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/services/input/InputDispatcher.h

https://github.com/aizuzi/platform_frameworks_base
C Header | 1123 lines | 633 code | 210 blank | 280 comment | 11 complexity | aaba9d79627767f56e569b3ad7b026c1 MD5 | raw file
   1/*
   2 * Copyright (C) 2010 The Android Open Source Project
   3 *
   4 * Licensed under the Apache License, Version 2.0 (the "License");
   5 * you may not use this file except in compliance with the License.
   6 * You may obtain a copy of the License at
   7 *
   8 *      http://www.apache.org/licenses/LICENSE-2.0
   9 *
  10 * Unless required by applicable law or agreed to in writing, software
  11 * distributed under the License is distributed on an "AS IS" BASIS,
  12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 * See the License for the specific language governing permissions and
  14 * limitations under the License.
  15 */
  16
  17#ifndef _UI_INPUT_DISPATCHER_H
  18#define _UI_INPUT_DISPATCHER_H
  19
  20#include <input/Input.h>
  21#include <input/InputTransport.h>
  22#include <utils/KeyedVector.h>
  23#include <utils/Vector.h>
  24#include <utils/threads.h>
  25#include <utils/Timers.h>
  26#include <utils/RefBase.h>
  27#include <utils/String8.h>
  28#include <utils/Looper.h>
  29#include <utils/BitSet.h>
  30#include <cutils/atomic.h>
  31
  32#include <stddef.h>
  33#include <unistd.h>
  34#include <limits.h>
  35
  36#include "InputWindow.h"
  37#include "InputApplication.h"
  38#include "InputListener.h"
  39
  40
  41namespace android {
  42
  43/*
  44 * Constants used to report the outcome of input event injection.
  45 */
  46enum {
  47    /* (INTERNAL USE ONLY) Specifies that injection is pending and its outcome is unknown. */
  48    INPUT_EVENT_INJECTION_PENDING = -1,
  49
  50    /* Injection succeeded. */
  51    INPUT_EVENT_INJECTION_SUCCEEDED = 0,
  52
  53    /* Injection failed because the injector did not have permission to inject
  54     * into the application with input focus. */
  55    INPUT_EVENT_INJECTION_PERMISSION_DENIED = 1,
  56
  57    /* Injection failed because there were no available input targets. */
  58    INPUT_EVENT_INJECTION_FAILED = 2,
  59
  60    /* Injection failed due to a timeout. */
  61    INPUT_EVENT_INJECTION_TIMED_OUT = 3
  62};
  63
  64/*
  65 * Constants used to determine the input event injection synchronization mode.
  66 */
  67enum {
  68    /* Injection is asynchronous and is assumed always to be successful. */
  69    INPUT_EVENT_INJECTION_SYNC_NONE = 0,
  70
  71    /* Waits for previous events to be dispatched so that the input dispatcher can determine
  72     * whether input event injection willbe permitted based on the current input focus.
  73     * Does not wait for the input event to finish processing. */
  74    INPUT_EVENT_INJECTION_SYNC_WAIT_FOR_RESULT = 1,
  75
  76    /* Waits for the input event to be completely processed. */
  77    INPUT_EVENT_INJECTION_SYNC_WAIT_FOR_FINISHED = 2,
  78};
  79
  80
  81/*
  82 * An input target specifies how an input event is to be dispatched to a particular window
  83 * including the window's input channel, control flags, a timeout, and an X / Y offset to
  84 * be added to input event coordinates to compensate for the absolute position of the
  85 * window area.
  86 */
  87struct InputTarget {
  88    enum {
  89        /* This flag indicates that the event is being delivered to a foreground application. */
  90        FLAG_FOREGROUND = 1 << 0,
  91
  92        /* This flag indicates that the target of a MotionEvent is partly or wholly
  93         * obscured by another visible window above it.  The motion event should be
  94         * delivered with flag AMOTION_EVENT_FLAG_WINDOW_IS_OBSCURED. */
  95        FLAG_WINDOW_IS_OBSCURED = 1 << 1,
  96
  97        /* This flag indicates that a motion event is being split across multiple windows. */
  98        FLAG_SPLIT = 1 << 2,
  99
 100        /* This flag indicates that the pointer coordinates dispatched to the application
 101         * will be zeroed out to avoid revealing information to an application. This is
 102         * used in conjunction with FLAG_DISPATCH_AS_OUTSIDE to prevent apps not sharing
 103         * the same UID from watching all touches. */
 104        FLAG_ZERO_COORDS = 1 << 3,
 105
 106        /* This flag indicates that the event should be sent as is.
 107         * Should always be set unless the event is to be transmuted. */
 108        FLAG_DISPATCH_AS_IS = 1 << 8,
 109
 110        /* This flag indicates that a MotionEvent with AMOTION_EVENT_ACTION_DOWN falls outside
 111         * of the area of this target and so should instead be delivered as an
 112         * AMOTION_EVENT_ACTION_OUTSIDE to this target. */
 113        FLAG_DISPATCH_AS_OUTSIDE = 1 << 9,
 114
 115        /* This flag indicates that a hover sequence is starting in the given window.
 116         * The event is transmuted into ACTION_HOVER_ENTER. */
 117        FLAG_DISPATCH_AS_HOVER_ENTER = 1 << 10,
 118
 119        /* This flag indicates that a hover event happened outside of a window which handled
 120         * previous hover events, signifying the end of the current hover sequence for that
 121         * window.
 122         * The event is transmuted into ACTION_HOVER_ENTER. */
 123        FLAG_DISPATCH_AS_HOVER_EXIT = 1 << 11,
 124
 125        /* This flag indicates that the event should be canceled.
 126         * It is used to transmute ACTION_MOVE into ACTION_CANCEL when a touch slips
 127         * outside of a window. */
 128        FLAG_DISPATCH_AS_SLIPPERY_EXIT = 1 << 12,
 129
 130        /* This flag indicates that the event should be dispatched as an initial down.
 131         * It is used to transmute ACTION_MOVE into ACTION_DOWN when a touch slips
 132         * into a new window. */
 133        FLAG_DISPATCH_AS_SLIPPERY_ENTER = 1 << 13,
 134
 135        /* Mask for all dispatch modes. */
 136        FLAG_DISPATCH_MASK = FLAG_DISPATCH_AS_IS
 137                | FLAG_DISPATCH_AS_OUTSIDE
 138                | FLAG_DISPATCH_AS_HOVER_ENTER
 139                | FLAG_DISPATCH_AS_HOVER_EXIT
 140                | FLAG_DISPATCH_AS_SLIPPERY_EXIT
 141                | FLAG_DISPATCH_AS_SLIPPERY_ENTER,
 142    };
 143
 144    // The input channel to be targeted.
 145    sp<InputChannel> inputChannel;
 146
 147    // Flags for the input target.
 148    int32_t flags;
 149
 150    // The x and y offset to add to a MotionEvent as it is delivered.
 151    // (ignored for KeyEvents)
 152    float xOffset, yOffset;
 153
 154    // Scaling factor to apply to MotionEvent as it is delivered.
 155    // (ignored for KeyEvents)
 156    float scaleFactor;
 157
 158    // The subset of pointer ids to include in motion events dispatched to this input target
 159    // if FLAG_SPLIT is set.
 160    BitSet32 pointerIds;
 161};
 162
 163
 164/*
 165 * Input dispatcher configuration.
 166 *
 167 * Specifies various options that modify the behavior of the input dispatcher.
 168 * The values provided here are merely defaults. The actual values will come from ViewConfiguration
 169 * and are passed into the dispatcher during initialization.
 170 */
 171struct InputDispatcherConfiguration {
 172    // The key repeat initial timeout.
 173    nsecs_t keyRepeatTimeout;
 174
 175    // The key repeat inter-key delay.
 176    nsecs_t keyRepeatDelay;
 177
 178    InputDispatcherConfiguration() :
 179            keyRepeatTimeout(500 * 1000000LL),
 180            keyRepeatDelay(50 * 1000000LL) { }
 181};
 182
 183
 184/*
 185 * Input dispatcher policy interface.
 186 *
 187 * The input reader policy is used by the input reader to interact with the Window Manager
 188 * and other system components.
 189 *
 190 * The actual implementation is partially supported by callbacks into the DVM
 191 * via JNI.  This interface is also mocked in the unit tests.
 192 */
 193class InputDispatcherPolicyInterface : public virtual RefBase {
 194protected:
 195    InputDispatcherPolicyInterface() { }
 196    virtual ~InputDispatcherPolicyInterface() { }
 197
 198public:
 199    /* Notifies the system that a configuration change has occurred. */
 200    virtual void notifyConfigurationChanged(nsecs_t when) = 0;
 201
 202    /* Notifies the system that an application is not responding.
 203     * Returns a new timeout to continue waiting, or 0 to abort dispatch. */
 204    virtual nsecs_t notifyANR(const sp<InputApplicationHandle>& inputApplicationHandle,
 205            const sp<InputWindowHandle>& inputWindowHandle,
 206            const String8& reason) = 0;
 207
 208    /* Notifies the system that an input channel is unrecoverably broken. */
 209    virtual void notifyInputChannelBroken(const sp<InputWindowHandle>& inputWindowHandle) = 0;
 210
 211    /* Gets the input dispatcher configuration. */
 212    virtual void getDispatcherConfiguration(InputDispatcherConfiguration* outConfig) = 0;
 213
 214    /* Returns true if automatic key repeating is enabled. */
 215    virtual bool isKeyRepeatEnabled() = 0;
 216
 217    /* Filters an input event.
 218     * Return true to dispatch the event unmodified, false to consume the event.
 219     * A filter can also transform and inject events later by passing POLICY_FLAG_FILTERED
 220     * to injectInputEvent.
 221     */
 222    virtual bool filterInputEvent(const InputEvent* inputEvent, uint32_t policyFlags) = 0;
 223
 224    /* Intercepts a key event immediately before queueing it.
 225     * The policy can use this method as an opportunity to perform power management functions
 226     * and early event preprocessing such as updating policy flags.
 227     *
 228     * This method is expected to set the POLICY_FLAG_PASS_TO_USER policy flag if the event
 229     * should be dispatched to applications.
 230     */
 231    virtual void interceptKeyBeforeQueueing(const KeyEvent* keyEvent, uint32_t& policyFlags) = 0;
 232
 233    /* Intercepts a touch, trackball or other motion event before queueing it.
 234     * The policy can use this method as an opportunity to perform power management functions
 235     * and early event preprocessing such as updating policy flags.
 236     *
 237     * This method is expected to set the POLICY_FLAG_PASS_TO_USER policy flag if the event
 238     * should be dispatched to applications.
 239     */
 240    virtual void interceptMotionBeforeQueueing(nsecs_t when, uint32_t& policyFlags) = 0;
 241
 242    /* Allows the policy a chance to intercept a key before dispatching. */
 243    virtual nsecs_t interceptKeyBeforeDispatching(const sp<InputWindowHandle>& inputWindowHandle,
 244            const KeyEvent* keyEvent, uint32_t policyFlags) = 0;
 245
 246    /* Allows the policy a chance to perform default processing for an unhandled key.
 247     * Returns an alternate keycode to redispatch as a fallback, or 0 to give up. */
 248    virtual bool dispatchUnhandledKey(const sp<InputWindowHandle>& inputWindowHandle,
 249            const KeyEvent* keyEvent, uint32_t policyFlags, KeyEvent* outFallbackKeyEvent) = 0;
 250
 251    /* Notifies the policy about switch events.
 252     */
 253    virtual void notifySwitch(nsecs_t when,
 254            uint32_t switchValues, uint32_t switchMask, uint32_t policyFlags) = 0;
 255
 256    /* Poke user activity for an event dispatched to a window. */
 257    virtual void pokeUserActivity(nsecs_t eventTime, int32_t eventType) = 0;
 258
 259    /* Checks whether a given application pid/uid has permission to inject input events
 260     * into other applications.
 261     *
 262     * This method is special in that its implementation promises to be non-reentrant and
 263     * is safe to call while holding other locks.  (Most other methods make no such guarantees!)
 264     */
 265    virtual bool checkInjectEventsPermissionNonReentrant(
 266            int32_t injectorPid, int32_t injectorUid) = 0;
 267};
 268
 269
 270/* Notifies the system about input events generated by the input reader.
 271 * The dispatcher is expected to be mostly asynchronous. */
 272class InputDispatcherInterface : public virtual RefBase, public InputListenerInterface {
 273protected:
 274    InputDispatcherInterface() { }
 275    virtual ~InputDispatcherInterface() { }
 276
 277public:
 278    /* Dumps the state of the input dispatcher.
 279     *
 280     * This method may be called on any thread (usually by the input manager). */
 281    virtual void dump(String8& dump) = 0;
 282
 283    /* Called by the heatbeat to ensures that the dispatcher has not deadlocked. */
 284    virtual void monitor() = 0;
 285
 286    /* Runs a single iteration of the dispatch loop.
 287     * Nominally processes one queued event, a timeout, or a response from an input consumer.
 288     *
 289     * This method should only be called on the input dispatcher thread.
 290     */
 291    virtual void dispatchOnce() = 0;
 292
 293    /* Injects an input event and optionally waits for sync.
 294     * The synchronization mode determines whether the method blocks while waiting for
 295     * input injection to proceed.
 296     * Returns one of the INPUT_EVENT_INJECTION_XXX constants.
 297     *
 298     * This method may be called on any thread (usually by the input manager).
 299     */
 300    virtual int32_t injectInputEvent(const InputEvent* event,
 301            int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis,
 302            uint32_t policyFlags) = 0;
 303
 304    /* Sets the list of input windows.
 305     *
 306     * This method may be called on any thread (usually by the input manager).
 307     */
 308    virtual void setInputWindows(const Vector<sp<InputWindowHandle> >& inputWindowHandles) = 0;
 309
 310    /* Sets the focused application.
 311     *
 312     * This method may be called on any thread (usually by the input manager).
 313     */
 314    virtual void setFocusedApplication(
 315            const sp<InputApplicationHandle>& inputApplicationHandle) = 0;
 316
 317    /* Sets the input dispatching mode.
 318     *
 319     * This method may be called on any thread (usually by the input manager).
 320     */
 321    virtual void setInputDispatchMode(bool enabled, bool frozen) = 0;
 322
 323    /* Sets whether input event filtering is enabled.
 324     * When enabled, incoming input events are sent to the policy's filterInputEvent
 325     * method instead of being dispatched.  The filter is expected to use
 326     * injectInputEvent to inject the events it would like to have dispatched.
 327     * It should include POLICY_FLAG_FILTERED in the policy flags during injection.
 328     */
 329    virtual void setInputFilterEnabled(bool enabled) = 0;
 330
 331    /* Transfers touch focus from the window associated with one channel to the
 332     * window associated with the other channel.
 333     *
 334     * Returns true on success.  False if the window did not actually have touch focus.
 335     */
 336    virtual bool transferTouchFocus(const sp<InputChannel>& fromChannel,
 337            const sp<InputChannel>& toChannel) = 0;
 338
 339    /* Registers or unregister input channels that may be used as targets for input events.
 340     * If monitor is true, the channel will receive a copy of all input events.
 341     *
 342     * These methods may be called on any thread (usually by the input manager).
 343     */
 344    virtual status_t registerInputChannel(const sp<InputChannel>& inputChannel,
 345            const sp<InputWindowHandle>& inputWindowHandle, bool monitor) = 0;
 346    virtual status_t unregisterInputChannel(const sp<InputChannel>& inputChannel) = 0;
 347};
 348
 349/* Dispatches events to input targets.  Some functions of the input dispatcher, such as
 350 * identifying input targets, are controlled by a separate policy object.
 351 *
 352 * IMPORTANT INVARIANT:
 353 *     Because the policy can potentially block or cause re-entrance into the input dispatcher,
 354 *     the input dispatcher never calls into the policy while holding its internal locks.
 355 *     The implementation is also carefully designed to recover from scenarios such as an
 356 *     input channel becoming unregistered while identifying input targets or processing timeouts.
 357 *
 358 *     Methods marked 'Locked' must be called with the lock acquired.
 359 *
 360 *     Methods marked 'LockedInterruptible' must be called with the lock acquired but
 361 *     may during the course of their execution release the lock, call into the policy, and
 362 *     then reacquire the lock.  The caller is responsible for recovering gracefully.
 363 *
 364 *     A 'LockedInterruptible' method may called a 'Locked' method, but NOT vice-versa.
 365 */
 366class InputDispatcher : public InputDispatcherInterface {
 367protected:
 368    virtual ~InputDispatcher();
 369
 370public:
 371    explicit InputDispatcher(const sp<InputDispatcherPolicyInterface>& policy);
 372
 373    virtual void dump(String8& dump);
 374    virtual void monitor();
 375
 376    virtual void dispatchOnce();
 377
 378    virtual void notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args);
 379    virtual void notifyKey(const NotifyKeyArgs* args);
 380    virtual void notifyMotion(const NotifyMotionArgs* args);
 381    virtual void notifySwitch(const NotifySwitchArgs* args);
 382    virtual void notifyDeviceReset(const NotifyDeviceResetArgs* args);
 383
 384    virtual int32_t injectInputEvent(const InputEvent* event,
 385            int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis,
 386            uint32_t policyFlags);
 387
 388    virtual void setInputWindows(const Vector<sp<InputWindowHandle> >& inputWindowHandles);
 389    virtual void setFocusedApplication(const sp<InputApplicationHandle>& inputApplicationHandle);
 390    virtual void setInputDispatchMode(bool enabled, bool frozen);
 391    virtual void setInputFilterEnabled(bool enabled);
 392
 393    virtual bool transferTouchFocus(const sp<InputChannel>& fromChannel,
 394            const sp<InputChannel>& toChannel);
 395
 396    virtual status_t registerInputChannel(const sp<InputChannel>& inputChannel,
 397            const sp<InputWindowHandle>& inputWindowHandle, bool monitor);
 398    virtual status_t unregisterInputChannel(const sp<InputChannel>& inputChannel);
 399
 400private:
 401    template <typename T>
 402    struct Link {
 403        T* next;
 404        T* prev;
 405
 406    protected:
 407        inline Link() : next(NULL), prev(NULL) { }
 408    };
 409
 410    struct InjectionState {
 411        mutable int32_t refCount;
 412
 413        int32_t injectorPid;
 414        int32_t injectorUid;
 415        int32_t injectionResult;  // initially INPUT_EVENT_INJECTION_PENDING
 416        bool injectionIsAsync; // set to true if injection is not waiting for the result
 417        int32_t pendingForegroundDispatches; // the number of foreground dispatches in progress
 418
 419        InjectionState(int32_t injectorPid, int32_t injectorUid);
 420        void release();
 421
 422    private:
 423        ~InjectionState();
 424    };
 425
 426    struct EventEntry : Link<EventEntry> {
 427        enum {
 428            TYPE_CONFIGURATION_CHANGED,
 429            TYPE_DEVICE_RESET,
 430            TYPE_KEY,
 431            TYPE_MOTION
 432        };
 433
 434        mutable int32_t refCount;
 435        int32_t type;
 436        nsecs_t eventTime;
 437        uint32_t policyFlags;
 438        InjectionState* injectionState;
 439
 440        bool dispatchInProgress; // initially false, set to true while dispatching
 441
 442        inline bool isInjected() const { return injectionState != NULL; }
 443
 444        void release();
 445
 446        virtual void appendDescription(String8& msg) const = 0;
 447
 448    protected:
 449        EventEntry(int32_t type, nsecs_t eventTime, uint32_t policyFlags);
 450        virtual ~EventEntry();
 451        void releaseInjectionState();
 452    };
 453
 454    struct ConfigurationChangedEntry : EventEntry {
 455        ConfigurationChangedEntry(nsecs_t eventTime);
 456        virtual void appendDescription(String8& msg) const;
 457
 458    protected:
 459        virtual ~ConfigurationChangedEntry();
 460    };
 461
 462    struct DeviceResetEntry : EventEntry {
 463        int32_t deviceId;
 464
 465        DeviceResetEntry(nsecs_t eventTime, int32_t deviceId);
 466        virtual void appendDescription(String8& msg) const;
 467
 468    protected:
 469        virtual ~DeviceResetEntry();
 470    };
 471
 472    struct KeyEntry : EventEntry {
 473        int32_t deviceId;
 474        uint32_t source;
 475        int32_t action;
 476        int32_t flags;
 477        int32_t keyCode;
 478        int32_t scanCode;
 479        int32_t metaState;
 480        int32_t repeatCount;
 481        nsecs_t downTime;
 482
 483        bool syntheticRepeat; // set to true for synthetic key repeats
 484
 485        enum InterceptKeyResult {
 486            INTERCEPT_KEY_RESULT_UNKNOWN,
 487            INTERCEPT_KEY_RESULT_SKIP,
 488            INTERCEPT_KEY_RESULT_CONTINUE,
 489            INTERCEPT_KEY_RESULT_TRY_AGAIN_LATER,
 490        };
 491        InterceptKeyResult interceptKeyResult; // set based on the interception result
 492        nsecs_t interceptKeyWakeupTime; // used with INTERCEPT_KEY_RESULT_TRY_AGAIN_LATER
 493
 494        KeyEntry(nsecs_t eventTime,
 495                int32_t deviceId, uint32_t source, uint32_t policyFlags, int32_t action,
 496                int32_t flags, int32_t keyCode, int32_t scanCode, int32_t metaState,
 497                int32_t repeatCount, nsecs_t downTime);
 498        virtual void appendDescription(String8& msg) const;
 499        void recycle();
 500
 501    protected:
 502        virtual ~KeyEntry();
 503    };
 504
 505    struct MotionEntry : EventEntry {
 506        nsecs_t eventTime;
 507        int32_t deviceId;
 508        uint32_t source;
 509        int32_t action;
 510        int32_t flags;
 511        int32_t metaState;
 512        int32_t buttonState;
 513        int32_t edgeFlags;
 514        float xPrecision;
 515        float yPrecision;
 516        nsecs_t downTime;
 517        int32_t displayId;
 518        uint32_t pointerCount;
 519        PointerProperties pointerProperties[MAX_POINTERS];
 520        PointerCoords pointerCoords[MAX_POINTERS];
 521
 522        MotionEntry(nsecs_t eventTime,
 523                int32_t deviceId, uint32_t source, uint32_t policyFlags,
 524                int32_t action, int32_t flags,
 525                int32_t metaState, int32_t buttonState, int32_t edgeFlags,
 526                float xPrecision, float yPrecision,
 527                nsecs_t downTime, int32_t displayId, uint32_t pointerCount,
 528                const PointerProperties* pointerProperties, const PointerCoords* pointerCoords);
 529        virtual void appendDescription(String8& msg) const;
 530
 531    protected:
 532        virtual ~MotionEntry();
 533    };
 534
 535    // Tracks the progress of dispatching a particular event to a particular connection.
 536    struct DispatchEntry : Link<DispatchEntry> {
 537        const uint32_t seq; // unique sequence number, never 0
 538
 539        EventEntry* eventEntry; // the event to dispatch
 540        int32_t targetFlags;
 541        float xOffset;
 542        float yOffset;
 543        float scaleFactor;
 544        nsecs_t deliveryTime; // time when the event was actually delivered
 545
 546        // Set to the resolved action and flags when the event is enqueued.
 547        int32_t resolvedAction;
 548        int32_t resolvedFlags;
 549
 550        DispatchEntry(EventEntry* eventEntry,
 551                int32_t targetFlags, float xOffset, float yOffset, float scaleFactor);
 552        ~DispatchEntry();
 553
 554        inline bool hasForegroundTarget() const {
 555            return targetFlags & InputTarget::FLAG_FOREGROUND;
 556        }
 557
 558        inline bool isSplit() const {
 559            return targetFlags & InputTarget::FLAG_SPLIT;
 560        }
 561
 562    private:
 563        static volatile int32_t sNextSeqAtomic;
 564
 565        static uint32_t nextSeq();
 566    };
 567
 568    // A command entry captures state and behavior for an action to be performed in the
 569    // dispatch loop after the initial processing has taken place.  It is essentially
 570    // a kind of continuation used to postpone sensitive policy interactions to a point
 571    // in the dispatch loop where it is safe to release the lock (generally after finishing
 572    // the critical parts of the dispatch cycle).
 573    //
 574    // The special thing about commands is that they can voluntarily release and reacquire
 575    // the dispatcher lock at will.  Initially when the command starts running, the
 576    // dispatcher lock is held.  However, if the command needs to call into the policy to
 577    // do some work, it can release the lock, do the work, then reacquire the lock again
 578    // before returning.
 579    //
 580    // This mechanism is a bit clunky but it helps to preserve the invariant that the dispatch
 581    // never calls into the policy while holding its lock.
 582    //
 583    // Commands are implicitly 'LockedInterruptible'.
 584    struct CommandEntry;
 585    typedef void (InputDispatcher::*Command)(CommandEntry* commandEntry);
 586
 587    class Connection;
 588    struct CommandEntry : Link<CommandEntry> {
 589        CommandEntry(Command command);
 590        ~CommandEntry();
 591
 592        Command command;
 593
 594        // parameters for the command (usage varies by command)
 595        sp<Connection> connection;
 596        nsecs_t eventTime;
 597        KeyEntry* keyEntry;
 598        sp<InputApplicationHandle> inputApplicationHandle;
 599        sp<InputWindowHandle> inputWindowHandle;
 600        String8 reason;
 601        int32_t userActivityEventType;
 602        uint32_t seq;
 603        bool handled;
 604    };
 605
 606    // Generic queue implementation.
 607    template <typename T>
 608    struct Queue {
 609        T* head;
 610        T* tail;
 611
 612        inline Queue() : head(NULL), tail(NULL) {
 613        }
 614
 615        inline bool isEmpty() const {
 616            return !head;
 617        }
 618
 619        inline void enqueueAtTail(T* entry) {
 620            entry->prev = tail;
 621            if (tail) {
 622                tail->next = entry;
 623            } else {
 624                head = entry;
 625            }
 626            entry->next = NULL;
 627            tail = entry;
 628        }
 629
 630        inline void enqueueAtHead(T* entry) {
 631            entry->next = head;
 632            if (head) {
 633                head->prev = entry;
 634            } else {
 635                tail = entry;
 636            }
 637            entry->prev = NULL;
 638            head = entry;
 639        }
 640
 641        inline void dequeue(T* entry) {
 642            if (entry->prev) {
 643                entry->prev->next = entry->next;
 644            } else {
 645                head = entry->next;
 646            }
 647            if (entry->next) {
 648                entry->next->prev = entry->prev;
 649            } else {
 650                tail = entry->prev;
 651            }
 652        }
 653
 654        inline T* dequeueAtHead() {
 655            T* entry = head;
 656            head = entry->next;
 657            if (head) {
 658                head->prev = NULL;
 659            } else {
 660                tail = NULL;
 661            }
 662            return entry;
 663        }
 664
 665        uint32_t count() const;
 666    };
 667
 668    /* Specifies which events are to be canceled and why. */
 669    struct CancelationOptions {
 670        enum Mode {
 671            CANCEL_ALL_EVENTS = 0,
 672            CANCEL_POINTER_EVENTS = 1,
 673            CANCEL_NON_POINTER_EVENTS = 2,
 674            CANCEL_FALLBACK_EVENTS = 3,
 675        };
 676
 677        // The criterion to use to determine which events should be canceled.
 678        Mode mode;
 679
 680        // Descriptive reason for the cancelation.
 681        const char* reason;
 682
 683        // The specific keycode of the key event to cancel, or -1 to cancel any key event.
 684        int32_t keyCode;
 685
 686        // The specific device id of events to cancel, or -1 to cancel events from any device.
 687        int32_t deviceId;
 688
 689        CancelationOptions(Mode mode, const char* reason) :
 690                mode(mode), reason(reason), keyCode(-1), deviceId(-1) { }
 691    };
 692
 693    /* Tracks dispatched key and motion event state so that cancelation events can be
 694     * synthesized when events are dropped. */
 695    class InputState {
 696    public:
 697        InputState();
 698        ~InputState();
 699
 700        // Returns true if there is no state to be canceled.
 701        bool isNeutral() const;
 702
 703        // Returns true if the specified source is known to have received a hover enter
 704        // motion event.
 705        bool isHovering(int32_t deviceId, uint32_t source, int32_t displayId) const;
 706
 707        // Records tracking information for a key event that has just been published.
 708        // Returns true if the event should be delivered, false if it is inconsistent
 709        // and should be skipped.
 710        bool trackKey(const KeyEntry* entry, int32_t action, int32_t flags);
 711
 712        // Records tracking information for a motion event that has just been published.
 713        // Returns true if the event should be delivered, false if it is inconsistent
 714        // and should be skipped.
 715        bool trackMotion(const MotionEntry* entry, int32_t action, int32_t flags);
 716
 717        // Synthesizes cancelation events for the current state and resets the tracked state.
 718        void synthesizeCancelationEvents(nsecs_t currentTime,
 719                Vector<EventEntry*>& outEvents, const CancelationOptions& options);
 720
 721        // Clears the current state.
 722        void clear();
 723
 724        // Copies pointer-related parts of the input state to another instance.
 725        void copyPointerStateTo(InputState& other) const;
 726
 727        // Gets the fallback key associated with a keycode.
 728        // Returns -1 if none.
 729        // Returns AKEYCODE_UNKNOWN if we are only dispatching the unhandled key to the policy.
 730        int32_t getFallbackKey(int32_t originalKeyCode);
 731
 732        // Sets the fallback key for a particular keycode.
 733        void setFallbackKey(int32_t originalKeyCode, int32_t fallbackKeyCode);
 734
 735        // Removes the fallback key for a particular keycode.
 736        void removeFallbackKey(int32_t originalKeyCode);
 737
 738        inline const KeyedVector<int32_t, int32_t>& getFallbackKeys() const {
 739            return mFallbackKeys;
 740        }
 741
 742    private:
 743        struct KeyMemento {
 744            int32_t deviceId;
 745            uint32_t source;
 746            int32_t keyCode;
 747            int32_t scanCode;
 748            int32_t metaState;
 749            int32_t flags;
 750            nsecs_t downTime;
 751            uint32_t policyFlags;
 752        };
 753
 754        struct MotionMemento {
 755            int32_t deviceId;
 756            uint32_t source;
 757            int32_t flags;
 758            float xPrecision;
 759            float yPrecision;
 760            nsecs_t downTime;
 761            int32_t displayId;
 762            uint32_t pointerCount;
 763            PointerProperties pointerProperties[MAX_POINTERS];
 764            PointerCoords pointerCoords[MAX_POINTERS];
 765            bool hovering;
 766            uint32_t policyFlags;
 767
 768            void setPointers(const MotionEntry* entry);
 769        };
 770
 771        Vector<KeyMemento> mKeyMementos;
 772        Vector<MotionMemento> mMotionMementos;
 773        KeyedVector<int32_t, int32_t> mFallbackKeys;
 774
 775        ssize_t findKeyMemento(const KeyEntry* entry) const;
 776        ssize_t findMotionMemento(const MotionEntry* entry, bool hovering) const;
 777
 778        void addKeyMemento(const KeyEntry* entry, int32_t flags);
 779        void addMotionMemento(const MotionEntry* entry, int32_t flags, bool hovering);
 780
 781        static bool shouldCancelKey(const KeyMemento& memento,
 782                const CancelationOptions& options);
 783        static bool shouldCancelMotion(const MotionMemento& memento,
 784                const CancelationOptions& options);
 785    };
 786
 787    /* Manages the dispatch state associated with a single input channel. */
 788    class Connection : public RefBase {
 789    protected:
 790        virtual ~Connection();
 791
 792    public:
 793        enum Status {
 794            // Everything is peachy.
 795            STATUS_NORMAL,
 796            // An unrecoverable communication error has occurred.
 797            STATUS_BROKEN,
 798            // The input channel has been unregistered.
 799            STATUS_ZOMBIE
 800        };
 801
 802        Status status;
 803        sp<InputChannel> inputChannel; // never null
 804        sp<InputWindowHandle> inputWindowHandle; // may be null
 805        bool monitor;
 806        InputPublisher inputPublisher;
 807        InputState inputState;
 808
 809        // True if the socket is full and no further events can be published until
 810        // the application consumes some of the input.
 811        bool inputPublisherBlocked;
 812
 813        // Queue of events that need to be published to the connection.
 814        Queue<DispatchEntry> outboundQueue;
 815
 816        // Queue of events that have been published to the connection but that have not
 817        // yet received a "finished" response from the application.
 818        Queue<DispatchEntry> waitQueue;
 819
 820        explicit Connection(const sp<InputChannel>& inputChannel,
 821                const sp<InputWindowHandle>& inputWindowHandle, bool monitor);
 822
 823        inline const char* getInputChannelName() const { return inputChannel->getName().string(); }
 824
 825        const char* getWindowName() const;
 826        const char* getStatusLabel() const;
 827
 828        DispatchEntry* findWaitQueueEntry(uint32_t seq);
 829    };
 830
 831    enum DropReason {
 832        DROP_REASON_NOT_DROPPED = 0,
 833        DROP_REASON_POLICY = 1,
 834        DROP_REASON_APP_SWITCH = 2,
 835        DROP_REASON_DISABLED = 3,
 836        DROP_REASON_BLOCKED = 4,
 837        DROP_REASON_STALE = 5,
 838    };
 839
 840    sp<InputDispatcherPolicyInterface> mPolicy;
 841    InputDispatcherConfiguration mConfig;
 842
 843    Mutex mLock;
 844
 845    Condition mDispatcherIsAliveCondition;
 846
 847    sp<Looper> mLooper;
 848
 849    EventEntry* mPendingEvent;
 850    Queue<EventEntry> mInboundQueue;
 851    Queue<EventEntry> mRecentQueue;
 852    Queue<CommandEntry> mCommandQueue;
 853
 854    void dispatchOnceInnerLocked(nsecs_t* nextWakeupTime);
 855
 856    // Enqueues an inbound event.  Returns true if mLooper->wake() should be called.
 857    bool enqueueInboundEventLocked(EventEntry* entry);
 858
 859    // Cleans up input state when dropping an inbound event.
 860    void dropInboundEventLocked(EventEntry* entry, DropReason dropReason);
 861
 862    // Adds an event to a queue of recent events for debugging purposes.
 863    void addRecentEventLocked(EventEntry* entry);
 864
 865    // App switch latency optimization.
 866    bool mAppSwitchSawKeyDown;
 867    nsecs_t mAppSwitchDueTime;
 868
 869    static bool isAppSwitchKeyCode(int32_t keyCode);
 870    bool isAppSwitchKeyEventLocked(KeyEntry* keyEntry);
 871    bool isAppSwitchPendingLocked();
 872    void resetPendingAppSwitchLocked(bool handled);
 873
 874    // Stale event latency optimization.
 875    static bool isStaleEventLocked(nsecs_t currentTime, EventEntry* entry);
 876
 877    // Blocked event latency optimization.  Drops old events when the user intends
 878    // to transfer focus to a new application.
 879    EventEntry* mNextUnblockedEvent;
 880
 881    sp<InputWindowHandle> findTouchedWindowAtLocked(int32_t displayId, int32_t x, int32_t y);
 882
 883    // All registered connections mapped by channel file descriptor.
 884    KeyedVector<int, sp<Connection> > mConnectionsByFd;
 885
 886    ssize_t getConnectionIndexLocked(const sp<InputChannel>& inputChannel);
 887
 888    // Input channels that will receive a copy of all input events.
 889    Vector<sp<InputChannel> > mMonitoringChannels;
 890
 891    // Event injection and synchronization.
 892    Condition mInjectionResultAvailableCondition;
 893    bool hasInjectionPermission(int32_t injectorPid, int32_t injectorUid);
 894    void setInjectionResultLocked(EventEntry* entry, int32_t injectionResult);
 895
 896    Condition mInjectionSyncFinishedCondition;
 897    void incrementPendingForegroundDispatchesLocked(EventEntry* entry);
 898    void decrementPendingForegroundDispatchesLocked(EventEntry* entry);
 899
 900    // Key repeat tracking.
 901    struct KeyRepeatState {
 902        KeyEntry* lastKeyEntry; // or null if no repeat
 903        nsecs_t nextRepeatTime;
 904    } mKeyRepeatState;
 905
 906    void resetKeyRepeatLocked();
 907    KeyEntry* synthesizeKeyRepeatLocked(nsecs_t currentTime);
 908
 909    // Deferred command processing.
 910    bool haveCommandsLocked() const;
 911    bool runCommandsLockedInterruptible();
 912    CommandEntry* postCommandLocked(Command command);
 913
 914    // Input filter processing.
 915    bool shouldSendKeyToInputFilterLocked(const NotifyKeyArgs* args);
 916    bool shouldSendMotionToInputFilterLocked(const NotifyMotionArgs* args);
 917
 918    // Inbound event processing.
 919    void drainInboundQueueLocked();
 920    void releasePendingEventLocked();
 921    void releaseInboundEventLocked(EventEntry* entry);
 922
 923    // Dispatch state.
 924    bool mDispatchEnabled;
 925    bool mDispatchFrozen;
 926    bool mInputFilterEnabled;
 927
 928    Vector<sp<InputWindowHandle> > mWindowHandles;
 929
 930    sp<InputWindowHandle> getWindowHandleLocked(const sp<InputChannel>& inputChannel) const;
 931    bool hasWindowHandleLocked(const sp<InputWindowHandle>& windowHandle) const;
 932
 933    // Focus tracking for keys, trackball, etc.
 934    sp<InputWindowHandle> mFocusedWindowHandle;
 935
 936    // Focus tracking for touch.
 937    struct TouchedWindow {
 938        sp<InputWindowHandle> windowHandle;
 939        int32_t targetFlags;
 940        BitSet32 pointerIds;        // zero unless target flag FLAG_SPLIT is set
 941    };
 942    struct TouchState {
 943        bool down;
 944        bool split;
 945        int32_t deviceId; // id of the device that is currently down, others are rejected
 946        uint32_t source;  // source of the device that is current down, others are rejected
 947        int32_t displayId; // id to the display that currently has a touch, others are rejected
 948        Vector<TouchedWindow> windows;
 949
 950        TouchState();
 951        ~TouchState();
 952        void reset();
 953        void copyFrom(const TouchState& other);
 954        void addOrUpdateWindow(const sp<InputWindowHandle>& windowHandle,
 955                int32_t targetFlags, BitSet32 pointerIds);
 956        void removeWindow(const sp<InputWindowHandle>& windowHandle);
 957        void filterNonAsIsTouchWindows();
 958        sp<InputWindowHandle> getFirstForegroundWindowHandle() const;
 959        bool isSlippery() const;
 960    };
 961
 962    TouchState mTouchState;
 963    TouchState mTempTouchState;
 964
 965    // Focused application.
 966    sp<InputApplicationHandle> mFocusedApplicationHandle;
 967
 968    // Dispatcher state at time of last ANR.
 969    String8 mLastANRState;
 970
 971    // Dispatch inbound events.
 972    bool dispatchConfigurationChangedLocked(
 973            nsecs_t currentTime, ConfigurationChangedEntry* entry);
 974    bool dispatchDeviceResetLocked(
 975            nsecs_t currentTime, DeviceResetEntry* entry);
 976    bool dispatchKeyLocked(
 977            nsecs_t currentTime, KeyEntry* entry,
 978            DropReason* dropReason, nsecs_t* nextWakeupTime);
 979    bool dispatchMotionLocked(
 980            nsecs_t currentTime, MotionEntry* entry,
 981            DropReason* dropReason, nsecs_t* nextWakeupTime);
 982    void dispatchEventLocked(nsecs_t currentTime, EventEntry* entry,
 983            const Vector<InputTarget>& inputTargets);
 984
 985    void logOutboundKeyDetailsLocked(const char* prefix, const KeyEntry* entry);
 986    void logOutboundMotionDetailsLocked(const char* prefix, const MotionEntry* entry);
 987
 988    // Keeping track of ANR timeouts.
 989    enum InputTargetWaitCause {
 990        INPUT_TARGET_WAIT_CAUSE_NONE,
 991        INPUT_TARGET_WAIT_CAUSE_SYSTEM_NOT_READY,
 992        INPUT_TARGET_WAIT_CAUSE_APPLICATION_NOT_READY,
 993    };
 994
 995    InputTargetWaitCause mInputTargetWaitCause;
 996    nsecs_t mInputTargetWaitStartTime;
 997    nsecs_t mInputTargetWaitTimeoutTime;
 998    bool mInputTargetWaitTimeoutExpired;
 999    sp<InputApplicationHandle> mInputTargetWaitApplicationHandle;
1000
1001    // Contains the last window which received a hover event.
1002    sp<InputWindowHandle> mLastHoverWindowHandle;
1003
1004    // Finding targets for input events.
1005    int32_t handleTargetsNotReadyLocked(nsecs_t currentTime, const EventEntry* entry,
1006            const sp<InputApplicationHandle>& applicationHandle,
1007            const sp<InputWindowHandle>& windowHandle,
1008            nsecs_t* nextWakeupTime, const char* reason);
1009    void resumeAfterTargetsNotReadyTimeoutLocked(nsecs_t newTimeout,
1010            const sp<InputChannel>& inputChannel);
1011    nsecs_t getTimeSpentWaitingForApplicationLocked(nsecs_t currentTime);
1012    void resetANRTimeoutsLocked();
1013
1014    int32_t findFocusedWindowTargetsLocked(nsecs_t currentTime, const EventEntry* entry,
1015            Vector<InputTarget>& inputTargets, nsecs_t* nextWakeupTime);
1016    int32_t findTouchedWindowTargetsLocked(nsecs_t currentTime, const MotionEntry* entry,
1017            Vector<InputTarget>& inputTargets, nsecs_t* nextWakeupTime,
1018            bool* outConflictingPointerActions);
1019
1020    void addWindowTargetLocked(const sp<InputWindowHandle>& windowHandle,
1021            int32_t targetFlags, BitSet32 pointerIds, Vector<InputTarget>& inputTargets);
1022    void addMonitoringTargetsLocked(Vector<InputTarget>& inputTargets);
1023
1024    void pokeUserActivityLocked(const EventEntry* eventEntry);
1025    bool checkInjectionPermission(const sp<InputWindowHandle>& windowHandle,
1026            const InjectionState* injectionState);
1027    bool isWindowObscuredAtPointLocked(const sp<InputWindowHandle>& windowHandle,
1028            int32_t x, int32_t y) const;
1029    bool isWindowReadyForMoreInputLocked(nsecs_t currentTime,
1030            const sp<InputWindowHandle>& windowHandle, const EventEntry* eventEntry);
1031    String8 getApplicationWindowLabelLocked(const sp<InputApplicationHandle>& applicationHandle,
1032            const sp<InputWindowHandle>& windowHandle);
1033
1034    // Manage the dispatch cycle for a single connection.
1035    // These methods are deliberately not Interruptible because doing all of the work
1036    // with the mutex held makes it easier to ensure that connection invariants are maintained.
1037    // If needed, the methods post commands to run later once the critical bits are done.
1038    void prepareDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
1039            EventEntry* eventEntry, const InputTarget* inputTarget);
1040    void enqueueDispatchEntriesLocked(nsecs_t currentTime, const sp<Connection>& connection,
1041            EventEntry* eventEntry, const InputTarget* inputTarget);
1042    void enqueueDispatchEntryLocked(const sp<Connection>& connection,
1043            EventEntry* eventEntry, const InputTarget* inputTarget, int32_t dispatchMode);
1044    void startDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection);
1045    void finishDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
1046            uint32_t seq, bool handled);
1047    void abortBrokenDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
1048            bool notify);
1049    void drainDispatchQueueLocked(Queue<DispatchEntry>* queue);
1050    void releaseDispatchEntryLocked(DispatchEntry* dispatchEntry);
1051    static int handleReceiveCallback(int fd, int events, void* data);
1052
1053    void synthesizeCancelationEventsForAllConnectionsLocked(
1054            const CancelationOptions& options);
1055    void synthesizeCancelationEventsForInputChannelLocked(const sp<InputChannel>& channel,
1056            const CancelationOptions& options);
1057    void synthesizeCancelationEventsForConnectionLocked(const sp<Connection>& connection,
1058            const CancelationOptions& options);
1059
1060    // Splitting motion events across windows.
1061    MotionEntry* splitMotionEvent(const MotionEntry* originalMotionEntry, BitSet32 pointerIds);
1062
1063    // Reset and drop everything the dispatcher is doing.
1064    void resetAndDropEverythingLocked(const char* reason);
1065
1066    // Dump state.
1067    void dumpDispatchStateLocked(String8& dump);
1068    void logDispatchStateLocked();
1069
1070    // Registration.
1071    void removeMonitorChannelLocked(const sp<InputChannel>& inputChannel);
1072    status_t unregisterInputChannelLocked(const sp<InputChannel>& inputChannel, bool notify);
1073
1074    // Add or remove a connection to the mActiveConnections vector.
1075    void activateConnectionLocked(Connection* connection);
1076    void deactivateConnectionLocked(Connection* connection);
1077
1078    // Interesting events that we might like to log or tell the framework about.
1079    void onDispatchCycleFinishedLocked(
1080            nsecs_t currentTime, const sp<Connection>& connection, uint32_t seq, bool handled);
1081    void onDispatchCycleBrokenLocked(
1082            nsecs_t currentTime, const sp<Connection>& connection);
1083    void onANRLocked(
1084            nsecs_t currentTime, const sp<InputApplicationHandle>& applicationHandle,
1085            const sp<InputWindowHandle>& windowHandle,
1086            nsecs_t eventTime, nsecs_t waitStartTime, const char* reason);
1087
1088    // Outbound policy interactions.
1089    void doNotifyConfigurationChangedInterruptible(CommandEntry* commandEntry);
1090    void doNotifyInputChannelBrokenLockedInterruptible(CommandEntry* commandEntry);
1091    void doNotifyANRLockedInterruptible(CommandEntry* commandEntry);
1092    void doInterceptKeyBeforeDispatchingLockedInterruptible(CommandEntry* commandEntry);
1093    void doDispatchCycleFinishedLockedInterruptible(CommandEntry* commandEntry);
1094    bool afterKeyEventLockedInterruptible(const sp<Connection>& connection,
1095            DispatchEntry* dispatchEntry, KeyEntry* keyEntry, bool handled);
1096    bool afterMotionEventLockedInterruptible(const sp<Connection>& connection,
1097            DispatchEntry* dispatchEntry, MotionEntry* motionEntry, bool handled);
1098    void doPokeUserActivityLockedInterruptible(CommandEntry* commandEntry);
1099    void initializeKeyEvent(KeyEvent* event, const KeyEntry* entry);
1100
1101    // Statistics gathering.
1102    void updateDispatchStatisticsLocked(nsecs_t currentTime, const EventEntry* entry,
1103            int32_t injectionResult, nsecs_t timeSpentWaitingForApplication);
1104    void traceInboundQueueLengthLocked();
1105    void traceOutboundQueueLengthLocked(const sp<Connection>& connection);
1106    void traceWaitQueueLengthLocked(const sp<Connection>& connection);
1107};
1108
1109/* Enqueues and dispatches input events, endlessly. */
1110class InputDispatcherThread : public Thread {
1111public:
1112    explicit InputDispatcherThread(const sp<InputDispatcherInterface>& dispatcher);
1113    ~InputDispatcherThread();
1114
1115private:
1116    virtual bool threadLoop();
1117
1118    sp<InputDispatcherInterface> mDispatcher;
1119};
1120
1121} // namespace android
1122
1123#endif // _UI_INPUT_DISPATCHER_H