[Java.Interop] JniRuntime.JniValueManager method renames.

Rename JniRuntime.JniValueManager.PeekObject() to PeekPeer().
Rationale: consistent terminology (51f7862). What's an "Object"?

Rename JniRuntime.JniValueManager.GetSurfacedObjects() to
GetSurfacedPeers().
Rationale: consistent terminology (51f7862). What's an "Object"?

Change the return type of
JniRuntime.JniValueManager.GetSurfacedPeers() from
List<WeakReference<IJavaPeerable>> to
List<JniSurfacedPeerInfo>>:

	- public abstract List<WeakReference<IJavaPeerable>>  GetSurfacedObjects ();
	+ public abstract List<JniSurfacedPeerInfo>           GetSurfacedPeers ();

Rationale: While trying to investigate object reference lifetimes in
Xamarin.Android, it is not unusual for
Java.Interop.Runtime.GetSurfacedObjects() -- which returns a
List<WeakReference> -- to contain a WeakReference which has been
collected -- i.e. the WeakReference is non-null while
WeakReference.Target is null.

Meaning I *know* there's an identityHashCode <=> peer mapping, but
there's no way -- in the *public* API -- to know what the
identityHashCode value *is*. (The identityHashCode value is desired
because that's also printed in the GREF log, so with the
identityHashCode value I could at least determine what *type* it was.)

Which makes it very hard to reason about anything without adding some
Console.WriteLine()s into the middle of things, to obtain information
that was "lost" because it was never provided.

The fix? Provide the identityHashCode value:

	class JniSurfacedPeerInfo {
		public  int                             JniIdentityHashCode     {get; private set;}
		public  WeakReference<IJavaPeerable>    SurfacedPeer            {get; private set;}
	}

JniSurfacedPeerInfo.JniIdentityHashCode is the original
identityHashCode value for the instance held by
JniSurfacedPeerInfo.SurfacedPeer, *even if* the peer has been
collected.

JniSurfacedPeerInfo is a class so that it can be optionally subclassed.

Author: jonpryor

src/Java.Interop/Java.Interop/JavaProxyObject.cs

@@ -72,7 +72,7 @@ static bool _Equals (IntPtr jnienv, IntPtr n_self, IntPtr n_value)
 		{
 			var envp = new JniTransition (jnienv);
 			try {
-				var self    = (JavaProxyObject) JniEnvironment.Runtime.ValueManager.PeekObject (new JniObjectReference (n_self));
+				var self    = (JavaProxyObject) JniEnvironment.Runtime.ValueManager.PeekPeer (new JniObjectReference (n_self));
 				var r_value = new JniObjectReference (n_value);
 				var value   = JniEnvironment.Runtime.ValueManager.GetValue (ref r_value, JniObjectReferenceOptions.Copy);
 				return self.Equals (value);
@@ -91,7 +91,7 @@ static int _GetHashCode (IntPtr jnienv, IntPtr n_self)
 		{
 			var envp = new JniTransition (jnienv);
 			try {
-				var self = (JavaProxyObject) JniEnvironment.Runtime.ValueManager.PeekObject (new JniObjectReference (n_self));
+				var self = (JavaProxyObject) JniEnvironment.Runtime.ValueManager.PeekPeer (new JniObjectReference (n_self));
 				return self.GetHashCode ();
 			}
 			catch (Exception e) {
@@ -107,7 +107,7 @@ static IntPtr _ToString (IntPtr jnienv, IntPtr n_self)
 		{
 			var envp = new JniTransition (jnienv);
 			try {
-				var self    = (JavaProxyObject) JniEnvironment.Runtime.ValueManager.PeekObject (new JniObjectReference (n_self));
+				var self    = (JavaProxyObject) JniEnvironment.Runtime.ValueManager.PeekPeer (new JniObjectReference (n_self));
 				var s       = self.ToString ();
 				var r       = JniEnvironment.Strings.NewString (s);
 				try {

src/Java.Interop/Java.Interop/JniRuntime.JniValueManager.cs

@@ -11,6 +11,18 @@
 
 namespace Java.Interop
 {
+	public class JniSurfacedPeerInfo {
+
+		public  int                             JniIdentityHashCode     {get; private set;}
+		public  WeakReference<IJavaPeerable>    SurfacedPeer            {get; private set;}
+
+		public JniSurfacedPeerInfo (int jniIdentityHashCode, WeakReference<IJavaPeerable> surfacedPeer)
+		{
+			JniIdentityHashCode     = jniIdentityHashCode;
+			SurfacedPeer            = surfacedPeer;
+		}
+	}
+
 	partial class JniRuntime
 	{
 		partial class CreationOptions {
@@ -58,7 +70,7 @@ protected virtual void Dispose (bool disposing)
 
 			public abstract void Finalize (IJavaPeerable value);
 
-			public abstract List<WeakReference<IJavaPeerable>> GetSurfacedObjects ();
+			public abstract List<JniSurfacedPeerInfo>   GetSurfacedPeers ();
 
 			public void Construct (IJavaPeerable value, ref JniObjectReference reference, JniObjectReferenceOptions options)
 			{
@@ -153,21 +165,21 @@ public virtual void DisposeUnlessReferenced (IJavaPeerable value)
 				if (!h.IsValid)
 					return;
 
-				var o = PeekObject (h);
+				var o = PeekPeer (h);
 				if (o != null && object.ReferenceEquals (o, value))
 					return;
 
 				Dispose (h, value);
 			}
 
-			public abstract IJavaPeerable PeekObject (JniObjectReference reference);
+			public abstract IJavaPeerable PeekPeer (JniObjectReference reference);
 
 			public object PeekValue (JniObjectReference reference)
 			{
 				if (!reference.IsValid)
 					return null;
 
-				var t   = PeekObject (reference);
+				var t   = PeekPeer (reference);
 				if (t == null)
 					return t;
 
@@ -195,7 +207,7 @@ protected virtual bool TryUnboxObject (IJavaPeerable value, out object result)
 
 			object PeekBoxedObject (JniObjectReference reference)
 			{
-				var t   = PeekObject (reference);
+				var t   = PeekPeer (reference);
 				if (t == null)
 					return null;
 				object r;

src/Java.Interop/Tests/Java.Interop/JavaObjectTest.cs

@@ -46,18 +46,18 @@ public void JavaReferencedInstanceSurvivesCollection ()
 		[Test]
 		public void UnregisterFromRuntime ()
 		{
-			int registeredCount = JniRuntime.CurrentRuntime.ValueManager.GetSurfacedObjects ().Count;
+			int registeredCount = JniRuntime.CurrentRuntime.ValueManager.GetSurfacedPeers ().Count;
 			JniObjectReference l;
 			JavaObject o;
 			using (o = new JavaObject ()) {
 				l   = o.PeerReference.NewLocalRef ();
 				Assert.AreEqual (JniObjectReferenceType.Global, o.PeerReference.Type);
-				Assert.AreEqual (registeredCount+1, JniRuntime.CurrentRuntime.ValueManager.GetSurfacedObjects ().Count);
+				Assert.AreEqual (registeredCount+1, JniRuntime.CurrentRuntime.ValueManager.GetSurfacedPeers ().Count);
 				Assert.IsNotNull (JniRuntime.CurrentRuntime.ValueManager.PeekValue (l));
 				Assert.AreNotSame (l, o.PeerReference);
 				Assert.AreSame (o, JniRuntime.CurrentRuntime.ValueManager.PeekValue (l));
 			}
-			Assert.AreEqual (registeredCount, JniRuntime.CurrentRuntime.ValueManager.GetSurfacedObjects ().Count);
+			Assert.AreEqual (registeredCount, JniRuntime.CurrentRuntime.ValueManager.GetSurfacedPeers ().Count);
 			Assert.IsNull (JniRuntime.CurrentRuntime.ValueManager.PeekValue (l));
 			JniObjectReference.Dispose (ref l);
 			Assert.Throws<ObjectDisposedException> (() => o.UnregisterFromRuntime ());

src/Java.Interop/Tests/Java.Interop/JniRuntime.JniValueManagerTests.cs

@@ -50,12 +50,12 @@ public override void Finalize (IJavaPeerable reference)
 			{
 			}
 
-			public override List<WeakReference<IJavaPeerable>> GetSurfacedObjects ()
+			public override List<JniSurfacedPeerInfo> GetSurfacedPeers ()
 			{
 				return null;
 			}
 
-			public override IJavaPeerable PeekObject (JniObjectReference reference)
+			public override IJavaPeerable PeekPeer (JniObjectReference reference)
 			{
 				return null;
 			}

src/Java.Runtime.Environment/Java.Interop/MonoRuntimeValueManager.cs

@@ -85,10 +85,14 @@ protected override void Dispose (bool disposing)
 		Dictionary<int, WeakReference<IJavaPeerable>>  RegisteredInstances = new Dictionary<int, WeakReference<IJavaPeerable>>();
 
 
-		public override List<WeakReference<IJavaPeerable>> GetSurfacedObjects ()
+		public override List<JniSurfacedPeerInfo> GetSurfacedPeers ()
 		{
 			lock (RegisteredInstances) {
-				return RegisteredInstances.Values.ToList ();
+				var peers = new List<JniSurfacedPeerInfo> (RegisteredInstances.Count);
+				foreach (var e in RegisteredInstances) {
+					peers.Add (new JniSurfacedPeerInfo (e.Key, e.Value));
+				}
+				return peers;
 			}
 		}
 
@@ -97,7 +101,7 @@ public override void Add (IJavaPeerable value)
 			var r = value.PeerReference;
 			if (!r.IsValid)
 				throw new ObjectDisposedException (value.GetType ().FullName);
-			var o = PeekObject (value.PeerReference);
+			var o = PeekPeer (value.PeerReference);
 			if (o != null)
 				return;
 
@@ -147,7 +151,7 @@ public override void Remove (IJavaPeerable value)
 			}
 		}
 
-		public override IJavaPeerable PeekObject (JniObjectReference reference)
+		public override IJavaPeerable PeekPeer (JniObjectReference reference)
 		{
 			if (!reference.IsValid)
 				return null;