commit ac9a96da65f6eae4513654adaad8a457d1c1575c
author Mathias Agopian <mathias@google.com> Fri Jul 12 02:01:16 2013 -0700
committer Mathias Agopian <mathias@google.com> Fri Jul 12 02:08:06 2013 -0700
tree 9b90978b05bcd43041eaeac3731d1838a0210c6d
parent c07b52060acd627c8510c1a9151e0753fce76330

fix a dead-lock in sensorservice

sensorservice would deadlock if for some reason
a sensor failed to enable.

simplifed the code a bit, and made it behave a little
closer to mr1.1 -- I couldn't convince myself that
some changes in how locks were used were correct.

Bug: 9794362
Change-Id: I6110f5dbb67e543f1c71d127de2299232badb36a

services/sensorservice/SensorService.cpp

diff --git a/services/sensorservice/SensorService.cpp b/services/sensorservice/SensorService.cpp
index ebf5cf0..6481584 100644
--- a/services/sensorservice/SensorService.cpp
+++ b/services/sensorservice/SensorService.cpp
@@ -249,10 +249,8 @@
         if (getSensorType(handle) == SENSOR_TYPE_SIGNIFICANT_MOTION) {
             if (connection->hasSensor(handle)) {
                 sensor = mSensorMap.valueFor(handle);
-                err = sensor ?sensor->resetStateWithoutActuatingHardware(connection.get(), handle)
-                        : status_t(BAD_VALUE);
-                if (err != NO_ERROR) {
-                    ALOGE("Sensor Inteface: Resetting state failed with err: %d", err);
+                if (sensor != NULL) {
+                    sensor->autoDisable(connection.get(), handle);
                 }
                 cleanupWithoutDisable(connection, handle);
             }
@@ -496,8 +494,12 @@
     if (mInitCheck != NO_ERROR)
         return mInitCheck;
 
-    Mutex::Autolock _l(mLock);
     SensorInterface* sensor = mSensorMap.valueFor(handle);
+    if (sensor == NULL) {
+        return BAD_VALUE;
+    }
+
+    Mutex::Autolock _l(mLock);
     SensorRecord* rec = mActiveSensors.valueFor(handle);
     if (rec == 0) {
         rec = new SensorRecord(connection);
@@ -533,16 +535,11 @@
             handle, connection.get());
     }
 
-
     // we are setup, now enable the sensor.
-    status_t err = sensor ? sensor->activate(connection.get(), true) : status_t(BAD_VALUE);
-
+    status_t err = sensor->activate(connection.get(), true);
     if (err != NO_ERROR) {
-        // enable has failed, reset state in SensorDevice.
-        status_t resetErr = sensor ? sensor->resetStateWithoutActuatingHardware(connection.get(),
-                handle) : status_t(BAD_VALUE);
         // enable has failed, reset our state.
-        cleanupWithoutDisable(connection, handle);
+        cleanupWithoutDisableLocked(connection, handle);
     }
     return err;
 }
@@ -553,7 +550,8 @@
     if (mInitCheck != NO_ERROR)
         return mInitCheck;
 
-    status_t err = cleanupWithoutDisable(connection, handle);
+    Mutex::Autolock _l(mLock);
+    status_t err = cleanupWithoutDisableLocked(connection, handle);
     if (err == NO_ERROR) {
         SensorInterface* sensor = mSensorMap.valueFor(handle);
         err = sensor ? sensor->activate(connection.get(), false) : status_t(BAD_VALUE);
@@ -561,9 +559,14 @@
     return err;
 }
 
-status_t SensorService::cleanupWithoutDisable(const sp<SensorEventConnection>& connection,
-        int handle) {
+status_t SensorService::cleanupWithoutDisable(
+        const sp<SensorEventConnection>& connection, int handle) {
     Mutex::Autolock _l(mLock);
+    return cleanupWithoutDisableLocked(connection, handle);
+}
+
+status_t SensorService::cleanupWithoutDisableLocked(
+        const sp<SensorEventConnection>& connection, int handle) {
     SensorRecord* rec = mActiveSensors.valueFor(handle);
     if (rec) {
         // see if this connection becomes inactive