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components/font_service/public/cpp/font_service_thread.h

+// Copyright 2015 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.
+
+#ifndef COMPONENTS_FONT_SERVICE_PUBLIC_CPP_FONT_SERVICE_THREAD_H_
+#define COMPONENTS_FONT_SERVICE_PUBLIC_CPP_FONT_SERVICE_THREAD_H_
+
+#include "base/files/file.h"
+#include "base/threading/thread.h"
+#include "components/font_service/public/interfaces/font_service.mojom.h"
+#include "third_party/skia/include/core/SkStream.h"
+#include "third_party/skia/include/core/SkTypeface.h"
+#include "third_party/skia/include/ports/SkFontConfigInterface.h"
+
+namespace font_service {
+namespace internal {
+
+class MappedFontFile;
+
+// The thread which services font requests.
+//
+// The SkFontConfigInterface is a global singleton which can be accessed from
+// multiple threads. However, mojo pipes are bound to a single thread. Because
+// of this mismatch, we create a thread which owns the mojo pipe, sends and
+// receives messages. The multiple threads which call through FontLoader class
+// do blocking message calls to this thread.
+class FontServiceThread : public base::Thread,
+                          public base::RefCountedThreadSafe<FontServiceThread> {
+ public:
+  explicit FontServiceThread(FontServicePtr font_service);
+
+  // These methods are proxies which run on your thread, post a blocking task
+  // to the FontServiceThread, and

[jam, 2015/08/06 21:34:38]

nit:

+  bool MatchFamilyName(const char family_name[],
+                       SkTypeface::Style requestedStyle,
+                       SkFontConfigInterface::FontIdentity* outFontIdentity,
+                       SkString* outFamilyName,
+                       SkTypeface::Style* outStyle);
+  scoped_refptr<MappedFontFile> OpenStream(
+      const SkFontConfigInterface::FontIdentity& identity);
+
+ private:
+  friend class base::RefCountedThreadSafe<FontServiceThread>;
+  ~FontServiceThread() override;
+
+  // Methods which run on the FontServiceThread. The public MatchFamilyName
+  // calls this method, this method calls the mojo interface, and

[jam, 2015/08/06 21:34:38]

nit: 

+  void MatchFamilyNameImpl(
+      base::WaitableEvent* done_event,
+      const char family_name[],
+      SkTypeface::Style requestedStyle,
+      bool* out_valid,
+      SkFontConfigInterface::FontIdentity* out_font_identity,
+      SkString* out_family_name,
+      SkTypeface::Style* out_style);
+
+  // Called on the FontServiceThread in response to receiving a message from
+  // our MatchFamily mojo IPC. This writes the data returned by mojo, and then
+  // signals |done_event| to wake up the other thread.
+  void OnMatchFamilyNameComplete(
+      base::WaitableEvent* done_event,
+      bool* out_valid,
+      SkFontConfigInterface::FontIdentity* out_font_identity,
+      SkString* out_family_name,
+      SkTypeface::Style* out_style,
+      FontIdentityPtr font_identity,
+      mojo::String family_name,
+      TypefaceStyle style);
+
+  // Implementation of OpenStream; same threading restrictions as MatchFamily.
+  void OpenStreamImpl(base::WaitableEvent* done_event,
+                      base::File* output_file,
+                      const uint32_t id_number);
+  void OnOpenStreamComplete(base::WaitableEvent* done_event,
+                            base::File* output_file,
+                            mojo::ScopedHandle handle);
+
+  // base::Thread
+  void Init() override;
+  void CleanUp() override;
+
+  // This member is used to safely pass data from one thread to another. It is
+  // set in the constructor and is consumed in Init().
+  mojo::InterfacePtrInfo<FontService> font_service_info_;
+
+  // This member is set in Init(). It takes |font_service_info_|, which is
+  // non-thread bound, and binds it to the newly created thread.
+  mojo::InterfacePtr<FontService> font_service_;
+
+  DISALLOW_COPY_AND_ASSIGN(FontServiceThread);
+};
+
+}  // namespace internal
+}  // namespace font_service
+
+#endif  // COMPONENTS_FONT_SERVICE_PUBLIC_CPP_FONT_SERVICE_THREAD_H_