Performance: SystemServer: Move sensor init to a new thread.

Move Sensor init to a separate thread so that it doesn't block the
critical booting path.
Initializing Sensors in separate thread has been seen to improve boot
time on customer devices with low-tier / ult chipsets(less cpu cores)

Change-Id: I5c46a5805c04ffe551019b4683523e3bf70274a2

1 files changed, 14 insertions, 2 deletions

diff --git a/services/core/jni/com_android_server_SystemServer.cpp b/services/core/jni/com_android_server_SystemServer.cpp
index 64514a9..3f46ec6 100644
--- a/services/core/jni/com_android_server_SystemServer.cpp
+++ b/services/core/jni/com_android_server_SystemServer.cpp
@@ -25,12 +25,24 @@
 
 namespace android {
 
+void* sensorInit(void *arg) {
+    ALOGI("System server: starting sensor init.\n");
+    // Start the sensor service
+    SensorService::instantiate();
+    ALOGI("System server: sensor init done.\n");
+    return NULL;
+}
+
 static void android_server_SystemServer_startSensorService(JNIEnv* /* env */, jobject /* clazz */) {
     char propBuf[PROPERTY_VALUE_MAX];
+    pthread_t sensor_init_thread;
+
     property_get("system_init.startsensorservice", propBuf, "1");
     if (strcmp(propBuf, "1") == 0) {
-        // Start the sensor service
-        SensorService::instantiate();
+        // We are safe to move this to a new thread because
+        // Android frame work has taken care to check whether the
+        // service is started or not before using it.
+        pthread_create( &sensor_init_thread, NULL, &sensorInit, NULL);
     }
 }