commit ae23e944243d531eaba31581cc33b0b49ffeb622
author Arthur Ishiguro <arthuri@google.com> Mon Sep 11 20:08:20 2023 +0000
committer Arthur Ishiguro <arthuri@google.com> Tue Sep 12 23:08:10 2023 +0000
tree b7929330c0d4550b2b26ce7bdb8f29ebef2bf4f4
parent 677aa4b1cb9655c812c679e4736720ae5db34a97

Increase HidRawSensor thread priority to reduce latency

Bug: 296157591
Test: Compile
Change-Id: Ia7eff3aa45b291d150b1c1e0f6a19d41644fd11f

modules/sensors/dynamic_sensor/HidRawSensorDevice.cpp

diff --git a/modules/sensors/dynamic_sensor/HidRawSensorDevice.cpp b/modules/sensors/dynamic_sensor/HidRawSensorDevice.cpp
index 8aa4cf9..5bc4abc 100644
--- a/modules/sensors/dynamic_sensor/HidRawSensorDevice.cpp
+++ b/modules/sensors/dynamic_sensor/HidRawSensorDevice.cpp
@@ -35,6 +35,15 @@
 const std::unordered_set<unsigned int> HidRawSensorDevice::sInterested{
         ACCELEROMETER_3D, GYROMETER_3D, COMPASS_3D, CUSTOM};
 
+void HidRawSensorDevice::enableSchedFifoMode() {
+  constexpr int kHidRawSensorPriority = 10;  // Matches with sensor service priority
+  struct sched_param param = {0};
+  param.sched_priority = kHidRawSensorPriority;
+  if (sched_setscheduler(getTid(), SCHED_FIFO | SCHED_RESET_ON_FORK, &param) != 0) {
+    ALOGE("Couldn't set SCHED_FIFO for HidRawSensor thread: %s", strerror(errno));
+  }
+}
+
 sp<HidRawSensorDevice> HidRawSensorDevice::create(const std::string &devName) {
     sp<HidRawSensorDevice> device(new HidRawSensorDevice(devName));
     // offset +1 strong count added by constructor
@@ -74,7 +83,8 @@
         return;
     }
 
-    run("HidRawSensor");
+    run("HidRawSensor", PRIORITY_URGENT_DISPLAY);
+    enableSchedFifoMode();
     mValid = true;
 }
 

modules/sensors/dynamic_sensor/HidRawSensorDevice.h

diff --git a/modules/sensors/dynamic_sensor/HidRawSensorDevice.h b/modules/sensors/dynamic_sensor/HidRawSensorDevice.h
index 06d435e..7818bf1 100644
--- a/modules/sensors/dynamic_sensor/HidRawSensorDevice.h
+++ b/modules/sensors/dynamic_sensor/HidRawSensorDevice.h
@@ -41,6 +41,7 @@
 
     // constructor will result in +1 strong count
     explicit HidRawSensorDevice(const std::string &devName);
+    void enableSchedFifoMode();
     // implement function of Thread
     virtual bool threadLoop() override;
     std::unordered_map<unsigned int/*reportId*/, sp<HidRawSensor>> mSensors;