Fix potential deadlock in measurements report

If Gnss Measurements callback is called at the same time
as Gnss Measurements close is called, this will cause
dead lock.
Remove using mutex in this case and instead use a simple
bool to know whether or not to call into a the callback.

Bug: 63909793
Change-Id: I98d2be5ebd2ee0f36e4d2e31d20a74585089fe31
CRs-fixed: 2089716

2 files changed, 13 insertions, 49 deletions

diff --git a/android/location_api/MeasurementAPIClient.cpp b/android/location_api/MeasurementAPIClient.cpp
index e3ae9ad..dd7ceac 100644
--- a/android/location_api/MeasurementAPIClient.cpp
+++ b/android/location_api/MeasurementAPIClient.cpp
@@ -50,25 +50,14 @@ static void convertGnssClock(GnssMeasurementsClock& in, IGnssMeasurementCallback
 
 MeasurementAPIClient::MeasurementAPIClient() :
     mGnssMeasurementCbIface(nullptr),
-    mLocationCapabilitiesMask(0)
+    mTracking(false)
 {
     LOC_LOGD("%s]: ()", __FUNCTION__);
-    pthread_mutex_init(&mLock, nullptr);
-    pthread_cond_init (&mCond, nullptr);
-
-    // set default LocationOptions.
-    memset(&mLocationOptions, 0, sizeof(LocationOptions));
-    mLocationOptions.size = sizeof(LocationOptions);
-    mLocationOptions.minInterval = 1000;
-    mLocationOptions.minDistance = 0;
-    mLocationOptions.mode = GNSS_SUPL_MODE_STANDALONE;
 }
 
 MeasurementAPIClient::~MeasurementAPIClient()
 {
     LOC_LOGD("%s]: ()", __FUNCTION__);
-    pthread_cond_destroy(&mCond);
-    pthread_mutex_destroy(&mLock);
 }
 
 // for GpsInterface
@@ -101,19 +90,14 @@ MeasurementAPIClient::measurementSetCallback(const sp<IGnssMeasurementCallback>&
     }
 
     locAPISetCallbacks(locationCallbacks);
-
-    while (!mLocationCapabilitiesMask) {
-        LOC_LOGD("%s]: wait for capabilities...", __FUNCTION__);
-        pthread_mutex_lock(&mLock);
-        pthread_cond_wait(&mCond, &mLock);
-        pthread_mutex_unlock(&mLock);
-    }
-    if (mLocationCapabilitiesMask & LOCATION_CAPABILITIES_GNSS_MSB_BIT)
-        mLocationOptions.mode = GNSS_SUPL_MODE_MSB;
-    else
-        mLocationOptions.mode = GNSS_SUPL_MODE_STANDALONE;
+    LocationOptions options;
+    memset(&options, 0, sizeof(LocationOptions));
+    options.size = sizeof(LocationOptions);
+    options.minInterval = 1000;
+    options.mode = GNSS_SUPL_MODE_STANDALONE;
+    mTracking = true;
     LOC_LOGD("%s]: start tracking session", __FUNCTION__);
-    locAPIStartTracking(mLocationOptions);
+    locAPIStartTracking(options);
 
     return IGnssMeasurement::GnssMeasurementStatus::SUCCESS;
 }
@@ -121,30 +105,17 @@ MeasurementAPIClient::measurementSetCallback(const sp<IGnssMeasurementCallback>&
 // for GpsMeasurementInterface
 void MeasurementAPIClient::measurementClose() {
     LOC_LOGD("%s]: ()", __FUNCTION__);
-    pthread_mutex_lock(&mLock);
-    mGnssMeasurementCbIface = nullptr;
-    pthread_mutex_unlock(&mLock);
+    mTracking = false;
     locAPIStopTracking();
 }
 
 // callbacks
-void MeasurementAPIClient::onCapabilitiesCb(LocationCapabilitiesMask capabilitiesMask)
-{
-    LOC_LOGD("%s]: (%02x)", __FUNCTION__, capabilitiesMask);
-    mLocationCapabilitiesMask = capabilitiesMask;
-    pthread_mutex_lock(&mLock);
-    pthread_cond_signal(&mCond);
-    pthread_mutex_unlock(&mLock);
-}
-
 void MeasurementAPIClient::onGnssMeasurementsCb(
         GnssMeasurementsNotification gnssMeasurementsNotification)
 {
-    LOC_LOGD("%s]: (count: %zu)", __FUNCTION__, gnssMeasurementsNotification.count);
-    // we don't need to lock the mutext
-    // if mGnssMeasurementCbIface is set to nullptr
-    if (mGnssMeasurementCbIface != nullptr) {
-        pthread_mutex_lock(&mLock);
+    LOC_LOGD("%s]: (count: %zu active: %zu)",
+            __FUNCTION__, gnssMeasurementsNotification.count, mTracking);
+    if (mTracking) {
         if (mGnssMeasurementCbIface != nullptr) {
             IGnssMeasurementCallback::GnssData gnssData;
             convertGnssData(gnssMeasurementsNotification, gnssData);
@@ -154,7 +125,6 @@ void MeasurementAPIClient::onGnssMeasurementsCb(
                     __func__, r.description().c_str());
             }
         }
-        pthread_mutex_unlock(&mLock);
     }
 }
 
diff --git a/android/location_api/MeasurementAPIClient.h b/android/location_api/MeasurementAPIClient.h
index e202192..422564d 100644
--- a/android/location_api/MeasurementAPIClient.h
+++ b/android/location_api/MeasurementAPIClient.h
@@ -59,18 +59,12 @@ public:
     void measurementClose();
 
     // callbacks we are interested in
-    void onCapabilitiesCb(LocationCapabilitiesMask capabilitiesMask) final;
     void onGnssMeasurementsCb(GnssMeasurementsNotification gnssMeasurementsNotification) final;
 
 private:
-    pthread_mutex_t mLock;
-    pthread_cond_t mCond;
-
     sp<IGnssMeasurementCallback> mGnssMeasurementCbIface;
 
-    LocationCapabilitiesMask mLocationCapabilitiesMask;
-
-    LocationOptions mLocationOptions;
+    bool mTracking;
 };
 
 }  // namespace implementation