commit 95019ac8d7b5217aa4b606fa5fe775f192c6baeb
author Prabir Pradhan <prabirmsp@google.com> Wed Dec 06 22:38:21 2023 +0000
committer Prabir Pradhan <prabirmsp@google.com> Thu Dec 07 16:28:31 2023 +0000
tree 1875b3a15c209550d1f961502083e38a5558ebe7
parent e209cdde92e60b36652fb078749500f8379c4e6b

Introduce thread safety to InputDeviceMetricsCollector

There are several threads that interact with the metrics collector, such
as the Reader thread, Dispatcher thread, and binder threads for
dumping.

However, thread safety was never added to it, since it started off only
running on the Reader thread. There is a high likelihood that this is
the root cause of crashes that we see when dumping the metrics
collector.

Add a lock to the metrics collector to guard its state.

Bug: 315193876
Test: atest inputflinger_tests
Change-Id: I6a53014fbc533cf15516e8b079ee5b715b4aa58f

services/inputflinger/InputDeviceMetricsCollector.cpp

diff --git a/services/inputflinger/InputDeviceMetricsCollector.cpp b/services/inputflinger/InputDeviceMetricsCollector.cpp
index cefb140..b5cb3cb 100644
--- a/services/inputflinger/InputDeviceMetricsCollector.cpp
+++ b/services/inputflinger/InputDeviceMetricsCollector.cpp
@@ -125,58 +125,84 @@
 
 void InputDeviceMetricsCollector::notifyInputDevicesChanged(
         const NotifyInputDevicesChangedArgs& args) {
-    reportCompletedSessions();
-    onInputDevicesChanged(args.inputDeviceInfos);
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+        onInputDevicesChanged(args.inputDeviceInfos);
+    }
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifyConfigurationChanged(
         const NotifyConfigurationChangedArgs& args) {
-    reportCompletedSessions();
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+    }
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifyKey(const NotifyKeyArgs& args) {
-    reportCompletedSessions();
-    const SourceProvider getSources = [&args](const MetricsDeviceInfo& info) {
-        return std::set{getUsageSourceForKeyArgs(info.keyboardType, args)};
-    };
-    onInputDeviceUsage(DeviceId{args.deviceId}, nanoseconds(args.eventTime), getSources);
-
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+        const SourceProvider getSources = [&args](const MetricsDeviceInfo& info) {
+            return std::set{getUsageSourceForKeyArgs(info.keyboardType, args)};
+        };
+        onInputDeviceUsage(DeviceId{args.deviceId}, nanoseconds(args.eventTime), getSources);
+    }
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifyMotion(const NotifyMotionArgs& args) {
-    reportCompletedSessions();
-    onInputDeviceUsage(DeviceId{args.deviceId}, nanoseconds(args.eventTime),
-                       [&args](const auto&) { return getUsageSourcesForMotionArgs(args); });
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+        onInputDeviceUsage(DeviceId{args.deviceId}, nanoseconds(args.eventTime),
+                           [&args](const auto&) { return getUsageSourcesForMotionArgs(args); });
+    }
 
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifySwitch(const NotifySwitchArgs& args) {
-    reportCompletedSessions();
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+    }
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifySensor(const NotifySensorArgs& args) {
-    reportCompletedSessions();
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+    }
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifyVibratorState(const NotifyVibratorStateArgs& args) {
-    reportCompletedSessions();
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+    }
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifyDeviceReset(const NotifyDeviceResetArgs& args) {
-    reportCompletedSessions();
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+    }
     mNextListener.notify(args);
 }
 
 void InputDeviceMetricsCollector::notifyPointerCaptureChanged(
         const NotifyPointerCaptureChangedArgs& args) {
-    reportCompletedSessions();
+    {
+        std::scoped_lock lock(mLock);
+        reportCompletedSessions();
+    }
     mNextListener.notify(args);
 }
 
@@ -185,10 +211,12 @@
     if (isIgnoredInputDeviceId(deviceId)) {
         return;
     }
+    std::scoped_lock lock(mLock);
     mInteractionsQueue.push(DeviceId{deviceId}, timestamp, uids);
 }
 
 void InputDeviceMetricsCollector::dump(std::string& dump) {
+    std::scoped_lock lock(mLock);
     dump += "InputDeviceMetricsCollector:\n";
 
     dump += "  Logged device IDs: " + dumpMapKeys(mLoggedDeviceInfos, &toString) + "\n";
@@ -196,6 +224,10 @@
             dumpMapKeys(mActiveUsageSessions, &toString) + "\n";
 }
 
+void InputDeviceMetricsCollector::monitor() {
+    std::scoped_lock lock(mLock);
+}
+
 void InputDeviceMetricsCollector::onInputDevicesChanged(const std::vector<InputDeviceInfo>& infos) {
     std::map<DeviceId, MetricsDeviceInfo> newDeviceInfos;