commit 6bbda89810061129abdc2e57c0a0d157745555e5
author Jim Kaye <jameskaye@google.com> Tue Sep 19 16:38:42 2017 -0700
committer Jim Kaye <jameskaye@google.com> Tue Sep 19 16:40:28 2017 -0700
tree beee7122b080b9fa4a5f58cf3b6ab2f3cf237e92
parent 57b8638b7b9193201eca68a0091b7d8be3ed67bf

Allow multiple Sensor Flush operations

Flush operations need to be tracked so we get the right number
of flush responses. This CL ensures that each flush response
gets handled.

(This is different from normal sensor events. Each new sensor
event overwrites the previous event, even if the previous event's
values have not been handled.)

Bug: 37465457

Test: This CTS test now passes:
      CtsSensorTestCases
      android.hardware.cts.SensorIntegrationTests#testSensorsMovingRates

CP from oc-emu-dev I6156732990d725bfe79a86c6370b0ff93c44102a

Change-Id: I66cfc0714919b44b1cf7e83af16cc78d3a16147e

sensors/sensors_qemu.c

diff --git a/sensors/sensors_qemu.c b/sensors/sensors_qemu.c
index f58505a..07d72c5 100644
--- a/sensors/sensors_qemu.c
+++ b/sensors/sensors_qemu.c
@@ -147,6 +147,7 @@
     int64_t                       timeOffset;
     uint32_t                      active_sensors;
     int                           fd;
+    int                           flush_count[MAX_NUM_SENSORS];
     pthread_mutex_t               lock;
 } SensorDevice;
 
@@ -226,12 +227,21 @@
         *event = d->sensors[i];
 
         if (d->sensors[i].type == SENSOR_TYPE_META_DATA) {
-            // sensor_device_poll_event_locked() will leave
-            // the meta-data in place until we have it.
-            // Set |type| to something other than META_DATA
-            // so sensor_device_poll_event_locked() can
-            // continue.
-            d->sensors[i].type = SENSOR_TYPE_META_DATA + 1;
+            if (d->flush_count[i] > 0) {
+                // Another 'flush' is queued after this one.
+                // Don't clear this event; just decrement the count.
+                (d->flush_count[i])--;
+                // And re-mark it as pending
+                d->pendingSensors |= (1U << i);
+            } else {
+                // We are done flushing
+                // sensor_device_poll_event_locked() will leave
+                // the meta-data in place until we have it.
+                // Set |type| to something other than META_DATA
+                // so sensor_device_poll_event_locked() can
+                // continue.
+                d->sensors[i].type = SENSOR_TYPE_META_DATA + 1;
+            }
         } else {
             event->sensor = i;
             event->version = sizeof(*event);
@@ -610,13 +620,21 @@
     }
 
     pthread_mutex_lock(&dev->lock);
-    dev->sensors[handle].version = META_DATA_VERSION;
-    dev->sensors[handle].type = SENSOR_TYPE_META_DATA;
-    dev->sensors[handle].sensor = 0;
-    dev->sensors[handle].timestamp = 0;
-    dev->sensors[handle].meta_data.sensor = handle;
-    dev->sensors[handle].meta_data.what = META_DATA_FLUSH_COMPLETE;
-    dev->pendingSensors |= (1U << handle);
+    if ((dev->pendingSensors & (1U << handle)) &&
+        dev->sensors[handle].type == SENSOR_TYPE_META_DATA)
+    {
+        // A 'flush' operation is already pending. Just increment the count.
+        (dev->flush_count[handle])++;
+    } else {
+        dev->flush_count[handle] = 0;
+        dev->sensors[handle].version = META_DATA_VERSION;
+        dev->sensors[handle].type = SENSOR_TYPE_META_DATA;
+        dev->sensors[handle].sensor = 0;
+        dev->sensors[handle].timestamp = 0;
+        dev->sensors[handle].meta_data.sensor = handle;
+        dev->sensors[handle].meta_data.what = META_DATA_FLUSH_COMPLETE;
+        dev->pendingSensors |= (1U << handle);
+    }
     pthread_mutex_unlock(&dev->lock);
 
     return 0;
@@ -914,6 +932,7 @@
         // sticky. Don't start off with that setting.
         for (int idx = 0; idx < MAX_NUM_SENSORS; idx++) {
             dev->sensors[idx].type = SENSOR_TYPE_META_DATA + 1;
+            dev->flush_count[idx] = 0;
         }
 
         // Version 1.3-specific functions