[Mojo] Remove dependency between mojo/public and gpu

This CL restructures how sample_app integrates with the GPU command buffer.
Instead of mojo/public containing code that depends directly on
gpu/command_buffer, this CL isolates that dependency into a dynamically linked
library modelled after mojo_system.

1) mojo/public/gles2 contains a simple C API to libmojo_gles2.so.
2) mojo/gles2 contains a "thin" implementation of this API in terms of
   gpu/command_buffer.
3) Instead of subclassing GLES2ClientStub in mojo/public/bindings, we now
   subclass the stub directly in sample_app and control the GLES2 C API via
   mojo/public/gles2.

I've also added a couple of README.md files that describe the purposes of the
various directories and the reasons why the code is structured in this way.

R=darin@chromium.org

Review URL: https://codereview.chromium.org/101413002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238517 0039d316-1c4b-4281-b951-d872f2087c98

mojo/README → mojo/README.md

-This is an effort to extract a common platform out of Chrome's renderer and
+Mojo
+====
+
+Mojo is an effort to extract a common platform out of Chrome's renderer and
 plugin processes that can support multiple types of sandboxed content, such as
 HTML, Pepper, or NaCl.

mojo/apps/js/bindings/threading.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef MOJO_APPS_JS_THREADING_H_
-#define MOJO_APPS_JS_THREADING_H_
+#ifndef MOJO_APPS_JS_BINDINGS_THREADING_H_
+#define MOJO_APPS_JS_BINDINGS_THREADING_H_
 
 #include "mojo/public/system/core.h"
 #include "v8/include/v8.h"
@@ -20,4 +20,4 @@ class Threading {
 }  // namespace apps
 }  // namespace mojo
 
-#endif  // MOJO_APPS_JS_THREADING_H_
+#endif  // MOJO_APPS_JS_BINDINGS_THREADING_H_

mojo/examples/sample_app/DEPS

-include_rules = [
-  # TODO(abarth): Rather than including this interface directly,
-  # we need to figure out the right way for apps to call GL.
-  "!gpu/command_buffer/client/gles2_interface.h",
-]

mojo/examples/sample_app/sample_gles2_delegate.cc → mojo/examples/sample_app/gles2_client_impl.cc

@@ -2,42 +2,47 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "mojo/examples/sample_app/sample_gles2_delegate.h"
+#include "mojo/examples/sample_app/gles2_client_impl.h"
 
-#include <stdio.h>
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 
+#include "mojo/public/gles2/gles2.h"
+
 namespace mojo {
 namespace examples {
 
-SampleGLES2Delegate::SampleGLES2Delegate()
-    : gl_(NULL) {
+GLES2ClientImpl::GLES2ClientImpl(ScopedMessagePipeHandle pipe)
+    : service_(pipe.Pass()) {
+  service_.SetPeer(this);
 }
 
-SampleGLES2Delegate::~SampleGLES2Delegate() {
+GLES2ClientImpl::~GLES2ClientImpl() {
+  service_->Destroy();
 }
 
-void SampleGLES2Delegate::DidCreateContext(
-    GLES2ClientImpl* gl, uint32_t width, uint32_t height) {
-  gl_ = gl;
+void GLES2ClientImpl::DidCreateContext(uint64_t encoded,
+                                       uint32_t width,
+                                       uint32_t height) {
+  MojoGLES2MakeCurrent(encoded);
+
   cube_.Init(width, height);
   last_time_ = base::Time::Now();
   timer_.Start(FROM_HERE, base::TimeDelta::FromMilliseconds(16),
-               this, &SampleGLES2Delegate::Draw);
+               this, &GLES2ClientImpl::Draw);
 }
 
-void SampleGLES2Delegate::Draw() {
+void GLES2ClientImpl::Draw() {
   base::Time now = base::Time::Now();
   base::TimeDelta offset = now - last_time_;
   last_time_ = now;
   cube_.Update(offset.InSecondsF());
   cube_.Draw();
-  gl_->SwapBuffers();
+
+  MojoGLES2SwapBuffers();
 }
 
-void SampleGLES2Delegate::ContextLost(GLES2ClientImpl* gl) {
-  gl_ = NULL;
+void GLES2ClientImpl::ContextLost() {
   timer_.Stop();
 }
 

mojo/examples/sample_app/sample_gles2_delegate.h → mojo/examples/sample_app/gles2_client_impl.h

@@ -2,35 +2,40 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef MOJO_EXAMPLES_SAMPLE_APP_SAMPLE_GLES2_DELEGATE_H_
-#define MOJO_EXAMPLES_SAMPLE_APP_SAMPLE_GLES2_DELEGATE_H_
+#ifndef MOJO_EXAMPLES_SAMPLE_APP_GLES2_CLIENT_IMPL_H_
+#define MOJO_EXAMPLES_SAMPLE_APP_GLES2_CLIENT_IMPL_H_
 
 #include "base/timer/timer.h"
 #include "mojo/examples/sample_app/spinning_cube.h"
-#include "mojo/public/bindings/gles2_client/gles2_client_impl.h"
+#include "mojo/public/bindings/lib/remote_ptr.h"
+#include "mojom/gles2.h"
 
 namespace mojo {
 namespace examples {
 
-class SampleGLES2Delegate : public GLES2Delegate {
+class GLES2ClientImpl : public GLES2ClientStub {
  public:
-  SampleGLES2Delegate();
-  virtual ~SampleGLES2Delegate();
+  explicit GLES2ClientImpl(ScopedMessagePipeHandle pipe);
+  virtual ~GLES2ClientImpl();
 
  private:
-  virtual void DidCreateContext(
-      GLES2ClientImpl* gl, uint32_t width, uint32_t height) MOJO_OVERRIDE;
-  virtual void ContextLost(GLES2ClientImpl* gl) MOJO_OVERRIDE;
+  virtual void DidCreateContext(uint64_t encoded,
+                                uint32_t width,
+                                uint32_t height) MOJO_OVERRIDE;
+  virtual void ContextLost() MOJO_OVERRIDE;
 
   void Draw();
 
   base::Time last_time_;
-  base::RepeatingTimer<SampleGLES2Delegate> timer_;
+  base::RepeatingTimer<GLES2ClientImpl> timer_;
   SpinningCube cube_;
-  GLES2ClientImpl* gl_;
+
+  RemotePtr<GLES2> service_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(GLES2ClientImpl);
 };
 
 }  // namespace examples
 }  // namespace mojo
 
-#endif  // MOJO_EXAMPLES_SAMPLE_APP_SAMPLE_GLES2_DELEGATE_H_
+#endif  // MOJO_EXAMPLES_SAMPLE_APP_GLES2_CLIENT_IMPL_H_

mojo/examples/sample_app/native_viewport_client_impl.cc

@@ -6,8 +6,6 @@
 
 #include <stdio.h>
 
-#include "mojo/public/bindings/gles2_client/gles2_client_impl.h"
-
 namespace mojo {
 namespace examples {
 
@@ -27,7 +25,7 @@ void NativeViewportClientImpl::Open() {
   ScopedMessagePipeHandle gles2_client;
   CreateMessagePipe(&gles2, &gles2_client);
 
-  gles2_client_.reset(new GLES2ClientImpl(&gles2_delegate_, gles2.Pass()));
+  gles2_client_.reset(new GLES2ClientImpl(gles2.Pass()));
   service_->CreateGLES2Context(gles2_client.release());
 }
 

mojo/examples/sample_app/native_viewport_client_impl.h

@@ -6,7 +6,7 @@
 #define MOJO_EXAMPLES_SAMPLE_APP_NATIVE_VIEWPORT_CLIENT_IMPL_H_
 
 #include "base/memory/scoped_ptr.h"
-#include "mojo/examples/sample_app/sample_gles2_delegate.h"
+#include "mojo/examples/sample_app/gles2_client_impl.h"
 #include "mojo/public/bindings/lib/remote_ptr.h"
 #include "mojom/native_viewport.h"
 
@@ -23,10 +23,11 @@ class NativeViewportClientImpl : public NativeViewportClientStub {
  private:
   virtual void DidOpen() MOJO_OVERRIDE;
 
-  SampleGLES2Delegate gles2_delegate_;
   scoped_ptr<GLES2ClientImpl> gles2_client_;
 
   RemotePtr<NativeViewport> service_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(NativeViewportClientImpl);
 };
 
 }  // namespace examples

mojo/examples/sample_app/sample_app.cc

@@ -8,8 +8,8 @@
 #include "base/message_loop/message_loop.h"
 #include "mojo/common/bindings_support_impl.h"
 #include "mojo/examples/sample_app/native_viewport_client_impl.h"
-#include "mojo/public/bindings/gles2_client/gles2_client_impl.h"
 #include "mojo/public/bindings/lib/bindings_support.h"
+#include "mojo/public/gles2/gles2.h"
 #include "mojo/public/system/core.h"
 #include "mojo/public/system/macros.h"
 
@@ -40,13 +40,13 @@ extern "C" SAMPLE_APP_EXPORT MojoResult CDECL MojoMain(MojoHandle pipe) {
   base::MessageLoop loop;
   mojo::common::BindingsSupportImpl bindings_support;
   mojo::BindingsSupport::Set(&bindings_support);
-  mojo::GLES2ClientImpl::Initialize();
+  MojoGLES2Initialize();
 
   mojo::ScopedMessagePipeHandle scoped_handle;
   scoped_handle.reset(mojo::MessagePipeHandle(pipe));
   mojo::examples::Start(scoped_handle.Pass());
 
-  mojo::GLES2ClientImpl::Terminate();
+  MojoGLES2Terminate();
   mojo::BindingsSupport::Set(NULL);
   return MOJO_RESULT_OK;
 }

mojo/gles2/README.md

+Mojo GLES2
+==========
+
+We export this dynamically linked library via mojo/public/gles2 in order to
+hide the gpu/command_buffer/client dependency from clients of the Mojo API.

mojo/public/bindings/gles2_client/gles2_client_impl.cc → mojo/gles2/gles2.cc

@@ -2,59 +2,21 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "mojo/public/bindings/gles2_client/gles2_client_impl.h"
-
-#include <assert.h>
+#include "mojo/public/gles2/gles2.h"
 
 #include "gpu/command_buffer/client/gles2_lib.h"
 
-namespace mojo {
-namespace {
-
-bool g_gles2_initialized = false;
-
-}  // namespace
-
-GLES2Delegate::~GLES2Delegate() {
-}
-
-void GLES2Delegate::DidCreateContext(
-    GLES2ClientImpl* gl, uint32_t width, uint32_t height) {
-}
-
-void GLES2Delegate::ContextLost(GLES2ClientImpl* gl) {
-}
-
-GLES2ClientImpl::GLES2ClientImpl(GLES2Delegate* delegate,
-                                 ScopedMessagePipeHandle gl)
-    : delegate_(delegate),
-      gl_(gl.Pass()) {
-  assert(g_gles2_initialized);
-  gl_.SetPeer(this);
-}
+extern "C" {
 
-GLES2ClientImpl::~GLES2ClientImpl() {
-  gl_->Destroy();
-}
-
-void GLES2ClientImpl::Initialize() {
-  assert(!g_gles2_initialized);
+void MojoGLES2Initialize() {
   gles2::Initialize();
-  g_gles2_initialized = true;
 }
 
-void GLES2ClientImpl::Terminate() {
-  assert(g_gles2_initialized);
+void MojoGLES2Terminate() {
   gles2::Terminate();
-  g_gles2_initialized = false;
 }
 
-void GLES2ClientImpl::SwapBuffers() {
-  gles2::GetGLContext()->SwapBuffers();
-}
-
-void GLES2ClientImpl::DidCreateContext(
-    uint64_t encoded, uint32_t width, uint32_t height) {
+void MojoGLES2MakeCurrent(uint64_t encoded) {
   // Ack, Hans! It's the giant hack.
   // TODO(abarth): Replace this hack with something more disciplined. Most
   // likley, we should receive a MojoHandle that we use to wire up the
@@ -64,12 +26,10 @@ void GLES2ClientImpl::DidCreateContext(
       reinterpret_cast<gpu::gles2::GLES2Interface*>(
           static_cast<uintptr_t>(encoded));
   gles2::SetGLContext(gl_interface);
-
-  delegate_->DidCreateContext(this, width, height);
 }
 
-void GLES2ClientImpl::ContextLost() {
-  delegate_->ContextLost(this);
+void MojoGLES2SwapBuffers() {
+  gles2::GetGLContext()->SwapBuffers();
 }
 
-}  // mojo
+}  // extern "C"

mojo/mojo.gyp

@@ -17,7 +17,7 @@
       'target_name': 'mojo',
       'type': 'none',
       'dependencies': [
-        'hello_world_service_impl',
+        'hello_world_service',
         'mojo_bindings',
         'mojo_bindings_unittests',
         'mojo_common_lib',
@@ -139,6 +139,19 @@
         'system/waiter_unittest.cc',
       ],
     },
+    {
+      'target_name': 'mojo_gles2',
+      'type': '<(component)',
+      'dependencies': [
+        '../gpu/gpu.gyp:gles2_c_lib',
+      ],
+      'defines': [
+        'MOJO_GLES2_IMPLEMENTATION',
+      ],
+      'sources': [
+        'gles2/gles2.cc',
+      ],
+    },
     {
       'target_name': 'mojo_common_lib',
       'type': '<(component)',
@@ -207,7 +220,7 @@
         '../url/url.gyp:url_lib',
         'mojo_bindings',
         'mojo_system',
-        'native_viewport_impl',
+        'mojo_native_viewport_service',
       ],
       'sources': [
         'shell/app_container.cc',
@@ -268,7 +281,7 @@
     ['OS=="android"', {
       'targets': [
         {
-          'target_name': 'native_viewport_java',
+          'target_name': 'mojo_native_viewport_java',
           'type': 'none',
           'dependencies': [
             '../base/base.gyp:base_java',
@@ -331,7 +344,7 @@
           'dependencies': [
             '../base/base.gyp:base_java',
             '../net/net.gyp:net_java',
-            'native_viewport_java',
+            'mojo_native_viewport_java',
             'libmojo_shell',
           ],
           'variables': {

mojo/mojo_examples.gypi

@@ -7,24 +7,24 @@
         '../base/base.gyp:base',
         '../gpu/gpu.gyp:gles2_c_lib',
         '../ui/gl/gl.gyp:gl',
-        'gles2',
-        'gles2_client_impl',
         'mojo_common_lib',
+        'mojo_gles2',
+        'mojo_gles2_bindings',
+        'mojo_native_viewport_bindings',
         'mojo_system',
-        'native_viewport',
       ],
       'sources': [
+        'examples/sample_app/gles2_client_impl.cc',
+        'examples/sample_app/gles2_client_impl.cc',
         'examples/sample_app/native_viewport_client_impl.cc',
         'examples/sample_app/native_viewport_client_impl.h',
         'examples/sample_app/sample_app.cc',
-        'examples/sample_app/sample_gles2_delegate.cc',
-        'examples/sample_app/sample_gles2_delegate.h',
         'examples/sample_app/spinning_cube.cc',
         'examples/sample_app/spinning_cube.h',
       ],
     },
     {
-      'target_name': 'hello_world_service',
+      'target_name': 'hello_world_bindings',
       'type': 'static_library',
       'sources': [
         'examples/hello_world_service/hello_world_service.mojom',
@@ -36,18 +36,18 @@
       ],
     },
     {
-      'target_name': 'hello_world_service_impl',
+      'target_name': 'hello_world_service',
       'type': 'static_library',
-      'sources': [
-        'examples/hello_world_service/hello_world_service_impl.cc',
-        'examples/hello_world_service/hello_world_service_impl.h',
+      'dependencies': [
+        '../base/base.gyp:base',
+        'hello_world_bindings',
       ],
       'export_dependent_settings': [
-        'hello_world_service',
+        'hello_world_bindings',
       ],
-      'dependencies': [
-        '../base/base.gyp:base',
-        'hello_world_service',
+      'sources': [
+        'examples/hello_world_service/hello_world_service_impl.cc',
+        'examples/hello_world_service/hello_world_service_impl.h',
       ],
     },
   ],

mojo/mojo_public.gypi

@@ -102,20 +102,5 @@
         'sample_service',
       ],
     },
-    {
-      'target_name': 'gles2_client_impl',
-      'type': 'static_library',
-      'dependencies': [
-        '../gpu/gpu.gyp:gles2_c_lib',
-        'gles2',
-      ],
-      'export_dependent_settings': [
-        'gles2',
-      ],
-      'sources': [
-        'public/bindings/gles2_client/gles2_client_impl.cc',
-        'public/bindings/gles2_client/gles2_client_impl.h',
-      ],
-    },
   ],
 }

mojo/mojo_services.gypi

 {
   'targets': [
     {
-      'target_name': 'gles2',
+      'target_name': 'mojo_gles2_bindings',
       'type': 'static_library',
       'sources': [
         'services/gles2/gles2.mojom',
@@ -13,7 +13,7 @@
       ],
     },
     {
-      'target_name': 'gles2_impl',
+      'target_name': 'mojo_gles2_service',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
@@ -21,10 +21,10 @@
         '../gpu/gpu.gyp:gles2_implementation',
         '../ui/gfx/gfx.gyp:gfx',
         '../ui/gl/gl.gyp:gl',
-        'gles2',
+        'mojo_gles2_bindings',
       ],
       'export_dependent_settings': [
-        'gles2',
+        'mojo_gles2_bindings',
       ],
       'sources': [
         'services/gles2/gles2_impl.cc',
@@ -32,7 +32,7 @@
       ],
     },
     {
-      'target_name': 'native_viewport',
+      'target_name': 'mojo_native_viewport_bindings',
       'type': 'static_library',
       'sources': [
         'services/native_viewport/native_viewport.mojom',
@@ -44,17 +44,17 @@
       ],
     },
     {
-      'target_name': 'native_viewport_impl',
+      'target_name': 'mojo_native_viewport_service',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../ui/events/events.gyp:events',
         '../ui/gfx/gfx.gyp:gfx',
-        'gles2_impl',
-        'native_viewport',
+        'mojo_gles2_service',
+        'mojo_native_viewport_bindings',
       ],
       'export_dependent_settings': [
-        'native_viewport',
+        'mojo_native_viewport_bindings',
       ],
       'sources': [
         'services/native_viewport/android/mojo_viewport.cc',

mojo/public/README.md

+Mojo Public API
+===============
+
+The Mojo Public API is a binary stable API to the Mojo system. There are
+several components to the API:
+
+Bindings
+--------
+
+This directory contains a static library that clients can link into their
+binary. The contents of this directory are not binary stable because each
+client is free to use whichever version they prefer.
+
+This directory also contains a compiler that translates mojom interface
+definition files into idiomatic bindings for various languages, including
+C++ and JavaScript. Clients are expected to statically link with the generated
+code, which reads and writes the binary stable IPC message format.
+
+GLES2
+-----
+
+The IPC protocol used to communicate between Mojo client and the GLES2
+service is not binary stable. To insulate themselves from changes in this
+protocol, clients are expected to link dynamically against the standard GLES2
+headers from Khronos and the headers in this directory, which provide an
+adaptor between the GLES2 C API and the underlying IPC protocol.
+
+System
+------
+
+This directory defines the interface between Mojo clients and the Mojo IPC
+system. Although the Mojo IPC message format is binary stable, the mechanism
+by which these messages are transported is not stable. To insulate themselves
+from changes in the underlying transport, clients are expected to link against
+these headers dynamically.
+
+Tests
+-----
+
+This directory contains tests for code contained in the public API. Mojo
+clients are expected to ignore this directory.

mojo/public/bindings/gles2_client/gles2_client_impl.h

-// Copyright 2013 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 MOJO_PUBLIC_BINDINGS_GLES2_CLIENT_GLES2_CLIENT_IMPL_H_
-#define MOJO_PUBLIC_BINDINGS_GLES2_CLIENT_GLES2_CLIENT_IMPL_H_
-
-#include "mojo/public/bindings/lib/remote_ptr.h"
-#include "mojom/gles2.h"
-
-namespace mojo {
-class GLES2ClientImpl;
-
-class GLES2Delegate {
- public:
-  virtual ~GLES2Delegate();
-  virtual void DidCreateContext(
-      GLES2ClientImpl* gl, uint32_t width, uint32_t height);
-  virtual void ContextLost(GLES2ClientImpl* gl);
-};
-
-class GLES2ClientImpl : public GLES2ClientStub {
- public:
-  explicit GLES2ClientImpl(GLES2Delegate* delegate,
-                           ScopedMessagePipeHandle gl);
-  virtual ~GLES2ClientImpl();
-
-  static void Initialize();
-  static void Terminate();
-
-  void SwapBuffers();
-
- private:
-  virtual void DidCreateContext(
-    uint64_t encoded, uint32_t width, uint32_t height) MOJO_OVERRIDE;
-  virtual void ContextLost() MOJO_OVERRIDE;
-
-  GLES2Delegate* delegate_;
-  RemotePtr<GLES2> gl_;
-};
-
-}  // mojo
-
-#endif  // MOJO_PUBLIC_BINDINGS_GLES2_CLIENT_GLES2_CLIENT_IMPL_H_

mojo/public/gles2/gles2.h

+// Copyright 2013 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 MOJO_PUBLIC_GLES2_ADAPTOR_H_
+#define MOJO_PUBLIC_GLES2_ADAPTOR_H_
+
+// Note: This header should be compilable as C.
+
+#include <stdint.h>
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(MOJO_GLES2_IMPLEMENTATION)
+#define MOJO_GLES2_EXPORT __declspec(dllexport)
+#else
+#define MOJO_GLES2_EXPORT __declspec(dllimport)
+#endif  // defined(GFX_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(MOJO_GLES2_IMPLEMENTATION)
+#define MOJO_GLES2_EXPORT __attribute__((visibility("default")))
+#else
+#define MOJO_GLES2_EXPORT
+#endif
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define MOJO_GLES2_EXPORT
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+MOJO_GLES2_EXPORT void MojoGLES2Initialize();
+MOJO_GLES2_EXPORT void MojoGLES2Terminate();
+// TODO(abarth): MojoGLES2MakeCurrent should take a MojoHandle.
+MOJO_GLES2_EXPORT void MojoGLES2MakeCurrent(uint64_t encoded);
+MOJO_GLES2_EXPORT void MojoGLES2SwapBuffers();
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // MOJO_PUBLIC_GLES2_ADAPTOR_H_