Add missing Java files to RN fbjni sync

Reviewed By: mhorowitz

Differential Revision: D5129224

fbshipit-source-id: d9fb5f95505f6be7d3d87ead67dbfaa951c03434

ReactAndroid/src/main/java/com/facebook/jni/CpuCapabilitiesJni.java

@@ -0,0 +1,27 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+package com.facebook.jni;
+
+import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.soloader.SoLoader;
+
+/**
+ * Utility class to determine CPU capabilities
+ */
+@DoNotStrip
+public class CpuCapabilitiesJni {
+
+  static {
+    SoLoader.loadLibrary("fb");
+  }
+
+  @DoNotStrip
+  public static native boolean nativeDeviceSupportsNeon();
+
+  @DoNotStrip
+  public static native boolean nativeDeviceSupportsVFPFP16();
+
+  @DoNotStrip
+  public static native boolean nativeDeviceSupportsX86();
+
+}

ReactAndroid/src/main/java/com/facebook/jni/DestructorThread.java

@@ -0,0 +1,132 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+package com.facebook.jni;
+
+import java.lang.ref.PhantomReference;
+import java.lang.ref.ReferenceQueue;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * A thread which invokes the "destruct" routine for objects after they have been garbage collected.
+ *
+ * An object which needs to be destructed should create a static subclass of {@link Destructor}.
+ * Once the referent object is garbage collected, the DestructorThread will callback to the
+ * {@link Destructor#destruct()} method.
+ *
+ * The underlying thread in DestructorThread starts when the first Destructor is constructed
+ * and then runs indefinitely.
+ */
+public class DestructorThread {
+
+  /**
+   * N.B The Destructor <b>SHOULD NOT</b> refer back to its referent object either explicitly or
+   * implicitly (for example, as a non-static inner class). This will create a reference cycle where
+   * the referent object will never be garbage collected.
+   */
+  public abstract static class Destructor extends PhantomReference<Object> {
+
+    private Destructor next;
+    private Destructor previous;
+
+    Destructor(Object referent) {
+      super(referent, sReferenceQueue);
+      sDestructorStack.push(this);
+    }
+
+    private Destructor() {
+      super(null, sReferenceQueue);
+    }
+
+    /** Callback which is invoked when the original object has been garbage collected. */
+    abstract void destruct();
+  }
+
+  /** A list to keep all active Destructors in memory confined to the Destructor thread. */
+  private static DestructorList sDestructorList;
+  /** A thread safe stack where new Destructors are placed before being add to sDestructorList. */
+  private static DestructorStack sDestructorStack;
+  private static ReferenceQueue sReferenceQueue;
+  private static Thread sThread;
+
+  static {
+    sDestructorStack = new DestructorStack();
+    sReferenceQueue = new ReferenceQueue();
+    sDestructorList = new DestructorList();
+    sThread = new Thread("HybridData DestructorThread") {
+      @Override
+      public void run() {
+        while (true) {
+          try {
+            Destructor current = (Destructor) sReferenceQueue.remove();
+            current.destruct();
+
+            // If current is in the sDestructorStack,
+            // transfer all the Destructors in the stack to the list.
+            if (current.previous == null) {
+              sDestructorStack.transferAllToList();
+            }
+
+            DestructorList.drop(current);
+          } catch (InterruptedException e) {
+            // Continue. This thread should never be terminated.
+          }
+        }
+      }
+    };
+
+    sThread.start();
+  }
+
+  private static class Terminus extends Destructor {
+    @Override
+    void destruct() {
+      throw new IllegalStateException("Cannot destroy Terminus Destructor.");
+    }
+  }
+
+  /** This is a thread safe, lock-free Treiber-like Stack of Destructors. */
+  private static class DestructorStack {
+    private AtomicReference<Destructor> mHead = new AtomicReference<>();
+
+    public void push(Destructor newHead) {
+      Destructor oldHead;
+      do {
+        oldHead = mHead.get();
+        newHead.next = oldHead;
+      } while (!mHead.compareAndSet(oldHead, newHead));
+    }
+
+    public void transferAllToList() {
+      Destructor current = mHead.getAndSet(null);
+      while (current != null) {
+        Destructor next = current.next;
+        sDestructorList.enqueue(current);
+        current = next;
+      }
+    }
+  }
+
+  /** A doubly-linked list of Destructors. */
+  private static class DestructorList {
+    private Destructor mHead;
+
+    public DestructorList() {
+      mHead = new Terminus();
+      mHead.next = new Terminus();
+      mHead.next.previous = mHead;
+    }
+
+    public void enqueue(Destructor current) {
+      current.next = mHead.next;
+      mHead.next = current;
+
+      current.next.previous = current;
+      current.previous = mHead;
+    }
+
+    private static void drop(Destructor current) {
+      current.next.previous = current.previous;
+      current.previous.next = current.next;
+    }
+  }
+}

ReactAndroid/src/main/java/com/facebook/jni/HybridClassBase.java

@@ -0,0 +1,8 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+package com.facebook.jni;
+import com.facebook.proguard.annotations.DoNotStrip;
+
+@DoNotStrip
+public abstract class HybridClassBase extends HybridData {
+}

ReactAndroid/src/main/java/com/facebook/jni/HybridData.java

@@ -2,6 +2,8 @@
 
 package com.facebook.jni;
 
+import android.util.Log;
+
 import com.facebook.proguard.annotations.DoNotStrip;
 import com.facebook.soloader.SoLoader;
 
@@ -10,11 +12,9 @@
  *
  * NB: THREAD SAFETY
  *
- * {@link #dispose} deletes the corresponding native object on whatever thread
- * the method is called on. In the common case when this is called by
- * HybridData#finalize(), this will be called on the system finalizer
- * thread. If you manually call resetNative() on the Java object, the C++
- * object will be deleted synchronously on that thread.
+ * {@link #resetNative} deletes the corresponding native object synchronously on whatever thread
+ * the method is called on. Otherwise, deletion will occur on the {@link DestructorThread}
+ * thread.
  */
 @DoNotStrip
 public class HybridData {
@@ -23,27 +23,57 @@ public class HybridData {
     SoLoader.loadLibrary("fb");
   }
 
-  // Private C++ instance
   @DoNotStrip
-  private long mNativePointer = 0;
+  private Destructor mDestructor = new Destructor(this);
 
   /**
    * To explicitly delete the instance, call resetNative().  If the C++
    * instance is referenced after this is called, a NullPointerException will
    * be thrown.  resetNative() may be called multiple times safely.  Because
-   * {@link #finalize} calls resetNative, the instance will not leak if this is
+   * the {@link DestructorThread} also calls resetNative, the instance will not leak if this is
    * not called, but timing of deletion and the thread the C++ dtor is called
    * on will be at the whim of the Java GC.  If you want to control the thread
    * and timing of the destructor, you should call resetNative() explicitly.
    */
-  public native void resetNative();
-
-  protected void finalize() throws Throwable {
-    resetNative();
-    super.finalize();
+  public synchronized void resetNative() {
+    mDestructor.destruct();
   }
 
+  /**
+   * N.B. Thread safety.
+   * If you call isValid from a different thread than {@link #resetNative()} then be sure to
+   * do so while synchronizing on the hybrid. For example:
+   * <pre><code>
+   * synchronized(hybrid) {
+   *   if (hybrid.isValid) {
+   *     // Do stuff.
+   *   }
+   * }
+   * </code></pre>
+   */
   public boolean isValid() {
-    return mNativePointer != 0;
+    return mDestructor.mNativePointer != 0;
+  }
+
+  public static class Destructor extends DestructorThread.Destructor {
+
+    // Private C++ instance
+    @DoNotStrip
+    private long mNativePointer;
+
+    Destructor(Object referent) {
+      super(referent);
+    }
+
+    @Override
+    void destruct() {
+      // When invoked from the DestructorThread instead of resetNative,
+      // the DestructorThread has exclusive ownership of the HybridData
+      // so synchronization is not necessary.
+      deleteNative(mNativePointer);
+      mNativePointer = 0;
+    }
+
+    static native void deleteNative(long pointer);
   }
 }

ReactAndroid/src/main/java/com/facebook/jni/JniTerminateHandler.java

@@ -0,0 +1,15 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+package com.facebook.jni;
+
+public class JniTerminateHandler {
+  public static void handleTerminate(Throwable t) throws Throwable {
+    Thread.UncaughtExceptionHandler h = Thread.getDefaultUncaughtExceptionHandler();
+    if (h == null) {
+      // Odd. Let the default std::terminate_handler deal with it.
+      return;
+    }
+    h.uncaughtException(Thread.currentThread(), t);
+    // That should exit. If it doesn't, let the default handler deal with it.
+  }
+}