1/* 2 * Copyright (C) 2011 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 "DisplayEventReceiver" 18 19//#define LOG_NDEBUG 0 20 21 22#include "JNIHelp.h" 23 24#include <android_runtime/AndroidRuntime.h> 25#include <utils/Log.h> 26#include <utils/Looper.h> 27#include <utils/threads.h> 28#include <gui/DisplayEventReceiver.h> 29#include "android_os_MessageQueue.h" 30 31namespace android { 32 33// Number of events to read at a time from the DisplayEventReceiver pipe. 34// The value should be large enough that we can quickly drain the pipe 35// using just a few large reads. 36static const size_t EVENT_BUFFER_SIZE = 100; 37 38static struct { 39 jclass clazz; 40 41 jmethodID dispatchVsync; 42 jmethodID dispatchHotplug; 43} gDisplayEventReceiverClassInfo; 44 45 46class NativeDisplayEventReceiver : public LooperCallback { 47public: 48 NativeDisplayEventReceiver(JNIEnv* env, 49 jobject receiverObj, const sp<MessageQueue>& messageQueue); 50 51 status_t initialize(); 52 void dispose(); 53 status_t scheduleVsync(); 54 55protected: 56 virtual ~NativeDisplayEventReceiver(); 57 58private: 59 jobject mReceiverObjGlobal; 60 sp<MessageQueue> mMessageQueue; 61 DisplayEventReceiver mReceiver; 62 bool mWaitingForVsync; 63 64 virtual int handleEvent(int receiveFd, int events, void* data); 65 bool readLastVsyncMessage(nsecs_t* outTimestamp, int32_t* id, uint32_t* outCount); 66 void dispatchVsync(nsecs_t timestamp, int32_t id, uint32_t count); 67 void dispatchHotplug(nsecs_t timestamp, int32_t id, bool connected); 68}; 69 70 71NativeDisplayEventReceiver::NativeDisplayEventReceiver(JNIEnv* env, 72 jobject receiverObj, const sp<MessageQueue>& messageQueue) : 73 mReceiverObjGlobal(env->NewGlobalRef(receiverObj)), 74 mMessageQueue(messageQueue), mWaitingForVsync(false) { 75 ALOGV("receiver %p ~ Initializing input event receiver.", this); 76} 77 78NativeDisplayEventReceiver::~NativeDisplayEventReceiver() { 79 JNIEnv* env = AndroidRuntime::getJNIEnv(); 80 env->DeleteGlobalRef(mReceiverObjGlobal); 81} 82 83status_t NativeDisplayEventReceiver::initialize() { 84 status_t result = mReceiver.initCheck(); 85 if (result) { 86 ALOGW("Failed to initialize display event receiver, status=%d", result); 87 return result; 88 } 89 90 int rc = mMessageQueue->getLooper()->addFd(mReceiver.getFd(), 0, ALOOPER_EVENT_INPUT, 91 this, NULL); 92 if (rc < 0) { 93 return UNKNOWN_ERROR; 94 } 95 return OK; 96} 97 98void NativeDisplayEventReceiver::dispose() { 99 ALOGV("receiver %p ~ Disposing display event receiver.", this); 100 101 if (!mReceiver.initCheck()) { 102 mMessageQueue->getLooper()->removeFd(mReceiver.getFd()); 103 } 104} 105 106status_t NativeDisplayEventReceiver::scheduleVsync() { 107 if (!mWaitingForVsync) { 108 ALOGV("receiver %p ~ Scheduling vsync.", this); 109 110 // Drain all pending events. 111 nsecs_t vsyncTimestamp; 112 int32_t vsyncDisplayId; 113 uint32_t vsyncCount; 114 readLastVsyncMessage(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount); 115 116 status_t status = mReceiver.requestNextVsync(); 117 if (status) { 118 ALOGW("Failed to request next vsync, status=%d", status); 119 return status; 120 } 121 122 mWaitingForVsync = true; 123 } 124 return OK; 125} 126 127int NativeDisplayEventReceiver::handleEvent(int receiveFd, int events, void* data) { 128 if (events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP)) { 129 ALOGE("Display event receiver pipe was closed or an error occurred. " 130 "events=0x%x", events); 131 return 0; // remove the callback 132 } 133 134 if (!(events & ALOOPER_EVENT_INPUT)) { 135 ALOGW("Received spurious callback for unhandled poll event. " 136 "events=0x%x", events); 137 return 1; // keep the callback 138 } 139 140 // Drain all pending events, keep the last vsync. 141 nsecs_t vsyncTimestamp; 142 int32_t vsyncDisplayId; 143 uint32_t vsyncCount; 144 if (!readLastVsyncMessage(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) { 145 ALOGV("receiver %p ~ Woke up but there was no vsync pulse!", this); 146 return 1; // keep the callback, did not obtain a vsync pulse 147 } 148 149 ALOGV("receiver %p ~ Vsync pulse: timestamp=%lld, id=%d, count=%d", 150 this, vsyncTimestamp, vsyncDisplayId, vsyncCount); 151 mWaitingForVsync = false; 152 153 dispatchVsync(vsyncTimestamp, vsyncDisplayId, vsyncCount); 154 return 1; // keep the callback 155} 156 157bool NativeDisplayEventReceiver::readLastVsyncMessage( 158 nsecs_t* outTimestamp, int32_t* outId, uint32_t* outCount) { 159 DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE]; 160 ssize_t n; 161 while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) { 162 ALOGV("receiver %p ~ Read %d events.", this, int(n)); 163 while (n-- > 0) { 164 const DisplayEventReceiver::Event& ev = buf[n]; 165 if (ev.header.type == DisplayEventReceiver::DISPLAY_EVENT_VSYNC) { 166 *outTimestamp = ev.header.timestamp; 167 *outId = ev.header.id; 168 *outCount = ev.vsync.count; 169 return true; // stop at last vsync in the buffer 170 } 171 172 if (ev.header.type == DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG) { 173 dispatchHotplug(ev.header.timestamp, ev.header.id, ev.hotplug.connected); 174 } 175 } 176 } 177 if (n < 0) { 178 ALOGW("Failed to get events from display event receiver, status=%d", status_t(n)); 179 } 180 return false; 181} 182 183void NativeDisplayEventReceiver::dispatchVsync(nsecs_t timestamp, int32_t id, uint32_t count) { 184 JNIEnv* env = AndroidRuntime::getJNIEnv(); 185 186 ALOGV("receiver %p ~ Invoking vsync handler.", this); 187 env->CallVoidMethod(mReceiverObjGlobal, 188 gDisplayEventReceiverClassInfo.dispatchVsync, timestamp, id, count); 189 ALOGV("receiver %p ~ Returned from vsync handler.", this); 190 191 mMessageQueue->raiseAndClearException(env, "dispatchVsync"); 192} 193 194void NativeDisplayEventReceiver::dispatchHotplug(nsecs_t timestamp, int32_t id, bool connected) { 195 JNIEnv* env = AndroidRuntime::getJNIEnv(); 196 197 ALOGV("receiver %p ~ Invoking hotplug handler.", this); 198 env->CallVoidMethod(mReceiverObjGlobal, 199 gDisplayEventReceiverClassInfo.dispatchHotplug, timestamp, id, connected); 200 ALOGV("receiver %p ~ Returned from hotplug handler.", this); 201 202 mMessageQueue->raiseAndClearException(env, "dispatchHotplug"); 203} 204 205 206static jint nativeInit(JNIEnv* env, jclass clazz, jobject receiverObj, 207 jobject messageQueueObj) { 208 sp<MessageQueue> messageQueue = android_os_MessageQueue_getMessageQueue(env, messageQueueObj); 209 if (messageQueue == NULL) { 210 jniThrowRuntimeException(env, "MessageQueue is not initialized."); 211 return 0; 212 } 213 214 sp<NativeDisplayEventReceiver> receiver = new NativeDisplayEventReceiver(env, 215 receiverObj, messageQueue); 216 status_t status = receiver->initialize(); 217 if (status) { 218 String8 message; 219 message.appendFormat("Failed to initialize display event receiver. status=%d", status); 220 jniThrowRuntimeException(env, message.string()); 221 return 0; 222 } 223 224 receiver->incStrong(gDisplayEventReceiverClassInfo.clazz); // retain a reference for the object 225 return reinterpret_cast<jint>(receiver.get()); 226} 227 228static void nativeDispose(JNIEnv* env, jclass clazz, jint receiverPtr) { 229 sp<NativeDisplayEventReceiver> receiver = 230 reinterpret_cast<NativeDisplayEventReceiver*>(receiverPtr); 231 receiver->dispose(); 232 receiver->decStrong(gDisplayEventReceiverClassInfo.clazz); // drop reference held by the object 233} 234 235static void nativeScheduleVsync(JNIEnv* env, jclass clazz, jint receiverPtr) { 236 sp<NativeDisplayEventReceiver> receiver = 237 reinterpret_cast<NativeDisplayEventReceiver*>(receiverPtr); 238 status_t status = receiver->scheduleVsync(); 239 if (status) { 240 String8 message; 241 message.appendFormat("Failed to schedule next vertical sync pulse. status=%d", status); 242 jniThrowRuntimeException(env, message.string()); 243 } 244} 245 246 247static JNINativeMethod gMethods[] = { 248 /* name, signature, funcPtr */ 249 { "nativeInit", 250 "(Landroid/view/DisplayEventReceiver;Landroid/os/MessageQueue;)I", 251 (void*)nativeInit }, 252 { "nativeDispose", 253 "(I)V", 254 (void*)nativeDispose }, 255 { "nativeScheduleVsync", "(I)V", 256 (void*)nativeScheduleVsync } 257}; 258 259#define FIND_CLASS(var, className) \ 260 var = env->FindClass(className); \ 261 LOG_FATAL_IF(! var, "Unable to find class " className); \ 262 var = jclass(env->NewGlobalRef(var)); 263 264#define GET_METHOD_ID(var, clazz, methodName, methodDescriptor) \ 265 var = env->GetMethodID(clazz, methodName, methodDescriptor); \ 266 LOG_FATAL_IF(! var, "Unable to find method " methodName); 267 268int register_android_view_DisplayEventReceiver(JNIEnv* env) { 269 int res = jniRegisterNativeMethods(env, "android/view/DisplayEventReceiver", 270 gMethods, NELEM(gMethods)); 271 LOG_FATAL_IF(res < 0, "Unable to register native methods."); 272 273 FIND_CLASS(gDisplayEventReceiverClassInfo.clazz, "android/view/DisplayEventReceiver"); 274 275 GET_METHOD_ID(gDisplayEventReceiverClassInfo.dispatchVsync, 276 gDisplayEventReceiverClassInfo.clazz, 277 "dispatchVsync", "(JII)V"); 278 GET_METHOD_ID(gDisplayEventReceiverClassInfo.dispatchHotplug, 279 gDisplayEventReceiverClassInfo.clazz, 280 "dispatchHotplug", "(JIZ)V"); 281 return 0; 282} 283 284} // namespace android 285