Revert of Mojo EDK: Introduce MojoQueryHandleSignalsState API

mojo/android/system/core_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/android/system/core_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/android/base_jni_registrar.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_registrar.h"
 #include "base/android/library_loader/library_loader_hooks.h"
 #include "base/android/scoped_java_ref.h"
 #include "jni/CoreImpl_jni.h"
 #include "mojo/public/c/system/core.h"
 
 namespace mojo {
 namespace android {
 
 using base::android::JavaParamRef;
 using base::android::ScopedJavaLocalRef;
 
 static jlong GetTimeTicksNow(JNIEnv* env,
                              const JavaParamRef<jobject>& jcaller) {
   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,
     const JavaParamRef<jobject>& options_buffer) {
   const MojoCreateMessagePipeOptions* options = NULL;
   if (options_buffer) {
     const void* buffer_start = env->GetDirectBufferAddress(options_buffer);
     DCHECK(buffer_start);
     DCHECK_EQ(reinterpret_cast<const uintptr_t>(buffer_start) % 8, 0u);
     const size_t buffer_size = env->GetDirectBufferCapacity(options_buffer);
@@ skipping 46 matching lines @@
   MojoResult result = MojoCreateSharedBuffer(options, num_bytes, &handle);
   return Java_CoreImpl_newResultAndInteger(env, result, handle);
 }
 
 static jint Close(JNIEnv* env,
                   const JavaParamRef<jobject>& jcaller,
                   jint mojo_handle) {
   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,
                          const JavaParamRef<jobject>& jcaller,
                          jint mojo_handle,
                          const JavaParamRef<jobject>& bytes,
                          jint num_bytes,
                          const JavaParamRef<jobject>& handles_buffer,
                          jint flags) {
   const void* buffer_start = 0;
@@ skipping 185 matching lines @@
     return 0;
   return alignment - offset;
 }
 
 bool RegisterCoreImpl(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace mojo