Adding support for OpenSL ES output in native WebRTC

BUG=4573,2982,2175,3590
TEST=modules_unittests --gtest_filter=AudioDevice*, AppRTCDemo and WebRTCDemo

Summary:

- Removes dependency of the 'enable_android_opensl' compiler flag.
  Instead, OpenSL ES is always supported, and will enabled for devices that
  supports low-latency output.
- WebRTC no longer supports OpenSL ES for the input/recording side.
- Removes old code and demos using OpenSL ES for audio input.
- Improves accuracy of total delay estimates (better AEC performance).
- Reduces roundtrip audio latency; especially when OpenSL can be used.

Performance verified on: Nexus 5, 6, 7 and 9. Samsung Galaxy S4 and S6.
Android One device.

R=magjed@webrtc.org, phoglund@webrtc.org, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/51759004

Cr-Commit-Position: refs/heads/master@{#9208}
diff --git a/webrtc/modules/utility/source/jvm_android.cc b/webrtc/modules/utility/source/jvm_android.cc
new file mode 100644
index 0000000..2655195
--- /dev/null
+++ b/webrtc/modules/utility/source/jvm_android.cc
@@ -0,0 +1,251 @@
+/*
+ *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <android/log.h>
+
+#include "webrtc/modules/utility/interface/jvm_android.h"
+
+#include "webrtc/base/checks.h"
+
+#define TAG "JVM"
+#define ALOGD(...) __android_log_print(ANDROID_LOG_DEBUG, TAG, __VA_ARGS__)
+#define ALOGE(...) __android_log_print(ANDROID_LOG_ERROR, TAG, __VA_ARGS__)
+
+namespace webrtc {
+
+JVM* g_jvm;
+
+// TODO(henrika): add more clases here if needed.
+struct {
+  const char* name;
+  jclass clazz;
+} loaded_classes[] = {
+  {"org/webrtc/voiceengine/WebRtcAudioManager", nullptr},
+  {"org/webrtc/voiceengine/BuildInfo", nullptr},
+};
+
+// Android's FindClass() is trickier than usual because the app-specific
+// ClassLoader is not consulted when there is no app-specific frame on the
+// stack.  Consequently, we only look up all classes once in native WebRTC.
+// http://developer.android.com/training/articles/perf-jni.html#faq_FindClass
+void LoadClasses(JNIEnv* jni) {
+  for (auto& c : loaded_classes) {
+    jclass localRef = FindClass(jni, c.name);
+    CHECK_EXCEPTION(jni) << "Error during FindClass: " << c.name;
+    CHECK(localRef) << c.name;
+    jclass globalRef = reinterpret_cast<jclass>(jni->NewGlobalRef(localRef));
+    CHECK_EXCEPTION(jni) << "Error during NewGlobalRef: " << c.name;
+    CHECK(globalRef) << c.name;
+    c.clazz = globalRef;
+  }
+}
+
+void FreeClassReferences(JNIEnv* jni) {
+  for (auto& c : loaded_classes) {
+    jni->DeleteGlobalRef(c.clazz);
+    c.clazz = nullptr;
+  }
+}
+
+jclass LookUpClass(const char* name) {
+  for (auto& c : loaded_classes) {
+    if (c.name == name)
+      return c.clazz;
+  }
+  CHECK(false) << "Unable to find class in lookup table";
+  return 0;
+}
+
+// AttachCurrentThreadIfNeeded implementation.
+AttachCurrentThreadIfNeeded::AttachCurrentThreadIfNeeded()
+    : attached_(false) {
+  ALOGD("AttachCurrentThreadIfNeeded::ctor%s", GetThreadInfo().c_str());
+  JavaVM* jvm = JVM::GetInstance()->jvm();
+  CHECK(jvm);
+  JNIEnv* jni = GetEnv(jvm);
+  if (!jni) {
+    ALOGD("Attaching thread to JVM");
+    JNIEnv* env = nullptr;
+    jint ret = jvm->AttachCurrentThread(&env, nullptr);
+    attached_ = (ret == JNI_OK);
+  }
+}
+
+AttachCurrentThreadIfNeeded::~AttachCurrentThreadIfNeeded() {
+  ALOGD("AttachCurrentThreadIfNeeded::dtor%s", GetThreadInfo().c_str());
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (attached_) {
+    ALOGD("Detaching thread from JVM");
+    jint res = JVM::GetInstance()->jvm()->DetachCurrentThread();
+    CHECK(res == JNI_OK) << "DetachCurrentThread failed: " << res;
+  }
+}
+
+// GlobalRef implementation.
+GlobalRef::GlobalRef(JNIEnv* jni, jobject object)
+    : jni_(jni), j_object_(NewGlobalRef(jni, object)) {
+  ALOGD("GlobalRef::ctor%s", GetThreadInfo().c_str());
+}
+
+GlobalRef::~GlobalRef() {
+  ALOGD("GlobalRef::dtor%s", GetThreadInfo().c_str());
+  DeleteGlobalRef(jni_, j_object_);
+}
+
+jboolean GlobalRef::CallBooleanMethod(jmethodID methodID, ...) {
+  va_list args;
+  va_start(args, methodID);
+  jboolean res = jni_->CallBooleanMethod(j_object_, methodID, args);
+  CHECK_EXCEPTION(jni_) << "Error during CallBooleanMethod";
+  return res;
+}
+
+void GlobalRef::CallVoidMethod(jmethodID methodID, ...) {
+  va_list args;
+  va_start(args, methodID);
+  jni_->CallVoidMethod(j_object_, methodID, args);
+  CHECK_EXCEPTION(jni_) << "Error during CallVoidMethod";
+}
+
+// NativeRegistration implementation.
+NativeRegistration::NativeRegistration(JNIEnv* jni, jclass clazz)
+    : JavaClass(jni, clazz), jni_(jni) {
+  ALOGD("NativeRegistration::ctor%s", GetThreadInfo().c_str());
+}
+
+NativeRegistration::~NativeRegistration() {
+  ALOGD("NativeRegistration::dtor%s", GetThreadInfo().c_str());
+  jni_->UnregisterNatives(j_class_);
+  CHECK_EXCEPTION(jni_) << "Error during UnregisterNatives";
+}
+
+rtc::scoped_ptr<GlobalRef> NativeRegistration::NewObject(
+    const char* name, const char* signature, ...) {
+  ALOGD("NativeRegistration::NewObject%s", GetThreadInfo().c_str());
+  va_list args;
+  va_start(args, signature);
+  jobject obj = jni_->NewObjectV(j_class_,
+                                 GetMethodID(jni_, j_class_, name, signature),
+                                 args);
+  CHECK_EXCEPTION(jni_) << "Error during NewObjectV";
+  va_end(args);
+  return rtc::scoped_ptr<GlobalRef>(new GlobalRef(jni_, obj));
+}
+
+// JavaClass implementation.
+jmethodID JavaClass::GetMethodId(
+    const char* name, const char* signature) {
+  return GetMethodID(jni_, j_class_, name, signature);
+}
+
+jmethodID JavaClass::GetStaticMethodId(
+    const char* name, const char* signature) {
+  return GetStaticMethodID(jni_, j_class_, name, signature);
+}
+
+jobject JavaClass::CallStaticObjectMethod(jmethodID methodID, ...) {
+  va_list args;
+  va_start(args, methodID);
+  jobject res = jni_->CallStaticObjectMethod(j_class_, methodID, args);
+  CHECK_EXCEPTION(jni_) << "Error during CallStaticObjectMethod";
+  return res;
+}
+
+// JNIEnvironment implementation.
+JNIEnvironment::JNIEnvironment(JNIEnv* jni) : jni_(jni) {
+  ALOGD("JNIEnvironment::ctor%s", GetThreadInfo().c_str());
+}
+
+JNIEnvironment::~JNIEnvironment() {
+  ALOGD("JNIEnvironment::dtor%s", GetThreadInfo().c_str());
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+rtc::scoped_ptr<NativeRegistration> JNIEnvironment::RegisterNatives(
+    const char* name, const JNINativeMethod *methods, int num_methods) {
+  ALOGD("JNIEnvironment::RegisterNatives(%s)", name);
+  DCHECK(thread_checker_.CalledOnValidThread());
+  jclass clazz = LookUpClass(name);
+  jni_->RegisterNatives(clazz, methods, num_methods);
+  CHECK_EXCEPTION(jni_) << "Error during RegisterNatives";
+  return rtc::scoped_ptr<NativeRegistration>(
+      new NativeRegistration(jni_, clazz));
+}
+
+std::string JNIEnvironment::JavaToStdString(const jstring& j_string) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  const char* jchars = jni_->GetStringUTFChars(j_string, nullptr);
+  CHECK_EXCEPTION(jni_);
+  const int size = jni_->GetStringUTFLength(j_string);
+  CHECK_EXCEPTION(jni_);
+  std::string ret(jchars, size);
+  jni_->ReleaseStringUTFChars(j_string, jchars);
+  CHECK_EXCEPTION(jni_);
+  return ret;
+}
+
+// static
+void JVM::Initialize(JavaVM* jvm, jobject context) {
+  ALOGD("JVM::Initialize%s", GetThreadInfo().c_str());
+  CHECK(!g_jvm);
+  g_jvm = new JVM(jvm, context);
+}
+
+// static
+void JVM::Uninitialize() {
+  ALOGD("JVM::Uninitialize%s", GetThreadInfo().c_str());
+  DCHECK(g_jvm);
+  delete g_jvm;
+  g_jvm = nullptr;
+}
+
+// static
+JVM* JVM::GetInstance() {
+  DCHECK(g_jvm);
+  return g_jvm;
+}
+
+JVM::JVM(JavaVM* jvm, jobject context)
+    : jvm_(jvm) {
+  ALOGD("JVM::JVM%s", GetThreadInfo().c_str());
+  CHECK(jni()) << "AttachCurrentThread() must be called on this thread.";
+  context_ = NewGlobalRef(jni(), context);
+  LoadClasses(jni());
+}
+
+JVM::~JVM() {
+  ALOGD("JVM::~JVM%s", GetThreadInfo().c_str());
+  DCHECK(thread_checker_.CalledOnValidThread());
+  FreeClassReferences(jni());
+  DeleteGlobalRef(jni(), context_);
+}
+
+rtc::scoped_ptr<JNIEnvironment> JVM::environment() {
+  ALOGD("JVM::environment%s", GetThreadInfo().c_str());
+  // The JNIEnv is used for thread-local storage. For this reason, we cannot
+  // share a JNIEnv between threads. If a piece of code has no other way to get
+  // its JNIEnv, we should share the JavaVM, and use GetEnv to discover the
+  // thread's JNIEnv. (Assuming it has one, if not, use AttachCurrentThread).
+  // See // http://developer.android.com/training/articles/perf-jni.html.
+  JNIEnv* jni = GetEnv(jvm_);
+  if (!jni) {
+    ALOGE("AttachCurrentThread() has not been called on this thread.");
+    return rtc::scoped_ptr<JNIEnvironment>();
+  }
+  return rtc::scoped_ptr<JNIEnvironment>(new JNIEnvironment(jni));
+}
+
+JavaClass JVM::GetClass(const char* name) {
+  ALOGD("JVM::GetClass(%s)%s", name, GetThreadInfo().c_str());
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return JavaClass(jni(), LookUpClass(name));
+}
+
+}  // namespace webrtc