commit 2404754226d6c168ed0e0723b1509ed8c173ed0c
author Prabir Pradhan <prabirmsp@google.com> Thu Nov 02 17:14:59 2023 +0000
committer Prabir Pradhan <prabirmsp@google.com> Thu Nov 16 18:39:45 2023 +0000
tree fabaa596d69cbe8f40bfad2886aae8e80aae5434
parent a0a24d7ca7460d9088a5fafd4706469be3884f01

Make EventEntry const throughout the Dispatcher pipieline

This will help ensure that parts of the event do not change throughout
the dispatching pipieline after they are traced, and that the parts that
do change during dispatch are explicitly tracked.

Bug: 210460522
Test: atest inputflinger_tests
Change-Id: I2738d1a37da7ce72525d59c65f910a6fec09f862

services/inputflinger/dispatcher/Entry.h

diff --git a/services/inputflinger/dispatcher/Entry.h b/services/inputflinger/dispatcher/Entry.h
index d44a211..04e7767 100644
--- a/services/inputflinger/dispatcher/Entry.h
+++ b/services/inputflinger/dispatcher/Entry.h
@@ -50,7 +50,7 @@
     uint32_t policyFlags;
     std::shared_ptr<InjectionState> injectionState;
 
-    bool dispatchInProgress; // initially false, set to true while dispatching
+    mutable bool dispatchInProgress; // initially false, set to true while dispatching
 
     /**
      * Injected keys are events from an external (probably untrusted) application
@@ -72,6 +72,8 @@
     virtual std::string getDescription() const = 0;
 
     EventEntry(int32_t id, Type type, nsecs_t eventTime, uint32_t policyFlags);
+    EventEntry(const EventEntry&) = delete;
+    EventEntry& operator=(const EventEntry&) = delete;
     virtual ~EventEntry() = default;
 };
 
@@ -119,11 +121,9 @@
     uint32_t source;
     int32_t displayId;
     int32_t action;
-    int32_t flags;
     int32_t keyCode;
     int32_t scanCode;
     int32_t metaState;
-    int32_t repeatCount;
     nsecs_t downTime;
 
     bool syntheticRepeat; // set to true for synthetic key repeats
@@ -134,8 +134,11 @@
         CONTINUE,
         TRY_AGAIN_LATER,
     };
-    InterceptKeyResult interceptKeyResult; // set based on the interception result
-    nsecs_t interceptKeyWakeupTime;        // used with INTERCEPT_KEY_RESULT_TRY_AGAIN_LATER
+    // These are special fields that may need to be modified while the event is being dispatched.
+    mutable InterceptKeyResult interceptKeyResult; // set based on the interception result
+    mutable nsecs_t interceptKeyWakeupTime;        // used with INTERCEPT_KEY_RESULT_TRY_AGAIN_LATER
+    mutable int32_t flags;
+    mutable int32_t repeatCount;
 
     KeyEntry(int32_t id, std::shared_ptr<InjectionState> injectionState, nsecs_t eventTime,
              int32_t deviceId, uint32_t source, int32_t displayId, uint32_t policyFlags,
@@ -206,7 +209,7 @@
 struct DispatchEntry {
     const uint32_t seq; // unique sequence number, never 0
 
-    std::shared_ptr<EventEntry> eventEntry; // the event to dispatch
+    std::shared_ptr<const EventEntry> eventEntry; // the event to dispatch
     const ftl::Flags<InputTarget::Flags> targetFlags;
     ui::Transform transform;
     ui::Transform rawTransform;
@@ -222,7 +225,7 @@
     int32_t resolvedAction;
     int32_t resolvedFlags;
 
-    DispatchEntry(std::shared_ptr<EventEntry> eventEntry,
+    DispatchEntry(std::shared_ptr<const EventEntry> eventEntry,
                   ftl::Flags<InputTarget::Flags> targetFlags, const ui::Transform& transform,
                   const ui::Transform& rawTransform, float globalScaleFactor);
     DispatchEntry(const DispatchEntry&) = delete;