Merge lp:~andreas-pokorny/mir/use-monotonic-clock-for-input into lp:mir

[Andreas Pokorny]

Switch to monotonic clock for everything input related

sytemTime from android-input is used by client and server within the input receiver to calculate an assumed frame time, and to attach timestamps to input events. The evdev platform now ensures with EVIOCSCLOCKID(CLOCK_MONOTONIC) that for every device opened through libinput CLOCK_MONOTONIC is used. Note that EventHub.cpp does the same.
KeyRepeatDispatcher used to emit timer events from system_clock which uses CLOCK_REALTIME. Similar reports and fake event devices required adaptation too.

Before this change CLOCK_REALTIME was used because the default build configuration of android-input refrained from using any other clock (c.f. HAVE_POSIX_CLOCKS). Hence the input event timestamps were replaced by CLOCK_REALTIME timestamps. And everything else had to follow that setup.

As opposed to the previous attempt, this MP does not introduce the idea of a Clock passed to platforms. Instead it relies on the underlying system to come up with good timestamps. Especially for evdev events the timestamps from the device are more accurate than the ones generated when the system compositor gets to interpret the results from libinput.

So in the end this MP just changes the already spread time stamp related bits to use the monotonic clock.

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:3104
http://jenkins.qa.ubuntu.com/job/mir-ci/5558/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-android-vivid-i386-build/4885
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-clang-vivid-amd64-build/3792/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-vivid-touch/4828/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-wily-touch/785/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-wily-amd64-ci/1712
        deb: http://jenkins.qa.ubuntu.com/job/mir-wily-amd64-ci/1712/artifact/work/output/*zip*/output.zip
    None: http://jenkins.qa.ubuntu.com/job/mir-wily-i386-ci/785/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/4829
        deb: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/4829/artifact/work/output/*zip*/output.zip
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-runner-touch/7408/console
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/25159
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-wily-armhf/786/console

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/mir-ci/5558/rebuild

review: Needs Fixing (continuous-integration)

[Chris Halse Rogers (raof)]

Seems reasonable.

review: Approve

[Alan Griffiths (alan-griffiths)]

+ auto age =
+ std::chrono::duration<double, std::milli>(std::chrono::steady_clock::now().time_since_epoch() - when);

1. A bit wordy.
2. could be const.

    using namespace std::chrono;
    ...
    duration<double, std::milli> const age{steady_clock::now().time_since_epoch() - when};

review: Approve

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:3105
http://jenkins.qa.ubuntu.com/job/mir-ci/5571/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-android-vivid-i386-build/4899
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-clang-vivid-amd64-build/3806/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-vivid-touch/4842/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-wily-touch/799/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-wily-amd64-ci/1725/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-wily-i386-ci/799
        deb: http://jenkins.qa.ubuntu.com/job/mir-wily-i386-ci/799/artifact/work/output/*zip*/output.zip
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-vivid-armhf/4843/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-builder-wily-armhf/800/console

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/mir-ci/5571/rebuild

review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

review: Approve (continuous-integration)

=== modified file '3rd_party/android-input/android/frameworks/native/libs/utils/Timers.cpp'
--- 3rd_party/android-input/android/frameworks/native/libs/utils/Timers.cpp	2015-08-18 01:35:15 +0000
+++ 3rd_party/android-input/android/frameworks/native/libs/utils/Timers.cpp	2015-11-18 09:58:11 +0000
@@ -20,38 +20,12 @@
 #include <utils/Timers.h>
 #include <std/Log.h>
 
-#include <stdlib.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <sys/time.h>
-#include <time.h>
-#include <errno.h>
 #include <limits.h>
-
-#ifdef HAVE_WIN32_THREADS
-#include <windows.h>
-#endif
-
-std::chrono::nanoseconds systemTime(int clock)
+#include <chrono>
+
+std::chrono::nanoseconds systemTime(int /*clock => always MONOTONIC*/)
 {
-#if defined(HAVE_POSIX_CLOCKS)
-    static const clockid_t clocks[] = {
-            CLOCK_REALTIME,
-            CLOCK_MONOTONIC,
-            CLOCK_PROCESS_CPUTIME_ID,
-            CLOCK_THREAD_CPUTIME_ID
-    };
-    struct timespec t;
-    t.tv_sec = t.tv_nsec = 0;
-    clock_gettime(clocks[clock], &t);
-    return std::chrono::nanoseconds(t.tv_sec)*1000000000LL + t.tv_nsec;
-#else
-    // we don't support the clocks here.
-    struct timeval t;
-    t.tv_sec = t.tv_usec = 0;
-    gettimeofday(&t, NULL);
-    return std::chrono::nanoseconds(t.tv_sec)*1000000000LL + std::chrono::nanoseconds(t.tv_usec)*1000LL;
-#endif
+    return {std::chrono::steady_clock::now().time_since_epoch()};
 }
 
 int toMillisecondTimeoutDelay(std::chrono::nanoseconds referenceTime, std::chrono::nanoseconds timeoutTime)

=== modified file 'src/common/logging/input_timestamp.cpp'
--- src/common/logging/input_timestamp.cpp	2015-06-17 05:20:42 +0000
+++ src/common/logging/input_timestamp.cpp	2015-11-18 09:58:11 +0000
@@ -19,21 +19,15 @@
 #include "mir/logging/input_timestamp.h"
 #include <cstdio>
 
-std::string mir::logging::input_timestamp(std::chrono::nanoseconds when)
+using namespace std::chrono;
+std::string mir::logging::input_timestamp(nanoseconds when)
 {
-    // Input events use CLOCK_REALTIME, and so we must...
-    struct timespec ts;
-    clock_gettime(CLOCK_REALTIME, &ts);
-
-    std::chrono::nanoseconds now = std::chrono::nanoseconds(ts.tv_sec * 1000000000LL + ts.tv_nsec);
-    std::chrono::nanoseconds age = now - when;
+    // Input events use CLOCK_MONOTONIC, and so we must...
+    duration<double, std::milli> const age = steady_clock::now().time_since_epoch() - when;
 
     char str[64];
-    snprintf(str, sizeof str, "%lld (%ld.%06ld ms ago)",
-             static_cast<long long>(when.count()),
-             static_cast<long>(age.count() / 1000000LL),
-             static_cast<long>(age.count() % 1000000LL));
+    snprintf(str, sizeof str, "%lld (%.6fms ago)",
+             static_cast<long long>(when.count()),age.count());
 
     return std::string(str);
 }
-

=== modified file 'src/platforms/evdev/libinput_ptr.cpp'
--- src/platforms/evdev/libinput_ptr.cpp	2015-08-07 16:51:20 +0000
+++ src/platforms/evdev/libinput_ptr.cpp	2015-11-18 09:58:11 +0000
@@ -23,14 +23,26 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <linux/input.h>
 
 namespace mie = mir::input::evdev;
 
 namespace
 {
+int use_monotonic_clock(int evdev)
+{
+    if (evdev != -1)
+    {
+        int const clockId = CLOCK_MONOTONIC;
+        // Switch each evdev 'client' to MONOTONIC
+        ioctl(evdev, EVIOCSCLOCKID, &clockId);
+    }
+    return evdev;
+}
+
 int fd_open(const char* path, int flags, void* /*userdata*/)
 {
-    return ::open(path, flags);
+    return use_monotonic_clock(::open(path, flags));
 }
 
 void fd_close(int fd, void* /*userdata*/)

=== modified file 'src/server/input/key_repeat_dispatcher.cpp'
--- src/server/input/key_repeat_dispatcher.cpp	2015-10-08 00:23:43 +0000
+++ src/server/input/key_repeat_dispatcher.cpp	2015-11-18 09:58:11 +0000
@@ -118,7 +118,7 @@
             {
                 std::lock_guard<std::mutex> lg(repeat_state_mutex);
 
-                ev.key.event_time = std::chrono::high_resolution_clock::now().time_since_epoch();
+                ev.key.event_time = std::chrono::steady_clock::now().time_since_epoch();
                 ev.key.mac = cookie_factory->timestamp_to_cookie(ev.key.event_time.count()).mac;
                 next_dispatcher->dispatch(ev);
 

=== modified file 'tests/mir_test_framework/fake_input_device_impl.cpp'
--- tests/mir_test_framework/fake_input_device_impl.cpp	2015-11-04 07:43:28 +0000
+++ tests/mir_test_framework/fake_input_device_impl.cpp	2015-11-18 09:58:11 +0000
@@ -97,7 +97,7 @@
     xkb_keysym_t key_code = 0;
 
     auto event_time = std::chrono::duration_cast<std::chrono::nanoseconds>(
-        std::chrono::system_clock::now().time_since_epoch());
+        std::chrono::steady_clock::now().time_since_epoch());
 
     auto input_action =
         (key_params.action == synthesis::EventAction::Down) ? mir_keyboard_action_down : mir_keyboard_action_up;
@@ -112,7 +112,7 @@
 void mtf::FakeInputDeviceImpl::InputDevice::synthesize_events(synthesis::ButtonParameters const& button)
 {
     auto event_time = std::chrono::duration_cast<std::chrono::nanoseconds>(
-        std::chrono::system_clock::now().time_since_epoch());
+        std::chrono::steady_clock::now().time_since_epoch());
     auto action = update_buttons(button.action, mie::to_pointer_button(button.button, settings.handedness));
     auto button_event = builder->pointer_event(event_time,
                                                action,
@@ -149,7 +149,7 @@
         BOOST_THROW_EXCEPTION(std::runtime_error("Device is not started."));
 
     auto event_time = std::chrono::duration_cast<std::chrono::nanoseconds>(
-        std::chrono::system_clock::now().time_since_epoch());
+        std::chrono::steady_clock::now().time_since_epoch());
     // constant scaling is used here to simplify checking for the
     // expected results. Default settings of the device lead to no
     // scaling at all.
@@ -183,7 +183,7 @@
         BOOST_THROW_EXCEPTION(std::runtime_error("Device is not started."));
 
     auto event_time = std::chrono::duration_cast<std::chrono::nanoseconds>(
-        std::chrono::system_clock::now().time_since_epoch());
+        std::chrono::steady_clock::now().time_since_epoch());
 
     auto touch_event = builder->touch_event(event_time);