--- /dev/null
+/*
+ * Copyright 2000-2006 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.misc;
+
+import java.security.*;
+import java.lang.reflect.*;
+
+
+/**
+ * A collection of methods for performing low-level, unsafe operations.
+ * Although the class and all methods are public, use of this class is
+ * limited because only trusted code can obtain instances of it.
+ *
+ * @author John R. Rose
+ * @see #getUnsafe
+ */
+
+public final class Unsafe {
+
+ private static native void registerNatives();
+ static {
+ registerNatives();
+// sun.reflect.Reflection.registerMethodsToFilter(Unsafe.class, "getUnsafe");
+ }
+
+ private Unsafe() {}
+
+ private static final Unsafe theUnsafe = new Unsafe();
+
+ /**
+ * Provides the caller with the capability of performing unsafe
+ * operations.
+ *
+ * <p> The returned <code>Unsafe</code> object should be carefully guarded
+ * by the caller, since it can be used to read and write data at arbitrary
+ * memory addresses. It must never be passed to untrusted code.
+ *
+ * <p> Most methods in this class are very low-level, and correspond to a
+ * small number of hardware instructions (on typical machines). Compilers
+ * are encouraged to optimize these methods accordingly.
+ *
+ * <p> Here is a suggested idiom for using unsafe operations:
+ *
+ * <blockquote><pre>
+ * class MyTrustedClass {
+ * private static final Unsafe unsafe = Unsafe.getUnsafe();
+ * ...
+ * private long myCountAddress = ...;
+ * public int getCount() { return unsafe.getByte(myCountAddress); }
+ * }
+ * </pre></blockquote>
+ *
+ * (It may assist compilers to make the local variable be
+ * <code>final</code>.)
+ *
+ * @exception SecurityException if a security manager exists and its
+ * <code>checkPropertiesAccess</code> method doesn't allow
+ * access to the system properties.
+ */
+ public static Unsafe getUnsafe() {
+ Class cc = sun.reflect.Reflection.getCallerClass(2);
+ if (cc.getClassLoader() != null)
+ throw new SecurityException("Unsafe");
+ return theUnsafe;
+ }
+
+ /// peek and poke operations
+ /// (compilers should optimize these to memory ops)
+
+ // These work on object fields in the Java heap.
+ // They will not work on elements of packed arrays.
+
+ /**
+ * Fetches a value from a given Java variable.
+ * More specifically, fetches a field or array element within the given
+ * object <code>o</code> at the given offset, or (if <code>o</code> is
+ * null) from the memory address whose numerical value is the given
+ * offset.
+ * <p>
+ * The results are undefined unless one of the following cases is true:
+ * <ul>
+ * <li>The offset was obtained from {@link #objectFieldOffset} on
+ * the {@link java.lang.reflect.Field} of some Java field and the object
+ * referred to by <code>o</code> is of a class compatible with that
+ * field's class.
+ *
+ * <li>The offset and object reference <code>o</code> (either null or
+ * non-null) were both obtained via {@link #staticFieldOffset}
+ * and {@link #staticFieldBase} (respectively) from the
+ * reflective {@link Field} representation of some Java field.
+ *
+ * <li>The object referred to by <code>o</code> is an array, and the offset
+ * is an integer of the form <code>B+N*S</code>, where <code>N</code> is
+ * a valid index into the array, and <code>B</code> and <code>S</code> are
+ * the values obtained by {@link #arrayBaseOffset} and {@link
+ * #arrayIndexScale} (respectively) from the array's class. The value
+ * referred to is the <code>N</code><em>th</em> element of the array.
+ *
+ * </ul>
+ * <p>
+ * If one of the above cases is true, the call references a specific Java
+ * variable (field or array element). However, the results are undefined
+ * if that variable is not in fact of the type returned by this method.
+ * <p>
+ * This method refers to a variable by means of two parameters, and so
+ * it provides (in effect) a <em>double-register</em> addressing mode
+ * for Java variables. When the object reference is null, this method
+ * uses its offset as an absolute address. This is similar in operation
+ * to methods such as {@link #getInt(long)}, which provide (in effect) a
+ * <em>single-register</em> addressing mode for non-Java variables.
+ * However, because Java variables may have a different layout in memory
+ * from non-Java variables, programmers should not assume that these
+ * two addressing modes are ever equivalent. Also, programmers should
+ * remember that offsets from the double-register addressing mode cannot
+ * be portably confused with longs used in the single-register addressing
+ * mode.
+ *
+ * @param o Java heap object in which the variable resides, if any, else
+ * null
+ * @param offset indication of where the variable resides in a Java heap
+ * object, if any, else a memory address locating the variable
+ * statically
+ * @return the value fetched from the indicated Java variable
+ * @throws RuntimeException No defined exceptions are thrown, not even
+ * {@link NullPointerException}
+ */
+ public native int getInt(Object o, long offset);
+
+ /**
+ * Stores a value into a given Java variable.
+ * <p>
+ * The first two parameters are interpreted exactly as with
+ * {@link #getInt(Object, long)} to refer to a specific
+ * Java variable (field or array element). The given value
+ * is stored into that variable.
+ * <p>
+ * The variable must be of the same type as the method
+ * parameter <code>x</code>.
+ *
+ * @param o Java heap object in which the variable resides, if any, else
+ * null
+ * @param offset indication of where the variable resides in a Java heap
+ * object, if any, else a memory address locating the variable
+ * statically
+ * @param x the value to store into the indicated Java variable
+ * @throws RuntimeException No defined exceptions are thrown, not even
+ * {@link NullPointerException}
+ */
+ public native void putInt(Object o, long offset, int x);
+
+ /**
+ * Fetches a reference value from a given Java variable.
+ * @see #getInt(Object, long)
+ */
+ public native Object getObject(Object o, long offset);
+
+ /**
+ * Stores a reference value into a given Java variable.
+ * <p>
+ * Unless the reference <code>x</code> being stored is either null
+ * or matches the field type, the results are undefined.
+ * If the reference <code>o</code> is non-null, car marks or
+ * other store barriers for that object (if the VM requires them)
+ * are updated.
+ * @see #putInt(Object, int, int)
+ */
+ public native void putObject(Object o, long offset, Object x);
+
+ /** @see #getInt(Object, long) */
+ public native boolean getBoolean(Object o, long offset);
+ /** @see #putInt(Object, int, int) */
+ public native void putBoolean(Object o, long offset, boolean x);
+ /** @see #getInt(Object, long) */
+ public native byte getByte(Object o, long offset);
+ /** @see #putInt(Object, int, int) */
+ public native void putByte(Object o, long offset, byte x);
+ /** @see #getInt(Object, long) */
+ public native short getShort(Object o, long offset);
+ /** @see #putInt(Object, int, int) */
+ public native void putShort(Object o, long offset, short x);
+ /** @see #getInt(Object, long) */
+ public native char getChar(Object o, long offset);
+ /** @see #putInt(Object, int, int) */
+ public native void putChar(Object o, long offset, char x);
+ /** @see #getInt(Object, long) */
+ public native long getLong(Object o, long offset);
+ /** @see #putInt(Object, int, int) */
+ public native void putLong(Object o, long offset, long x);
+ /** @see #getInt(Object, long) */
+ public native float getFloat(Object o, long offset);
+ /** @see #putInt(Object, int, int) */
+ public native void putFloat(Object o, long offset, float x);
+ /** @see #getInt(Object, long) */
+ public native double getDouble(Object o, long offset);
+ /** @see #putInt(Object, int, int) */
+ public native void putDouble(Object o, long offset, double x);
+
+ /**
+ * This method, like all others with 32-bit offsets, was native
+ * in a previous release but is now a wrapper which simply casts
+ * the offset to a long value. It provides backward compatibility
+ * with bytecodes compiled against 1.4.
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public int getInt(Object o, int offset) {
+ return getInt(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putInt(Object o, int offset, int x) {
+ putInt(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public Object getObject(Object o, int offset) {
+ return getObject(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putObject(Object o, int offset, Object x) {
+ putObject(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public boolean getBoolean(Object o, int offset) {
+ return getBoolean(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putBoolean(Object o, int offset, boolean x) {
+ putBoolean(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public byte getByte(Object o, int offset) {
+ return getByte(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putByte(Object o, int offset, byte x) {
+ putByte(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public short getShort(Object o, int offset) {
+ return getShort(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putShort(Object o, int offset, short x) {
+ putShort(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public char getChar(Object o, int offset) {
+ return getChar(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putChar(Object o, int offset, char x) {
+ putChar(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public long getLong(Object o, int offset) {
+ return getLong(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putLong(Object o, int offset, long x) {
+ putLong(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public float getFloat(Object o, int offset) {
+ return getFloat(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putFloat(Object o, int offset, float x) {
+ putFloat(o, (long)offset, x);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public double getDouble(Object o, int offset) {
+ return getDouble(o, (long)offset);
+ }
+
+ /**
+ * @deprecated As of 1.4.1, cast the 32-bit offset argument to a long.
+ * See {@link #staticFieldOffset}.
+ */
+ @Deprecated
+ public void putDouble(Object o, int offset, double x) {
+ putDouble(o, (long)offset, x);
+ }
+
+ // These work on values in the C heap.
+
+ /**
+ * Fetches a value from a given memory address. If the address is zero, or
+ * does not point into a block obtained from {@link #allocateMemory}, the
+ * results are undefined.
+ *
+ * @see #allocateMemory
+ */
+ public native byte getByte(long address);
+
+ /**
+ * Stores a value into a given memory address. If the address is zero, or
+ * does not point into a block obtained from {@link #allocateMemory}, the
+ * results are undefined.
+ *
+ * @see #getByte(long)
+ */
+ public native void putByte(long address, byte x);
+
+ /** @see #getByte(long) */
+ public native short getShort(long address);
+ /** @see #putByte(long, byte) */
+ public native void putShort(long address, short x);
+ /** @see #getByte(long) */
+ public native char getChar(long address);
+ /** @see #putByte(long, byte) */
+ public native void putChar(long address, char x);
+ /** @see #getByte(long) */
+ public native int getInt(long address);
+ /** @see #putByte(long, byte) */
+ public native void putInt(long address, int x);
+ /** @see #getByte(long) */
+ public native long getLong(long address);
+ /** @see #putByte(long, byte) */
+ public native void putLong(long address, long x);
+ /** @see #getByte(long) */
+ public native float getFloat(long address);
+ /** @see #putByte(long, byte) */
+ public native void putFloat(long address, float x);
+ /** @see #getByte(long) */
+ public native double getDouble(long address);
+ /** @see #putByte(long, byte) */
+ public native void putDouble(long address, double x);
+
+ /**
+ * Fetches a native pointer from a given memory address. If the address is
+ * zero, or does not point into a block obtained from {@link
+ * #allocateMemory}, the results are undefined.
+ *
+ * <p> If the native pointer is less than 64 bits wide, it is extended as
+ * an unsigned number to a Java long. The pointer may be indexed by any
+ * given byte offset, simply by adding that offset (as a simple integer) to
+ * the long representing the pointer. The number of bytes actually read
+ * from the target address maybe determined by consulting {@link
+ * #addressSize}.
+ *
+ * @see #allocateMemory
+ */
+ public native long getAddress(long address);
+
+ /**
+ * Stores a native pointer into a given memory address. If the address is
+ * zero, or does not point into a block obtained from {@link
+ * #allocateMemory}, the results are undefined.
+ *
+ * <p> The number of bytes actually written at the target address maybe
+ * determined by consulting {@link #addressSize}.
+ *
+ * @see #getAddress(long)
+ */
+ public native void putAddress(long address, long x);
+
+ /// wrappers for malloc, realloc, free:
+
+ /**
+ * Allocates a new block of native memory, of the given size in bytes. The
+ * contents of the memory are uninitialized; they will generally be
+ * garbage. The resulting native pointer will never be zero, and will be
+ * aligned for all value types. Dispose of this memory by calling {@link
+ * #freeMemory}, or resize it with {@link #reallocateMemory}.
+ *
+ * @throws IllegalArgumentException if the size is negative or too large
+ * for the native size_t type
+ *
+ * @throws OutOfMemoryError if the allocation is refused by the system
+ *
+ * @see #getByte(long)
+ * @see #putByte(long, byte)
+ */
+ public native long allocateMemory(long bytes);
+
+ /**
+ * Resizes a new block of native memory, to the given size in bytes. The
+ * contents of the new block past the size of the old block are
+ * uninitialized; they will generally be garbage. The resulting native
+ * pointer will be zero if and only if the requested size is zero. The
+ * resulting native pointer will be aligned for all value types. Dispose
+ * of this memory by calling {@link #freeMemory}, or resize it with {@link
+ * #reallocateMemory}. The address passed to this method may be null, in
+ * which case an allocation will be performed.
+ *
+ * @throws IllegalArgumentException if the size is negative or too large
+ * for the native size_t type
+ *
+ * @throws OutOfMemoryError if the allocation is refused by the system
+ *
+ * @see #allocateMemory
+ */
+ public native long reallocateMemory(long address, long bytes);
+
+ /**
+ * Sets all bytes in a given block of memory to a fixed value
+ * (usually zero).
+ */
+ public native void setMemory(long address, long bytes, byte value);
+
+ /**
+ * Sets all bytes in a given block of memory to a copy of another
+ * block.
+ */
+ public native void copyMemory(long srcAddress, long destAddress,
+ long bytes);
+
+ /**
+ * Disposes of a block of native memory, as obtained from {@link
+ * #allocateMemory} or {@link #reallocateMemory}. The address passed to
+ * this method may be null, in which case no action is taken.
+ *
+ * @see #allocateMemory
+ */
+ public native void freeMemory(long address);
+
+ /// random queries
+
+ /**
+ * This constant differs from all results that will ever be returned from
+ * {@link #staticFieldOffset}, {@link #objectFieldOffset},
+ * or {@link #arrayBaseOffset}.
+ */
+ public static final int INVALID_FIELD_OFFSET = -1;
+
+ /**
+ * Returns the offset of a field, truncated to 32 bits.
+ * This method is implemented as follows:
+ * <blockquote><pre>
+ * public int fieldOffset(Field f) {
+ * if (Modifier.isStatic(f.getModifiers()))
+ * return (int) staticFieldOffset(f);
+ * else
+ * return (int) objectFieldOffset(f);
+ * }
+ * </pre></blockquote>
+ * @deprecated As of 1.4.1, use {@link #staticFieldOffset} for static
+ * fields and {@link #objectFieldOffset} for non-static fields.
+ */
+ @Deprecated
+ public int fieldOffset(Field f) {
+ if (Modifier.isStatic(f.getModifiers()))
+ return (int) staticFieldOffset(f);
+ else
+ return (int) objectFieldOffset(f);
+ }
+
+ /**
+ * Returns the base address for accessing some static field
+ * in the given class. This method is implemented as follows:
+ * <blockquote><pre>
+ * public Object staticFieldBase(Class c) {
+ * Field[] fields = c.getDeclaredFields();
+ * for (int i = 0; i < fields.length; i++) {
+ * if (Modifier.isStatic(fields[i].getModifiers())) {
+ * return staticFieldBase(fields[i]);
+ * }
+ * }
+ * return null;
+ * }
+ * </pre></blockquote>
+ * @deprecated As of 1.4.1, use {@link #staticFieldBase(Field)}
+ * to obtain the base pertaining to a specific {@link Field}.
+ * This method works only for JVMs which store all statics
+ * for a given class in one place.
+ */
+ @Deprecated
+ public Object staticFieldBase(Class c) {
+ Field[] fields = c.getDeclaredFields();
+ for (int i = 0; i < fields.length; i++) {
+ if (Modifier.isStatic(fields[i].getModifiers())) {
+ return staticFieldBase(fields[i]);
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Report the location of a given field in the storage allocation of its
+ * class. Do not expect to perform any sort of arithmetic on this offset;
+ * it is just a cookie which is passed to the unsafe heap memory accessors.
+ *
+ * <p>Any given field will always have the same offset and base, and no
+ * two distinct fields of the same class will ever have the same offset
+ * and base.
+ *
+ * <p>As of 1.4.1, offsets for fields are represented as long values,
+ * although the Sun JVM does not use the most significant 32 bits.
+ * However, JVM implementations which store static fields at absolute
+ * addresses can use long offsets and null base pointers to express
+ * the field locations in a form usable by {@link #getInt(Object,long)}.
+ * Therefore, code which will be ported to such JVMs on 64-bit platforms
+ * must preserve all bits of static field offsets.
+ * @see #getInt(Object, long)
+ */
+ public native long staticFieldOffset(Field f);
+
+ /**
+ * Report the location of a given static field, in conjunction with {@link
+ * #staticFieldBase}.
+ * <p>Do not expect to perform any sort of arithmetic on this offset;
+ * it is just a cookie which is passed to the unsafe heap memory accessors.
+ *
+ * <p>Any given field will always have the same offset, and no two distinct
+ * fields of the same class will ever have the same offset.
+ *
+ * <p>As of 1.4.1, offsets for fields are represented as long values,
+ * although the Sun JVM does not use the most significant 32 bits.
+ * It is hard to imagine a JVM technology which needs more than
+ * a few bits to encode an offset within a non-array object,
+ * However, for consistency with other methods in this class,
+ * this method reports its result as a long value.
+ * @see #getInt(Object, long)
+ */
+ public native long objectFieldOffset(Field f);
+
+ /**
+ * Report the location of a given static field, in conjunction with {@link
+ * #staticFieldOffset}.
+ * <p>Fetch the base "Object", if any, with which static fields of the
+ * given class can be accessed via methods like {@link #getInt(Object,
+ * long)}. This value may be null. This value may refer to an object
+ * which is a "cookie", not guaranteed to be a real Object, and it should
+ * not be used in any way except as argument to the get and put routines in
+ * this class.
+ */
+ public native Object staticFieldBase(Field f);
+
+ /**
+ * Ensure the given class has been initialized. This is often
+ * needed in conjunction with obtaining the static field base of a
+ * class.
+ */
+ public native void ensureClassInitialized(Class c);
+
+ /**
+ * Report the offset of the first element in the storage allocation of a
+ * given array class. If {@link #arrayIndexScale} returns a non-zero value
+ * for the same class, you may use that scale factor, together with this
+ * base offset, to form new offsets to access elements of arrays of the
+ * given class.
+ *
+ * @see #getInt(Object, long)
+ * @see #putInt(Object, long, int)
+ */
+ public native int arrayBaseOffset(Class arrayClass);
+
+ /**
+ * Report the scale factor for addressing elements in the storage
+ * allocation of a given array class. However, arrays of "narrow" types
+ * will generally not work properly with accessors like {@link
+ * #getByte(Object, int)}, so the scale factor for such classes is reported
+ * as zero.
+ *
+ * @see #arrayBaseOffset
+ * @see #getInt(Object, long)
+ * @see #putInt(Object, long, int)
+ */
+ public native int arrayIndexScale(Class arrayClass);
+
+ /**
+ * Report the size in bytes of a native pointer, as stored via {@link
+ * #putAddress}. This value will be either 4 or 8. Note that the sizes of
+ * other primitive types (as stored in native memory blocks) is determined
+ * fully by their information content.
+ */
+ public native int addressSize();
+
+ /**
+ * Report the size in bytes of a native memory page (whatever that is).
+ * This value will always be a power of two.
+ */
+ public native int pageSize();
+
+
+ /// random trusted operations from JNI:
+
+ /**
+ * Tell the VM to define a class, without security checks. By default, the
+ * class loader and protection domain come from the caller's class.
+ */
+ public native Class defineClass(String name, byte[] b, int off, int len,
+ ClassLoader loader,
+ ProtectionDomain protectionDomain);
+
+ public native Class defineClass(String name, byte[] b, int off, int len);
+
+ /** Allocate an instance but do not run any constructor.
+ Initializes the class if it has not yet been. */
+ public native Object allocateInstance(Class cls)
+ throws InstantiationException;
+
+ /** Lock the object. It must get unlocked via {@link #monitorExit}. */
+ public native void monitorEnter(Object o);
+
+ /**
+ * Unlock the object. It must have been locked via {@link
+ * #monitorEnter}.
+ */
+ public native void monitorExit(Object o);
+
+ /**
+ * Tries to lock the object. Returns true or false to indicate
+ * whether the lock succeeded. If it did, the object must be
+ * unlocked via {@link #monitorExit}.
+ */
+ public native boolean tryMonitorEnter(Object o);
+
+ /** Throw the exception without telling the verifier. */
+ public native void throwException(Throwable ee);
+
+
+ /**
+ * Atomically update Java variable to <tt>x</tt> if it is currently
+ * holding <tt>expected</tt>.
+ * @return <tt>true</tt> if successful
+ */
+ public final native boolean compareAndSwapObject(Object o, long offset,
+ Object expected,
+ Object x);
+
+ /**
+ * Atomically update Java variable to <tt>x</tt> if it is currently
+ * holding <tt>expected</tt>.
+ * @return <tt>true</tt> if successful
+ */
+ public final native boolean compareAndSwapInt(Object o, long offset,
+ int expected,
+ int x);
+
+ /**
+ * Atomically update Java variable to <tt>x</tt> if it is currently
+ * holding <tt>expected</tt>.
+ * @return <tt>true</tt> if successful
+ */
+ public final native boolean compareAndSwapLong(Object o, long offset,
+ long expected,
+ long x);
+
+ /**
+ * Fetches a reference value from a given Java variable, with volatile
+ * load semantics. Otherwise identical to {@link #getObject(Object, long)}
+ */
+ public native Object getObjectVolatile(Object o, long offset);
+
+ /**
+ * Stores a reference value into a given Java variable, with
+ * volatile store semantics. Otherwise identical to {@link #putObject(Object, long, Object)}
+ */
+ public native void putObjectVolatile(Object o, long offset, Object x);
+
+ /** Volatile version of {@link #getInt(Object, long)} */
+ public native int getIntVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putInt(Object, long, int)} */
+ public native void putIntVolatile(Object o, long offset, int x);
+
+ /** Volatile version of {@link #getBoolean(Object, long)} */
+ public native boolean getBooleanVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putBoolean(Object, long, boolean)} */
+ public native void putBooleanVolatile(Object o, long offset, boolean x);
+
+ /** Volatile version of {@link #getByte(Object, long)} */
+ public native byte getByteVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putByte(Object, long, byte)} */
+ public native void putByteVolatile(Object o, long offset, byte x);
+
+ /** Volatile version of {@link #getShort(Object, long)} */
+ public native short getShortVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putShort(Object, long, short)} */
+ public native void putShortVolatile(Object o, long offset, short x);
+
+ /** Volatile version of {@link #getChar(Object, long)} */
+ public native char getCharVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putChar(Object, long, char)} */
+ public native void putCharVolatile(Object o, long offset, char x);
+
+ /** Volatile version of {@link #getLong(Object, long)} */
+ public native long getLongVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putLong(Object, long, long)} */
+ public native void putLongVolatile(Object o, long offset, long x);
+
+ /** Volatile version of {@link #getFloat(Object, long)} */
+ public native float getFloatVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putFloat(Object, long, float)} */
+ public native void putFloatVolatile(Object o, long offset, float x);
+
+ /** Volatile version of {@link #getDouble(Object, long)} */
+ public native double getDoubleVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putDouble(Object, long, double)} */
+ public native void putDoubleVolatile(Object o, long offset, double x);
+
+ /**
+ * Version of {@link #putObjectVolatile(Object, long, Object)}
+ * that does not guarantee immediate visibility of the store to
+ * other threads. This method is generally only useful if the
+ * underlying field is a Java volatile (or if an array cell, one
+ * that is otherwise only accessed using volatile accesses).
+ */
+ public native void putOrderedObject(Object o, long offset, Object x);
+
+ /** Ordered/Lazy version of {@link #putIntVolatile(Object, long, int)} */
+ public native void putOrderedInt(Object o, long offset, int x);
+
+ /** Ordered/Lazy version of {@link #putLongVolatile(Object, long, long)} */
+ public native void putOrderedLong(Object o, long offset, long x);
+
+ /**
+ * Unblock the given thread blocked on <tt>park</tt>, or, if it is
+ * not blocked, cause the subsequent call to <tt>park</tt> not to
+ * block. Note: this operation is "unsafe" solely because the
+ * caller must somehow ensure that the thread has not been
+ * destroyed. Nothing special is usually required to ensure this
+ * when called from Java (in which there will ordinarily be a live
+ * reference to the thread) but this is not nearly-automatically
+ * so when calling from native code.
+ * @param thread the thread to unpark.
+ *
+ */
+ public native void unpark(Object thread);
+
+ /**
+ * Block current thread, returning when a balancing
+ * <tt>unpark</tt> occurs, or a balancing <tt>unpark</tt> has
+ * already occurred, or the thread is interrupted, or, if not
+ * absolute and time is not zero, the given time nanoseconds have
+ * elapsed, or if absolute, the given deadline in milliseconds
+ * since Epoch has passed, or spuriously (i.e., returning for no
+ * "reason"). Note: This operation is in the Unsafe class only
+ * because <tt>unpark</tt> is, so it would be strange to place it
+ * elsewhere.
+ */
+ public native void park(boolean isAbsolute, long time);
+
+ /**
+ * Gets the load average in the system run queue assigned
+ * to the available processors averaged over various periods of time.
+ * This method retrieves the given <tt>nelem</tt> samples and
+ * assigns to the elements of the given <tt>loadavg</tt> array.
+ * The system imposes a maximum of 3 samples, representing
+ * averages over the last 1, 5, and 15 minutes, respectively.
+ *
+ * @params loadavg an array of double of size nelems
+ * @params nelems the number of samples to be retrieved and
+ * must be 1 to 3.
+ *
+ * @return the number of samples actually retrieved; or -1
+ * if the load average is unobtainable.
+ */
+ public native int getLoadAverage(double[] loadavg, int nelems);
+}
projects / cacao.git / blobdiff