Add lock to protect UnwantedInteractionBlocker

The call to 'dump' may come from any thread, and therefore could cause a
crash. Add a lock to protect this input stage.

To run the test:
adb shell -t "/data/nativetest64/inputflinger_tests/inputflinger_tests --gtest_filter='*Dump*' --gtest_repeat=100000 --gtest_break_on_failure"

Before this patch, the test failed after ~5K - ~13K iterations (took
10-20 seconds to crash).

Bug: 232645962
Test: m inputflinger_tests && adb sync data && <run the test>
Change-Id: I2a199690450bc5bb4a8576aa59075e99d37a531b

1 files changed, 10 insertions, 3 deletions

diff --git a/services/inputflinger/InputManager.cpp b/services/inputflinger/InputManager.cpp
index 7b03631e1f..9767cd9b71 100644
--- a/services/inputflinger/InputManager.cpp
+++ b/services/inputflinger/InputManager.cpp
@@ -62,8 +62,8 @@ InputManager::InputManager(
         const sp<InputDispatcherPolicyInterface>& dispatcherPolicy) {
     mDispatcher = createInputDispatcher(dispatcherPolicy);
     mClassifier = std::make_unique<InputClassifier>(*mDispatcher);
-    mUnwantedInteractionBlocker = std::make_unique<UnwantedInteractionBlocker>(*mClassifier);
-    mReader = createInputReader(readerPolicy, *mUnwantedInteractionBlocker);
+    mBlocker = std::make_unique<UnwantedInteractionBlocker>(*mClassifier);
+    mReader = createInputReader(readerPolicy, *mBlocker);
 }
 
 InputManager::~InputManager() {
@@ -111,7 +111,7 @@ InputReaderInterface& InputManager::getReader() {
 }
 
 UnwantedInteractionBlockerInterface& InputManager::getUnwantedInteractionBlocker() {
-    return *mUnwantedInteractionBlocker;
+    return *mBlocker;
 }
 
 InputClassifierInterface& InputManager::getClassifier() {
@@ -122,6 +122,13 @@ InputDispatcherInterface& InputManager::getDispatcher() {
     return *mDispatcher;
 }
 
+void InputManager::monitor() {
+    mReader->monitor();
+    mBlocker->monitor();
+    mClassifier->monitor();
+    mDispatcher->monitor();
+}
+
 // Used by tests only.
 binder::Status InputManager::createInputChannel(const std::string& name, InputChannel* outChannel) {
     IPCThreadState* ipc = IPCThreadState::self();