManager#checkPermission checkPermission}
* method doesn't allow access to the process environment
* @see #getenv(String)
* @see ProcessBuilder#environment()
* @since 1.5
*/
public static java.util.Map<String,String> getenv() {
SecurityManager sm = getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("getenv.*"));
}
return ProcessEnvironment.getenv();
}
/**
* Terminates the currently running Java Virtual Machine. The
* argument serves as a status code; by convention, a nonzero status
* code indicates abnormal termination.
* <p>
* This method calls the <code>exit</code> method in class
* <code>Runtime</code>. This method never returns normally.
* <p>
* The call <code>System.exit(n)</code> is effectively equivalent to
* the call:
* <blockquote><pre>
* Runtime.getRuntime().exit(n)
* </pre></blockquote>
*
* @param status exit status.
* @throws SecurityException
* if a security manager exists and its <code>checkExit</code>
* method doesn't allow exit with the specified status.
* @see java.lang.Runtime#exit(int)
*/
public static void exit(int status) {
Runtime.getRuntime().exit(status);
}
/**
* Runs the garbage collector.
* <p>
* Calling the <code>gc</code> method suggests that the Java Virtual
* Machine expend effort toward recycling unused objects in order to
* make the memory they currently occupy available for quick reuse.
* When control returns from the method call, the Java Virtual
* Machine has made a best effort to reclaim space from all discarded
* objects.
* <p>
* The call <code>System.gc()</code> is effectively equivalent to the
* call:
* <blockquote><pre>
* Runtime.getRuntime().gc()
* </pre></blockquote>
* At API level 34 and lower, this does nothing unless it is preceded or
* followed by a runFinalization call. Runtime.getRuntime().gc() always
* attempts to reclaim space.
* <p>
* Calling this indiscriminately is likely to severely degrade performance.
* Intended primarily for testing.
*
* @see java.lang.Runtime#gc()
*/
public static void gc() {
int targetSdkVersion = VMRuntime.getRuntime().getTargetSdkVersion();
if (targetSdkVersion > 34) {
Runtime.getRuntime().gc();
} else {
boolean shouldRunGC;
synchronized (LOCK) {
shouldRunGC = targetSdkVersion <= 34 ? justRanFinalization : true;
if (shouldRunGC) {
justRanFinalization = false;
} else {
runGC = true;
}
}
if (shouldRunGC) {
Runtime.getRuntime().gc();
}
}
}
/**
* Runs the finalization methods of any objects pending finalization.
* <p>
* Calling this method suggests that the Java Virtual Machine expend
* effort toward running the <code>finalize</code> methods of objects
* that have been found to be discarded but whose <code>finalize</code>
* methods have not yet been run. When control returns from the
* method call, the Java Virtual Machine has made a best effort to
* complete all outstanding finalizations.
* <p>
* The call <code>System.runFinalization()</code> is effectively
* equivalent to the call:
* <blockquote><pre>
* Runtime.getRuntime().runFinalization()
* </pre></blockquote>
*
* @see java.lang.Runtime#runFinalization()
*/
public static void runFinalization() {
int targetSdkVersion = VMRuntime.getRuntime().getTargetSdkVersion();
if (targetSdkVersion <= 34) {
boolean shouldRunGC;
synchronized (LOCK) {
shouldRunGC = runGC;
runGC = false;
}
if (shouldRunGC) {
Runtime.getRuntime().gc();
}
}
Runtime.getRuntime().runFinalization();
if (targetSdkVersion <= 34) {
synchronized (LOCK) {
justRanFinalization = true;
}
}
}
/**
* Enable or disable finalization on exit; doing so specifies that the
* finalizers of all objects that have finalizers that have not yet been
* automatically invoked are to be run before the Java runtime exits.
* By default, finalization on exit is disabled.
*
* <p>If there is a security manager,
* its <code>checkExit</code> method is first called
* with 0 as its argument to ensure the exit is allowed.
* This could result in a SecurityException.
*
* @deprecated This method is inherently unsafe. It may result in
* finalizers being called on live objects while other threads are
* concurrently manipulating those objects, resulting in erratic
* behavior or deadlock.
* @param value indicating enabling or disabling of finalization
* @throws SecurityException
* if a security manager exists and its <code>checkExit</code>
* method doesn't allow the exit.
*
* @see java.lang.Runtime#exit(int)
* @see java.lang.Runtime#gc()
* @see java.lang.SecurityManager#checkExit(int)
* @since JDK1.1
*/
@Deprecated
public static void runFinalizersOnExit(boolean value) {
Runtime.runFinalizersOnExit(value);
}
/**
* Loads the native library specified by the filename argument. The filename
* argument must be an absolute path name.
*
* If the filename argument, when stripped of any platform-specific library
* prefix, path, and file extension, indicates a library whose name is,
* for example, L, and a native library called L is statically linked
* with the VM, then the JNI_OnLoad_L function exported by the library
* is invoked rather than attempting to load a dynamic library.
* A filename matching the argument does not have to exist in the
* file system.
* See the JNI Specification for more details.
*
* Otherwise, the filename argument is mapped to a native library image in
* an implementation-dependent manner.
*
* <p>
* The call <code>System.load(name)</code> is effectively equivalent
* to the call:
* <blockquote><pre>
* Runtime.getRuntime().load(name)
* </pre></blockquote>
*
* @param filename the file to load.
* @exception SecurityException if a security manager exists and its
* <code>checkLink</code> method doesn't allow
* loading of the specified dynamic library
* @exception UnsatisfiedLinkError if either the filename is not an
* absolute path name, the native library is not statically
* linked with the VM, or the library cannot be mapped to
* a native library image by the host system.
* @exception NullPointerException if <code>filename</code> is
* <code>null</code>
* @see java.lang.Runtime#load(java.lang.String)
* @see java.lang.SecurityManager#checkLink(java.lang.String)
*/
@CallerSensitive
public static void load(String filename) {
Runtime.getRuntime().load0(Reflection.getCallerClass(), filename);
}
/**
* Loads the native library specified by the <code>libname</code>
* argument. The <code>libname</code> argument must not contain any platform
* specific prefix, file extension or path. If a native library
* called <code>libname</code> is statically linked with the VM, then the
* JNI_OnLoad_<code>libname</code> function exported by the library is invoked.
* See the JNI Specification for more details.
*
* Otherwise, the libname argument is loaded from a system library
* location and mapped to a native library image in an implementation-
* dependent manner.
* <p>
* The call <code>System.loadLibrary(name)</code> is effectively
* equivalent to the call
* <blockquote><pre>
* Runtime.getRuntime().loadLibrary(name)
* </pre></blockquote>
*
* @param libname the name of the library.
* @exception SecurityException if a security manager exists and its
* <code>checkLink</code> method doesn't allow
* loading of the specified dynamic library
* @exception UnsatisfiedLinkError if either the libname argument
* contains a file path, the native library is not statically
* linked with the VM, or the library cannot be mapped to a
* native library image by the host system.
* @exception NullPointerException if <code>libname</code> is
* <code>null</code>
* @see java.lang.Runtime#loadLibrary(java.lang.String)
* @see java.lang.SecurityManager#checkLink(java.lang.String)
*/
@CallerSensitive
public static void loadLibrary(String libname) {
Runtime.getRuntime().loadLibrary0(Reflection.getCallerClass(), libname);
}
/**
* Maps a library name into a platform-specific string representing
* a native library.
*
* @param libname the name of the library.
* @return a platform-dependent native library name.
* @exception NullPointerException if <code>libname</code> is
* <code>null</code>
* @see java.lang.System#loadLibrary(java.lang.String)
* @see java.lang.ClassLoader#findLibrary(java.lang.String)
* @since 1.2
*/
public static native String mapLibraryName(String libname);
/**
* Create PrintStream for stdout/err based on encoding.
*/
private static PrintStream newPrintStream(FileOutputStream fos, String enc) {
if (enc != null) {
try {
return new PrintStream(new BufferedOutputStream(fos, 128), true, enc);
} catch (UnsupportedEncodingException uee) {}
}
return new PrintStream(new BufferedOutputStream(fos, 128), true);
}
/**
* Initialize the system class. Called after thread initialization.
*/
static {
unchangeableProps = initUnchangeableSystemProperties();
props = initProperties();
addLegacyLocaleSystemProperties();
sun.misc.Version.initSystemProperties();
// TODO: Confirm that this isn't something super important.
// sun.misc.VM.saveAndRemoveProperties(props);
lineSeparator = props.getProperty("line.separator");
FileInputStream fdIn = new FileInputStream(FileDescriptor.in);
FileOutputStream fdOut = new FileOutputStream(FileDescriptor.out);
FileOutputStream fdErr = new FileOutputStream(FileDescriptor.err);
// BEGIN Android-changed: lower buffer size.
// in = new BufferedInputStream(fdIn);
in = new BufferedInputStream(fdIn, 128);
// END Android-changed: lower buffer size.
out = newPrintStream(fdOut, props.getProperty("sun.stdout.encoding"));
err = newPrintStream(fdErr, props.getProperty("sun.stderr.encoding"));
// Initialize any miscellenous operating system settings that need to be
// set for the class libraries. Currently this is no-op everywhere except
// for Windows where the process-wide error mode is set before the java.io
// classes are used.
sun.misc.VM.initializeOSEnvironment();
// Subsystems that are invoked during initialization can invoke
// sun.misc.VM.isBooted() in order to avoid doing things that should
// wait until the application class loader has been set up.
// IMPORTANT: Ensure that this remains the last initialization action!
sun.misc.VM.booted();
jdk.internal.misc.VM.booted();
}
/**
* @hide internal use only
*/
public static void logE(String message) {
log('E', message, null);
}
/**
* @hide internal use only
*/
public static void logE(String message, Throwable th) {
log('E', message, th);
}
/**
* @hide internal use only
*/
public static void logI(String message) {
log('I', message, null);
}
/**
* @hide internal use only
*/
public static void logI(String message, Throwable th) {
log('I', message, th);
}
/**
* @hide internal use only
*/
public static void logW(String message) {
log('W', message, null);
}
/**
* @hide internal use only
*/
public static void logW(String message, Throwable th) {
log('W', message, th);
}
private static native void log(char type, String message, Throwable th);
}
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