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 ATRACE_TAG ATRACE_TAG_GRAPHICS 18 19#include <stdint.h> 20#include <sys/types.h> 21 22#include <cutils/compiler.h> 23 24#include <gui/BitTube.h> 25#include <gui/IDisplayEventConnection.h> 26#include <gui/DisplayEventReceiver.h> 27 28#include <utils/Errors.h> 29#include <utils/String8.h> 30#include <utils/Trace.h> 31 32#include "EventThread.h" 33#include "SurfaceFlinger.h" 34 35// --------------------------------------------------------------------------- 36namespace android { 37// --------------------------------------------------------------------------- 38 39EventThread::EventThread(const sp<SurfaceFlinger>& flinger) 40 : mFlinger(flinger), 41 mUseSoftwareVSync(false), 42 mDebugVsyncEnabled(false) { 43 44 for (int32_t i=0 ; i<HWC_DISPLAY_TYPES_SUPPORTED ; i++) { 45 mVSyncEvent[i].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC; 46 mVSyncEvent[i].header.id = 0; 47 mVSyncEvent[i].header.timestamp = 0; 48 mVSyncEvent[i].vsync.count = 0; 49 } 50} 51 52void EventThread::onFirstRef() { 53 run("EventThread", PRIORITY_URGENT_DISPLAY + PRIORITY_MORE_FAVORABLE); 54} 55 56sp<EventThread::Connection> EventThread::createEventConnection() const { 57 return new Connection(const_cast<EventThread*>(this)); 58} 59 60status_t EventThread::registerDisplayEventConnection( 61 const sp<EventThread::Connection>& connection) { 62 Mutex::Autolock _l(mLock); 63 mDisplayEventConnections.add(connection); 64 mCondition.broadcast(); 65 return NO_ERROR; 66} 67 68void EventThread::removeDisplayEventConnection( 69 const wp<EventThread::Connection>& connection) { 70 Mutex::Autolock _l(mLock); 71 mDisplayEventConnections.remove(connection); 72} 73 74void EventThread::setVsyncRate(uint32_t count, 75 const sp<EventThread::Connection>& connection) { 76 if (int32_t(count) >= 0) { // server must protect against bad params 77 Mutex::Autolock _l(mLock); 78 const int32_t new_count = (count == 0) ? -1 : count; 79 if (connection->count != new_count) { 80 connection->count = new_count; 81 mCondition.broadcast(); 82 } 83 } 84} 85 86void EventThread::requestNextVsync( 87 const sp<EventThread::Connection>& connection) { 88 Mutex::Autolock _l(mLock); 89 if (connection->count < 0) { 90 connection->count = 0; 91 mCondition.broadcast(); 92 } 93} 94 95void EventThread::onScreenReleased() { 96 Mutex::Autolock _l(mLock); 97 if (!mUseSoftwareVSync) { 98 // disable reliance on h/w vsync 99 mUseSoftwareVSync = true; 100 mCondition.broadcast(); 101 } 102} 103 104void EventThread::onScreenAcquired() { 105 Mutex::Autolock _l(mLock); 106 if (mUseSoftwareVSync) { 107 // resume use of h/w vsync 108 mUseSoftwareVSync = false; 109 mCondition.broadcast(); 110 } 111} 112 113 114void EventThread::onVSyncReceived(int type, nsecs_t timestamp) { 115 ALOGE_IF(type >= HWC_DISPLAY_TYPES_SUPPORTED, 116 "received event for an invalid display (id=%d)", type); 117 118 Mutex::Autolock _l(mLock); 119 if (type < HWC_DISPLAY_TYPES_SUPPORTED) { 120 mVSyncEvent[type].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC; 121 mVSyncEvent[type].header.id = type; 122 mVSyncEvent[type].header.timestamp = timestamp; 123 mVSyncEvent[type].vsync.count++; 124 mCondition.broadcast(); 125 } 126} 127 128void EventThread::onHotplugReceived(int type, bool connected) { 129 ALOGE_IF(type >= HWC_DISPLAY_TYPES_SUPPORTED, 130 "received event for an invalid display (id=%d)", type); 131 132 Mutex::Autolock _l(mLock); 133 if (type < HWC_DISPLAY_TYPES_SUPPORTED) { 134 DisplayEventReceiver::Event event; 135 event.header.type = DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG; 136 event.header.id = type; 137 event.header.timestamp = systemTime(); 138 event.hotplug.connected = connected; 139 mPendingEvents.add(event); 140 mCondition.broadcast(); 141 } 142} 143 144bool EventThread::threadLoop() { 145 DisplayEventReceiver::Event event; 146 Vector< sp<EventThread::Connection> > signalConnections; 147 signalConnections = waitForEvent(&event); 148 149 // dispatch events to listeners... 150 const size_t count = signalConnections.size(); 151 for (size_t i=0 ; i<count ; i++) { 152 const sp<Connection>& conn(signalConnections[i]); 153 // now see if we still need to report this event 154 status_t err = conn->postEvent(event); 155 if (err == -EAGAIN || err == -EWOULDBLOCK) { 156 // The destination doesn't accept events anymore, it's probably 157 // full. For now, we just drop the events on the floor. 158 // FIXME: Note that some events cannot be dropped and would have 159 // to be re-sent later. 160 // Right-now we don't have the ability to do this. 161 ALOGW("EventThread: dropping event (%08x) for connection %p", 162 event.header.type, conn.get()); 163 } else if (err < 0) { 164 // handle any other error on the pipe as fatal. the only 165 // reasonable thing to do is to clean-up this connection. 166 // The most common error we'll get here is -EPIPE. 167 removeDisplayEventConnection(signalConnections[i]); 168 } 169 } 170 return true; 171} 172 173// This will return when (1) a vsync event has been received, and (2) there was 174// at least one connection interested in receiving it when we started waiting. 175Vector< sp<EventThread::Connection> > EventThread::waitForEvent( 176 DisplayEventReceiver::Event* event) 177{ 178 Mutex::Autolock _l(mLock); 179 Vector< sp<EventThread::Connection> > signalConnections; 180 181 do { 182 bool eventPending = false; 183 bool waitForVSync = false; 184 185 size_t vsyncCount = 0; 186 nsecs_t timestamp = 0; 187 for (int32_t i=0 ; i<HWC_DISPLAY_TYPES_SUPPORTED ; i++) { 188 timestamp = mVSyncEvent[i].header.timestamp; 189 if (timestamp) { 190 // we have a vsync event to dispatch 191 *event = mVSyncEvent[i]; 192 mVSyncEvent[i].header.timestamp = 0; 193 vsyncCount = mVSyncEvent[i].vsync.count; 194 break; 195 } 196 } 197 198 if (!timestamp) { 199 // no vsync event, see if there are some other event 200 eventPending = !mPendingEvents.isEmpty(); 201 if (eventPending) { 202 // we have some other event to dispatch 203 *event = mPendingEvents[0]; 204 mPendingEvents.removeAt(0); 205 } 206 } 207 208 // find out connections waiting for events 209 size_t count = mDisplayEventConnections.size(); 210 for (size_t i=0 ; i<count ; i++) { 211 sp<Connection> connection(mDisplayEventConnections[i].promote()); 212 if (connection != NULL) { 213 bool added = false; 214 if (connection->count >= 0) { 215 // we need vsync events because at least 216 // one connection is waiting for it 217 waitForVSync = true; 218 if (timestamp) { 219 // we consume the event only if it's time 220 // (ie: we received a vsync event) 221 if (connection->count == 0) { 222 // fired this time around 223 connection->count = -1; 224 signalConnections.add(connection); 225 added = true; 226 } else if (connection->count == 1 || 227 (vsyncCount % connection->count) == 0) { 228 // continuous event, and time to report it 229 signalConnections.add(connection); 230 added = true; 231 } 232 } 233 } 234 235 if (eventPending && !timestamp && !added) { 236 // we don't have a vsync event to process 237 // (timestamp==0), but we have some pending 238 // messages. 239 signalConnections.add(connection); 240 } 241 } else { 242 // we couldn't promote this reference, the connection has 243 // died, so clean-up! 244 mDisplayEventConnections.removeAt(i); 245 --i; --count; 246 } 247 } 248 249 // Here we figure out if we need to enable or disable vsyncs 250 if (timestamp && !waitForVSync) { 251 // we received a VSYNC but we have no clients 252 // don't report it, and disable VSYNC events 253 disableVSyncLocked(); 254 } else if (!timestamp && waitForVSync) { 255 // we have at least one client, so we want vsync enabled 256 // (TODO: this function is called right after we finish 257 // notifying clients of a vsync, so this call will be made 258 // at the vsync rate, e.g. 60fps. If we can accurately 259 // track the current state we could avoid making this call 260 // so often.) 261 enableVSyncLocked(); 262 } 263 264 // note: !timestamp implies signalConnections.isEmpty(), because we 265 // don't populate signalConnections if there's no vsync pending 266 if (!timestamp && !eventPending) { 267 // wait for something to happen 268 if (waitForVSync) { 269 // This is where we spend most of our time, waiting 270 // for vsync events and new client registrations. 271 // 272 // If the screen is off, we can't use h/w vsync, so we 273 // use a 16ms timeout instead. It doesn't need to be 274 // precise, we just need to keep feeding our clients. 275 // 276 // We don't want to stall if there's a driver bug, so we 277 // use a (long) timeout when waiting for h/w vsync, and 278 // generate fake events when necessary. 279 bool softwareSync = mUseSoftwareVSync; 280 nsecs_t timeout = softwareSync ? ms2ns(16) : ms2ns(1000); 281 if (mCondition.waitRelative(mLock, timeout) == TIMED_OUT) { 282 if (!softwareSync) { 283 ALOGW("Timed out waiting for hw vsync; faking it"); 284 } 285 // FIXME: how do we decide which display id the fake 286 // vsync came from ? 287 mVSyncEvent[0].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC; 288 mVSyncEvent[0].header.id = HWC_DISPLAY_PRIMARY; 289 mVSyncEvent[0].header.timestamp = systemTime(SYSTEM_TIME_MONOTONIC); 290 mVSyncEvent[0].vsync.count++; 291 } 292 } else { 293 // Nobody is interested in vsync, so we just want to sleep. 294 // h/w vsync should be disabled, so this will wait until we 295 // get a new connection, or an existing connection becomes 296 // interested in receiving vsync again. 297 mCondition.wait(mLock); 298 } 299 } 300 } while (signalConnections.isEmpty()); 301 302 // here we're guaranteed to have a timestamp and some connections to signal 303 // (The connections might have dropped out of mDisplayEventConnections 304 // while we were asleep, but we'll still have strong references to them.) 305 return signalConnections; 306} 307 308void EventThread::enableVSyncLocked() { 309 if (!mUseSoftwareVSync) { 310 // never enable h/w VSYNC when screen is off 311 mFlinger->eventControl(HWC_DISPLAY_PRIMARY, SurfaceFlinger::EVENT_VSYNC, true); 312 mPowerHAL.vsyncHint(true); 313 } 314 mDebugVsyncEnabled = true; 315} 316 317void EventThread::disableVSyncLocked() { 318 mFlinger->eventControl(HWC_DISPLAY_PRIMARY, SurfaceFlinger::EVENT_VSYNC, false); 319 mPowerHAL.vsyncHint(false); 320 mDebugVsyncEnabled = false; 321} 322 323void EventThread::dump(String8& result, char* buffer, size_t SIZE) const { 324 Mutex::Autolock _l(mLock); 325 result.appendFormat("VSYNC state: %s\n", 326 mDebugVsyncEnabled?"enabled":"disabled"); 327 result.appendFormat(" soft-vsync: %s\n", 328 mUseSoftwareVSync?"enabled":"disabled"); 329 result.appendFormat(" numListeners=%u,\n events-delivered: %u\n", 330 mDisplayEventConnections.size(), 331 mVSyncEvent[HWC_DISPLAY_PRIMARY].vsync.count); 332 for (size_t i=0 ; i<mDisplayEventConnections.size() ; i++) { 333 sp<Connection> connection = 334 mDisplayEventConnections.itemAt(i).promote(); 335 result.appendFormat(" %p: count=%d\n", 336 connection.get(), connection!=NULL ? connection->count : 0); 337 } 338} 339 340// --------------------------------------------------------------------------- 341 342EventThread::Connection::Connection( 343 const sp<EventThread>& eventThread) 344 : count(-1), mEventThread(eventThread), mChannel(new BitTube()) 345{ 346} 347 348EventThread::Connection::~Connection() { 349 // do nothing here -- clean-up will happen automatically 350 // when the main thread wakes up 351} 352 353void EventThread::Connection::onFirstRef() { 354 // NOTE: mEventThread doesn't hold a strong reference on us 355 mEventThread->registerDisplayEventConnection(this); 356} 357 358sp<BitTube> EventThread::Connection::getDataChannel() const { 359 return mChannel; 360} 361 362void EventThread::Connection::setVsyncRate(uint32_t count) { 363 mEventThread->setVsyncRate(count, this); 364} 365 366void EventThread::Connection::requestNextVsync() { 367 mEventThread->requestNextVsync(this); 368} 369 370status_t EventThread::Connection::postEvent( 371 const DisplayEventReceiver::Event& event) { 372 ssize_t size = DisplayEventReceiver::sendEvents(mChannel, &event, 1); 373 return size < 0 ? status_t(size) : status_t(NO_ERROR); 374} 375 376// --------------------------------------------------------------------------- 377 378}; // namespace android 379