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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain. Use, modify, and |
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* redistribute this code in any way without acknowledgement. |
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*/ |
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|
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package java.util.concurrent; |
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import sun.misc.Unsafe; |
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import java.lang.reflect.*; |
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|
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/** |
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* Package-private native methods for classes introduced in JSR166 |
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*/ |
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final class JSR166Support { |
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private static native void registerNatives(); |
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private static final Unsafe unsafe = Unsafe.getUnsafe(); |
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private static int addressSize = unsafe.addressSize(); |
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static { |
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registerNatives(); |
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} |
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|
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/** |
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* Native implementation of trylock entry in Locks.attempt. |
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*/ |
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static native boolean tryLockEnter(Object o); |
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|
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/** |
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* Native implementation of trylock exit in Locks.attempt. |
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*/ |
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static native void tryLockExit(Object o); |
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|
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/** |
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* Native implementation of Locks.newConditionFor(obj).wait() |
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*/ |
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static native void conditionWait(Object obj, |
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Object cond |
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) throws InterruptedException; |
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|
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|
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/** |
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* Native implementation of Locks.newConditionFor(obj).waitNanos() |
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*/ |
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static native long conditionRelWait(Object obj, |
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Object cond, |
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long nanos) throws InterruptedException; |
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|
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/** |
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* Native implementation of Locks.newConditionFor(obj).waitUntil() |
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*/ |
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static native boolean conditionAbsWait(Object obj, |
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Object cond, |
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long deadline) throws InterruptedException; |
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|
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/** |
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* Native implementation of Locks.newConditionFor(obj).signal() |
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*/ |
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static native void conditionNotify(Object base, Object cond); |
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|
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/** |
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* Native implementation of Locks.newConditionFor(obj).signalAll() |
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*/ |
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static native void conditionNotifyAll(Object base, Object cond); |
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|
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/** |
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* Native implementation of TimeUnit.nanoTime |
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*/ |
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static native long currentTimeNanos(); |
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|
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/** |
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* Native implementation of thread-blocking primitive used in |
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* ReentrantLock (and possibly elsewhere). Block current thread |
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* until a balancing unpark occurs, or the thread is interrupted, |
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* or if isAbsolute is false, the relative time in nanoseconds |
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* elapses, or if true, the time of day in millisecs since epoch |
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* elapses, or if a balancing unpark has already been |
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* issued, or just spuriously. |
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* @param isAbsolute true if time represents a deadline, false if a timeout. |
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* @param time the deadline or timeout. If zero and isAbsolute is |
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* false, means to wait forever. |
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*/ |
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static native void park(boolean isAbsolute, long time); |
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|
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/** |
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* Native implementation of thread-unblocking primitive used in |
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* ReentrantLock (and possibly elsewhere). Unblock the given |
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* thread blocked on park, or, if it is not blocked, cause the |
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* subsequent call to park not to block. |
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* @param thread the thread to unpark (no-op if null). |
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*/ |
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static native void unpark(Object thread); |
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|
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/** |
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* Implementation of Locks.mightBeLocked. |
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*/ |
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static boolean mightBeLocked(Object x) { |
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// This is actually done non-natively via unsafe, but is |
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// highly dependent on JVM object layout details. |
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boolean l = (addressSize == 4)? |
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((unsafe.getInt(x, 0L) & 3) == 1) : |
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((unsafe.getLong(x, 0L) & 3) == 1); |
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unsafe.loadLoadBarrier(); |
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return l; |
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} |
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|
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} |
