Update mojo sdk to rev cc531b32182099a5a034a99daff35ed5d38a61c8

BUG=none
R=jamesr@chromium.org
TBR=jbudorick@chromium.org, thestig@chromium.org

Review URL: https://codereview.chromium.org/795593004

Cr-Commit-Position: refs/heads/master@{#309785}

5 files changed, 228 insertions, 174 deletions

diff --git a/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java b/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java
index 9a7b473..427fbec 100644
--- a/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java
+++ b/mojo/android/javatests/src/org/chromium/mojo/HandleMock.java
@@ -5,6 +5,7 @@
 package org.chromium.mojo;
 
 import org.chromium.mojo.system.Core;
+import org.chromium.mojo.system.Core.WaitResult;
 import org.chromium.mojo.system.DataPipe;
 import org.chromium.mojo.system.DataPipe.ConsumerHandle;
 import org.chromium.mojo.system.DataPipe.ProducerHandle;
@@ -36,9 +37,11 @@ public class HandleMock implements UntypedHandle, MessagePipeHandle,
      * @see Handle#wait(Core.HandleSignals, long)
      */
     @Override
-    public int wait(Core.HandleSignals signals, long deadline) {
+    public WaitResult wait(Core.HandleSignals signals, long deadline) {
         // Do nothing.
-        return MojoResult.OK;
+        WaitResult result = new WaitResult();
+        result.setMojoResult(MojoResult.OK);
+        return result;
     }
 
     /**
diff --git a/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java b/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java
index 9c4718c..b35e119 100644
--- a/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java
+++ b/mojo/android/javatests/src/org/chromium/mojo/system/impl/CoreImplTest.java
@@ -11,7 +11,10 @@ import org.chromium.mojo.system.AsyncWaiter;
 import org.chromium.mojo.system.AsyncWaiter.Callback;
 import org.chromium.mojo.system.AsyncWaiter.Cancellable;
 import org.chromium.mojo.system.Core;
+import org.chromium.mojo.system.Core.HandleSignals;
+import org.chromium.mojo.system.Core.HandleSignalsState;
 import org.chromium.mojo.system.Core.WaitManyResult;
+import org.chromium.mojo.system.Core.WaitResult;
 import org.chromium.mojo.system.DataPipe;
 import org.chromium.mojo.system.Handle;
 import org.chromium.mojo.system.InvalidHandle;
@@ -35,12 +38,14 @@ import java.util.concurrent.TimeUnit;
  * Testing the core API.
  */
 public class CoreImplTest extends MojoTestCase {
-
     private static final long RUN_LOOP_TIMEOUT_MS = 5;
 
     private static final ScheduledExecutorService WORKER =
             Executors.newSingleThreadScheduledExecutor();
 
+    private static final HandleSignals ALL_SIGNALS =
+            HandleSignals.none().setPeerClosed(true).setReadable(true).setWritable(true);
+
     private List<Handle> mHandlesToClose = new ArrayList<Handle>();
 
     /**
@@ -101,8 +106,8 @@ public class CoreImplTest extends MojoTestCase {
 
         // Try to read into a small buffer.
         ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(bytes.length / 2);
-        MessagePipeHandle.ReadMessageResult result = out.readMessage(
-                receiveBuffer, 0, MessagePipeHandle.ReadFlags.NONE);
+        MessagePipeHandle.ReadMessageResult result =
+                out.readMessage(receiveBuffer, 0, MessagePipeHandle.ReadFlags.NONE);
         assertEquals(MojoResult.RESOURCE_EXHAUSTED, result.getMojoResult());
         assertEquals(bytes.length, result.getMessageSize());
         assertEquals(0, result.getHandlesCount());
@@ -118,7 +123,6 @@ public class CoreImplTest extends MojoTestCase {
         byte[] receivedBytes = new byte[result.getMessageSize()];
         receiveBuffer.get(receivedBytes);
         assertTrue(Arrays.equals(bytes, receivedBytes));
-
     }
 
     private static void checkSendingData(DataPipe.ProducerHandle in, DataPipe.ConsumerHandle out) {
@@ -136,6 +140,16 @@ public class CoreImplTest extends MojoTestCase {
         result = out.readData(null, DataPipe.ReadFlags.none().query(true));
         assertEquals(bytes.length, result);
 
+        // Peek data into a buffer.
+        ByteBuffer peekBuffer = ByteBuffer.allocateDirect(bytes.length);
+        result = out.readData(peekBuffer, DataPipe.ReadFlags.none().peek(true));
+        assertEquals(bytes.length, result);
+        assertEquals(0, peekBuffer.position());
+        assertEquals(bytes.length, peekBuffer.limit());
+        byte[] peekBytes = new byte[bytes.length];
+        peekBuffer.get(peekBytes);
+        assertTrue(Arrays.equals(bytes, peekBytes));
+
         // Read into a buffer.
         ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(bytes.length);
         result = out.readData(receiveBuffer, DataPipe.ReadFlags.NONE);
@@ -177,8 +191,10 @@ public class CoreImplTest extends MojoTestCase {
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe(null);
         addHandlePairToClose(handles);
 
-        List<Pair<Handle, Core.HandleSignals>> handlesToWaitOn = new ArrayList<
-                Pair<Handle, Core.HandleSignals>>();
+        // Test waiting on handles of a newly created message pipe - each should be writable, but
+        // not readable.
+        List<Pair<Handle, Core.HandleSignals>> handlesToWaitOn =
+                new ArrayList<Pair<Handle, Core.HandleSignals>>();
         handlesToWaitOn.add(
                 new Pair<Handle, Core.HandleSignals>(handles.second, Core.HandleSignals.READABLE));
         handlesToWaitOn.add(
@@ -186,7 +202,12 @@ public class CoreImplTest extends MojoTestCase {
         WaitManyResult result = core.waitMany(handlesToWaitOn, 0);
         assertEquals(MojoResult.OK, result.getMojoResult());
         assertEquals(1, result.getHandleIndex());
+        for (HandleSignalsState state : result.getSignalStates()) {
+            assertEquals(HandleSignals.WRITABLE, state.getSatisfiedSignals());
+            assertEquals(ALL_SIGNALS, state.getSatisfiableSignals());
+        }
 
+        // Same test, but swap the handles around.
         handlesToWaitOn.clear();
         handlesToWaitOn.add(
                 new Pair<Handle, Core.HandleSignals>(handles.first, Core.HandleSignals.WRITABLE));
@@ -195,6 +216,10 @@ public class CoreImplTest extends MojoTestCase {
         result = core.waitMany(handlesToWaitOn, 0);
         assertEquals(MojoResult.OK, result.getMojoResult());
         assertEquals(0, result.getHandleIndex());
+        for (HandleSignalsState state : result.getSignalStates()) {
+            assertEquals(HandleSignals.WRITABLE, state.getSatisfiedSignals());
+            assertEquals(ALL_SIGNALS, state.getSatisfiableSignals());
+        }
     }
 
     /**
@@ -248,37 +273,53 @@ public class CoreImplTest extends MojoTestCase {
         Core core = CoreImpl.getInstance();
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe(null);
         addHandlePairToClose(handles);
-        // Testing wait.
-        assertEquals(MojoResult.OK,
-                handles.first.wait(Core.HandleSignals.none().setReadable(true).setWritable(true),
-                        0));
-        assertEquals(MojoResult.OK, handles.first.wait(Core.HandleSignals.WRITABLE, 0));
-        assertEquals(MojoResult.DEADLINE_EXCEEDED,
-                handles.first.wait(Core.HandleSignals.READABLE, 0));
+        // Test waiting on handles of a newly created message pipe.
+        WaitResult waitResult = handles.first.wait(
+                Core.HandleSignals.none().setReadable(true).setWritable(true), 0);
+        assertEquals(MojoResult.OK, waitResult.getMojoResult());
+        assertEquals(
+                HandleSignals.WRITABLE, waitResult.getHandleSignalsState().getSatisfiedSignals());
+        assertEquals(ALL_SIGNALS, waitResult.getHandleSignalsState().getSatisfiableSignals());
+
+        waitResult = handles.first.wait(Core.HandleSignals.WRITABLE, 0);
+        assertEquals(MojoResult.OK, waitResult.getMojoResult());
+        assertEquals(
+                HandleSignals.WRITABLE, waitResult.getHandleSignalsState().getSatisfiedSignals());
+        assertEquals(ALL_SIGNALS, waitResult.getHandleSignalsState().getSatisfiableSignals());
+
+        waitResult = handles.first.wait(Core.HandleSignals.READABLE, 0);
+        assertEquals(MojoResult.DEADLINE_EXCEEDED, waitResult.getMojoResult());
+        assertEquals(
+                HandleSignals.WRITABLE, waitResult.getHandleSignalsState().getSatisfiedSignals());
+        assertEquals(ALL_SIGNALS, waitResult.getHandleSignalsState().getSatisfiableSignals());
 
         // Testing read on an empty pipe.
-        MessagePipeHandle.ReadMessageResult result = handles.first.readMessage(null, 0,
-                MessagePipeHandle.ReadFlags.NONE);
-        assertEquals(MojoResult.SHOULD_WAIT, result.getMojoResult());
+        MessagePipeHandle.ReadMessageResult readResult =
+                handles.first.readMessage(null, 0, MessagePipeHandle.ReadFlags.NONE);
+        assertEquals(MojoResult.SHOULD_WAIT, readResult.getMojoResult());
 
         // Closing a pipe while waiting.
         WORKER.schedule(new CloseHandle(handles.first), 10, TimeUnit.MILLISECONDS);
-        assertEquals(MojoResult.CANCELLED,
-                handles.first.wait(Core.HandleSignals.READABLE, 1000000L));
+        waitResult = handles.first.wait(Core.HandleSignals.READABLE, 1000000L);
+        assertEquals(MojoResult.CANCELLED, waitResult.getMojoResult());
+        assertEquals(
+                HandleSignals.none(), waitResult.getHandleSignalsState().getSatisfiedSignals());
+        assertEquals(
+                HandleSignals.none(), waitResult.getHandleSignalsState().getSatisfiableSignals());
 
         handles = core.createMessagePipe(null);
         addHandlePairToClose(handles);
 
         // Closing the other pipe while waiting.
         WORKER.schedule(new CloseHandle(handles.first), 10, TimeUnit.MILLISECONDS);
-        assertEquals(MojoResult.FAILED_PRECONDITION,
-                handles.second.wait(Core.HandleSignals.READABLE, 1000000L));
+        waitResult = handles.second.wait(Core.HandleSignals.READABLE, 1000000L);
+        assertEquals(MojoResult.FAILED_PRECONDITION, waitResult.getMojoResult());
 
         // Waiting on a closed pipe.
-        assertEquals(MojoResult.FAILED_PRECONDITION,
-                handles.second.wait(Core.HandleSignals.READABLE, 0));
-        assertEquals(MojoResult.FAILED_PRECONDITION,
-                handles.second.wait(Core.HandleSignals.WRITABLE, 0));
+        waitResult = handles.second.wait(Core.HandleSignals.READABLE, 0);
+        assertEquals(MojoResult.FAILED_PRECONDITION, waitResult.getMojoResult());
+        waitResult = handles.second.wait(Core.HandleSignals.WRITABLE, 0);
+        assertEquals(MojoResult.FAILED_PRECONDITION, waitResult.getMojoResult());
     }
 
     /**
@@ -312,8 +353,8 @@ public class CoreImplTest extends MojoTestCase {
         handles.first.writeMessage(buffer, null, MessagePipeHandle.WriteFlags.NONE);
 
         ByteBuffer receiveBuffer = ByteBuffer.allocateDirect(1);
-        MessagePipeHandle.ReadMessageResult result = handles.second
-                .readMessage(receiveBuffer, 0, MessagePipeHandle.ReadFlags.NONE);
+        MessagePipeHandle.ReadMessageResult result =
+                handles.second.readMessage(receiveBuffer, 0, MessagePipeHandle.ReadFlags.NONE);
         assertEquals(MojoResult.RESOURCE_EXHAUSTED, result.getMojoResult());
         assertEquals(bytes.length, result.getMessageSize());
         assertEquals(0, result.getHandlesCount());
@@ -330,15 +371,13 @@ public class CoreImplTest extends MojoTestCase {
         addHandlePairToClose(handles);
         addHandlePairToClose(handlesToShare);
 
-        handles.first.writeMessage(null,
-                Collections.<Handle> singletonList(handlesToShare.second),
+        handles.first.writeMessage(null, Collections.<Handle>singletonList(handlesToShare.second),
                 MessagePipeHandle.WriteFlags.NONE);
         assertFalse(handlesToShare.second.isValid());
         MessagePipeHandle.ReadMessageResult readMessageResult =
                 handles.second.readMessage(null, 1, MessagePipeHandle.ReadFlags.NONE);
         assertEquals(1, readMessageResult.getHandlesCount());
-        MessagePipeHandle newHandle = readMessageResult.getHandles().get(0)
-                .toMessagePipeHandle();
+        MessagePipeHandle newHandle = readMessageResult.getHandles().get(0).toMessagePipeHandle();
         addHandleToClose(newHandle);
         assertTrue(newHandle.isValid());
         checkSendingMessage(handlesToShare.first, newHandle);
@@ -347,8 +386,8 @@ public class CoreImplTest extends MojoTestCase {
 
     private static void createAndCloseDataPipe(DataPipe.CreateOptions options) {
         Core core = CoreImpl.getInstance();
-        Pair<DataPipe.ProducerHandle, DataPipe.ConsumerHandle> handles = core.createDataPipe(
-                options);
+        Pair<DataPipe.ProducerHandle, DataPipe.ConsumerHandle> handles =
+                core.createDataPipe(options);
         handles.first.close();
         handles.second.close();
     }
@@ -398,15 +437,14 @@ public class CoreImplTest extends MojoTestCase {
         // Writing a random 8 bytes message.
         byte[] bytes = new byte[8];
         random.nextBytes(bytes);
-        ByteBuffer buffer = handles.first.beginWriteData(bytes.length,
-                DataPipe.WriteFlags.NONE);
+        ByteBuffer buffer = handles.first.beginWriteData(bytes.length, DataPipe.WriteFlags.NONE);
         assertTrue(buffer.capacity() >= bytes.length);
         buffer.put(bytes);
         handles.first.endWriteData(bytes.length);
 
         // Read into a buffer.
-        ByteBuffer receiveBuffer = handles.second.beginReadData(bytes.length,
-                DataPipe.ReadFlags.NONE);
+        ByteBuffer receiveBuffer =
+                handles.second.beginReadData(bytes.length, DataPipe.ReadFlags.NONE);
         assertEquals(0, receiveBuffer.position());
         assertEquals(bytes.length, receiveBuffer.limit());
         byte[] receivedBytes = new byte[bytes.length];
@@ -446,8 +484,8 @@ public class CoreImplTest extends MojoTestCase {
         assertEquals(bytes.length - nbBytesToDiscard, receiveBuffer.limit());
         byte[] receivedBytes = new byte[bytes.length - nbBytesToDiscard];
         receiveBuffer.get(receivedBytes);
-        assertTrue(Arrays.equals(Arrays.copyOfRange(bytes, nbBytesToDiscard, bytes.length),
-                receivedBytes));
+        assertTrue(Arrays.equals(
+                Arrays.copyOfRange(bytes, nbBytesToDiscard, bytes.length), receivedBytes));
     }
 
     /**
@@ -513,8 +551,8 @@ public class CoreImplTest extends MojoTestCase {
         // Checking waitMany.
         exception = false;
         try {
-            List<Pair<Handle, Core.HandleSignals>> handles = new ArrayList<
-                    Pair<Handle, Core.HandleSignals>>();
+            List<Pair<Handle, Core.HandleSignals>> handles =
+                    new ArrayList<Pair<Handle, Core.HandleSignals>>();
             handles.add(Pair.create(handle, Core.HandleSignals.WRITABLE));
             core.waitMany(handles, 0);
         } catch (MojoException e) {
@@ -530,7 +568,7 @@ public class CoreImplTest extends MojoTestCase {
         Pair<MessagePipeHandle, MessagePipeHandle> handles = core.createMessagePipe(null);
         addHandlePairToClose(handles);
         try {
-            handles.first.writeMessage(null, Collections.<Handle> singletonList(handle),
+            handles.first.writeMessage(null, Collections.<Handle>singletonList(handle),
                     MessagePipeHandle.WriteFlags.NONE);
             MessagePipeHandle.ReadMessageResult readMessageResult =
                     handles.second.readMessage(null, 1, MessagePipeHandle.ReadFlags.NONE);
@@ -574,7 +612,6 @@ public class CoreImplTest extends MojoTestCase {
         public MojoException getException() {
             return mException;
         }
-
     }
 
     /**
@@ -596,8 +633,8 @@ public class CoreImplTest extends MojoTestCase {
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
 
-        handles.second.writeMessage(ByteBuffer.allocateDirect(1), null,
-                MessagePipeHandle.WriteFlags.NONE);
+        handles.second.writeMessage(
+                ByteBuffer.allocateDirect(1), null, MessagePipeHandle.WriteFlags.NONE);
         runLoopUntilIdle();
         assertNull(asyncWaiterResult.getException());
         assertEquals(MojoResult.OK, asyncWaiterResult.getResult());
@@ -679,8 +716,8 @@ public class CoreImplTest extends MojoTestCase {
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
 
-        core.getDefaultAsyncWaiter().asyncWait(handles.first, Core.HandleSignals.READABLE,
-                RUN_LOOP_TIMEOUT_MS, asyncWaiterResult);
+        core.getDefaultAsyncWaiter().asyncWait(
+                handles.first, Core.HandleSignals.READABLE, RUN_LOOP_TIMEOUT_MS, asyncWaiterResult);
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
 
@@ -718,8 +755,8 @@ public class CoreImplTest extends MojoTestCase {
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
 
-        handles.second.writeMessage(ByteBuffer.allocateDirect(1), null,
-                MessagePipeHandle.WriteFlags.NONE);
+        handles.second.writeMessage(
+                ByteBuffer.allocateDirect(1), null, MessagePipeHandle.WriteFlags.NONE);
         runLoopUntilIdle();
         assertEquals(Integer.MIN_VALUE, asyncWaiterResult.getResult());
         assertEquals(null, asyncWaiterResult.getException());
diff --git a/mojo/android/system/core_impl.cc b/mojo/android/system/core_impl.cc
index b862130..35d1b36 100644
--- a/mojo/android/system/core_impl.cc
+++ b/mojo/android/system/core_impl.cc
@@ -57,19 +57,35 @@ static jint WaitMany(JNIEnv* env,
                      jobject jcaller,
                      jobject buffer,
                      jlong deadline) {
-  // Buffer contains first the list of handles, then the list of signals.
-  const void* buffer_start = env->GetDirectBufferAddress(buffer);
+  // |buffer| contains, in this order
+  // input: The array of N handles (MojoHandle, 4 bytes each)
+  // input: The array of N signals (MojoHandleSignals, 4 bytes each)
+  // space for output: The array of N handle states (MojoHandleSignalsState, 8
+  //                   bytes each)
+  // space for output: The result index (uint32_t, 4 bytes)
+  uint8_t* buffer_start =
+      static_cast<uint8_t*>(env->GetDirectBufferAddress(buffer));
   DCHECK(buffer_start);
-  DCHECK_EQ(reinterpret_cast<const uintptr_t>(buffer_start) % 8, 0u);
-  const size_t record_size = 8;
+  DCHECK_EQ(reinterpret_cast<uintptr_t>(buffer_start) % 8, 0u);
+  // Each handle of the input array contributes 4 (MojoHandle) + 4
+  // (MojoHandleSignals) + 8 (MojoHandleSignalsState) = 16 bytes to the size of
+  // the buffer.
+  const size_t size_per_handle = 16;
   const size_t buffer_size = env->GetDirectBufferCapacity(buffer);
-  DCHECK_EQ(buffer_size % record_size, 0u);
+  DCHECK_EQ((buffer_size - 4) % size_per_handle, 0u);
 
-  const size_t nb_handles = buffer_size / record_size;
-  const MojoHandle* handle_start = static_cast<const MojoHandle*>(buffer_start);
+  const size_t nb_handles = (buffer_size - 4) / size_per_handle;
+  const MojoHandle* handle_start =
+      reinterpret_cast<const MojoHandle*>(buffer_start);
   const MojoHandleSignals* signals_start =
-      static_cast<const MojoHandleSignals*>(handle_start + nb_handles);
-  return MojoWaitMany(handle_start, signals_start, nb_handles, deadline);
+      reinterpret_cast<const MojoHandleSignals*>(buffer_start + 4 * nb_handles);
+  MojoHandleSignalsState* states_start =
+      reinterpret_cast<MojoHandleSignalsState*>(buffer_start + 8 * nb_handles);
+  uint32_t* result_index =
+      reinterpret_cast<uint32_t*>(buffer_start + 16 * nb_handles);
+  *result_index = static_cast<uint32_t>(-1);
+  return MojoNewWaitMany(handle_start, signals_start, nb_handles, deadline,
+                         result_index, states_start);
 }
 
 static jobject CreateMessagePipe(JNIEnv* env,
@@ -138,10 +154,19 @@ static jint Close(JNIEnv* env, jobject jcaller, jint mojo_handle) {
 
 static jint Wait(JNIEnv* env,
                  jobject jcaller,
+                 jobject buffer,
                  jint mojo_handle,
                  jint signals,
                  jlong deadline) {
-  return MojoWait(mojo_handle, signals, deadline);
+  // Buffer contains space for the MojoHandleSignalsState
+  void* buffer_start = env->GetDirectBufferAddress(buffer);
+  DCHECK(buffer_start);
+  DCHECK_EQ(reinterpret_cast<const uintptr_t>(buffer_start) % 8, 0u);
+  DCHECK_EQ(sizeof(struct MojoHandleSignalsState),
+            static_cast<size_t>(env->GetDirectBufferCapacity(buffer)));
+  struct MojoHandleSignalsState* signals_state =
+      static_cast<struct MojoHandleSignalsState*>(buffer_start);
+  return MojoNewWait(mojo_handle, signals, deadline, signals_state);
 }
 
 static jint WriteMessage(JNIEnv* env,
diff --git a/mojo/android/system/src/org/chromium/mojo/system/impl/CoreImpl.java b/mojo/android/system/src/org/chromium/mojo/system/impl/CoreImpl.java
index 1fd8076..0dc9839 100644
--- a/mojo/android/system/src/org/chromium/mojo/system/impl/CoreImpl.java
+++ b/mojo/android/system/src/org/chromium/mojo/system/impl/CoreImpl.java
@@ -31,7 +31,6 @@ import java.util.List;
  */
 @JNINamespace("mojo::android")
 public class CoreImpl implements Core, AsyncWaiter {
-
     /**
      * Discard flag for the |MojoReadData| operation.
      */
@@ -52,9 +51,7 @@ public class CoreImpl implements Core, AsyncWaiter {
      */
     static final int INVALID_HANDLE = 0;
 
-    private static class LazyHolder {
-        private static final Core INSTANCE = new CoreImpl();
-    }
+    private static class LazyHolder { private static final Core INSTANCE = new CoreImpl(); }
 
     /**
      * @return the instance.
@@ -63,8 +60,7 @@ public class CoreImpl implements Core, AsyncWaiter {
         return LazyHolder.INSTANCE;
     }
 
-    private CoreImpl() {
-    }
+    private CoreImpl() {}
 
     /**
      * @see Core#getTimeTicksNow()
@@ -79,22 +75,36 @@ public class CoreImpl implements Core, AsyncWaiter {
      */
     @Override
     public WaitManyResult waitMany(List<Pair<Handle, HandleSignals>> handles, long deadline) {
-        // Allocate a direct buffer to allow native code not to reach back to java. Buffer will
-        // contain all mojo handles, followed by all flags values.
-        ByteBuffer buffer = allocateDirectBuffer(handles.size() * 8);
+        // Allocate a direct buffer to allow native code not to reach back to java. The buffer
+        // layout will be:
+        // input: The array of handles (int, 4 bytes each)
+        // input: The array of signals (int, 4 bytes each)
+        // space for output: The array of handle states (2 ints, 8 bytes each)
+        // Space for output: The result index (int, 4 bytes)
+        // The handles and signals will be filled before calling the native method. When the native
+        // method returns, the handle states and the index will have been set.
+        ByteBuffer buffer = allocateDirectBuffer(handles.size() * 16 + 4);
         int index = 0;
         for (Pair<Handle, HandleSignals> handle : handles) {
             buffer.putInt(HANDLE_SIZE * index, getMojoHandle(handle.first));
-            buffer.putInt(HANDLE_SIZE * handles.size() + FLAG_SIZE * index,
-                    handle.second.getFlags());
+            buffer.putInt(
+                    HANDLE_SIZE * handles.size() + FLAG_SIZE * index, handle.second.getFlags());
             index++;
         }
         int code = nativeWaitMany(buffer, deadline);
         WaitManyResult result = new WaitManyResult();
-        // If result is greater than 0, result is the indexed of the available handle. To make sure
-        // it cannot be misinterpreted, set handleIndex to a negative number in case of error.
-        result.setHandleIndex(code);
         result.setMojoResult(filterMojoResultForWait(code));
+        result.setHandleIndex(buffer.getInt(handles.size() * 16));
+        if (result.getMojoResult() != MojoResult.INVALID_ARGUMENT
+                && result.getMojoResult() != MojoResult.RESOURCE_EXHAUSTED) {
+            HandleSignalsState[] states = new HandleSignalsState[handles.size()];
+            for (int i = 0; i < handles.size(); ++i) {
+                states[i] = new HandleSignalsState(
+                        new HandleSignals(buffer.getInt(8 * (handles.size() + i))),
+                        new HandleSignals(buffer.getInt(8 * (handles.size() + i) + 4)));
+            }
+            result.setSignalStates(states);
+        }
         return result;
     }
 
@@ -102,9 +112,17 @@ public class CoreImpl implements Core, AsyncWaiter {
      * @see Core#wait(Handle, HandleSignals, long)
      */
     @Override
-    public int wait(Handle handle, HandleSignals signals, long deadline) {
-        return filterMojoResultForWait(nativeWait(getMojoHandle(handle),
-                signals.getFlags(), deadline));
+    public WaitResult wait(Handle handle, HandleSignals signals, long deadline) {
+        // Allocate a direct buffer to allow native code not to reach back to java. Buffer will
+        // contain spaces to write the handle state.
+        ByteBuffer buffer = allocateDirectBuffer(8);
+        WaitResult result = new WaitResult();
+        result.setMojoResult(filterMojoResultForWait(
+                nativeWait(buffer, getMojoHandle(handle), signals.getFlags(), deadline)));
+        HandleSignalsState signalsState = new HandleSignalsState(
+                new HandleSignals(buffer.getInt(0)), new HandleSignals(buffer.getInt(4)));
+        result.setHandleSignalsState(signalsState);
+        return result;
     }
 
     /**
@@ -123,7 +141,7 @@ public class CoreImpl implements Core, AsyncWaiter {
         if (result.getMojoResult() != MojoResult.OK) {
             throw new MojoException(result.getMojoResult());
         }
-        return Pair.<MessagePipeHandle, MessagePipeHandle> create(
+        return Pair.<MessagePipeHandle, MessagePipeHandle>create(
                 new MessagePipeHandleImpl(this, result.getMojoHandle1()),
                 new MessagePipeHandleImpl(this, result.getMojoHandle2()));
     }
@@ -145,7 +163,7 @@ public class CoreImpl implements Core, AsyncWaiter {
         if (result.getMojoResult() != MojoResult.OK) {
             throw new MojoException(result.getMojoResult());
         }
-        return Pair.<ProducerHandle, ConsumerHandle> create(
+        return Pair.<ProducerHandle, ConsumerHandle>create(
                 new DataPipeProducerHandleImpl(this, result.getMojoHandle1()),
                 new DataPipeConsumerHandleImpl(this, result.getMojoHandle2()));
     }
@@ -190,8 +208,8 @@ public class CoreImpl implements Core, AsyncWaiter {
      * @see AsyncWaiter#asyncWait(Handle, Core.HandleSignals, long, Callback)
      */
     @Override
-    public Cancellable asyncWait(Handle handle, HandleSignals signals, long deadline,
-            Callback callback) {
+    public Cancellable asyncWait(
+            Handle handle, HandleSignals signals, long deadline, Callback callback) {
         return nativeAsyncWait(getMojoHandle(handle), signals.getFlags(), deadline, callback);
     }
 
@@ -220,8 +238,7 @@ public class CoreImpl implements Core, AsyncWaiter {
             handlesBuffer.position(0);
         }
         int mojoResult = nativeWriteMessage(pipeHandle.getMojoHandle(), bytes,
-                bytes == null ? 0 : bytes.limit(), handlesBuffer,
-                flags.getFlags());
+                bytes == null ? 0 : bytes.limit(), handlesBuffer, flags.getFlags());
         if (mojoResult != MojoResult.OK) {
             throw new MojoException(mojoResult);
         }
@@ -238,18 +255,17 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see MessagePipeHandle#readMessage(ByteBuffer, int, MessagePipeHandle.ReadFlags)
      */
-    MessagePipeHandle.ReadMessageResult readMessage(MessagePipeHandleImpl handle,
-            ByteBuffer bytes, int maxNumberOfHandles,
-            MessagePipeHandle.ReadFlags flags) {
+    MessagePipeHandle.ReadMessageResult readMessage(MessagePipeHandleImpl handle, ByteBuffer bytes,
+            int maxNumberOfHandles, MessagePipeHandle.ReadFlags flags) {
         ByteBuffer handlesBuffer = null;
         if (maxNumberOfHandles > 0) {
             handlesBuffer = allocateDirectBuffer(maxNumberOfHandles * HANDLE_SIZE);
         }
-        MessagePipeHandle.ReadMessageResult result = nativeReadMessage(
-                handle.getMojoHandle(), bytes, handlesBuffer, flags.getFlags());
-        if (result.getMojoResult() != MojoResult.OK &&
-                result.getMojoResult() != MojoResult.RESOURCE_EXHAUSTED &&
-                result.getMojoResult() != MojoResult.SHOULD_WAIT) {
+        MessagePipeHandle.ReadMessageResult result =
+                nativeReadMessage(handle.getMojoHandle(), bytes, handlesBuffer, flags.getFlags());
+        if (result.getMojoResult() != MojoResult.OK
+                && result.getMojoResult() != MojoResult.RESOURCE_EXHAUSTED
+                && result.getMojoResult() != MojoResult.SHOULD_WAIT) {
             throw new MojoException(result.getMojoResult());
         }
 
@@ -259,8 +275,7 @@ public class CoreImpl implements Core, AsyncWaiter {
                 bytes.limit(result.getMessageSize());
             }
 
-            List<UntypedHandle> handles = new ArrayList<UntypedHandle>(
-                    result.getHandlesCount());
+            List<UntypedHandle> handles = new ArrayList<UntypedHandle>(result.getHandlesCount());
             for (int i = 0; i < result.getHandlesCount(); ++i) {
                 int mojoHandle = handlesBuffer.getInt(HANDLE_SIZE * i);
                 handles.add(new UntypedHandleImpl(this, mojoHandle));
@@ -273,8 +288,7 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see ConsumerHandle#discardData(int, DataPipe.ReadFlags)
      */
-    int discardData(DataPipeConsumerHandleImpl handle, int numBytes,
-            DataPipe.ReadFlags flags) {
+    int discardData(DataPipeConsumerHandleImpl handle, int numBytes, DataPipe.ReadFlags flags) {
         int result = nativeReadData(handle.getMojoHandle(), null, numBytes,
                 flags.getFlags() | MOJO_READ_DATA_FLAG_DISCARD);
         if (result < 0) {
@@ -286,11 +300,9 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see ConsumerHandle#readData(ByteBuffer, DataPipe.ReadFlags)
      */
-    int readData(DataPipeConsumerHandleImpl handle, ByteBuffer elements,
-            DataPipe.ReadFlags flags) {
+    int readData(DataPipeConsumerHandleImpl handle, ByteBuffer elements, DataPipe.ReadFlags flags) {
         int result = nativeReadData(handle.getMojoHandle(), elements,
-                elements == null ? 0 : elements.capacity(),
-                flags.getFlags());
+                elements == null ? 0 : elements.capacity(), flags.getFlags());
         if (result < 0) {
             throw new MojoException(result);
         }
@@ -303,12 +315,10 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see ConsumerHandle#beginReadData(int, DataPipe.ReadFlags)
      */
-    ByteBuffer beginReadData(DataPipeConsumerHandleImpl handle,
-            int numBytes, DataPipe.ReadFlags flags) {
-        NativeCodeAndBufferResult result = nativeBeginReadData(
-                handle.getMojoHandle(),
-                numBytes,
-                flags.getFlags());
+    ByteBuffer beginReadData(
+            DataPipeConsumerHandleImpl handle, int numBytes, DataPipe.ReadFlags flags) {
+        NativeCodeAndBufferResult result =
+                nativeBeginReadData(handle.getMojoHandle(), numBytes, flags.getFlags());
         if (result.getMojoResult() != MojoResult.OK) {
             throw new MojoException(result.getMojoResult());
         }
@@ -318,8 +328,7 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see ConsumerHandle#endReadData(int)
      */
-    void endReadData(DataPipeConsumerHandleImpl handle,
-            int numBytesRead) {
+    void endReadData(DataPipeConsumerHandleImpl handle, int numBytesRead) {
         int result = nativeEndReadData(handle.getMojoHandle(), numBytesRead);
         if (result != MojoResult.OK) {
             throw new MojoException(result);
@@ -329,21 +338,19 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see ProducerHandle#writeData(ByteBuffer, DataPipe.WriteFlags)
      */
-    int writeData(DataPipeProducerHandleImpl handle, ByteBuffer elements,
-            DataPipe.WriteFlags flags) {
-        return nativeWriteData(handle.getMojoHandle(), elements, elements.limit(),
-                flags.getFlags());
+    int writeData(
+            DataPipeProducerHandleImpl handle, ByteBuffer elements, DataPipe.WriteFlags flags) {
+        return nativeWriteData(
+                handle.getMojoHandle(), elements, elements.limit(), flags.getFlags());
     }
 
     /**
      * @see ProducerHandle#beginWriteData(int, DataPipe.WriteFlags)
      */
-    ByteBuffer beginWriteData(DataPipeProducerHandleImpl handle,
-            int numBytes, DataPipe.WriteFlags flags) {
-        NativeCodeAndBufferResult result = nativeBeginWriteData(
-                handle.getMojoHandle(),
-                numBytes,
-                flags.getFlags());
+    ByteBuffer beginWriteData(
+            DataPipeProducerHandleImpl handle, int numBytes, DataPipe.WriteFlags flags) {
+        NativeCodeAndBufferResult result =
+                nativeBeginWriteData(handle.getMojoHandle(), numBytes, flags.getFlags());
         if (result.getMojoResult() != MojoResult.OK) {
             throw new MojoException(result.getMojoResult());
         }
@@ -353,8 +360,7 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see ProducerHandle#endWriteData(int)
      */
-    void endWriteData(DataPipeProducerHandleImpl handle,
-            int numBytesWritten) {
+    void endWriteData(DataPipeProducerHandleImpl handle, int numBytesWritten) {
         int result = nativeEndWriteData(handle.getMojoHandle(), numBytesWritten);
         if (result != MojoResult.OK) {
             throw new MojoException(result);
@@ -364,16 +370,14 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see SharedBufferHandle#duplicate(DuplicateOptions)
      */
-    SharedBufferHandle duplicate(SharedBufferHandleImpl handle,
-            DuplicateOptions options) {
+    SharedBufferHandle duplicate(SharedBufferHandleImpl handle, DuplicateOptions options) {
         ByteBuffer optionsBuffer = null;
         if (options != null) {
             optionsBuffer = allocateDirectBuffer(8);
             optionsBuffer.putInt(0, 8);
             optionsBuffer.putInt(4, options.getFlags().getFlags());
         }
-        NativeCreationResult result = nativeDuplicate(handle.getMojoHandle(),
-                optionsBuffer);
+        NativeCreationResult result = nativeDuplicate(handle.getMojoHandle(), optionsBuffer);
         if (result.getMojoResult() != MojoResult.OK) {
             throw new MojoException(result.getMojoResult());
         }
@@ -384,10 +388,9 @@ public class CoreImpl implements Core, AsyncWaiter {
     /**
      * @see SharedBufferHandle#map(long, long, MapFlags)
      */
-    ByteBuffer map(SharedBufferHandleImpl handle, long offset, long numBytes,
-            MapFlags flags) {
-        NativeCodeAndBufferResult result = nativeMap(handle.getMojoHandle(), offset, numBytes,
-                flags.getFlags());
+    ByteBuffer map(SharedBufferHandleImpl handle, long offset, long numBytes, MapFlags flags) {
+        NativeCodeAndBufferResult result =
+                nativeMap(handle.getMojoHandle(), offset, numBytes, flags.getFlags());
         if (result.getMojoResult() != MojoResult.OK) {
             throw new MojoException(result.getMojoResult());
         }
@@ -426,19 +429,11 @@ public class CoreImpl implements Core, AsyncWaiter {
         }
     }
 
-    private static int filterMojoResult(int code) {
-        if (code >= 0) {
-            return MojoResult.OK;
-        }
-        return code;
-    }
-
     private static int filterMojoResultForWait(int code) {
-        int finalCode = filterMojoResult(code);
-        if (isUnrecoverableError(finalCode)) {
-            throw new MojoException(finalCode);
+        if (isUnrecoverableError(code)) {
+            throw new MojoException(code);
         }
-        return finalCode;
+        return code;
     }
 
     private static ByteBuffer allocateDirectBuffer(int capacity) {
@@ -478,14 +473,12 @@ public class CoreImpl implements Core, AsyncWaiter {
         public void setBuffer(ByteBuffer buffer) {
             mBuffer = buffer;
         }
-
     }
 
     /**
      * Implementation of {@link org.chromium.mojo.system.AsyncWaiter.Cancellable}.
      */
     private class AsyncWaiterCancellableImpl implements AsyncWaiter.Cancellable {
-
         private final long mId;
         private final long mDataPtr;
         private boolean mActive = true;
@@ -521,25 +514,23 @@ public class CoreImpl implements Core, AsyncWaiter {
     }
 
     @CalledByNative
-    private void onAsyncWaitResult(int mojoResult,
-            AsyncWaiter.Callback callback,
-            AsyncWaiterCancellableImpl cancellable) {
+    private void onAsyncWaitResult(
+            int mojoResult, AsyncWaiter.Callback callback, AsyncWaiterCancellableImpl cancellable) {
         if (!cancellable.isActive()) {
             // If cancellable is not active, the user cancelled the wait.
             return;
         }
         cancellable.deactivate();
-        int finalCode = filterMojoResult(mojoResult);
-        if (isUnrecoverableError(finalCode)) {
-            callback.onError(new MojoException(finalCode));
+        if (isUnrecoverableError(mojoResult)) {
+            callback.onError(new MojoException(mojoResult));
             return;
         }
-        callback.onResult(finalCode);
+        callback.onResult(mojoResult);
     }
 
     @CalledByNative
-    private static NativeCodeAndBufferResult newNativeCodeAndBufferResult(int mojoResult,
-            ByteBuffer buffer) {
+    private static NativeCodeAndBufferResult newNativeCodeAndBufferResult(
+            int mojoResult, ByteBuffer buffer) {
         NativeCodeAndBufferResult result = new NativeCodeAndBufferResult();
         result.setMojoResult(mojoResult);
         result.setBuffer(buffer);
@@ -547,9 +538,8 @@ public class CoreImpl implements Core, AsyncWaiter {
     }
 
     @CalledByNative
-    private static MessagePipeHandle.ReadMessageResult newReadMessageResult(int mojoResult,
-            int messageSize,
-            int handlesCount) {
+    private static MessagePipeHandle.ReadMessageResult newReadMessageResult(
+            int mojoResult, int messageSize, int handlesCount) {
         MessagePipeHandle.ReadMessageResult result = new MessagePipeHandle.ReadMessageResult();
         if (mojoResult >= 0) {
             result.setMojoResult(MojoResult.OK);
@@ -610,8 +600,8 @@ public class CoreImpl implements Core, AsyncWaiter {
     }
 
     @CalledByNative
-    private static NativeCreationResult newNativeCreationResult(int mojoResult,
-            int mojoHandle1, int mojoHandle2) {
+    private static NativeCreationResult newNativeCreationResult(
+            int mojoResult, int mojoHandle1, int mojoHandle2) {
         NativeCreationResult result = new NativeCreationResult();
         result.setMojoResult(mojoResult);
         result.setMojoHandle1(mojoHandle1);
@@ -627,45 +617,43 @@ public class CoreImpl implements Core, AsyncWaiter {
 
     private native NativeCreationResult nativeCreateDataPipe(ByteBuffer optionsBuffer);
 
-    private native NativeCreationResult nativeCreateSharedBuffer(ByteBuffer optionsBuffer,
-            long numBytes);
+    private native NativeCreationResult nativeCreateSharedBuffer(
+            ByteBuffer optionsBuffer, long numBytes);
 
     private native int nativeClose(int mojoHandle);
 
-    private native int nativeWait(int mojoHandle, int signals, long deadline);
+    private native int nativeWait(ByteBuffer buffer, int mojoHandle, int signals, long deadline);
 
-    private native int nativeWriteMessage(int mojoHandle, ByteBuffer bytes, int numBytes,
-            ByteBuffer handlesBuffer, int flags);
+    private native int nativeWriteMessage(
+            int mojoHandle, ByteBuffer bytes, int numBytes, ByteBuffer handlesBuffer, int flags);
 
-    private native MessagePipeHandle.ReadMessageResult nativeReadMessage(int mojoHandle,
-            ByteBuffer bytes,
-            ByteBuffer handlesBuffer,
-            int flags);
+    private native MessagePipeHandle.ReadMessageResult nativeReadMessage(
+            int mojoHandle, ByteBuffer bytes, ByteBuffer handlesBuffer, int flags);
 
-    private native int nativeReadData(int mojoHandle, ByteBuffer elements, int elementsSize,
-            int flags);
+    private native int nativeReadData(
+            int mojoHandle, ByteBuffer elements, int elementsSize, int flags);
 
-    private native NativeCodeAndBufferResult nativeBeginReadData(int mojoHandle, int numBytes,
-            int flags);
+    private native NativeCodeAndBufferResult nativeBeginReadData(
+            int mojoHandle, int numBytes, int flags);
 
     private native int nativeEndReadData(int mojoHandle, int numBytesRead);
 
     private native int nativeWriteData(int mojoHandle, ByteBuffer elements, int limit, int flags);
 
-    private native NativeCodeAndBufferResult nativeBeginWriteData(int mojoHandle, int numBytes,
-            int flags);
+    private native NativeCodeAndBufferResult nativeBeginWriteData(
+            int mojoHandle, int numBytes, int flags);
 
     private native int nativeEndWriteData(int mojoHandle, int numBytesWritten);
 
     private native NativeCreationResult nativeDuplicate(int mojoHandle, ByteBuffer optionsBuffer);
 
-    private native NativeCodeAndBufferResult nativeMap(int mojoHandle, long offset, long numBytes,
-            int flags);
+    private native NativeCodeAndBufferResult nativeMap(
+            int mojoHandle, long offset, long numBytes, int flags);
 
     private native int nativeUnmap(ByteBuffer buffer);
 
-    private native AsyncWaiterCancellableImpl nativeAsyncWait(int mojoHandle, int signals,
-            long deadline, AsyncWaiter.Callback callback);
+    private native AsyncWaiterCancellableImpl nativeAsyncWait(
+            int mojoHandle, int signals, long deadline, AsyncWaiter.Callback callback);
 
     private native void nativeCancelAsyncWait(long mId, long dataPtr);
 }
diff --git a/mojo/android/system/src/org/chromium/mojo/system/impl/HandleBase.java b/mojo/android/system/src/org/chromium/mojo/system/impl/HandleBase.java
index 81bfac72..a8870a8 100644
--- a/mojo/android/system/src/org/chromium/mojo/system/impl/HandleBase.java
+++ b/mojo/android/system/src/org/chromium/mojo/system/impl/HandleBase.java
@@ -8,6 +8,7 @@ import android.util.Log;
 
 import org.chromium.mojo.system.Core;
 import org.chromium.mojo.system.Core.HandleSignals;
+import org.chromium.mojo.system.Core.WaitResult;
 import org.chromium.mojo.system.Handle;
 import org.chromium.mojo.system.UntypedHandle;
 
@@ -65,7 +66,7 @@ abstract class HandleBase implements Handle {
      * @see org.chromium.mojo.system.Handle#wait(HandleSignals, long)
      */
     @Override
-    public int wait(HandleSignals signals, long deadline) {
+    public WaitResult wait(HandleSignals signals, long deadline) {
         return mCore.wait(this, signals, deadline);
     }