Metrics for touch latency
Add some basic metrics for touch latency here.
Currently just measure the time from evdev to eventhub.
This will later become "hard interrupt" to eventhub, after we fix
b/119840121.
Bug: 111431676
Test: set reporting interval to 5 seconds instead of 5 minutes, then run
'statsd_testdrive 34' and touch the screen for a minute. Review the
results to ensure that times are reported as expected.
Change-Id: I6144aa0feab897a161f1ee058686dd0a790d17f1
diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index 2b31f6e..64070e3 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -57,6 +57,7 @@
#include <android-base/stringprintf.h>
#include <input/Keyboard.h>
#include <input/VirtualKeyMap.h>
+#include <statslog.h>
#define INDENT " "
#define INDENT2 " "
@@ -71,18 +72,21 @@
// --- Constants ---
// Maximum number of slots supported when using the slot-based Multitouch Protocol B.
-static const size_t MAX_SLOTS = 32;
+static constexpr size_t MAX_SLOTS = 32;
// Maximum amount of latency to add to touch events while waiting for data from an
// external stylus.
-static const nsecs_t EXTERNAL_STYLUS_DATA_TIMEOUT = ms2ns(72);
+static constexpr nsecs_t EXTERNAL_STYLUS_DATA_TIMEOUT = ms2ns(72);
// Maximum amount of time to wait on touch data before pushing out new pressure data.
-static const nsecs_t TOUCH_DATA_TIMEOUT = ms2ns(20);
+static constexpr nsecs_t TOUCH_DATA_TIMEOUT = ms2ns(20);
// Artificial latency on synthetic events created from stylus data without corresponding touch
// data.
-static const nsecs_t STYLUS_DATA_LATENCY = ms2ns(10);
+static constexpr nsecs_t STYLUS_DATA_LATENCY = ms2ns(10);
+
+// How often to report input event statistics
+static constexpr nsecs_t STATISTICS_REPORT_FREQUENCY = seconds_to_nanoseconds(5 * 60);
// --- Static Functions ---
@@ -4287,12 +4291,25 @@
mExternalStylusFusionTimeout = LLONG_MAX;
}
+void TouchInputMapper::reportEventForStatistics(nsecs_t evdevTime) {
+ nsecs_t now = systemTime(CLOCK_MONOTONIC);
+ nsecs_t latency = now - evdevTime;
+ mStatistics.addValue(nanoseconds_to_microseconds(latency));
+ nsecs_t timeSinceLastReport = now - mStatistics.lastReportTime;
+ if (timeSinceLastReport > STATISTICS_REPORT_FREQUENCY) {
+ android::util::stats_write(android::util::TOUCH_EVENT_REPORTED,
+ mStatistics.min, mStatistics.max, mStatistics.mean(), mStatistics.stdev());
+ mStatistics.reset(now);
+ }
+}
+
void TouchInputMapper::process(const RawEvent* rawEvent) {
mCursorButtonAccumulator.process(rawEvent);
mCursorScrollAccumulator.process(rawEvent);
mTouchButtonAccumulator.process(rawEvent);
if (rawEvent->type == EV_SYN && rawEvent->code == SYN_REPORT) {
+ reportEventForStatistics(rawEvent->when);
sync(rawEvent->when);
}
}