Revert of Mojo EDK: Introduce MojoQueryHandleSignalsState API

mojo/android/system/core_impl.cc

Index: mojo/android/system/core_impl.cc
diff --git a/mojo/android/system/core_impl.cc b/mojo/android/system/core_impl.cc
index e53ed75c32cb55086bf10d9fbfcb682909c23460..5cbd754fe90cb84e4667cf6ff4851aeb1920fc95 100644
--- a/mojo/android/system/core_impl.cc
+++ b/mojo/android/system/core_impl.cc
@@ -26,6 +26,41 @@
   return MojoGetTimeTicksNow();
 }
 
+static jint WaitMany(JNIEnv* env,
+                     const JavaParamRef<jobject>& jcaller,
+                     const JavaParamRef<jobject>& buffer,
+                     jlong deadline) {
+  // |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<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 - 4) % size_per_handle, 0u);
+
+  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 =
+      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 MojoWaitMany(handle_start, signals_start, nb_handles, deadline,
+                      result_index, states_start);
+}
+
 static ScopedJavaLocalRef<jobject> CreateMessagePipe(
     JNIEnv* env,
     const JavaParamRef<jobject>& jcaller,
@@ -92,16 +127,21 @@
   return MojoClose(mojo_handle);
 }
 
-static jint QueryHandleSignalsState(JNIEnv* env,
-                                    const JavaParamRef<jobject>& jcaller,
-                                    jint mojo_handle,
-                                    const JavaParamRef<jobject>& buffer) {
-  MojoHandleSignalsState* signals_state =
-      static_cast<MojoHandleSignalsState*>(env->GetDirectBufferAddress(buffer));
-  DCHECK(signals_state);
-  DCHECK_EQ(sizeof(MojoHandleSignalsState),
+static jint Wait(JNIEnv* env,
+                 const JavaParamRef<jobject>& jcaller,
+                 const JavaParamRef<jobject>& buffer,
+                 jint mojo_handle,
+                 jint signals,
+                 jlong 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)));
-  return MojoQueryHandleSignalsState(mojo_handle, signals_state);
+  struct MojoHandleSignalsState* signals_state =
+      static_cast<struct MojoHandleSignalsState*>(buffer_start);
+  return MojoWait(mojo_handle, signals, deadline, signals_state);
 }
 
 static jint WriteMessage(JNIEnv* env,