commit f3cb5562b22f587c8ec238bcc4331b82f4370d53
author Yu-Han Yang <yuhany@google.com> Thu Mar 05 22:41:23 2020 -0800
committer Yu-Han Yang <yuhany@google.com> Fri Mar 06 22:57:25 2020 +0000
tree 82ccada89e44b67294feeaf59cee245910aa32b9
parent 77d161d09efd570c60c01714aaa2efc1c8f94f48

Fix deadlock in cuttlefish/default implementation

Bug: 150830099

Test: atest LocationManagerFineTest#testRegisterGnssMeasurementsCallback
-c --iterations 100

Change-Id: I70aec19a481781d924ed3008765ca624a7eeb950
Merged-In: I70aec19a481781d924ed3008765ca624a7eeb950

(cherry picked from commit 3d652709ed40f8070c990bb275d3709d603d318e)

gnss/2.0/default/GnssMeasurement.cpp

diff --git a/gnss/2.0/default/GnssMeasurement.cpp b/gnss/2.0/default/GnssMeasurement.cpp
index d778d50..a3ea807 100644
--- a/gnss/2.0/default/GnssMeasurement.cpp
+++ b/gnss/2.0/default/GnssMeasurement.cpp
@@ -49,8 +49,8 @@
 
 Return<void> GnssMeasurement::close() {
     ALOGD("close");
-    std::unique_lock<std::mutex> lock(mMutex);
     stop();
+    std::unique_lock<std::mutex> lock(mMutex);
     sCallback = nullptr;
     return Void();
 }

gnss/2.0/default/GnssMeasurement.h

diff --git a/gnss/2.0/default/GnssMeasurement.h b/gnss/2.0/default/GnssMeasurement.h
index d8ffd59..73eaa13 100644
--- a/gnss/2.0/default/GnssMeasurement.h
+++ b/gnss/2.0/default/GnssMeasurement.h
@@ -61,10 +61,14 @@
     void stop();
     void reportMeasurement(const GnssData&);
 
+    // Guarded by mMutex
     static sp<IGnssMeasurementCallback> sCallback;
+
     std::atomic<long> mMinIntervalMillis;
     std::atomic<bool> mIsActive;
     std::thread mThread;
+
+    // Synchronization lock for sCallback
     mutable std::mutex mMutex;
 };