Introduce the devices Mojo app

device/usb/device_manager_impl.cc

Index: device/usb/device_manager_impl.cc
diff --git a/device/usb/device_manager_impl.cc b/device/usb/device_manager_impl.cc
index bf444a4aa737eed588891e6ba9944eaf0c2937eb..166c8a0d97682a65419a5f43955b394110d70fcb 100644
--- a/device/usb/device_manager_impl.cc
+++ b/device/usb/device_manager_impl.cc
@@ -5,11 +5,13 @@
 #include "device/usb/device_manager_impl.h"
 
 #include "base/bind.h"
+#include "base/location.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/sequenced_task_runner.h"
+#include "base/thread_task_runner_handle.h"
 #include "device/core/device_client.h"
 #include "device/usb/device_impl.h"
 #include "device/usb/public/cpp/device_manager_delegate.h"
-#include "device/usb/public/cpp/device_manager_factory.h"
 #include "device/usb/public/interfaces/device.mojom.h"
 #include "device/usb/type_converters.h"
 #include "device/usb/usb_device.h"
@@ -21,64 +23,123 @@
 namespace device {
 namespace usb {
 
-// static
-void DeviceManagerFactory::Build(mojo::InterfaceRequest<DeviceManager> request,
-                                 scoped_ptr<DeviceManagerDelegate> delegate) {
+namespace {
+
+void OnGetDevicesOnServiceThread(
+    const UsbService::GetDevicesCallback& callback,
+    scoped_refptr<base::TaskRunner> callback_task_runner,
+    const std::vector<scoped_refptr<UsbDevice>>& devices) {
+  callback_task_runner->PostTask(FROM_HERE, base::Bind(callback, devices));
+}
+
+void GetDevicesOnServiceThread(
+    const UsbService::GetDevicesCallback& callback,
+    scoped_refptr<base::TaskRunner> callback_task_runner) {
+  DCHECK(DeviceClient::Get());
+  UsbService* usb_service = DeviceClient::Get()->GetUsbService();
+  if (!usb_service) {
+    std::vector<scoped_refptr<UsbDevice>> no_devices;
+    callback_task_runner->PostTask(FROM_HERE, base::Bind(callback, no_devices));
+    return;
+  }
+  usb_service->GetDevices(
+      base::Bind(&OnGetDevicesOnServiceThread, callback, callback_task_runner));
+}
+
+void RunOpenDeviceCallback(const DeviceManager::OpenDeviceCallback& callback,
+                           OpenDeviceError error) {
+  callback.Run(error);
+}
+
+void OnOpenDeviceOnServiceThread(
+    mojo::InterfaceRequest<Device> device_request,
+    const DeviceManager::OpenDeviceCallback& callback,
+    scoped_refptr<base::TaskRunner> callback_task_runner,
+    scoped_refptr<UsbDeviceHandle> device_handle) {
+  if (!device_handle) {
+    callback_task_runner->PostTask(FROM_HERE,
+                                   base::Bind(&RunOpenDeviceCallback, callback,
+                                              OPEN_DEVICE_ERROR_ACCESS_DENIED));

[Reilly Grant (use Gerrit), 2015/06/10 20:02:47]

Why not base::Bind(callback, OPEN_DEVICE_ERROR_ACCESS_DENIED) here and below?

[Ken Rockot(use gerrit already), 2015/06/10 20:15:51]

base::Bind unfortunately does not know how to rebind a mojo::Callback, and
probably never will since base can't depend on core mojo and core mojo can't
depend on base.

If this ends up being a frequent occurrence, we can add some utility code to
//mojo/common

[Reilly Grant (use Gerrit), 2015/06/10 21:33:16]

I'm going to put in a strong vote in favor of importing some equivalent of
base::Bind into Mojo. It doesn't have to support all the memory safety stuff
that base::Bind does though there may be equivalent concepts useful in Mojo.

+    return;
+  }
+
   // Owned by its MessagePipe.
-  new DeviceManagerImpl(request.Pass(), delegate.Pass());
+  new DeviceImpl(device_handle, device_request.Pass());
+
+  callback_task_runner->PostTask(
+      FROM_HERE,
+      base::Bind(&RunOpenDeviceCallback, callback, OPEN_DEVICE_ERROR_OK));
 }
 
+void OpenDeviceOnServiceThread(
+    const std::string& guid,
+    mojo::InterfaceRequest<Device> device_request,
+    const DeviceManager::OpenDeviceCallback& callback,
+    scoped_refptr<base::TaskRunner> callback_task_runner) {
+  DCHECK(DeviceClient::Get());
+  UsbService* usb_service = DeviceClient::Get()->GetUsbService();
+  if (!usb_service) {
+    callback_task_runner->PostTask(FROM_HERE,
+                                   base::Bind(&RunOpenDeviceCallback, callback,
+                                              OPEN_DEVICE_ERROR_NOT_FOUND));
+    return;
+  }
+  scoped_refptr<UsbDevice> device = usb_service->GetDevice(guid);
+  if (!device) {
+    callback_task_runner->PostTask(FROM_HERE,
+                                   base::Bind(&RunOpenDeviceCallback, callback,
+                                              OPEN_DEVICE_ERROR_NOT_FOUND));
+    return;
+  }
+  device->Open(base::Bind(&OnOpenDeviceOnServiceThread,
+                          base::Passed(&device_request), callback,
+                          callback_task_runner));
+}
+
+}  // namespace
+
 DeviceManagerImpl::DeviceManagerImpl(
     mojo::InterfaceRequest<DeviceManager> request,
-    scoped_ptr<DeviceManagerDelegate> delegate)
+    scoped_ptr<DeviceManagerDelegate> delegate,
+    scoped_refptr<base::SequencedTaskRunner> service_task_runner)
     : binding_(this, request.Pass()),
       delegate_(delegate.Pass()),
+      service_task_runner_(service_task_runner),
       weak_factory_(this) {
 }
 
 DeviceManagerImpl::~DeviceManagerImpl() {
 }
 
+void DeviceManagerImpl::set_error_handler(mojo::ErrorHandler* error_handler) {
+  binding_.set_error_handler(error_handler);
+}
+
 void DeviceManagerImpl::GetDevices(EnumerationOptionsPtr options,
                                    const GetDevicesCallback& callback) {
-  DCHECK(DeviceClient::Get());
-  UsbService* usb_service = DeviceClient::Get()->GetUsbService();
-  if (!usb_service) {
-    mojo::Array<DeviceInfoPtr> results(0);
-    callback.Run(results.Pass());
-    return;
-  }
-  std::vector<UsbDeviceFilter> filters =
-      options->filters.To<std::vector<UsbDeviceFilter>>();
-  usb_service->GetDevices(base::Bind(&DeviceManagerImpl::OnGetDevices,
-                                     weak_factory_.GetWeakPtr(), callback,
-                                     filters));
+  auto get_devices_callback =
+      base::Bind(&DeviceManagerImpl::OnGetDevices, weak_factory_.GetWeakPtr(),
+                 base::Passed(&options), callback);
+  service_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&GetDevicesOnServiceThread, get_devices_callback,
+                            base::ThreadTaskRunnerHandle::Get()));
 }
 
 void DeviceManagerImpl::OpenDevice(
     const mojo::String& guid,
     mojo::InterfaceRequest<Device> device_request,
     const OpenDeviceCallback& callback) {
-  DCHECK(DeviceClient::Get());
-  UsbService* usb_service = DeviceClient::Get()->GetUsbService();
-  if (!usb_service) {
-    callback.Run(OPEN_DEVICE_ERROR_NOT_FOUND);
-    return;
-  }
-  scoped_refptr<UsbDevice> device = usb_service->GetDevice(guid);
-  if (!device) {
-    callback.Run(OPEN_DEVICE_ERROR_NOT_FOUND);
-    return;
-  }
-  device->Open(base::Bind(&DeviceManagerImpl::OnOpenDevice,
-                          weak_factory_.GetWeakPtr(), callback,
-                          base::Passed(&device_request)));
+  service_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&OpenDeviceOnServiceThread, guid,
+                            base::Passed(&device_request), callback,
+                            base::ThreadTaskRunnerHandle::Get()));
 }
 
 void DeviceManagerImpl::OnGetDevices(
+    EnumerationOptionsPtr options,
     const GetDevicesCallback& callback,
-    const std::vector<UsbDeviceFilter>& filters,
     const std::vector<scoped_refptr<UsbDevice>>& devices) {
+  auto filters = options->filters.To<std::vector<UsbDeviceFilter>>();
   mojo::Array<DeviceInfoPtr> device_infos(0);
   for (size_t i = 0; i < devices.size(); ++i) {
     DeviceInfoPtr device_info = DeviceInfo::From(*devices[i]);
@@ -94,20 +155,5 @@ void DeviceManagerImpl::OnGetDevices(
   callback.Run(device_infos.Pass());
 }
 
-void DeviceManagerImpl::OnOpenDevice(
-    const OpenDeviceCallback& callback,
-    mojo::InterfaceRequest<Device> device_request,
-    scoped_refptr<UsbDeviceHandle> device_handle) {
-  if (!device_handle) {
-    callback.Run(OPEN_DEVICE_ERROR_ACCESS_DENIED);
-    return;
-  }
-
-  // Owned by its MessagePipe.
-  new DeviceImpl(device_handle, device_request.Pass());
-
-  callback.Run(OPEN_DEVICE_ERROR_OK);
-}
-
 }  // namespace usb
 }  // namespace device