Merge lp:~kdub/mir/resettable-buffer-cb into lp:mir

[Kevin DuBois]

client: add a function to the MirBuffer set of functions that allows a user to set the callback and context of a MirBuffer. Callback and context were provided in the construction; allow changing these via the new client api function.

client: add a function to the MirBuffer set of functions that allows a user to set the callback and context of a MirBuffer. Callback and context were provided in the construction; allow changing these via the new client api function.

[Cemil Azizoglu (cemil-azizoglu)]

LGTM.

Nit : Line #110 (extraneous space) and line #116 (split at the comma) could use better formatting.
        +/** Reassign the callback that the MirBuffer will call when the buffer is
107 + * available for use again
108 + * \param [in] buffer The buffer
109 + * \param [in] available_callback The callback called when the buffer
110 + * is available
111 + * \param [in] available_context The context for the available_callback
112 + **/
113 +
114 +void mir_buffer_set_callback(
115 + MirBuffer* buffer,
116 + mir_buffer_callback available_callback, void* available_context);

review: Approve

[Mir CI Bot (mir-ci-bot)]

FAILED: Continuous integration, rev:3509
https://mir-jenkins.ubuntu.com/job/mir-ci/990/
Executed test runs:
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-mir/1072/console
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/1119
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/1111
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/1111
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1083/console
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1083
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1083/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1083
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1083/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1083
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1083/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1083
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1083/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/990/rebuild

review: Needs Fixing (continuous-integration)

[Alan Griffiths (alan-griffiths)]

I'm not entirely convinced that a recursive lock allows useful behaviour, but OK.

review: Approve

[Chris Halse Rogers (raof)]

This *seems* like the sort of thing mcl::AtomicCallback is for? It doesn't currently handle changing the callback from an active callback, but that'd be a simple matter of copy-then-unlock.

review: Needs Fixing

[Kevin DuBois (kdub)]

 Ah yes, that class would make the code better, will use it.

[Mir CI Bot (mir-ci-bot)]

PASSED: Continuous integration, rev:3512
https://mir-jenkins.ubuntu.com/job/mir-ci/1092/
Executed test runs:
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-mir/1209
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/1259
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/1250
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/1250
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1219
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1219/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1219
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1219/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1219
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1219/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1219
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1219/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1219
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1219/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1092/rebuild

review: Approve (continuous-integration)

[Mir CI Bot (mir-ci-bot)]

FAILED: Autolanding.
More details in the following jenkins job:
https://mir-jenkins.ubuntu.com/job/mir-autolanding/324/
Executed test runs:
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-mir/1305/console
    None: https://mir-jenkins.ubuntu.com/job/generic-land-mp/350/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-0-fetch/1355/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/1346/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/1346/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1317/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1317/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1317/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1317/console
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1317/console

review: Needs Fixing (continuous-integration)

[Mir CI Bot (mir-ci-bot)]

FAILED: Continuous integration, rev:3513
https://mir-jenkins.ubuntu.com/job/mir-ci/1194/
Executed test runs:
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-mir/1354/console
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/1405
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/1396
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/1396
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1368
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1368/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1368
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1368/artifact/output/*zip*/output.zip
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1368/console
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1368/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1368
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1368/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1368
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1368/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1194/rebuild

review: Needs Fixing (continuous-integration)

[Kevin DuBois (kdub)]

krillin image 515 fails to come up, retriggering.

[Mir CI Bot (mir-ci-bot)]

PASSED: Continuous integration, rev:3513
https://mir-jenkins.ubuntu.com/job/mir-ci/1198/
Executed test runs:
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-mir/1365
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/1416
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/1407
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/1407
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1379
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/1379/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1379
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/1379/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1379
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/1379/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1379
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/1379/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1379
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/1379/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1198/rebuild

review: Approve (continuous-integration)

[Chris Halse Rogers (raof)]

+ cb.set_callback([&, callback, context]{ (*callback)(reinterpret_cast<::MirBuffer*>(this), context); });

The ‘&’ is rather strange there - you only really want to capture /this/ by value.

But that's a stylistic nit.

review: Approve

=== modified file 'src/client/atomic_callback.h'
--- src/client/atomic_callback.h	2016-01-29 08:18:22 +0000
+++ src/client/atomic_callback.h	2016-06-24 11:42:58 +0000
@@ -35,6 +35,11 @@
     {
     }
 
+    AtomicCallback(std::function<void(Args...)> const& fn)
+        : callback(fn)
+    {
+    }
+
     ~AtomicCallback() = default;
 
     void set_callback(std::function<void(Args...)> const& fn)

=== modified file 'src/client/buffer.cpp'
--- src/client/buffer.cpp	2016-06-06 11:51:31 +0000
+++ src/client/buffer.cpp	2016-06-24 11:42:58 +0000
@@ -28,10 +28,9 @@
     std::shared_ptr<ClientBuffer> const& buffer,
     MirConnection* connection,
     MirBufferUsage usage) :
-    cb(cb),
-    cb_context(context),
     buffer_id(buffer_id),
     buffer(buffer),
+    cb([this, cb, context]{ (*cb)(reinterpret_cast<::MirBuffer*>(this), context); }),
     owned(false),
     connection(connection),
     usage(usage)
@@ -60,8 +59,8 @@
         if (!owned)
             owned = true;
     }
-    cb(reinterpret_cast<::MirBuffer*>(static_cast<mcl::MirBuffer*>(this)), cb_context);
 
+    cb();
 }
 
 void mcl::Buffer::received(MirBufferPackage const& update_package)
@@ -74,7 +73,8 @@
             buffer->update_from(update_package);
         }
     }
-    cb(reinterpret_cast<::MirBuffer*>(static_cast<mcl::MirBuffer*>(this)), cb_context);
+
+    cb();
 }
     
 MirGraphicsRegion mcl::Buffer::map_region()
@@ -138,3 +138,8 @@
 {
     buffer->increment_age();
 }
+
+void mcl::Buffer::set_callback(mir_buffer_callback callback, void* context)
+{
+    cb.set_callback([&, callback, context]{ (*callback)(reinterpret_cast<::MirBuffer*>(this), context); });
+}

=== modified file 'src/client/buffer.h'
--- src/client/buffer.h	2016-06-06 11:51:31 +0000
+++ src/client/buffer.h	2016-06-24 11:42:58 +0000
@@ -21,6 +21,7 @@
 
 #include "mir_toolkit/mir_buffer.h"
 #include "mir/geometry/size.h"
+#include "atomic_callback.h"
 #include "mir_buffer.h"
 #include <memory>
 #include <chrono>
@@ -41,6 +42,7 @@
         std::shared_ptr<ClientBuffer> const& buffer,
         MirConnection* connection,
         MirBufferUsage usage);
+
     int rpc_id() const override;
 
     void submitted() override;
@@ -62,11 +64,12 @@
     MirConnection* allocating_connection() const override;
 
     void increment_age() override;
+    void set_callback(mir_buffer_callback callback, void* context) override;
 private:
-    mir_buffer_callback cb;
-    void* cb_context;
     int const buffer_id;
-    std::shared_ptr<ClientBuffer> buffer;
+    std::shared_ptr<ClientBuffer> const buffer;
+
+    AtomicCallback<> cb;
 
     std::mutex mutex;
     bool owned;

=== modified file 'src/client/error_buffer.cpp'
--- src/client/error_buffer.cpp	2016-05-19 13:22:43 +0000
+++ src/client/error_buffer.cpp	2016-06-24 11:42:58 +0000
@@ -68,3 +68,4 @@
 geom::Size mcl::ErrorBuffer::size() const THROW_EXCEPTION
 MirConnection* mcl::ErrorBuffer::allocating_connection() const THROW_EXCEPTION
 void mcl::ErrorBuffer::increment_age() THROW_EXCEPTION
+void mcl::ErrorBuffer::set_callback(mir_buffer_callback, void*) THROW_EXCEPTION

=== modified file 'src/client/error_buffer.h'
--- src/client/error_buffer.h	2016-05-19 13:22:43 +0000
+++ src/client/error_buffer.h	2016-06-24 11:42:58 +0000
@@ -47,6 +47,7 @@
     geometry::Size size() const override;
     MirConnection* allocating_connection() const override;
     void increment_age() override;
+    void set_callback(mir_buffer_callback callback, void* context) override;
 
     bool valid() const;
     char const* error_message() const;

=== modified file 'src/client/mir_buffer.h'
--- src/client/mir_buffer.h	2016-05-16 14:45:02 +0000
+++ src/client/mir_buffer.h	2016-06-24 11:42:58 +0000
@@ -52,6 +52,7 @@
     virtual geometry::Size size() const = 0;
     virtual MirConnection* allocating_connection() const = 0;
     virtual void increment_age() = 0;
+    virtual void set_callback(mir_buffer_callback callback, void* context) = 0;
 protected:
     MirBuffer() = default;
     MirBuffer(MirBuffer const&) = delete;

=== modified file 'src/client/mir_buffer_api.cpp'
--- src/client/mir_buffer_api.cpp	2016-06-06 11:51:31 +0000
+++ src/client/mir_buffer_api.cpp	2016-06-24 11:42:58 +0000
@@ -174,3 +174,16 @@
     MIR_LOG_UNCAUGHT_EXCEPTION(ex);
     return mir_buffer_usage_hardware;
 }
+
+void mir_buffer_set_callback(
+    MirBuffer* b, mir_buffer_callback available_callback, void* available_context)
+try
+{
+    mir::require(b);
+    auto buffer = reinterpret_cast<mcl::Buffer*>(b);
+    buffer->set_callback(available_callback, available_context);
+}
+catch (std::exception const& ex)
+{
+    MIR_LOG_UNCAUGHT_EXCEPTION(ex);
+}

=== modified file 'src/client/symbols.map'
--- src/client/symbols.map	2016-06-09 17:42:21 +0000
+++ src/client/symbols.map	2016-06-24 11:42:58 +0000
@@ -366,6 +366,7 @@
     mir_buffer_wait_fence;
     mir_buffer_get_native_buffer;
     mir_buffer_get_graphics_region;
+    mir_buffer_set_callback;
     mir_buffer_release;
     mir_connection_create_presentation_chain_sync;
     mir_presentation_chain_is_valid;

=== modified file 'src/include/client/mir_toolkit/mir_buffer.h'
--- src/include/client/mir_toolkit/mir_buffer.h	2016-06-06 11:51:31 +0000
+++ src/include/client/mir_toolkit/mir_buffer.h	2016-06-24 11:42:58 +0000
@@ -50,6 +50,18 @@
     MirBufferUsage buffer_usage,
     mir_buffer_callback available_callback, void* available_context);
 
+/** Reassign the callback that the MirBuffer will call when the buffer is
+ *  available for use again
+ *  \param [in] buffer      The buffer
+ *  \param [in] available_callback    The callback called when the buffer
+ *                                     is available
+ *  \param [in] available_context     The context for the available_callback
+ **/
+
+void mir_buffer_set_callback(
+    MirBuffer* buffer,
+    mir_buffer_callback available_callback, void* available_context);
+
 /** @name Fenced Buffer content access functions.
  *
  * These functions will wait until it is safe to access the buffer for the given purpose.

=== modified file 'tests/acceptance-tests/throwback/test_presentation_chain.cpp'
--- tests/acceptance-tests/throwback/test_presentation_chain.cpp	2016-06-06 11:51:31 +0000
+++ tests/acceptance-tests/throwback/test_presentation_chain.cpp	2016-06-24 11:42:58 +0000
@@ -355,3 +355,41 @@
     EXPECT_THAT(mir_buffer_get_buffer_usage(buffer), Eq(usage));
     EXPECT_THAT(mir_buffer_get_pixel_format(buffer), Eq(format));
 }
+
+namespace
+{
+void another_buffer_callback(MirBuffer* buffer, void* context)
+{
+    buffer_callback(buffer, context);
+}
+}
+TEST_F(PresentationChain, buffers_callback_can_be_reassigned)
+{
+    SurfaceWithChainFromStart surface(connection, size, pf);
+
+    MirBufferSync second_buffer_context;
+    MirBufferSync context;
+    MirBufferSync another_context;
+    mir_connection_allocate_buffer(
+        connection,
+        size.width.as_int(), size.height.as_int(), pf, usage,
+        buffer_callback, &context);
+    mir_connection_allocate_buffer(
+        connection,
+        size.width.as_int(), size.height.as_int(), pf, usage,
+        buffer_callback, &second_buffer_context);
+
+    ASSERT_TRUE(context.wait_for_buffer(10s));
+    ASSERT_THAT(context.buffer(), Ne(nullptr));
+    ASSERT_TRUE(second_buffer_context.wait_for_buffer(10s));
+    ASSERT_THAT(second_buffer_context.buffer(), Ne(nullptr));
+
+    mir_buffer_set_callback(context.buffer(), another_buffer_callback, &another_context);
+
+    mir_presentation_chain_submit_buffer(surface.chain(), context.buffer());
+    //flush the 1st buffer out
+    mir_presentation_chain_submit_buffer(surface.chain(), second_buffer_context.buffer());
+
+    ASSERT_TRUE(another_context.wait_for_buffer(10s));
+    ASSERT_THAT(another_context.buffer(), Ne(nullptr));
+}

=== modified file 'tests/include/mir/test/doubles/mock_mir_buffer.h'
--- tests/include/mir/test/doubles/mock_mir_buffer.h	2016-05-13 18:55:24 +0000
+++ tests/include/mir/test/doubles/mock_mir_buffer.h	2016-06-24 11:42:58 +0000
@@ -55,6 +55,7 @@
     MOCK_CONST_METHOD0(size, geometry::Size());
     MOCK_CONST_METHOD0(allocating_connection, MirConnection*());
     MOCK_METHOD0(increment_age, void());
+    MOCK_METHOD2(set_callback, void(mir_buffer_callback callback, void* context));
 };
 
 using StubMirBuffer = testing::NiceMock<MockMirBuffer>; 

=== modified file 'tests/unit-tests/client/test_mir_buffer.cpp'
--- tests/unit-tests/client/test_mir_buffer.cpp	2016-06-06 11:51:31 +0000
+++ tests/unit-tests/client/test_mir_buffer.cpp	2016-06-24 11:42:58 +0000
@@ -177,6 +177,24 @@
     EXPECT_THAT(call_count, Eq(1));
 }
 
+TEST_F(MirBufferTest, callback_called_after_change_when_available_from_creation)
+{
+    int call_count = 0;
+    mcl::Buffer buffer(cb, nullptr, buffer_id, mock_client_buffer, nullptr, usage);
+    buffer.set_callback(cb, &call_count); 
+    buffer.received();
+    EXPECT_THAT(call_count, Eq(1));
+}
+
+TEST_F(MirBufferTest, callback_called_after_change_when_available_from_server_return)
+{
+    int call_count = 0;
+    mcl::Buffer buffer(cb, nullptr, buffer_id, mock_client_buffer, nullptr, usage);
+    buffer.set_callback(cb, &call_count); 
+    buffer.received(update_message);
+    EXPECT_THAT(call_count, Eq(1));
+}
+
 TEST_F(MirBufferTest, updates_package_when_server_returns)
 {
     EXPECT_CALL(*mock_client_buffer, update_from(Ref(update_message)));