DialogSurfaceManager implementation.

media/base/android/android_overlay_callback.cc

+// Copyright 2016 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 "media/base/android/android_overlay_callback.h"
+
+#include <map>
+
+#include "base/android/jni_android.h"
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/synchronization/lock.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "jni/AndroidOverlayCallback_jni.h"
+
+using base::android::AttachCurrentThread;
+
+namespace media {
+
+static long next_id_ = 1;
+
+scoped_refptr<base::SingleThreadTaskRunner>
+    AndroidOverlayCallback::task_runner_;
+
+// Map of ids to AndroidOverlayCallbacks.  This is called from multiple threads.
+class AndroidOverlayCallbackmap {
+ public:
+  // Associate |thiz| with |id| from any thread.
+  void Insert(long id, AndroidOverlayCallback* thiz) {
+    base::AutoLock _l(lock_);
+    DCHECK(map_.find(id) == map_.end());
+    map_[id] = thiz;
+  }
+
+  // Forget about |id| from any thread.  It's okay if it's not present.
+  // if it's not present.
+  void Erase(long id) {
+    base::AutoLock _l(lock_);
+    map_.erase(id);
+  }
+
+  // Return the associated callback for |id|, or null, from any thread.
+  AndroidOverlayCallback* Lookup(long id) {
+    base::AutoLock _l(lock_);
+    return LookupLocked(id);
+  }
+
+ private:
+  // Lookup |id|.  The caller must hold |lock_|.
+  AndroidOverlayCallback* LookupLocked(long id) {
+    lock_.AssertAcquired();
+    AndroidOverlayCallback* thiz = nullptr;
+    Map::const_iterator it = map_.find(id);
+    if (it != map_.end())
+      thiz = it->second;
+
+    return thiz;
+  }
+
+  // Alternatively, we could put in a callback that is bound to the correct
+  // thread, and use a weak ref.  However, since we still need a default
+  // action when the weak ref is cleared to unblock the callback, it ends up
+  // not being any simpler.
+  using Map = std::map<long, AndroidOverlayCallback*>;
+  Map map_;
+
+  base::Lock lock_;
+};
+
+static base::LazyInstance<AndroidOverlayCallbackmap>::Leaky g_map =
+    LAZY_INSTANCE_INITIALIZER;
+
+AndroidOverlayCallback::AndroidOverlayCallback(
+    const AndroidOverlayProxy::Callback& callback)
+    : id_(next_id_++), callback_(callback) {
+  if (!task_runner_)
+    task_runner_ = base::ThreadTaskRunnerHandle::Get();

[boliu, 2017/02/08 00:01:58]

else DCHECK it's still the same thread?

+
+  JNIEnv* env = AttachCurrentThread();
+  j_surface_callback_.Reset(Java_AndroidOverlayCallback_create(env, id_));
+
+  g_map.Pointer()->Insert(id_, this);
+}
+
+AndroidOverlayCallback::~AndroidOverlayCallback() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  g_map.Pointer()->Erase(id_);
+}
+
+void AndroidOverlayCallback::SetAndroidSurfaceCB(
+    const AndroidSurfaceCB& android_surface_cb) {
+  android_surface_cb_ = android_surface_cb;
+}
+
+bool AndroidOverlayCallback::RegisterAndroidOverlayCallback(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+AndroidOverlayCallback::GetTaskRunner() {
+  // May be called on any thread.
+  return task_runner_;
+}
+
+bool AndroidOverlayCallback::CalledOnValidThread() const {
+  return thread_checker_.CalledOnValidThread();
+}
+
+void AndroidOverlayCallback::OnCallbackProperThread(
+    long id,
+    AndroidOverlayProxy::CallbackOp what,
+    base::android::ScopedJavaGlobalRef<jobject> jobject_opt,
+    base::android::ScopedJavaGlobalRef<jobject> jcompletion_opt) {
+  // A callback has happened on some other thread.  We're run on the correct
+  // thread in response to it.
+  AndroidOverlayCallback* thiz = g_map.Pointer()->Lookup(id);
+  // |thiz| cannot be deleted here, since we're on the main thread.  However,
+  // it might have been deleted earlier, so it can be null.
+
+  if (thiz) {
+    // If this is SURFACE_DESTROYED, then no further callbacks are permitted.
+    // Erase the map entry in case the IAndroidOverlay decides to send another.
+    if (what == AndroidOverlayProxy::CallbackOp::SURFACE_DESTROYED)
+      g_map.Pointer()->Erase(id);
+
+    DCHECK(thiz->CalledOnValidThread());
+    // Send the java surface to the AndroidOverlay before the callback.
+    if (what == AndroidOverlayProxy::CallbackOp::SURFACE_CREATED &&
+        !thiz->android_surface_cb_.is_null()) {
+      thiz->android_surface_cb_.Run(jobject_opt);
+    }
+
+    // Run the client-supplied callback.
+    thiz->callback_.Run(what);
+  }
+
+  // If this is a synchronous callback, then signal that we've completed.
+  if (!jcompletion_opt.is_null()) {
+    JNIEnv* env = AttachCurrentThread();
+    Java_AndroidOverlayCallback_signalCompletion(env, jcompletion_opt);
+  }
+}
+
+void OnAndroidOverlayCallbackCreated(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jclass>& jcaller,
+    jlong id,
+    const base::android::JavaParamRef<jobject>& jsurface) {
+  // Called from some random thread in java.
+  // Post back to the main thread.  We get a strong ref here to the task
+  // runner, so that it's okay if the controller is deleted.  Holding the
+  // lock during the callback is not safe; the caller might require it to
+  // complete the callback.
+  // Remember that we're on a random thread, but |g_map| is thread safe.
+  base::Closure cb = base::Bind(
+      &AndroidOverlayCallback::OnCallbackProperThread, id,
+      AndroidOverlayProxy::CallbackOp::SURFACE_CREATED,
+      base::android::ScopedJavaGlobalRef<jobject>(jsurface), nullptr);
+#if 1
+  AndroidOverlayCallback::GetTaskRunner()->PostTask(FROM_HERE, cb);
+#else
+  // DO NOT COMMIT -- just so that picture buffer manager can wait.
+  // (I'll remove this before landing)
+  LOG(ERROR) << "AVDA: DO NOT COMMIT";
+  cb.Run();
+#endif
+}
+
+void OnAndroidOverlayCallbackDestroyed(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jclass>& jcaller,
+    jlong id,
+    const base::android::JavaParamRef<jobject>& jcompletion) {
+  // Called from some random thread in java.
+  base::Closure cb =
+      base::Bind(&AndroidOverlayCallback::OnCallbackProperThread, id,
+                 AndroidOverlayProxy::CallbackOp::SURFACE_DESTROYED, nullptr,
+                 base::android::ScopedJavaGlobalRef<jobject>(jcompletion));
+  AndroidOverlayCallback::GetTaskRunner()->PostTask(FROM_HERE, cb);
+}
+
+}  // namespace media