Thread-safety at log processor level.

Test: statsd unit test passed.

Change-Id: Ibe8c8d3cc8297875b16ee385c077b71c87353147
diff --git a/cmds/statsd/src/StatsLogProcessor.cpp b/cmds/statsd/src/StatsLogProcessor.cpp
index 991badc..a9e0f23 100644
--- a/cmds/statsd/src/StatsLogProcessor.cpp
+++ b/cmds/statsd/src/StatsLogProcessor.cpp
@@ -82,9 +82,7 @@
 void StatsLogProcessor::onAnomalyAlarmFired(
         const uint64_t timestampNs,
         unordered_set<sp<const AnomalyAlarm>, SpHash<AnomalyAlarm>> anomalySet) {
-    // TODO: This is a thread-safety issue. mMetricsManagers could change under our feet.
-    // TODO: Solution? Lock everything! :(
-    // TODO: Question: Can we replace the other lock (broadcast), or do we need to supplement it?
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     for (const auto& itr : mMetricsManagers) {
         itr.second->onAnomalyAlarmFired(timestampNs, anomalySet);
     }
@@ -92,11 +90,13 @@
 
 // TODO: what if statsd service restarts? How do we know what logs are already processed before?
 void StatsLogProcessor::OnLogEvent(const LogEvent& msg) {
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
+
     StatsdStats::getInstance().noteAtomLogged(msg.GetTagId(), msg.GetTimestampNs() / NS_PER_SEC);
     // pass the event to metrics managers.
     for (auto& pair : mMetricsManagers) {
         pair.second->onLogEvent(msg);
-        flushIfNecessary(msg.GetTimestampNs(), pair.first, *(pair.second));
+        flushIfNecessaryLocked(msg.GetTimestampNs(), pair.first, *(pair.second));
     }
     // Hard-coded logic to update the isolated uid's in the uid-map.
     // The field numbers need to be currently updated by hand with atoms.proto
@@ -116,6 +116,7 @@
 }
 
 void StatsLogProcessor::OnConfigUpdated(const ConfigKey& key, const StatsdConfig& config) {
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     ALOGD("Updated configuration for key %s", key.ToString().c_str());
     sp<MetricsManager> newMetricsManager = new MetricsManager(key, config, mTimeBaseSec, mUidMap);
     auto it = mMetricsManagers.find(key);
@@ -142,6 +143,7 @@
 }
 
 size_t StatsLogProcessor::GetMetricsSize(const ConfigKey& key) const {
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     auto it = mMetricsManagers.find(key);
     if (it == mMetricsManagers.end()) {
         ALOGW("Config source %s does not exist", key.ToString().c_str());
@@ -152,6 +154,7 @@
 
 void StatsLogProcessor::onDumpReport(const ConfigKey& key, const uint64_t& dumpTimeStampNs,
                                      ConfigMetricsReportList* report) {
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     auto it = mMetricsManagers.find(key);
     if (it == mMetricsManagers.end()) {
         ALOGW("Config source %s does not exist", key.ToString().c_str());
@@ -165,6 +168,7 @@
 }
 
 void StatsLogProcessor::onDumpReport(const ConfigKey& key, vector<uint8_t>* outData) {
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     auto it = mMetricsManagers.find(key);
     if (it == mMetricsManagers.end()) {
         ALOGW("Config source %s does not exist", key.ToString().c_str());
@@ -173,9 +177,7 @@
 
     // This allows another broadcast to be sent within the rate-limit period if we get close to
     // filling the buffer again soon.
-    mBroadcastTimesMutex.lock();
     mLastBroadcastTimes.erase(key);
-    mBroadcastTimesMutex.unlock();
 
     ProtoOutputStream proto;
 
@@ -224,6 +226,7 @@
 }
 
 void StatsLogProcessor::OnConfigRemoved(const ConfigKey& key) {
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     auto it = mMetricsManagers.find(key);
     if (it != mMetricsManagers.end()) {
         mMetricsManagers.erase(it);
@@ -231,14 +234,11 @@
     }
     StatsdStats::getInstance().noteConfigRemoved(key);
 
-    std::lock_guard<std::mutex> lock(mBroadcastTimesMutex);
     mLastBroadcastTimes.erase(key);
 }
 
-void StatsLogProcessor::flushIfNecessary(uint64_t timestampNs, const ConfigKey& key,
-                                         MetricsManager& metricsManager) {
-    std::lock_guard<std::mutex> lock(mBroadcastTimesMutex);
-
+void StatsLogProcessor::flushIfNecessaryLocked(
+    uint64_t timestampNs, const ConfigKey& key, MetricsManager& metricsManager) {
     auto lastCheckTime = mLastByteSizeTimes.find(key);
     if (lastCheckTime != mLastByteSizeTimes.end()) {
         if (timestampNs - lastCheckTime->second < StatsdStats::kMinByteSizeCheckPeriodNs) {
@@ -274,6 +274,7 @@
 
 void StatsLogProcessor::WriteDataToDisk() {
     mkdir(STATS_DATA_DIR, S_IRWXU);
+    std::lock_guard<std::mutex> lock(mMetricsMutex);
     for (auto& pair : mMetricsManagers) {
         const ConfigKey& key = pair.first;
         vector<uint8_t> data;