File	Doc	Category	Size	Date	Package
Unsafe.java	API Doc	Android 1.5 API	11868	Wed May 06 22:41:06 BST 2009	sun.misc

Unsafe

• java.lang.Object

Fields Summary
private static final Unsafe	THE_ONE non-null; unique instance of this class
private final org.apache.harmony.kernel.vm.LangAccess	lang non-null; the lang-access utility instance

Constructors Summary
private Unsafe() This class is only privately instantiable. lang = LangAccess.getInstance();

Methods Summary
public int	arrayBaseOffset(java.lang.Class clazz) Gets the offset from the start of an array object's memory to the memory used to store its initial (zeroeth) element. param clazz non-null; class in question; must be an array class return the offset to the initial element if (! clazz.isArray()) { throw new IllegalArgumentException( "valid for array classes only"); } return arrayBaseOffset0(clazz);
private static native int	arrayBaseOffset0(java.lang.Class clazz) Helper for {@link #arrayBaseOffset}, which does all the work, assuming the parameter is deemed valid. param field non-null; the instance field return the offset to the field
public int	arrayIndexScale(java.lang.Class clazz) Gets the size of each element of the given array class. param clazz non-null; class in question; must be an array class return > 0; the size of each element of the array if (! clazz.isArray()) { throw new IllegalArgumentException( "valid for array classes only"); } return arrayIndexScale0(clazz);
private static native int	arrayIndexScale0(java.lang.Class clazz) Helper for {@link #arrayIndexScale}, which does all the work, assuming the parameter is deemed valid. param field non-null; the instance field return the offset to the field
public native boolean	compareAndSwapInt(java.lang.Object obj, long offset, int expectedValue, int newValue) Performs a compare-and-set operation on an int field within the given object. param obj non-null; object containing the field param offset offset to the field within obj param expectedValue expected value of the field param newValue new value to store in the field if the contents are as expected return true if the new value was in fact stored, and false if not
public native boolean	compareAndSwapLong(java.lang.Object obj, long offset, long expectedValue, long newValue) Performs a compare-and-set operation on a long field within the given object. param obj non-null; object containing the field param offset offset to the field within obj param expectedValue expected value of the field param newValue new value to store in the field if the contents are as expected return true if the new value was in fact stored, and false if not
public native boolean	compareAndSwapObject(java.lang.Object obj, long offset, java.lang.Object expectedValue, java.lang.Object newValue) Performs a compare-and-set operation on an Object field (that is, a reference field) within the given object. param obj non-null; object containing the field param offset offset to the field within obj param expectedValue expected value of the field param newValue new value to store in the field if the contents are as expected return true if the new value was in fact stored, and false if not
public native int	getInt(java.lang.Object obj, long offset) Gets an int field from the given object. param obj non-null; object containing the field param offset offset to the field within obj return the retrieved value
public native int	getIntVolatile(java.lang.Object obj, long offset) Gets an int field from the given object, using volatile semantics. param obj non-null; object containing the field param offset offset to the field within obj return the retrieved value
public native long	getLong(java.lang.Object obj, long offset) Gets a long field from the given object. param obj non-null; object containing the field param offset offset to the field within obj return the retrieved value
public native long	getLongVolatile(java.lang.Object obj, long offset) Gets a long field from the given object, using volatile semantics. param obj non-null; object containing the field param offset offset to the field within obj return the retrieved value
public native java.lang.Object	getObject(java.lang.Object obj, long offset) Gets an Object field from the given object. param obj non-null; object containing the field param offset offset to the field within obj return the retrieved value
public native java.lang.Object	getObjectVolatile(java.lang.Object obj, long offset) Gets an Object field from the given object, using volatile semantics. param obj non-null; object containing the field param offset offset to the field within obj return the retrieved value
public static sun.misc.Unsafe	getUnsafe() Gets the unique instance of this class. This is only allowed in very limited situations. /* * Only code on the bootclasspath is allowed to get at the * Unsafe instance. */ ClassLoader calling = VMStack.getCallingClassLoader2(); ClassLoader current = Unsafe.class.getClassLoader(); if ((calling != null) && (calling != Unsafe.class.getClassLoader())) { throw new SecurityException("Unsafe access denied"); } return THE_ONE;
public long	objectFieldOffset(java.lang.reflect.Field field) Gets the raw byte offset from the start of an object's memory to the memory used to store the indicated instance field. param field non-null; the field in question, which must be an instance field return the offset to the field if (Modifier.isStatic(field.getModifiers())) { throw new IllegalArgumentException( "valid for instance fields only"); } return objectFieldOffset0(field);
private static native long	objectFieldOffset0(java.lang.reflect.Field field) Helper for {@link #objectFieldOffset}, which does all the work, assuming the parameter is deemed valid. param field non-null; the instance field return the offset to the field
public void	park(boolean absolute, long time) Parks the calling thread for the specified amount of time, unless the "permit" for the thread is already available (due to a previous call to {@link #unpark}. This method may also return spuriously (that is, without the thread being told to unpark and without the indicated amount of time elapsing). See {@link java.util.concurrent.locks.LockSupport} for more in-depth information of the behavior of this method. param absolute whether the given time value is absolute milliseconds-since-the-epoch (true) or relative nanoseconds-from-now (false) param time the (absolute millis or relative nanos) time value if (absolute) { lang.parkUntil(time); } else { lang.parkFor(time); }
public native void	putInt(java.lang.Object obj, long offset, int newValue) Stores an int field into the given object. param obj non-null; object containing the field param offset offset to the field within obj param newValue the value to store
public native void	putIntVolatile(java.lang.Object obj, long offset, int newValue) Stores an int field into the given object, using volatile semantics. param obj non-null; object containing the field param offset offset to the field within obj param newValue the value to store
public native void	putLong(java.lang.Object obj, long offset, long newValue) Stores a long field into the given object. param obj non-null; object containing the field param offset offset to the field within obj param newValue the value to store
public native void	putLongVolatile(java.lang.Object obj, long offset, long newValue) Stores a long field into the given object, using volatile semantics. param obj non-null; object containing the field param offset offset to the field within obj param newValue the value to store
public native void	putObject(java.lang.Object obj, long offset, java.lang.Object newValue) Stores an Object field into the given object. param obj non-null; object containing the field param offset offset to the field within obj param newValue the value to store
public native void	putObjectVolatile(java.lang.Object obj, long offset, java.lang.Object newValue) Stores an Object field into the given object, using volatile semantics. param obj non-null; object containing the field param offset offset to the field within obj param newValue the value to store
public void	unpark(java.lang.Object obj) Unparks the given object, which must be a {@link Thread}. See {@link java.util.concurrent.locks.LockSupport} for more in-depth information of the behavior of this method. param obj non-null; the object to unpark if (obj instanceof Thread) { lang.unpark((Thread) obj); } else { throw new IllegalArgumentException("valid for Threads only"); }