Merge lp://qastaging/~vanvugt/mir/earlier-release-2 into lp://qastaging/mir

PASSED: Continuous integration, rev:2890
http://jenkins.qa.ubuntu.com/job/mir-ci/4693/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-android-vivid-i386-build/3698
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/mir-clang-ts-vivid-amd64-build/119
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-clang-vivid-amd64-build/2609
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-vivid-touch/3648
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-wily-amd64-ci/842
        deb: http://jenkins.qa.ubuntu.com/job/mir-wily-amd64-ci/842/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/3648
        deb: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/3648/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-runner-mako/6413
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/22862

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/mir-ci/4693/rebuild

LGTM. I think that the tricky part (single vs multimonitor detection) comes from the fact that the MM code doesn't know how many user id's can exist, so we have to infer after-the-call (of compositor acquire). We could resolve if we handed out the ID's, and then we'd know for sure.

I think the term 'overclocking' is introducing another loaded word into the system... Its really designating a different consumption pattern with different tradeoffs. At any rate, I think I have to update the logic in the nbs multimonitor....

+1 to the logic, could the integration tests make more use of the scheduling system? There's some rigging already for blocking detection, and the tests will be slightly tricky as-is to refactor to get the new buffer semantics under this test.

All good points and they were on my mind already.

It really is a prediction algorithm, whether there's a single or multiple compositors. If we get the prediction wrong for a frame or so (second monitor hotplugged?) the client will get a buffer back a little too quickly, but that's really just one frame so not important.

Yes "overclocking" is an overloaded word here. I was looking for a single term to describe the problem and that's the best short description I've found. But it's definitely confusing and not related to physical monitor signal overclocking, which is a thing.

The new integration tests - I've used your new interfaces previously where it was clear how to do so. Sorry in some of this work it's not clear to me how to do so. I imagine some translation will happen later...

71 + mtd::MockFrameDroppingPolicyFactory policy_factory;
72 + mc::BufferQueue queue{nbuffers, mt::fake_shared(server_buffer_factory),
73 + properties, policy_factory};
74 + queue.allow_framedropping(false);
75 +
76 + mg::Buffer* client_buffer = nullptr;
77 + auto callback = [&](mg::Buffer* buffer)
78 + {
79 + client_buffer = buffer;
80 + };
81 +
82 + auto client_try_acquire = [&]() -> bool
83 + {
84 + queue.client_acquire(callback);
85 + return client_buffer != nullptr;
86 + };

C++11 is shiny bit this is being too clever.

Why aren't queue, client_try_acquire etc. just members of a fixture?

To keep the diff small. Also it's temporary and will be replaced when BufferQueue goes away, so better to not bake it into a fixture.

FAILED: Autolanding.
More details in the following jenkins job:
http://jenkins.qa.ubuntu.com/job/mir-autolanding/1825/
Executed test runs:
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-android-vivid-i386-build/3779/console
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/mir-clang-ts-vivid-amd64-build/200
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-clang-vivid-amd64-build/2690
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-vivid-touch/3729
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-wily-amd64-autolanding/378
        deb: http://jenkins.qa.ubuntu.com/job/mir-wily-amd64-autolanding/378/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/3729
        deb: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/3729/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-runner-mako/6464
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/22942