Native input dispatch rewrite work in progress.
The old dispatch mechanism has been left in place and continues to
be used by default for now. To enable native input dispatch,
edit the ENABLE_NATIVE_DISPATCH constant in WindowManagerPolicy.
Includes part of the new input event NDK API. Some details TBD.
To wire up input dispatch, as the ViewRoot adds a window to the
window session it receives an InputChannel object as an output
argument. The InputChannel encapsulates the file descriptors for a
shared memory region and two pipe end-points. The ViewRoot then
provides the InputChannel to the InputQueue. Behind the
scenes, InputQueue simply attaches handlers to the native PollLoop object
that underlies the MessageQueue. This way MessageQueue doesn't need
to know anything about input dispatch per-se, it just exposes (in native
code) a PollLoop that other components can use to monitor file descriptor
state changes.
There can be zero or more targets for any given input event. Each
input target is specified by its input channel and some parameters
including flags, an X/Y coordinate offset, and the dispatch timeout.
An input target can request either synchronous dispatch (for foreground apps)
or asynchronous dispatch (fire-and-forget for wallpapers and "outside"
targets). Currently, finding the appropriate input targets for an event
requires a call back into the WindowManagerServer from native code.
In the future this will be refactored to avoid most of these callbacks
except as required to handle pending focus transitions.
End-to-end event dispatch mostly works!
To do: event injection, rate limiting, ANRs, testing, optimization, etc.
Change-Id: I8c36b2b9e0a2d27392040ecda0f51b636456de25
diff --git a/include/ui/InputDispatcher.h b/include/ui/InputDispatcher.h
new file mode 100644
index 0000000..bde07f2
--- /dev/null
+++ b/include/ui/InputDispatcher.h
@@ -0,0 +1,409 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _UI_INPUT_DISPATCHER_H
+#define _UI_INPUT_DISPATCHER_H
+
+#include <ui/Input.h>
+#include <ui/InputDispatchPolicy.h>
+#include <ui/InputTransport.h>
+#include <utils/KeyedVector.h>
+#include <utils/Vector.h>
+#include <utils/threads.h>
+#include <utils/Timers.h>
+#include <utils/RefBase.h>
+#include <utils/String8.h>
+#include <utils/PollLoop.h>
+#include <utils/Pool.h>
+
+#include <stddef.h>
+#include <unistd.h>
+
+
+namespace android {
+
+/* Notifies the system about input events generated by the input reader.
+ * The dispatcher is expected to be mostly asynchronous. */
+class InputDispatcherInterface : public virtual RefBase {
+protected:
+ InputDispatcherInterface() { }
+ virtual ~InputDispatcherInterface() { }
+
+public:
+ /* Runs a single iteration of the dispatch loop.
+ * Nominally processes one queued event, a timeout, or a response from an input consumer.
+ *
+ * This method should only be called on the input dispatcher thread.
+ */
+ virtual void dispatchOnce() = 0;
+
+ /* Notifies the dispatcher about new events.
+ * The dispatcher will process most of these events asynchronously although some
+ * policy processing may occur synchronously.
+ *
+ * These methods should only be called on the input reader thread.
+ */
+ virtual void notifyConfigurationChanged(nsecs_t eventTime,
+ int32_t touchScreenConfig, int32_t keyboardConfig, int32_t navigationConfig) = 0;
+ virtual void notifyLidSwitchChanged(nsecs_t eventTime, bool lidOpen) = 0;
+ virtual void notifyAppSwitchComing(nsecs_t eventTime) = 0;
+ virtual void notifyKey(nsecs_t eventTime, int32_t deviceId, int32_t nature,
+ uint32_t policyFlags, int32_t action, int32_t flags, int32_t keyCode,
+ int32_t scanCode, int32_t metaState, nsecs_t downTime) = 0;
+ virtual void notifyMotion(nsecs_t eventTime, int32_t deviceId, int32_t nature,
+ uint32_t policyFlags, int32_t action, int32_t metaState, int32_t edgeFlags,
+ uint32_t pointerCount, const int32_t* pointerIds, const PointerCoords* pointerCoords,
+ float xPrecision, float yPrecision, nsecs_t downTime) = 0;
+
+ /* Registers or unregister input channels that may be used as targets for input events.
+ *
+ * These methods may be called on any thread (usually by the input manager).
+ */
+ virtual status_t registerInputChannel(const sp<InputChannel>& inputChannel) = 0;
+ virtual status_t unregisterInputChannel(const sp<InputChannel>& inputChannel) = 0;
+};
+
+/* Dispatches events. */
+class InputDispatcher : public InputDispatcherInterface {
+protected:
+ virtual ~InputDispatcher();
+
+public:
+ explicit InputDispatcher(const sp<InputDispatchPolicyInterface>& policy);
+
+ virtual void dispatchOnce();
+
+ virtual void notifyConfigurationChanged(nsecs_t eventTime,
+ int32_t touchScreenConfig, int32_t keyboardConfig, int32_t navigationConfig);
+ virtual void notifyLidSwitchChanged(nsecs_t eventTime, bool lidOpen);
+ virtual void notifyAppSwitchComing(nsecs_t eventTime);
+ virtual void notifyKey(nsecs_t eventTime, int32_t deviceId, int32_t nature,
+ uint32_t policyFlags, int32_t action, int32_t flags, int32_t keyCode,
+ int32_t scanCode, int32_t metaState, nsecs_t downTime);
+ virtual void notifyMotion(nsecs_t eventTime, int32_t deviceId, int32_t nature,
+ uint32_t policyFlags, int32_t action, int32_t metaState, int32_t edgeFlags,
+ uint32_t pointerCount, const int32_t* pointerIds, const PointerCoords* pointerCoords,
+ float xPrecision, float yPrecision, nsecs_t downTime);
+
+ virtual status_t registerInputChannel(const sp<InputChannel>& inputChannel);
+ virtual status_t unregisterInputChannel(const sp<InputChannel>& inputChannel);
+
+private:
+ template <typename T>
+ struct Link {
+ T* next;
+ T* prev;
+ };
+
+ struct EventEntry : Link<EventEntry> {
+ enum {
+ TYPE_SENTINEL,
+ TYPE_CONFIGURATION_CHANGED,
+ TYPE_KEY,
+ TYPE_MOTION
+ };
+
+ int32_t refCount;
+ int32_t type;
+ nsecs_t eventTime;
+ };
+
+ struct ConfigurationChangedEntry : EventEntry {
+ int32_t touchScreenConfig;
+ int32_t keyboardConfig;
+ int32_t navigationConfig;
+ };
+
+ struct KeyEntry : EventEntry {
+ int32_t deviceId;
+ int32_t nature;
+ uint32_t policyFlags;
+ int32_t action;
+ int32_t flags;
+ int32_t keyCode;
+ int32_t scanCode;
+ int32_t metaState;
+ int32_t repeatCount;
+ nsecs_t downTime;
+ };
+
+ struct MotionSample {
+ MotionSample* next;
+
+ nsecs_t eventTime;
+ PointerCoords pointerCoords[MAX_POINTERS];
+ };
+
+ struct MotionEntry : EventEntry {
+ int32_t deviceId;
+ int32_t nature;
+ uint32_t policyFlags;
+ int32_t action;
+ int32_t metaState;
+ int32_t edgeFlags;
+ float xPrecision;
+ float yPrecision;
+ nsecs_t downTime;
+ uint32_t pointerCount;
+ int32_t pointerIds[MAX_POINTERS];
+
+ // Linked list of motion samples associated with this motion event.
+ MotionSample firstSample;
+ MotionSample* lastSample;
+ };
+
+ struct DispatchEntry : Link<DispatchEntry> {
+ EventEntry* eventEntry; // the event to dispatch
+ int32_t targetFlags;
+ float xOffset;
+ float yOffset;
+ nsecs_t timeout;
+
+ // True if dispatch has started.
+ bool inProgress;
+
+ // For motion events:
+ // Pointer to the first motion sample to dispatch in this cycle.
+ // Usually NULL to indicate that the list of motion samples begins at
+ // MotionEntry::firstSample. Otherwise, some samples were dispatched in a previous
+ // cycle and this pointer indicates the location of the first remainining sample
+ // to dispatch during the current cycle.
+ MotionSample* headMotionSample;
+ // Pointer to a motion sample to dispatch in the next cycle if the dispatcher was
+ // unable to send all motion samples during this cycle. On the next cycle,
+ // headMotionSample will be initialized to tailMotionSample and tailMotionSample
+ // will be set to NULL.
+ MotionSample* tailMotionSample;
+ };
+
+ template <typename T>
+ struct Queue {
+ T head;
+ T tail;
+
+ inline Queue() {
+ head.prev = NULL;
+ head.next = & tail;
+ tail.prev = & head;
+ tail.next = NULL;
+ }
+
+ inline bool isEmpty() {
+ return head.next == & tail;
+ }
+
+ inline void enqueueAtTail(T* entry) {
+ T* last = tail.prev;
+ last->next = entry;
+ entry->prev = last;
+ entry->next = & tail;
+ tail.prev = entry;
+ }
+
+ inline void enqueueAtHead(T* entry) {
+ T* first = head.next;
+ head.next = entry;
+ entry->prev = & head;
+ entry->next = first;
+ first->prev = entry;
+ }
+
+ inline void dequeue(T* entry) {
+ entry->prev->next = entry->next;
+ entry->next->prev = entry->prev;
+ }
+
+ inline T* dequeueAtHead() {
+ T* first = head.next;
+ dequeue(first);
+ return first;
+ }
+ };
+
+ /* Allocates queue entries and performs reference counting as needed. */
+ class Allocator {
+ public:
+ Allocator();
+
+ ConfigurationChangedEntry* obtainConfigurationChangedEntry();
+ KeyEntry* obtainKeyEntry();
+ MotionEntry* obtainMotionEntry();
+ DispatchEntry* obtainDispatchEntry(EventEntry* eventEntry);
+
+ void releaseEventEntry(EventEntry* entry);
+ void releaseConfigurationChangedEntry(ConfigurationChangedEntry* entry);
+ void releaseKeyEntry(KeyEntry* entry);
+ void releaseMotionEntry(MotionEntry* entry);
+ void releaseDispatchEntry(DispatchEntry* entry);
+
+ void appendMotionSample(MotionEntry* motionEntry,
+ nsecs_t eventTime, int32_t pointerCount, const PointerCoords* pointerCoords);
+ void freeMotionSample(MotionSample* sample);
+ void freeMotionSampleList(MotionSample* head);
+
+ private:
+ Pool<ConfigurationChangedEntry> mConfigurationChangeEntryPool;
+ Pool<KeyEntry> mKeyEntryPool;
+ Pool<MotionEntry> mMotionEntryPool;
+ Pool<MotionSample> mMotionSamplePool;
+ Pool<DispatchEntry> mDispatchEntryPool;
+ };
+
+ /* Manages the dispatch state associated with a single input channel. */
+ class Connection : public RefBase {
+ protected:
+ virtual ~Connection();
+
+ public:
+ enum Status {
+ // Everything is peachy.
+ STATUS_NORMAL,
+ // An unrecoverable communication error has occurred.
+ STATUS_BROKEN,
+ // The client is not responding.
+ STATUS_NOT_RESPONDING,
+ // The input channel has been unregistered.
+ STATUS_ZOMBIE
+ };
+
+ Status status;
+ sp<InputChannel> inputChannel;
+ InputPublisher inputPublisher;
+ Queue<DispatchEntry> outboundQueue;
+ nsecs_t nextTimeoutTime; // next timeout time (LONG_LONG_MAX if none)
+
+ nsecs_t lastEventTime; // the time when the event was originally captured
+ nsecs_t lastDispatchTime; // the time when the last event was dispatched
+ nsecs_t lastANRTime; // the time when the last ANR was recorded
+
+ explicit Connection(const sp<InputChannel>& inputChannel);
+
+ inline const char* getInputChannelName() { return inputChannel->getName().string(); }
+
+ // Finds a DispatchEntry in the outbound queue associated with the specified event.
+ // Returns NULL if not found.
+ DispatchEntry* findQueuedDispatchEntryForEvent(const EventEntry* eventEntry) const;
+
+ // Determine whether this connection has a pending synchronous dispatch target.
+ // Since there can only ever be at most one such target at a time, if there is one,
+ // it must be at the tail because nothing else can be enqueued after it.
+ inline bool hasPendingSyncTarget() {
+ return ! outboundQueue.isEmpty()
+ && (outboundQueue.tail.prev->targetFlags & InputTarget::FLAG_SYNC);
+ }
+
+ // Gets the time since the current event was originally obtained from the input driver.
+ inline double getEventLatencyMillis(nsecs_t currentTime) {
+ return (currentTime - lastEventTime) / 1000000.0;
+ }
+
+ // Gets the time since the current event entered the outbound dispatch queue.
+ inline double getDispatchLatencyMillis(nsecs_t currentTime) {
+ return (currentTime - lastDispatchTime) / 1000000.0;
+ }
+
+ // Gets the time since the current event ANR was declared, if applicable.
+ inline double getANRLatencyMillis(nsecs_t currentTime) {
+ return (currentTime - lastANRTime) / 1000000.0;
+ }
+
+ status_t initialize();
+ };
+
+ sp<InputDispatchPolicyInterface> mPolicy;
+
+ Mutex mLock;
+
+ Queue<EventEntry> mInboundQueue;
+ Allocator mAllocator;
+
+ sp<PollLoop> mPollLoop;
+
+ // All registered connections mapped by receive pipe file descriptor.
+ KeyedVector<int, sp<Connection> > mConnectionsByReceiveFd;
+
+ // Active connections are connections that have a non-empty outbound queue.
+ Vector<Connection*> mActiveConnections;
+
+ // Pool of key and motion event objects used only to ask the input dispatch policy
+ // for the targets of an event that is to be dispatched.
+ KeyEvent mReusableKeyEvent;
+ MotionEvent mReusableMotionEvent;
+
+ // The input targets that were most recently identified for dispatch.
+ // If there is a synchronous event dispatch in progress, the current input targets will
+ // remain unchanged until the dispatch has completed or been aborted.
+ Vector<InputTarget> mCurrentInputTargets;
+
+ // Key repeat tracking.
+ // XXX Move this up to the input reader instead.
+ struct KeyRepeatState {
+ KeyEntry* lastKeyEntry; // or null if no repeat
+ nsecs_t nextRepeatTime;
+ } mKeyRepeatState;
+
+ void resetKeyRepeatLocked();
+
+ // Process events that have just been dequeued from the head of the input queue.
+ void processConfigurationChangedLocked(nsecs_t currentTime, ConfigurationChangedEntry* entry);
+ void processKeyLocked(nsecs_t currentTime, KeyEntry* entry);
+ void processKeyRepeatLocked(nsecs_t currentTime);
+ void processMotionLocked(nsecs_t currentTime, MotionEntry* entry);
+
+ // Identify input targets for an event and dispatch to them.
+ void identifyInputTargetsAndDispatchKeyLocked(nsecs_t currentTime, KeyEntry* entry);
+ void identifyInputTargetsAndDispatchMotionLocked(nsecs_t currentTime, MotionEntry* entry);
+ void dispatchEventToCurrentInputTargetsLocked(nsecs_t currentTime, EventEntry* entry,
+ bool resumeWithAppendedMotionSample);
+
+ // Manage the dispatch cycle for a single connection.
+ void prepareDispatchCycleLocked(nsecs_t currentTime, Connection* connection,
+ EventEntry* eventEntry, const InputTarget* inputTarget,
+ bool resumeWithAppendedMotionSample);
+ void startDispatchCycleLocked(nsecs_t currentTime, Connection* connection);
+ void finishDispatchCycleLocked(nsecs_t currentTime, Connection* connection);
+ bool timeoutDispatchCycleLocked(nsecs_t currentTime, Connection* connection);
+ bool abortDispatchCycleLocked(nsecs_t currentTime, Connection* connection,
+ bool broken);
+ static bool handleReceiveCallback(int receiveFd, int events, void* data);
+
+ // Add or remove a connection to the mActiveConnections vector.
+ void activateConnectionLocked(Connection* connection);
+ void deactivateConnectionLocked(Connection* connection);
+
+ // Interesting events that we might like to log or tell the framework about.
+ void onDispatchCycleStartedLocked(nsecs_t currentTime, Connection* connection);
+ void onDispatchCycleFinishedLocked(nsecs_t currentTime, Connection* connection,
+ bool recoveredFromANR);
+ void onDispatchCycleANRLocked(nsecs_t currentTime, Connection* connection);
+ void onDispatchCycleBrokenLocked(nsecs_t currentTime, Connection* connection);
+};
+
+/* Enqueues and dispatches input events, endlessly. */
+class InputDispatcherThread : public Thread {
+public:
+ explicit InputDispatcherThread(const sp<InputDispatcherInterface>& dispatcher);
+ ~InputDispatcherThread();
+
+private:
+ virtual bool threadLoop();
+
+ sp<InputDispatcherInterface> mDispatcher;
+};
+
+} // namespace android
+
+#endif // _UI_INPUT_DISPATCHER_PRIV_H