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      1 /*
      2  * Copyright (C) 2013 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 #define LOG_TAG "InputQueue"
     18 
     19 #include <fcntl.h>
     20 #include <string.h>
     21 #include <unistd.h>
     22 
     23 #include <android/input.h>
     24 #include <android_runtime/AndroidRuntime.h>
     25 #include <android_runtime/android_view_InputQueue.h>
     26 #include <input/Input.h>
     27 #include <utils/Looper.h>
     28 #include <utils/TypeHelpers.h>
     29 #include <nativehelper/ScopedLocalRef.h>
     30 
     31 #include <nativehelper/JNIHelp.h>
     32 #include "android_os_MessageQueue.h"
     33 #include "android_view_KeyEvent.h"
     34 #include "android_view_MotionEvent.h"
     35 
     36 #include "core_jni_helpers.h"
     37 
     38 namespace android {
     39 
     40 static struct {
     41     jmethodID finishInputEvent;
     42 } gInputQueueClassInfo;
     43 
     44 enum {
     45     MSG_FINISH_INPUT = 1,
     46 };
     47 
     48 InputQueue::InputQueue(jobject inputQueueObj, const sp<Looper>& looper,
     49         int dispatchReadFd, int dispatchWriteFd) :
     50         mDispatchReadFd(dispatchReadFd), mDispatchWriteFd(dispatchWriteFd),
     51         mDispatchLooper(looper), mHandler(new WeakMessageHandler(this)) {
     52     JNIEnv* env = AndroidRuntime::getJNIEnv();
     53     mInputQueueWeakGlobal = env->NewGlobalRef(inputQueueObj);
     54 }
     55 
     56 InputQueue::~InputQueue() {
     57     mDispatchLooper->removeMessages(mHandler);
     58     JNIEnv* env = AndroidRuntime::getJNIEnv();
     59     env->DeleteGlobalRef(mInputQueueWeakGlobal);
     60     close(mDispatchReadFd);
     61     close(mDispatchWriteFd);
     62 }
     63 
     64 void InputQueue::attachLooper(Looper* looper, int ident,
     65         ALooper_callbackFunc callback, void* data) {
     66     Mutex::Autolock _l(mLock);
     67     for (size_t i = 0; i < mAppLoopers.size(); i++) {
     68         if (looper == mAppLoopers[i]) {
     69             return;
     70         }
     71     }
     72     mAppLoopers.push(looper);
     73     looper->addFd(mDispatchReadFd, ident, ALOOPER_EVENT_INPUT, callback, data);
     74 }
     75 
     76 void InputQueue::detachLooper() {
     77     Mutex::Autolock _l(mLock);
     78     detachLooperLocked();
     79 }
     80 
     81 void InputQueue::detachLooperLocked() {
     82     for (size_t i = 0; i < mAppLoopers.size(); i++) {
     83         mAppLoopers[i]->removeFd(mDispatchReadFd);
     84     }
     85     mAppLoopers.clear();
     86 }
     87 
     88 bool InputQueue::hasEvents() {
     89     Mutex::Autolock _l(mLock);
     90     return mPendingEvents.size() > 0;
     91 }
     92 
     93 status_t InputQueue::getEvent(InputEvent** outEvent) {
     94     Mutex::Autolock _l(mLock);
     95     *outEvent = NULL;
     96     if (!mPendingEvents.isEmpty()) {
     97         *outEvent = mPendingEvents[0];
     98         mPendingEvents.removeAt(0);
     99     }
    100 
    101     if (mPendingEvents.isEmpty()) {
    102         char byteread[16];
    103         ssize_t nRead;
    104         do {
    105             nRead = TEMP_FAILURE_RETRY(read(mDispatchReadFd, &byteread, sizeof(byteread)));
    106             if (nRead < 0 && errno != EAGAIN) {
    107                 ALOGW("Failed to read from native dispatch pipe: %s", strerror(errno));
    108             }
    109         } while (nRead > 0);
    110     }
    111 
    112     return *outEvent != NULL ? OK : WOULD_BLOCK;
    113 }
    114 
    115 bool InputQueue::preDispatchEvent(InputEvent* e) {
    116     if (e->getType() == AINPUT_EVENT_TYPE_KEY) {
    117         KeyEvent* keyEvent = static_cast<KeyEvent*>(e);
    118         if (keyEvent->getFlags() & AKEY_EVENT_FLAG_PREDISPATCH) {
    119             finishEvent(e, false);
    120             return true;
    121         }
    122     }
    123     return false;
    124 }
    125 
    126 void InputQueue::finishEvent(InputEvent* event, bool handled) {
    127     Mutex::Autolock _l(mLock);
    128     mFinishedEvents.push(key_value_pair_t<InputEvent*, bool>(event, handled));
    129     if (mFinishedEvents.size() == 1) {
    130         mDispatchLooper->sendMessage(this, Message(MSG_FINISH_INPUT));
    131     }
    132 }
    133 
    134 void InputQueue::handleMessage(const Message& message) {
    135     switch(message.what) {
    136     case MSG_FINISH_INPUT:
    137         JNIEnv* env = AndroidRuntime::getJNIEnv();
    138         ScopedLocalRef<jobject> inputQueueObj(env, jniGetReferent(env, mInputQueueWeakGlobal));
    139         if (!inputQueueObj.get()) {
    140             ALOGW("InputQueue was finalized without being disposed");
    141             return;
    142         }
    143         while (true) {
    144             InputEvent* event;
    145             bool handled;
    146             {
    147                 Mutex::Autolock _l(mLock);
    148                 if (mFinishedEvents.isEmpty()) {
    149                     break;
    150                 }
    151                 event = mFinishedEvents[0].getKey();
    152                 handled = mFinishedEvents[0].getValue();
    153                 mFinishedEvents.removeAt(0);
    154             }
    155             env->CallVoidMethod(inputQueueObj.get(), gInputQueueClassInfo.finishInputEvent,
    156                     reinterpret_cast<jlong>(event), handled);
    157             recycleInputEvent(event);
    158         }
    159         break;
    160     }
    161 }
    162 
    163 void InputQueue::recycleInputEvent(InputEvent* event) {
    164     mPooledInputEventFactory.recycle(event);
    165 }
    166 
    167 KeyEvent* InputQueue::createKeyEvent() {
    168     return mPooledInputEventFactory.createKeyEvent();
    169 }
    170 
    171 MotionEvent* InputQueue::createMotionEvent() {
    172     return mPooledInputEventFactory.createMotionEvent();
    173 }
    174 
    175 void InputQueue::enqueueEvent(InputEvent* event) {
    176     Mutex::Autolock _l(mLock);
    177     mPendingEvents.push(event);
    178     if (mPendingEvents.size() == 1) {
    179         char dummy = 0;
    180         int res = TEMP_FAILURE_RETRY(write(mDispatchWriteFd, &dummy, sizeof(dummy)));
    181         if (res < 0 && errno != EAGAIN) {
    182             ALOGW("Failed writing to dispatch fd: %s", strerror(errno));
    183         }
    184     }
    185 }
    186 
    187 InputQueue* InputQueue::createQueue(jobject inputQueueObj, const sp<Looper>& looper) {
    188     int pipeFds[2];
    189     if (pipe(pipeFds)) {
    190         ALOGW("Could not create native input dispatching pipe: %s", strerror(errno));
    191         return NULL;
    192     }
    193     fcntl(pipeFds[0], F_SETFL, O_NONBLOCK);
    194     fcntl(pipeFds[1], F_SETFL, O_NONBLOCK);
    195     return new InputQueue(inputQueueObj, looper, pipeFds[0], pipeFds[1]);
    196 }
    197 
    198 static jlong nativeInit(JNIEnv* env, jobject clazz, jobject queueWeak, jobject jMsgQueue) {
    199     sp<MessageQueue> messageQueue = android_os_MessageQueue_getMessageQueue(env, jMsgQueue);
    200     if (messageQueue == NULL) {
    201         jniThrowRuntimeException(env, "MessageQueue is not initialized.");
    202         return 0;
    203     }
    204     sp<InputQueue> queue = InputQueue::createQueue(queueWeak, messageQueue->getLooper());
    205     if (!queue.get()) {
    206         jniThrowRuntimeException(env, "InputQueue failed to initialize");
    207         return 0;
    208     }
    209     queue->incStrong(&gInputQueueClassInfo);
    210     return reinterpret_cast<jlong>(queue.get());
    211 }
    212 
    213 static void nativeDispose(JNIEnv* env, jobject clazz, jlong ptr) {
    214     sp<InputQueue> queue = reinterpret_cast<InputQueue*>(ptr);
    215     queue->detachLooper();
    216     queue->decStrong(&gInputQueueClassInfo);
    217 }
    218 
    219 static jlong nativeSendKeyEvent(JNIEnv* env, jobject clazz, jlong ptr, jobject eventObj,
    220         jboolean predispatch) {
    221     InputQueue* queue = reinterpret_cast<InputQueue*>(ptr);
    222     KeyEvent* event = queue->createKeyEvent();
    223     status_t status = android_view_KeyEvent_toNative(env, eventObj, event);
    224     if (status) {
    225         queue->recycleInputEvent(event);
    226         jniThrowRuntimeException(env, "Could not read contents of KeyEvent object.");
    227         return -1;
    228     }
    229 
    230     if (predispatch) {
    231         event->setFlags(event->getFlags() | AKEY_EVENT_FLAG_PREDISPATCH);
    232     }
    233 
    234     queue->enqueueEvent(event);
    235     return reinterpret_cast<jlong>(event);
    236 }
    237 
    238 static jlong nativeSendMotionEvent(JNIEnv* env, jobject clazz, jlong ptr, jobject eventObj) {
    239     sp<InputQueue> queue = reinterpret_cast<InputQueue*>(ptr);
    240     MotionEvent* originalEvent = android_view_MotionEvent_getNativePtr(env, eventObj);
    241     if (!originalEvent) {
    242         jniThrowRuntimeException(env, "Could not obtain MotionEvent pointer.");
    243         return -1;
    244     }
    245     MotionEvent* event = queue->createMotionEvent();
    246     event->copyFrom(originalEvent, true /* keepHistory */);
    247     queue->enqueueEvent(event);
    248     return reinterpret_cast<jlong>(event);
    249 }
    250 
    251 static const JNINativeMethod g_methods[] = {
    252     { "nativeInit", "(Ljava/lang/ref/WeakReference;Landroid/os/MessageQueue;)J",
    253         (void*) nativeInit },
    254     { "nativeDispose", "(J)V", (void*) nativeDispose },
    255     { "nativeSendKeyEvent", "(JLandroid/view/KeyEvent;Z)J", (void*) nativeSendKeyEvent },
    256     { "nativeSendMotionEvent", "(JLandroid/view/MotionEvent;)J", (void*) nativeSendMotionEvent },
    257 };
    258 
    259 static const char* const kInputQueuePathName = "android/view/InputQueue";
    260 
    261 int register_android_view_InputQueue(JNIEnv* env)
    262 {
    263     jclass clazz = FindClassOrDie(env, kInputQueuePathName);
    264     gInputQueueClassInfo.finishInputEvent = GetMethodIDOrDie(env, clazz, "finishInputEvent",
    265                                                              "(JZ)V");
    266 
    267     return RegisterMethodsOrDie(env, kInputQueuePathName, g_methods, NELEM(g_methods));
    268 }
    269 
    270 } // namespace android
    271