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Diffstat (limited to 'include/ui/InputDispatcher.h')
| -rw-r--r-- | include/ui/InputDispatcher.h | 549 |
1 files changed, 549 insertions, 0 deletions
diff --git a/include/ui/InputDispatcher.h b/include/ui/InputDispatcher.h new file mode 100644 index 0000000..80a20c9 --- /dev/null +++ b/include/ui/InputDispatcher.h @@ -0,0 +1,549 @@ +/* + * 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/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 { + +/* + * An input target specifies how an input event is to be dispatched to a particular window + * including the window's input channel, control flags, a timeout, and an X / Y offset to + * be added to input event coordinates to compensate for the absolute position of the + * window area. + */ +struct InputTarget { + enum { + /* This flag indicates that subsequent event delivery should be held until the + * current event is delivered to this target or a timeout occurs. */ + FLAG_SYNC = 0x01, + + /* This flag indicates that a MotionEvent with ACTION_DOWN falls outside of the area of + * this target and so should instead be delivered as an ACTION_OUTSIDE to this target. */ + FLAG_OUTSIDE = 0x02, + + /* This flag indicates that a KeyEvent or MotionEvent is being canceled. + * In the case of a key event, it should be delivered with KeyEvent.FLAG_CANCELED set. + * In the case of a motion event, it should be delivered as MotionEvent.ACTION_CANCEL. */ + FLAG_CANCEL = 0x04 + }; + + // The input channel to be targeted. + sp<InputChannel> inputChannel; + + // Flags for the input target. + int32_t flags; + + // The timeout for event delivery to this target in nanoseconds. Or -1 if none. + nsecs_t timeout; + + // The x and y offset to add to a MotionEvent as it is delivered. + // (ignored for KeyEvents) + float xOffset, yOffset; +}; + +/* + * Input dispatcher policy interface. + * + * The input reader policy is used by the input reader to interact with the Window Manager + * and other system components. + * + * The actual implementation is partially supported by callbacks into the DVM + * via JNI. This interface is also mocked in the unit tests. + */ +class InputDispatcherPolicyInterface : public virtual RefBase { +protected: + InputDispatcherPolicyInterface() { } + virtual ~InputDispatcherPolicyInterface() { } + +public: + /* Notifies the system that a configuration change has occurred. */ + virtual void notifyConfigurationChanged(nsecs_t when) = 0; + + /* Notifies the system that an input channel is unrecoverably broken. */ + virtual void notifyInputChannelBroken(const sp<InputChannel>& inputChannel) = 0; + + /* Notifies the system that an input channel is not responding. */ + virtual void notifyInputChannelANR(const sp<InputChannel>& inputChannel) = 0; + + /* Notifies the system that an input channel recovered from ANR. */ + virtual void notifyInputChannelRecoveredFromANR(const sp<InputChannel>& inputChannel) = 0; + + /* Gets the key repeat timeout or -1 if automatic key repeating is disabled. */ + virtual nsecs_t getKeyRepeatTimeout() = 0; + + /* Gets the input targets for a key event. */ + virtual void getKeyEventTargets(KeyEvent* keyEvent, uint32_t policyFlags, + Vector<InputTarget>& outTargets) = 0; + + /* Gets the input targets for a motion event. */ + virtual void getMotionEventTargets(MotionEvent* motionEvent, uint32_t policyFlags, + Vector<InputTarget>& outTargets) = 0; +}; + + +/* 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. + * + * These methods should only be called on the input reader thread. + */ + virtual void notifyConfigurationChanged(nsecs_t eventTime) = 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 to input targets. Some functions of the input dispatcher, such as + * identifying input targets, are controlled by a separate policy object. + * + * IMPORTANT INVARIANT: + * Because the policy can potentially block or cause re-entrance into the input dispatcher, + * the input dispatcher never calls into the policy while holding its internal locks. + * The implementation is also carefully designed to recover from scenarios such as an + * input channel becoming unregistered while identifying input targets or processing timeouts. + * + * Methods marked 'Locked' must be called with the lock acquired. + * + * Methods marked 'LockedInterruptible' must be called with the lock acquired but + * may during the course of their execution release the lock, call into the policy, and + * then reacquire the lock. The caller is responsible for recovering gracefully. + * + * A 'LockedInterruptible' method may called a 'Locked' method, but NOT vice-versa. + */ +class InputDispatcher : public InputDispatcherInterface { +protected: + virtual ~InputDispatcher(); + +public: + explicit InputDispatcher(const sp<InputDispatcherPolicyInterface>& policy); + + virtual void dispatchOnce(); + + virtual void notifyConfigurationChanged(nsecs_t eventTime); + 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; + + bool dispatchInProgress; // initially false, set to true while dispatching + }; + + struct ConfigurationChangedEntry : EventEntry { + }; + + 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; + }; + + // Tracks the progress of dispatching a particular event to a particular connection. + 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; + }; + + // A command entry captures state and behavior for an action to be performed in the + // dispatch loop after the initial processing has taken place. It is essentially + // a kind of continuation used to postpone sensitive policy interactions to a point + // in the dispatch loop where it is safe to release the lock (generally after finishing + // the critical parts of the dispatch cycle). + // + // The special thing about commands is that they can voluntarily release and reacquire + // the dispatcher lock at will. Initially when the command starts running, the + // dispatcher lock is held. However, if the command needs to call into the policy to + // do some work, it can release the lock, do the work, then reacquire the lock again + // before returning. + // + // This mechanism is a bit clunky but it helps to preserve the invariant that the dispatch + // never calls into the policy while holding its lock. + // + // Commands are implicitly 'LockedInterruptible'. + struct CommandEntry; + typedef void (InputDispatcher::*Command)(CommandEntry* commandEntry); + + struct CommandEntry : Link<CommandEntry> { + CommandEntry(); + ~CommandEntry(); + + Command command; + + // parameters for the command (usage varies by command) + sp<InputChannel> inputChannel; + }; + + // Generic queue implementation. + 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); + CommandEntry* obtainCommandEntry(Command command); + + void releaseEventEntry(EventEntry* entry); + void releaseConfigurationChangedEntry(ConfigurationChangedEntry* entry); + void releaseKeyEntry(KeyEntry* entry); + void releaseMotionEntry(MotionEntry* entry); + void releaseDispatchEntry(DispatchEntry* entry); + void releaseCommandEntry(CommandEntry* entry); + + void appendMotionSample(MotionEntry* motionEntry, + nsecs_t eventTime, int32_t pointerCount, const PointerCoords* pointerCoords); + + private: + Pool<ConfigurationChangedEntry> mConfigurationChangeEntryPool; + Pool<KeyEntry> mKeyEntryPool; + Pool<MotionEntry> mMotionEntryPool; + Pool<MotionSample> mMotionSamplePool; + Pool<DispatchEntry> mDispatchEntryPool; + Pool<CommandEntry> mCommandEntryPool; + }; + + /* 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() const { return inputChannel->getName().string(); } + + const char* getStatusLabel() const; + + // 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<InputDispatcherPolicyInterface> mPolicy; + + Mutex mLock; + + Allocator mAllocator; + sp<PollLoop> mPollLoop; + + Queue<EventEntry> mInboundQueue; + Queue<CommandEntry> mCommandQueue; + + // 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; + + // Preallocated key and motion event objects used only to ask the input dispatcher 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; + bool mCurrentInputTargetsValid; // false while targets are being recomputed + + // 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(); + + // Deferred command processing. + bool runCommandsLockedInterruptible(); + CommandEntry* postCommandLocked(Command command); + + // Process events that have just been dequeued from the head of the input queue. + void processConfigurationChangedLockedInterruptible( + nsecs_t currentTime, ConfigurationChangedEntry* entry); + void processKeyLockedInterruptible( + nsecs_t currentTime, KeyEntry* entry, nsecs_t keyRepeatTimeout); + void processKeyRepeatLockedInterruptible( + nsecs_t currentTime, nsecs_t keyRepeatTimeout); + void processMotionLockedInterruptible( + nsecs_t currentTime, MotionEntry* entry); + + // Identify input targets for an event and dispatch to them. + void identifyInputTargetsAndDispatchKeyLockedInterruptible( + nsecs_t currentTime, KeyEntry* entry); + void identifyInputTargetsAndDispatchMotionLockedInterruptible( + 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); + + // Outbound policy interactions. + void doNotifyConfigurationChangedLockedInterruptible(CommandEntry* commandEntry); + + // 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); + + void doNotifyInputChannelBrokenLockedInterruptible(CommandEntry* commandEntry); + void doNotifyInputChannelANRLockedInterruptible(CommandEntry* commandEntry); + void doNotifyInputChannelRecoveredFromANRLockedInterruptible(CommandEntry* commandEntry); +}; + +/* 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 |