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/*
* 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 {
/*
* Constants used to report the outcome of input event injection.
*/
enum {
/* (INTERNAL USE ONLY) Specifies that injection is pending and its outcome is unknown. */
INPUT_EVENT_INJECTION_PENDING = -1,
/* Injection succeeded. */
INPUT_EVENT_INJECTION_SUCCEEDED = 0,
/* Injection failed because the injector did not have permission to inject
* into the application with input focus. */
INPUT_EVENT_INJECTION_PERMISSION_DENIED = 1,
/* Injection failed because there were no available input targets. */
INPUT_EVENT_INJECTION_FAILED = 2,
/* Injection failed due to a timeout. */
INPUT_EVENT_INJECTION_TIMED_OUT = 3
};
/*
* Constants used to determine the input event injection synchronization mode.
*/
enum {
/* Injection is asynchronous and is assumed always to be successful. */
INPUT_EVENT_INJECTION_SYNC_NONE = 0,
/* Waits for previous events to be dispatched so that the input dispatcher can determine
* whether input event injection willbe permitted based on the current input focus.
* Does not wait for the input event to finish processing. */
INPUT_EVENT_INJECTION_SYNC_WAIT_FOR_RESULT = 1,
/* Waits for the input event to be completely processed. */
INPUT_EVENT_INJECTION_SYNC_WAIT_FOR_FINISHED = 2,
};
/*
* 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.
* Returns true and a new timeout value if the dispatcher should keep waiting.
* Otherwise returns false. */
virtual bool notifyInputChannelANR(const sp<InputChannel>& inputChannel,
nsecs_t& outNewTimeout) = 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;
/* Waits for key event input targets to become available.
* If the event is being injected, injectorPid and injectorUid should specify the
* process id and used id of the injecting application, otherwise they should both
* be -1.
* Returns one of the INPUT_EVENT_INJECTION_XXX constants. */
virtual int32_t waitForKeyEventTargets(KeyEvent* keyEvent, uint32_t policyFlags,
int32_t injectorPid, int32_t injectorUid,
Vector<InputTarget>& outTargets) = 0;
/* Waits for motion event targets to become available.
* If the event is being injected, injectorPid and injectorUid should specify the
* process id and used id of the injecting application, otherwise they should both
* be -1.
* Returns one of the INPUT_EVENT_INJECTION_XXX constants. */
virtual int32_t waitForMotionEventTargets(MotionEvent* motionEvent, uint32_t policyFlags,
int32_t injectorPid, int32_t injectorUid,
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 source,
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 source,
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;
/* Injects an input event and optionally waits for sync.
* The synchronization mode determines whether the method blocks while waiting for
* input injection to proceed.
* Returns one of the INPUT_EVENT_INJECTION_XXX constants.
*
* This method may be called on any thread (usually by the input manager).
*/
virtual int32_t injectInputEvent(const InputEvent* event,
int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis) = 0;
/* Preempts input dispatch in progress by making pending synchronous
* dispatches asynchronous instead. This method is generally called during a focus
* transition from one application to the next so as to enable the new application
* to start receiving input as soon as possible without having to wait for the
* old application to finish up.
*
* This method may be called on any thread (usually by the input manager).
*/
virtual void preemptInputDispatch() = 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 source,
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 source,
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 int32_t injectInputEvent(const InputEvent* event,
int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis);
virtual void preemptInputDispatch();
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;
int32_t injectionResult; // initially INPUT_EVENT_INJECTION_PENDING
bool injectionIsAsync; // set to true if injection is not waiting for the result
int32_t injectorPid; // -1 if not injected
int32_t injectorUid; // -1 if not injected
bool dispatchInProgress; // initially false, set to true while dispatching
int32_t pendingSyncDispatches; // the number of synchronous dispatches in progress
inline bool isInjected() { return injectorPid >= 0; }
};
struct ConfigurationChangedEntry : EventEntry {
};
struct KeyEntry : EventEntry {
int32_t deviceId;
int32_t source;
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 source;
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;
inline bool isSyncTarget() {
return targetFlags & InputTarget::FLAG_SYNC;
}
};
// 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);
class Connection;
struct CommandEntry : Link<CommandEntry> {
CommandEntry();
~CommandEntry();
Command command;
// parameters for the command (usage varies by command)
sp<Connection> connection;
};
// 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(nsecs_t eventTime);
KeyEntry* obtainKeyEntry(nsecs_t eventTime,
int32_t deviceId, int32_t source, uint32_t policyFlags, int32_t action,
int32_t flags, int32_t keyCode, int32_t scanCode, int32_t metaState,
int32_t repeatCount, nsecs_t downTime);
MotionEntry* obtainMotionEntry(nsecs_t eventTime,
int32_t deviceId, int32_t source, uint32_t policyFlags, int32_t action,
int32_t metaState, int32_t edgeFlags, float xPrecision, float yPrecision,
nsecs_t downTime, uint32_t pointerCount,
const int32_t* pointerIds, const PointerCoords* pointerCoords);
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, const PointerCoords* pointerCoords);
private:
Pool<ConfigurationChangedEntry> mConfigurationChangeEntryPool;
Pool<KeyEntry> mKeyEntryPool;
Pool<MotionEntry> mMotionEntryPool;
Pool<MotionSample> mMotionSamplePool;
Pool<DispatchEntry> mDispatchEntryPool;
Pool<CommandEntry> mCommandEntryPool;
void initializeEventEntry(EventEntry* entry, int32_t type, nsecs_t eventTime);
};
/* 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->isSyncTarget();
}
// 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();
void setNextTimeoutTime(nsecs_t currentTime, nsecs_t timeout);
};
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.
// We don't use a ref-counted pointer here because we explicitly abort connections
// during unregistration which causes the connection's outbound queue to be cleared
// and the connection itself to be deactivated.
Vector<Connection*> mActiveConnections;
// List of connections that have timed out. Only used by dispatchOnce()
// We don't use a ref-counted pointer here because it is not possible for a connection
// to be unregistered while processing timed out connections since we hold the lock for
// the duration.
Vector<Connection*> mTimedOutConnections;
// 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
// Event injection and synchronization.
Condition mInjectionResultAvailableCondition;
EventEntry* createEntryFromInputEventLocked(const InputEvent* event);
void setInjectionResultLocked(EventEntry* entry, int32_t injectionResult);
Condition mInjectionSyncFinishedCondition;
void decrementPendingSyncDispatchesLocked(EventEntry* entry);
// 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.
// These methods are deliberately not Interruptible because doing all of the work
// with the mutex held makes it easier to ensure that connection invariants are maintained.
// If needed, the methods post commands to run later once the critical bits are done.
void prepareDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
EventEntry* eventEntry, const InputTarget* inputTarget,
bool resumeWithAppendedMotionSample);
void startDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection);
void finishDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection);
void timeoutDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection);
void resumeAfterTimeoutDispatchCycleLocked(nsecs_t currentTime,
const sp<Connection>& connection, nsecs_t newTimeout);
void abortDispatchCycleLocked(nsecs_t currentTime, const sp<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, const sp<Connection>& connection);
void onDispatchCycleFinishedLocked(
nsecs_t currentTime, const sp<Connection>& connection, bool recoveredFromANR);
void onDispatchCycleANRLocked(
nsecs_t currentTime, const sp<Connection>& connection);
void onDispatchCycleBrokenLocked(
nsecs_t currentTime, const sp<Connection>& connection);
// Outbound policy interactions.
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