Merge lp:~afrantzis/mir/platform-operation-set-gbm-device into lp:mir

[Alexandros Frantzis]

client: Add set_gbm_device platform operation

client: Add set_gbm_device platform operation

Implement the set_gbm_device functionality as a platform operation. The mir_connection_drm_set_gbm_device() function is kept (for now) for backward compatibility and implemented in terms of the platform operation.

This changes also allows us to remove the final platform specific piece from the nested server, which will happen in an upcoming MP.

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:2280
http://jenkins.qa.ubuntu.com/job/mir-ci/2863/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-android-vivid-i386-build/1137
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-clang-vivid-amd64-build/1136/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-vivid-touch/1098
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-vivid-amd64-ci/860
        deb: http://jenkins.qa.ubuntu.com/job/mir-vivid-amd64-ci/860/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/1098
        deb: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/1098/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-runner-mako/4151
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/17634

Click here to trigger a rebuild:
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review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:2281
http://jenkins.qa.ubuntu.com/job/mir-ci/2866/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-android-vivid-i386-build/1143
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-clang-vivid-amd64-build/1142
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-vivid-touch/1104
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-vivid-amd64-ci/863
        deb: http://jenkins.qa.ubuntu.com/job/mir-vivid-amd64-ci/863/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/1104
        deb: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/1104/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-runner-mako/4157
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/17644

Click here to trigger a rebuild:
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review: Approve (continuous-integration)

[Alan Griffiths (alan-griffiths)]

OK

review: Approve

[Robert Carr (robertcarr)]

LGTM

review: Approve

[PS Jenkins bot (ps-jenkins)]

review: Approve (continuous-integration)

=== modified file 'src/client/mir_connection.cpp'
--- src/client/mir_connection.cpp	2015-01-30 14:38:25 +0000
+++ src/client/mir_connection.cpp	2015-01-30 14:38:25 +0000
@@ -361,6 +361,14 @@
     MirPlatformMessage const* request,
     mir_platform_operation_callback callback, void* context)
 {
+    auto const client_response = platform->platform_operation(request);
+    if (client_response)
+    {
+        set_error_message("");
+        callback(this, client_response, context);
+        return nullptr;
+    }
+
     mir::protobuf::PlatformOperationMessage protobuf_request;
 
     protobuf_request.set_opcode(opcode);
@@ -420,11 +428,6 @@
         platform_package.fd_items = platform.fd_size();
         for (int i = 0; i != platform.fd_size(); ++i)
             platform_package.fd[i] = platform.fd(i);
-
-        // TODO: Replace the extra platform data mechanism with a
-        // client side, platform specific operation
-        for (auto d : extra_platform_data)
-            platform_package.data[platform_package.data_items++] = d;
     }
     else
     {
@@ -567,21 +570,6 @@
     return &configure_display_wait_handle;
 }
 
-bool MirConnection::set_extra_platform_data(
-    std::vector<int> const& extra_platform_data_arg)
-{
-    std::lock_guard<decltype(mutex)> lock(mutex);
-
-    auto const total_data_size =
-        connect_result.platform().data_size() + extra_platform_data_arg.size();
-
-    if (total_data_size > mir_platform_package_max)
-        return false;
-
-    extra_platform_data = extra_platform_data_arg;
-    return true;
-}
-
 mir::protobuf::DisplayServer& MirConnection::display_server()
 {
     return server;
 
=== modified file 'src/client/mir_connection.h'
--- src/client/mir_connection.h	2015-01-30 14:38:25 +0000
+++ src/client/mir_connection.h	2015-01-30 14:38:25 +0000
@@ -137,8 +137,6 @@
     MirWaitHandle* configure_display(MirDisplayConfiguration* configuration);
     void done_display_configure();
 
-    bool set_extra_platform_data(std::vector<int> const& extra_platform_data);
-
     std::shared_ptr<google::protobuf::RpcChannel> rpc_channel() const
     {
         return channel;
@@ -197,8 +195,6 @@
     std::shared_ptr<mir::client::EventHandlerRegister> const event_handler_register;
 
     std::unique_ptr<mir::dispatch::SimpleDispatchThread> const eventloop;
-
-    std::vector<int> extra_platform_data;
     
     std::shared_ptr<mir::client::ClientBufferStreamFactory> buffer_stream_factory;
 
 
=== modified file 'src/client/mir_connection_api.cpp'
--- src/client/mir_connection_api.cpp	2015-01-26 15:53:18 +0000
+++ src/client/mir_connection_api.cpp	2015-01-30 14:38:25 +0000
@@ -51,11 +51,6 @@
         *context = result;
 }
 
-size_t division_ceiling(size_t a, size_t b)
-{
-    return ((a - 1) / b) + 1;
-}
-
 class DefaultMirConnectionAPI : public mcl::MirConnectionAPI
 {
 public:
@@ -356,6 +351,21 @@
     auth_magic_context->callback(auth_response->status, auth_magic_context->context);
 }
 
+void assign_set_gbm_device_status(
+    MirConnection*, MirPlatformMessage* response, void* context)
+{
+    auto const response_msg = mir::raii::deleter_for(
+        response,
+        &mir_platform_message_release);
+
+    auto const response_data = mir_platform_message_get_data(response_msg.get());
+    auto const set_gbm_device_response_ptr =
+        reinterpret_cast<MirMesaSetGBMDeviceResponse const*>(response_data.data);
+
+    auto status_ptr = static_cast<int*>(context);
+    *status_ptr = set_gbm_device_response_ptr->status;
+}
+
 }
 
 MirWaitHandle* mir_connection_drm_auth_magic(MirConnection* connection,
@@ -386,10 +396,25 @@
 int mir_connection_drm_set_gbm_device(MirConnection* connection,
                                       struct gbm_device* gbm_dev)
 {
-    size_t const pointer_size_in_ints = division_ceiling(sizeof(gbm_dev), sizeof(int));
-    std::vector<int> extra_data(pointer_size_in_ints);
-
-    memcpy(extra_data.data(), &gbm_dev, sizeof(gbm_dev));
-
-    return connection->set_extra_platform_data(extra_data);
+    MirMesaSetGBMDeviceRequest const request{gbm_dev};
+
+    auto const msg = mir::raii::deleter_for(
+        mir_platform_message_create(MirMesaPlatformOperation::set_gbm_device),
+        &mir_platform_message_release);
+
+    mir_platform_message_set_data(msg.get(), &request, sizeof(request));
+
+    static int const success{0};
+    int status{-1};
+
+    auto wh = mir_connection_platform_operation(
+        connection,
+        MirMesaPlatformOperation::set_gbm_device,
+        msg.get(),
+        assign_set_gbm_device_status,
+        &status);
+
+    mir_wait_for(wh);
+
+    return status == success;
 }
 
=== modified file 'src/include/client/mir/client_platform.h'
--- src/include/client/mir/client_platform.h	2015-01-30 14:38:25 +0000
+++ src/include/client/mir/client_platform.h	2015-01-30 14:38:25 +0000
@@ -49,6 +49,17 @@
 
     virtual MirPlatformType platform_type() const = 0;
     virtual void populate(MirPlatformPackage& package) const = 0;
+    /**
+     * Perform a platform operation.
+     *
+     * The returned platform message is owned by the caller and should be
+     * released with mir_platform_message_release().
+     *
+     *   \param [in] request      The platform operation request
+     *   \return                  The platform operation reply, or a nullptr if the
+     *                            requested operation is not supported
+     */
+    virtual MirPlatformMessage* platform_operation(MirPlatformMessage const* request) = 0;
     virtual std::shared_ptr<ClientBufferFactory> create_buffer_factory() = 0;
     virtual std::shared_ptr<EGLNativeWindowType> create_egl_native_window(EGLNativeSurface *surface) = 0;
     virtual std::shared_ptr<EGLNativeDisplayType> create_egl_native_display() = 0;
 
=== modified file 'src/platforms/android/client/android_client_platform.cpp'
--- src/platforms/android/client/android_client_platform.cpp	2015-01-30 14:38:25 +0000
+++ src/platforms/android/client/android_client_platform.cpp	2015-01-30 14:38:25 +0000
@@ -112,6 +112,12 @@
     context->populate_server_package(package);
 }
 
+MirPlatformMessage* mcla::AndroidClientPlatform::platform_operation(
+    MirPlatformMessage const*)
+{
+    return nullptr;
+}
+
 MirNativeBuffer* mcla::AndroidClientPlatform::convert_native_buffer(graphics::NativeBuffer* buf) const
 {
     return buf->anwb();
 
=== modified file 'src/platforms/android/client/android_client_platform.h'
--- src/platforms/android/client/android_client_platform.h	2015-01-30 14:38:25 +0000
+++ src/platforms/android/client/android_client_platform.h	2015-01-30 14:38:25 +0000
@@ -35,6 +35,7 @@
     AndroidClientPlatform(ClientContext* const context);
     MirPlatformType platform_type() const override;
     void populate(MirPlatformPackage& package) const override;
+    MirPlatformMessage* platform_operation(MirPlatformMessage const* request) override;
     std::shared_ptr<ClientBufferFactory> create_buffer_factory() override;
     std::shared_ptr<EGLNativeWindowType> create_egl_native_window(EGLNativeSurface *surface) override;
     std::shared_ptr<EGLNativeDisplayType> create_egl_native_display() override;
@@ -42,7 +43,6 @@
 
 private:
     ClientContext* const context;
-
 };
 
 }
 
=== modified file 'src/platforms/mesa/client/client_platform.cpp'
--- src/platforms/mesa/client/client_platform.cpp	2015-01-30 14:38:25 +0000
+++ src/platforms/mesa/client/client_platform.cpp	2015-01-30 14:38:25 +0000
@@ -23,6 +23,9 @@
 #include "native_surface.h"
 #include "mir/client_buffer_factory.h"
 #include "mir/client_context.h"
+#include "mir_toolkit/mesa/platform_operation.h"
+
+#include <cstring>
 
 namespace mcl=mir::client;
 namespace mclm=mir::client::mesa;
@@ -47,6 +50,11 @@
     mcl::EGLNativeDisplayContainer& container;
 };
 
+constexpr size_t division_ceiling(size_t a, size_t b)
+{
+    return ((a - 1) / b) + 1;
+}
+
 }
 
 mclm::ClientPlatform::ClientPlatform(
@@ -55,7 +63,8 @@
         mcl::EGLNativeDisplayContainer& display_container)
     : context{context},
       buffer_file_ops{buffer_file_ops},
-      display_container(display_container)
+      display_container(display_container),
+      gbm_dev{nullptr}
 {
 }
 
@@ -108,7 +117,43 @@
 
 void mclm::ClientPlatform::populate(MirPlatformPackage& package) const
 {
+    size_t constexpr pointer_size_in_ints = division_ceiling(sizeof(gbm_dev), sizeof(int));
+
     context->populate_server_package(package);
+
+    auto const total_data_size = package.data_items + pointer_size_in_ints;
+    if (gbm_dev && total_data_size <= mir_platform_package_max)
+    {
+        int gbm_ptr[pointer_size_in_ints]{};
+        std::memcpy(&gbm_ptr, &gbm_dev, sizeof(gbm_dev));
+
+        for (auto i : gbm_ptr)
+            package.data[package.data_items++] = i;
+    }
+}
+
+MirPlatformMessage* mclm::ClientPlatform::platform_operation(
+    MirPlatformMessage const* msg)
+{
+    auto const op = mir_platform_message_get_opcode(msg);
+
+    if (op == MirMesaPlatformOperation::set_gbm_device)
+    {
+        auto const msg_data = mir_platform_message_get_data(msg);
+        auto const set_gbm_device_request_ptr =
+            reinterpret_cast<MirMesaSetGBMDeviceRequest const*>(msg_data.data);
+
+        gbm_dev = set_gbm_device_request_ptr->device;
+
+        static int const success{0};
+        MirMesaSetGBMDeviceResponse const response{success};
+        auto const response_msg = mir_platform_message_create(op);
+        mir_platform_message_set_data(response_msg, &response, sizeof(response));
+
+        return response_msg;
+    }
+
+    return nullptr;
 }
 
 MirNativeBuffer* mclm::ClientPlatform::convert_native_buffer(graphics::NativeBuffer* buf) const
 
=== modified file 'src/platforms/mesa/client/client_platform.h'
--- src/platforms/mesa/client/client_platform.h	2015-01-30 14:38:25 +0000
+++ src/platforms/mesa/client/client_platform.h	2015-01-30 14:38:25 +0000
@@ -20,6 +20,8 @@
 
 #include "mir/client_platform.h"
 
+struct gbm_device;
+
 namespace mir
 {
 namespace client
@@ -41,6 +43,7 @@
 
     MirPlatformType platform_type() const override;
     void populate(MirPlatformPackage& package) const override;
+    MirPlatformMessage* platform_operation(MirPlatformMessage const* request) override;
     std::shared_ptr<ClientBufferFactory> create_buffer_factory() override;
     std::shared_ptr<EGLNativeWindowType> create_egl_native_window(EGLNativeSurface *surface) override;
     std::shared_ptr<EGLNativeDisplayType> create_egl_native_display() override;
@@ -50,6 +53,7 @@
     ClientContext* const context;
     std::shared_ptr<BufferFileOps> const buffer_file_ops;
     EGLNativeDisplayContainer& display_container;
+    gbm_device* gbm_dev;
 };
 
 }
 
=== modified file 'src/platforms/mesa/include/mir_toolkit/mesa/platform_operation.h'
--- src/platforms/mesa/include/mir_toolkit/mesa/platform_operation.h	2015-01-27 14:59:08 +0000
+++ src/platforms/mesa/include/mir_toolkit/mesa/platform_operation.h	2015-01-30 14:38:25 +0000
@@ -35,7 +35,8 @@
 enum MirMesaPlatformOperation
 {
     auth_magic = 1,
-    auth_fd = 2
+    auth_fd = 2,
+    set_gbm_device = 3
 };
 
 /*
@@ -49,7 +50,23 @@
 
 struct MirMesaAuthMagicResponse
 {
-    int status;
+    int status; /* 0 on success, a positive error number on failure */
+};
+
+/*
+ * MesaPlatformOperation::set_gbm_device related structures
+ */
+
+struct gbm_device;
+
+struct MirMesaSetGBMDeviceRequest
+{
+    struct gbm_device* device;
+};
+
+struct MirMesaSetGBMDeviceResponse
+{
+    int status; /* 0 on success, a positive error number on failure */
 };
 
 #ifdef __cplusplus
 
=== modified file 'tests/acceptance-tests/CMakeLists.txt'
--- tests/acceptance-tests/CMakeLists.txt	2015-01-19 06:55:41 +0000
+++ tests/acceptance-tests/CMakeLists.txt	2015-01-30 14:38:25 +0000
@@ -25,7 +25,6 @@
   test_display_configuration.cpp
   test_surfaces_with_output_id.cpp
   test_server_disconnect.cpp
-  test_client_library_drm.cpp
   test_prompt_session_client_api.cpp
   test_client_screencast.cpp
   test_client_surface_visibility.cpp
 
=== removed file 'tests/acceptance-tests/test_client_library_drm.cpp'
--- tests/acceptance-tests/test_client_library_drm.cpp	2015-01-14 06:39:13 +0000
+++ tests/acceptance-tests/test_client_library_drm.cpp	1970-01-01 00:00:00 +0000
@@ -1,46 +0,0 @@
-/*
- * Copyright © 2013-2014 Canonical Ltd.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 3 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- * Authored by: Alexandros Frantzis <[e-mail]>
- */
-
-#include "mir_toolkit/mir_client_library_drm.h"
-
-#include "mir_test_framework/connected_client_headless_server.h"
-
-#include <gtest/gtest.h>
-#include <gmock/gmock.h>
-
-namespace mtf = mir_test_framework;
-using namespace testing;
-
-using MirClientLibraryDrmTest = mtf::ConnectedClientHeadlessServer;
-
-TEST_F(MirClientLibraryDrmTest, sets_gbm_device_in_platform_data)
-{
-    struct gbm_device* dev = reinterpret_cast<struct gbm_device*>(connection);
-
-    MirPlatformPackage pkg;
-
-    mir_connection_get_platform(connection, &pkg);
-    int const previous_data_count{pkg.data_items};
-
-    mir_connection_drm_set_gbm_device(connection, dev);
-    mir_connection_get_platform(connection, &pkg);
-
-    EXPECT_THAT(pkg.data_items, Eq(previous_data_count + (sizeof(dev) / sizeof(int))));
-    EXPECT_THAT(reinterpret_cast<struct gbm_device*>(pkg.data[previous_data_count]),
-                Eq(dev));
-}
 
=== modified file 'tests/acceptance-tests/test_client_library_errors.cpp'
--- tests/acceptance-tests/test_client_library_errors.cpp	2015-01-30 14:38:25 +0000
+++ tests/acceptance-tests/test_client_library_errors.cpp	2015-01-30 14:38:25 +0000
@@ -77,6 +77,11 @@
     {
     }
 
+    MirPlatformMessage* platform_operation(MirPlatformMessage const*) override
+    {
+        return nullptr;
+    }
+
     MirPlatformType platform_type() const
     {
         BOOST_THROW_EXCEPTION(std::runtime_error{exception_text});
 
=== modified file 'tests/include/mir_test_framework/client_platform_factory.h'
--- tests/include/mir_test_framework/client_platform_factory.h	2015-01-30 14:38:25 +0000
+++ tests/include/mir_test_framework/client_platform_factory.h	2015-01-30 14:38:25 +0000
@@ -42,19 +42,13 @@
     return platform_factory(&ctx);
 }
 
-std::shared_ptr<mir::client::ClientPlatform> create_mesa_client_platform()
+std::shared_ptr<mir::client::ClientPlatform> create_mesa_client_platform(
+    mir::client::ClientContext* client_context)
 {
     using namespace testing;
-    mtd::MockClientContext ctx;
-    ON_CALL(ctx, populate_server_package(_))
-        .WillByDefault(Invoke([](MirPlatformPackage& package)
-                              {
-                                  ::memset(&package, 0, sizeof(package));
-                                  package.fd_items = 1;
-                              }));
     platform_library = std::make_shared<mir::SharedLibrary>(client_platform("mesa.so"));
     auto platform_factory = platform_library->load_function<mir::client::CreateClientPlatform>("create_client_platform");
-    return platform_factory(&ctx);
+    return platform_factory(client_context);
 }
 
 std::shared_ptr<mir::SharedLibrary>
 
=== modified file 'tests/mir_test_framework/stub_client_platform_factory.cpp'
--- tests/mir_test_framework/stub_client_platform_factory.cpp	2015-01-30 14:38:25 +0000
+++ tests/mir_test_framework/stub_client_platform_factory.cpp	2015-01-30 14:38:25 +0000
@@ -50,6 +50,11 @@
         context->populate_server_package(package);
     }
 
+    MirPlatformMessage* platform_operation(MirPlatformMessage const*) override
+    {
+        return nullptr;
+    }
+
     std::shared_ptr<mcl::ClientBufferFactory> create_buffer_factory()
     {
         return std::make_shared<mtd::StubClientBufferFactory>();
 
=== modified file 'tests/unit-tests/client/mesa/test_client_platform.cpp'
--- tests/unit-tests/client/mesa/test_client_platform.cpp	2015-01-22 21:42:26 +0000
+++ tests/unit-tests/client/mesa/test_client_platform.cpp	2015-01-30 14:38:25 +0000
@@ -18,23 +18,56 @@
 
 #include "mir/client_platform.h"
 #include "mir/shared_library.h"
+#include "mir/raii.h"
 #include "src/platforms/mesa/client/mesa_native_display_container.h"
 #include "mir_test_framework/client_platform_factory.h"
-#include "mir_test_doubles/mock_egl_native_surface.h"
 
+#include "mir_toolkit/mir_client_library.h"
 #include "mir_toolkit/mesa/native_display.h"
+#include "mir_toolkit/mesa/platform_operation.h"
 
 #include <gtest/gtest.h>
+#include <gmock/gmock.h>
 
 namespace mcl = mir::client;
 namespace mclm = mir::client::mesa;
-namespace mt = mir::test;
-namespace mtd = mir::test::doubles;
 namespace mtf = mir_test_framework;
 
-TEST(MesaClientPlatformTest, egl_native_display_is_valid_until_released)
-{
-    auto platform = mtf::create_mesa_client_platform();
+namespace
+{
+
+struct StubClientContext : mcl::ClientContext
+{
+    void populate_server_package(MirPlatformPackage& platform_package) override
+    {
+        platform_package.data_items = 0;
+        platform_package.fd_items = 1;
+    }
+
+};
+
+struct MesaClientPlatformTest : testing::Test
+{
+    MirPlatformMessage* set_gbm_device(gbm_device* dev)
+    {
+        auto request_msg = mir::raii::deleter_for(
+            mir_platform_message_create(MirMesaPlatformOperation::set_gbm_device),
+            &mir_platform_message_release);
+        MirMesaSetGBMDeviceRequest const request{dev};
+        mir_platform_message_set_data(request_msg.get(), &request, sizeof(request));
+
+        return platform->platform_operation(request_msg.get());
+    }
+
+    StubClientContext client_context;
+    std::shared_ptr<mir::client::ClientPlatform> platform =
+        mtf::create_mesa_client_platform(&client_context);
+};
+
+}
+
+TEST_F(MesaClientPlatformTest, egl_native_display_is_valid_until_released)
+{
     auto platform_lib = mtf::get_platform_library();
 
     MirMesaEGLNativeDisplay* nd;
@@ -47,3 +80,41 @@
     }
     EXPECT_EQ(MIR_MESA_FALSE, mclm::mir_client_mesa_egl_native_display_is_valid(nd));
 }
+
+TEST_F(MesaClientPlatformTest, handles_set_gbm_device_platform_operation)
+{
+    using namespace testing;
+
+    int const success{0};
+    auto const gbm_dev_dummy = reinterpret_cast<gbm_device*>(this);
+
+    auto response_msg = mir::raii::deleter_for(
+        set_gbm_device(gbm_dev_dummy),
+        &mir_platform_message_release);
+
+    ASSERT_THAT(response_msg, NotNull());
+    auto const response_data = mir_platform_message_get_data(response_msg.get());
+    ASSERT_THAT(response_data.size, Eq(sizeof(MirMesaSetGBMDeviceResponse)));
+    auto const response_ptr =
+        reinterpret_cast<MirMesaSetGBMDeviceResponse const*>(response_data.data);
+    EXPECT_THAT(response_ptr->status, Eq(success));
+}
+
+TEST_F(MesaClientPlatformTest, appends_gbm_device_to_platform_package)
+{
+    using namespace testing;
+
+    MirPlatformPackage pkg;
+    platform->populate(pkg);
+    int const previous_data_count{pkg.data_items};
+    auto const gbm_dev_dummy = reinterpret_cast<gbm_device*>(this);
+
+    auto response_msg = mir::raii::deleter_for(
+        set_gbm_device(gbm_dev_dummy),
+        &mir_platform_message_release);
+
+    platform->populate(pkg);
+    EXPECT_THAT(pkg.data_items, Eq(previous_data_count + (sizeof(gbm_dev_dummy) / sizeof(int))));
+    EXPECT_THAT(reinterpret_cast<struct gbm_device*>(pkg.data[previous_data_count]),
+                Eq(gbm_dev_dummy));
+}
 
=== modified file 'tests/unit-tests/client/test_client_mir_surface.cpp'
--- tests/unit-tests/client/test_client_mir_surface.cpp	2015-01-30 14:38:25 +0000
+++ tests/unit-tests/client/test_client_mir_surface.cpp	2015-01-30 14:38:25 +0000
@@ -211,6 +211,12 @@
     {
     }
 
+    MirPlatformMessage* platform_operation(
+        MirPlatformMessage const*) override
+    {
+        return nullptr;
+    }
+
     std::shared_ptr<mcl::ClientBufferFactory> create_buffer_factory()
     {
         return std::make_shared<mtd::StubClientBufferFactory>();
 
=== modified file 'tests/unit-tests/client/test_mir_connection.cpp'
--- tests/unit-tests/client/test_mir_connection.cpp	2015-01-30 14:38:25 +0000
+++ tests/unit-tests/client/test_mir_connection.cpp	2015-01-30 14:38:25 +0000
@@ -28,6 +28,7 @@
 #include "src/client/mir_surface.h"
 #include "mir/client_buffer_factory.h"
 #include "mir/dispatch/dispatchable.h"
+#include "mir/raii.h"
 
 #include "src/server/frontend/resource_cache.h" /* needed by test_server.h */
 #include "mir_test/test_protobuf_server.h"
@@ -74,12 +75,19 @@
         {
             configure_display_sent(static_cast<mp::DisplayConfiguration const*>(parameters));
         }
+        else if (method->name() == "platform_operation")
+        {
+            platform_operation(static_cast<mp::PlatformOperationMessage const*>(parameters),
+                               static_cast<mp::PlatformOperationMessage*>(response));
+        }
 
         complete->Run();
     }
 
     MOCK_METHOD2(connect, void(mp::ConnectParameters const*,mp::Connection*));
     MOCK_METHOD1(configure_display_sent, void(mp::DisplayConfiguration const*));
+    MOCK_METHOD2(platform_operation,
+                 void(mp::PlatformOperationMessage const*, mp::PlatformOperationMessage*));
 
     MOCK_CONST_METHOD0(watch_fd, mir::Fd());
     MOCK_METHOD1(dispatch, bool(md::FdEvents));
@@ -101,6 +109,8 @@
             .WillByDefault(Return(std::make_shared<mtd::StubClientBufferFactory>()));
         ON_CALL(*this, create_egl_native_window(_))
             .WillByDefault(Return(std::shared_ptr<EGLNativeWindowType>()));
+        ON_CALL(*this, platform_operation(_))
+            .WillByDefault(Return(nullptr));
     }
 
     void set_client_context(mcl::ClientContext* ctx)
@@ -115,6 +125,7 @@
 
     MOCK_CONST_METHOD1(convert_native_buffer, MirNativeBuffer*(mir::graphics::NativeBuffer*));
     MOCK_CONST_METHOD0(platform_type, MirPlatformType());
+    MOCK_METHOD1(platform_operation, MirPlatformMessage*(MirPlatformMessage const*));
     MOCK_METHOD0(create_buffer_factory, std::shared_ptr<mcl::ClientBufferFactory>());
     MOCK_METHOD1(create_egl_native_window, std::shared_ptr<EGLNativeWindowType>(mcl::EGLNativeSurface*));
     MOCK_METHOD0(create_egl_native_display, std::shared_ptr<EGLNativeDisplayType>());
@@ -568,46 +579,72 @@
 namespace
 {
 
-ACTION_P(FillPlatformDataWith, sample_data)
-{
-    for (auto d : sample_data)
-        arg1->mutable_platform()->add_data(d);
-}
-
-}
-
-TEST_F(MirConnectionTest, sets_extra_platform_data)
-{
-    using namespace testing;
-    std::vector<int> const initial_data{0x66, 0x67, 0x68};
-    std::vector<int> const extra_data{0x11, 0x12, 0x13};
-
-    EXPECT_CALL(*mock_channel, connect(_,_))
-        .WillOnce(FillPlatformDataWith(initial_data));
-
-    MirWaitHandle *wait_handle =
-        connection->connect("MirClientSurfaceTest", &connected_callback, nullptr);
-    wait_handle->wait_for_all();
-
-    MirPlatformPackage pkg;
-
-    /* Check initial data */
-    connection->populate(pkg);
-
-    EXPECT_EQ(initial_data.size(), static_cast<size_t>(pkg.data_items));
-    for (size_t i = 0; i < initial_data.size(); i++)
-        EXPECT_EQ(initial_data[i], pkg.data[i]) << " i=" << i;
-
-    /* Check initial data plus extra data*/
-    connection->set_extra_platform_data(extra_data);
-    connection->populate(pkg);
-
-    EXPECT_EQ(initial_data.size() + extra_data.size(),
-              static_cast<size_t>(pkg.data_items));
-
-    for (size_t i = 0; i < initial_data.size(); i++)
-        EXPECT_EQ(initial_data[i], pkg.data[i]) << " i=" << i;
-
-    for (size_t i = 0; i < extra_data.size(); i++)
-        EXPECT_EQ(extra_data[i], pkg.data[i + initial_data.size()]) << " i=" << i;
+void assign_response(MirConnection*, MirPlatformMessage* response, void* context)
+{
+    auto response_ptr = static_cast<MirPlatformMessage**>(context);
+    *response_ptr = response;
+}
+
+ACTION(CopyRequestToResponse)
+{
+    *arg1 = *arg0;
+}
+}
+
+TEST_F(MirConnectionTest, uses_client_platform_for_platform_operation)
+{
+    using namespace testing;
+
+    unsigned int const opcode{42};
+    auto const request = mir::raii::deleter_for(
+        mir_platform_message_create(opcode),
+        &mir_platform_message_release);
+    auto const response = mir::raii::deleter_for(
+        mir_platform_message_create(opcode),
+        &mir_platform_message_release);
+
+    EXPECT_CALL(*mock_platform, platform_operation(request.get()))
+        .WillOnce(Return(response.get()));
+    EXPECT_CALL(*mock_channel, platform_operation(_,_))
+        .Times(0);
+
+    auto connect_wh =
+        connection->connect("MirClientSurfaceTest", &connected_callback, nullptr);
+    mir_wait_for(connect_wh);
+
+    MirPlatformMessage* returned_response{nullptr};
+
+    auto op_wh = connection->platform_operation(
+        opcode, request.get(), assign_response, &returned_response);
+    mir_wait_for(op_wh);
+
+    EXPECT_THAT(returned_response, Eq(response.get()));
+}
+
+TEST_F(MirConnectionTest, contacts_server_if_client_platform_cannot_handle_platform_operation)
+{
+    using namespace testing;
+
+    unsigned int const opcode{42};
+    auto const request = mir::raii::deleter_for(
+        mir_platform_message_create(opcode),
+        &mir_platform_message_release);
+
+    EXPECT_CALL(*mock_platform, platform_operation(_))
+        .WillOnce(Return(nullptr));
+    EXPECT_CALL(*mock_channel, platform_operation(_,_))
+        .WillOnce(CopyRequestToResponse());
+
+    auto connect_wh =
+        connection->connect("MirClientSurfaceTest", &connected_callback, nullptr);
+    mir_wait_for(connect_wh);
+
+    MirPlatformMessage* returned_response{nullptr};
+
+    auto op_wh = connection->platform_operation(
+        opcode, request.get(), assign_response, &returned_response);
+    mir_wait_for(op_wh);
+
+    EXPECT_THAT(mir_platform_message_get_opcode(returned_response), Eq(opcode));
+    mir_platform_message_release(returned_response);
 }