Use sequence numbers to synchronize enabling Pointer Capture (1/2)
InputReader only processes configuration change from its main thread.
This means that if there is more than one Pointer Capture change
request when the thread is busy or sleeping, it will only process the
latest one. To ensure requests to enable Pointer Capture are synchronized
with Dispatcher, we must use sequence numbers.
Requests to enable Pointer Capture have a sequence number. Requests to
disable Pointer Capture do not have a value.
Bug: 195312888
Test: atest inputflinger_tests
Test: manual with GeforceNow app, see bug.
Merged-In: I6ae9c5498dc2f783b4c7211fa3665d42e29d2919
Change-Id: I6ae9c5498dc2f783b4c7211fa3665d42e29d2919
diff --git a/services/inputflinger/dispatcher/Entry.cpp b/services/inputflinger/dispatcher/Entry.cpp
index b5ed064..82b4fe4 100644
--- a/services/inputflinger/dispatcher/Entry.cpp
+++ b/services/inputflinger/dispatcher/Entry.cpp
@@ -119,15 +119,15 @@
// PointerCaptureChanged notifications always go to apps, so set the flag POLICY_FLAG_PASS_TO_USER
// for all entries.
PointerCaptureChangedEntry::PointerCaptureChangedEntry(int32_t id, nsecs_t eventTime,
- bool hasPointerCapture)
+ const PointerCaptureRequest& request)
: EventEntry(id, Type::POINTER_CAPTURE_CHANGED, eventTime, POLICY_FLAG_PASS_TO_USER),
- pointerCaptureEnabled(hasPointerCapture) {}
+ pointerCaptureRequest(request) {}
PointerCaptureChangedEntry::~PointerCaptureChangedEntry() {}
std::string PointerCaptureChangedEntry::getDescription() const {
return StringPrintf("PointerCaptureChangedEvent(pointerCaptureEnabled=%s)",
- pointerCaptureEnabled ? "true" : "false");
+ pointerCaptureRequest.enable ? "true" : "false");
}
// --- DragEntry ---
@@ -326,8 +326,7 @@
keyEntry(nullptr),
userActivityEventType(0),
seq(0),
- handled(false),
- enabled(false) {}
+ handled(false) {}
CommandEntry::~CommandEntry() {}
diff --git a/services/inputflinger/dispatcher/Entry.h b/services/inputflinger/dispatcher/Entry.h
index 1b7fcf2..ffe3bb6 100644
--- a/services/inputflinger/dispatcher/Entry.h
+++ b/services/inputflinger/dispatcher/Entry.h
@@ -104,9 +104,9 @@
};
struct PointerCaptureChangedEntry : EventEntry {
- bool pointerCaptureEnabled;
+ const PointerCaptureRequest pointerCaptureRequest;
- PointerCaptureChangedEntry(int32_t id, nsecs_t eventTime, bool hasPointerCapture);
+ PointerCaptureChangedEntry(int32_t id, nsecs_t eventTime, const PointerCaptureRequest&);
std::string getDescription() const override;
~PointerCaptureChangedEntry() override;
@@ -286,7 +286,7 @@
sp<IBinder> oldToken;
sp<IBinder> newToken;
std::string obscuringPackage;
- bool enabled;
+ PointerCaptureRequest pointerCaptureRequest;
int32_t pid;
nsecs_t consumeTime; // time when the event was consumed by InputConsumer
int32_t displayId;
diff --git a/services/inputflinger/dispatcher/InputDispatcher.cpp b/services/inputflinger/dispatcher/InputDispatcher.cpp
index c60a62f..58ecb6b 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.cpp
+++ b/services/inputflinger/dispatcher/InputDispatcher.cpp
@@ -532,7 +532,6 @@
mInTouchMode(true),
mMaximumObscuringOpacityForTouch(1.0f),
mFocusedDisplayId(ADISPLAY_ID_DEFAULT),
- mFocusedWindowRequestedPointerCapture(false),
mWindowTokenWithPointerCapture(nullptr),
mLatencyAggregator(),
mLatencyTracker(&mLatencyAggregator),
@@ -1319,36 +1318,51 @@
void InputDispatcher::dispatchPointerCaptureChangedLocked(
nsecs_t currentTime, const std::shared_ptr<PointerCaptureChangedEntry>& entry,
DropReason& dropReason) {
+ dropReason = DropReason::NOT_DROPPED;
+
const bool haveWindowWithPointerCapture = mWindowTokenWithPointerCapture != nullptr;
- if (entry->pointerCaptureEnabled && haveWindowWithPointerCapture) {
- LOG_ALWAYS_FATAL("Pointer Capture has already been enabled for the window.");
- }
- if (!entry->pointerCaptureEnabled && !haveWindowWithPointerCapture) {
- // Pointer capture was already forcefully disabled because of focus change.
- dropReason = DropReason::NOT_DROPPED;
- return;
- }
-
- // Set drop reason for early returns
- dropReason = DropReason::NO_POINTER_CAPTURE;
-
sp<IBinder> token;
- if (entry->pointerCaptureEnabled) {
- // Enable Pointer Capture
- if (!mFocusedWindowRequestedPointerCapture) {
+
+ if (entry->pointerCaptureRequest.enable) {
+ // Enable Pointer Capture.
+ if (haveWindowWithPointerCapture &&
+ (entry->pointerCaptureRequest == mCurrentPointerCaptureRequest)) {
+ LOG_ALWAYS_FATAL("This request to enable Pointer Capture has already been dispatched "
+ "to the window.");
+ }
+ if (!mCurrentPointerCaptureRequest.enable) {
// This can happen if a window requests capture and immediately releases capture.
ALOGW("No window requested Pointer Capture.");
+ dropReason = DropReason::NO_POINTER_CAPTURE;
return;
}
+ if (entry->pointerCaptureRequest.seq != mCurrentPointerCaptureRequest.seq) {
+ ALOGI("Skipping dispatch of Pointer Capture being enabled: sequence number mismatch.");
+ return;
+ }
+
token = mFocusResolver.getFocusedWindowToken(mFocusedDisplayId);
LOG_ALWAYS_FATAL_IF(!token, "Cannot find focused window for Pointer Capture.");
mWindowTokenWithPointerCapture = token;
} else {
- // Disable Pointer Capture
+ // Disable Pointer Capture.
+ // We do not check if the sequence number matches for requests to disable Pointer Capture
+ // for two reasons:
+ // 1. Pointer Capture can be disabled by a focus change, which means we can get two entries
+ // to disable capture with the same sequence number: one generated by
+ // disablePointerCaptureForcedLocked() and another as an acknowledgement of Pointer
+ // Capture being disabled in InputReader.
+ // 2. We respect any request to disable Pointer Capture generated by InputReader, since the
+ // actual Pointer Capture state that affects events being generated by input devices is
+ // in InputReader.
+ if (!haveWindowWithPointerCapture) {
+ // Pointer capture was already forcefully disabled because of focus change.
+ dropReason = DropReason::NOT_DROPPED;
+ return;
+ }
token = mWindowTokenWithPointerCapture;
mWindowTokenWithPointerCapture = nullptr;
- if (mFocusedWindowRequestedPointerCapture) {
- mFocusedWindowRequestedPointerCapture = false;
+ if (mCurrentPointerCaptureRequest.enable) {
setPointerCaptureLocked(false);
}
}
@@ -1357,8 +1371,7 @@
if (channel == nullptr) {
// Window has gone away, clean up Pointer Capture state.
mWindowTokenWithPointerCapture = nullptr;
- if (mFocusedWindowRequestedPointerCapture) {
- mFocusedWindowRequestedPointerCapture = false;
+ if (mCurrentPointerCaptureRequest.enable) {
setPointerCaptureLocked(false);
}
return;
@@ -3193,7 +3206,7 @@
static_cast<const PointerCaptureChangedEntry&>(eventEntry);
status = connection->inputPublisher
.publishCaptureEvent(dispatchEntry->seq, captureEntry.id,
- captureEntry.pointerCaptureEnabled);
+ captureEntry.pointerCaptureRequest.enable);
break;
}
@@ -3991,14 +4004,14 @@
void InputDispatcher::notifyPointerCaptureChanged(const NotifyPointerCaptureChangedArgs* args) {
#if DEBUG_INBOUND_EVENT_DETAILS
ALOGD("notifyPointerCaptureChanged - eventTime=%" PRId64 ", enabled=%s", args->eventTime,
- args->enabled ? "true" : "false");
+ args->request.enable ? "true" : "false");
#endif
bool needWake;
{ // acquire lock
std::scoped_lock _l(mLock);
auto entry = std::make_unique<PointerCaptureChangedEntry>(args->id, args->eventTime,
- args->enabled);
+ args->request);
needWake = enqueueInboundEventLocked(std::move(entry));
} // release lock
@@ -4937,8 +4950,8 @@
std::string InputDispatcher::dumpPointerCaptureStateLocked() {
std::string dump;
- dump += StringPrintf(INDENT "FocusedWindowRequestedPointerCapture: %s\n",
- toString(mFocusedWindowRequestedPointerCapture));
+ dump += StringPrintf(INDENT "Pointer Capture Requested: %s\n",
+ toString(mCurrentPointerCaptureRequest.enable));
std::string windowName = "None";
if (mWindowTokenWithPointerCapture) {
@@ -4947,7 +4960,7 @@
windowName = captureWindowHandle ? captureWindowHandle->getName().c_str()
: "token has capture without window";
}
- dump += StringPrintf(INDENT "CurrentWindowWithPointerCapture: %s\n", windowName.c_str());
+ dump += StringPrintf(INDENT "Current Window with Pointer Capture: %s\n", windowName.c_str());
return dump;
}
@@ -5416,14 +5429,13 @@
return;
}
- if (enabled == mFocusedWindowRequestedPointerCapture) {
+ if (enabled == mCurrentPointerCaptureRequest.enable) {
ALOGW("Ignoring request to %s Pointer Capture: "
"window has %s requested pointer capture.",
enabled ? "enable" : "disable", enabled ? "already" : "not");
return;
}
- mFocusedWindowRequestedPointerCapture = enabled;
setPointerCaptureLocked(enabled);
} // release lock
@@ -6182,14 +6194,13 @@
}
void InputDispatcher::disablePointerCaptureForcedLocked() {
- if (!mFocusedWindowRequestedPointerCapture && !mWindowTokenWithPointerCapture) {
+ if (!mCurrentPointerCaptureRequest.enable && !mWindowTokenWithPointerCapture) {
return;
}
ALOGD_IF(DEBUG_FOCUS, "Disabling Pointer Capture because the window lost focus.");
- if (mFocusedWindowRequestedPointerCapture) {
- mFocusedWindowRequestedPointerCapture = false;
+ if (mCurrentPointerCaptureRequest.enable) {
setPointerCaptureLocked(false);
}
@@ -6206,14 +6217,16 @@
}
auto entry = std::make_unique<PointerCaptureChangedEntry>(mIdGenerator.nextId(), now(),
- false /* hasCapture */);
+ mCurrentPointerCaptureRequest);
mInboundQueue.push_front(std::move(entry));
}
void InputDispatcher::setPointerCaptureLocked(bool enabled) {
+ mCurrentPointerCaptureRequest.enable = enabled;
+ mCurrentPointerCaptureRequest.seq++;
std::unique_ptr<CommandEntry> commandEntry = std::make_unique<CommandEntry>(
&InputDispatcher::doSetPointerCaptureLockedInterruptible);
- commandEntry->enabled = enabled;
+ commandEntry->pointerCaptureRequest = mCurrentPointerCaptureRequest;
postCommandLocked(std::move(commandEntry));
}
@@ -6221,7 +6234,7 @@
android::inputdispatcher::CommandEntry* commandEntry) {
mLock.unlock();
- mPolicy->setPointerCapture(commandEntry->enabled);
+ mPolicy->setPointerCapture(commandEntry->pointerCaptureRequest);
mLock.lock();
}
diff --git a/services/inputflinger/dispatcher/InputDispatcher.h b/services/inputflinger/dispatcher/InputDispatcher.h
index 2436e73..b92b8ea 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.h
+++ b/services/inputflinger/dispatcher/InputDispatcher.h
@@ -365,10 +365,12 @@
// Keeps track of the focused window per display and determines focus changes.
FocusResolver mFocusResolver GUARDED_BY(mLock);
- // Whether the focused window on the focused display has requested Pointer Capture.
- // The state of this variable should always be in sync with the state of Pointer Capture in the
- // policy, which is updated through setPointerCaptureLocked(enabled).
- bool mFocusedWindowRequestedPointerCapture GUARDED_BY(mLock);
+
+ // The enabled state of this request is true iff the focused window on the focused display has
+ // requested Pointer Capture. This request also contains the sequence number associated with the
+ // current request. The state of this variable should always be in sync with the state of
+ // Pointer Capture in the policy, and is only updated through setPointerCaptureLocked(request).
+ PointerCaptureRequest mCurrentPointerCaptureRequest GUARDED_BY(mLock);
// The window token that has Pointer Capture.
// This should be in sync with PointerCaptureChangedEvents dispatched to the input channel.
@@ -378,7 +380,7 @@
void disablePointerCaptureForcedLocked() REQUIRES(mLock);
// Set the Pointer Capture state in the Policy.
- void setPointerCaptureLocked(bool enabled) REQUIRES(mLock);
+ void setPointerCaptureLocked(bool enable) REQUIRES(mLock);
// Dispatcher state at time of last ANR.
std::string mLastAnrState GUARDED_BY(mLock);
diff --git a/services/inputflinger/dispatcher/include/InputDispatcherPolicyInterface.h b/services/inputflinger/dispatcher/include/InputDispatcherPolicyInterface.h
index ebfcbe1..3c1e637 100644
--- a/services/inputflinger/dispatcher/include/InputDispatcherPolicyInterface.h
+++ b/services/inputflinger/dispatcher/include/InputDispatcherPolicyInterface.h
@@ -156,7 +156,7 @@
*
* InputDispatcher is solely responsible for updating the Pointer Capture state.
*/
- virtual void setPointerCapture(bool enabled) = 0;
+ virtual void setPointerCapture(const PointerCaptureRequest&) = 0;
/* Notifies the policy that the drag window has moved over to another window */
virtual void notifyDropWindow(const sp<IBinder>& token, float x, float y) = 0;