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/IDisplayEventConnection.h> 25 #include <gui/DisplayEventReceiver.h> 26 27 #include <utils/Errors.h> 28 #include <utils/String8.h> 29 #include <utils/Trace.h> 30 31 #include "EventThread.h" 32 #include "SurfaceFlinger.h" 33 34 // --------------------------------------------------------------------------- 35 namespace android { 36 // --------------------------------------------------------------------------- 37 // time to wait between VSYNC requests before sending a VSYNC OFF power hint: 40msec. 38 const long vsyncHintOffDelay = 40000000; 39 40 static void vsyncOffCallback(union sigval val) { 41 EventThread *ev = (EventThread *)val.sival_ptr; 42 ev->sendVsyncHintOff(); 43 return; 44 } 45 46 EventThread::EventThread(const sp<VSyncSource>& src, SurfaceFlinger& flinger, bool interceptVSyncs) 47 : mVSyncSource(src), 48 mFlinger(flinger), 49 mUseSoftwareVSync(false), 50 mVsyncEnabled(false), 51 mDebugVsyncEnabled(false), 52 mVsyncHintSent(false), 53 mInterceptVSyncs(interceptVSyncs) { 54 55 for (int32_t i=0 ; i<DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES ; i++) { 56 mVSyncEvent[i].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC; 57 mVSyncEvent[i].header.id = 0; 58 mVSyncEvent[i].header.timestamp = 0; 59 mVSyncEvent[i].vsync.count = 0; 60 } 61 struct sigevent se; 62 se.sigev_notify = SIGEV_THREAD; 63 se.sigev_value.sival_ptr = this; 64 se.sigev_notify_function = vsyncOffCallback; 65 se.sigev_notify_attributes = NULL; 66 timer_create(CLOCK_MONOTONIC, &se, &mTimerId); 67 } 68 69 void EventThread::sendVsyncHintOff() { 70 Mutex::Autolock _l(mLock); 71 mPowerHAL.vsyncHint(false); 72 mVsyncHintSent = false; 73 } 74 75 void EventThread::setPhaseOffset(nsecs_t phaseOffset) { 76 Mutex::Autolock _l(mLock); 77 mVSyncSource->setPhaseOffset(phaseOffset); 78 } 79 80 void EventThread::sendVsyncHintOnLocked() { 81 struct itimerspec ts; 82 if(!mVsyncHintSent) { 83 mPowerHAL.vsyncHint(true); 84 mVsyncHintSent = true; 85 } 86 ts.it_value.tv_sec = 0; 87 ts.it_value.tv_nsec = vsyncHintOffDelay; 88 ts.it_interval.tv_sec = 0; 89 ts.it_interval.tv_nsec = 0; 90 timer_settime(mTimerId, 0, &ts, NULL); 91 } 92 93 void EventThread::onFirstRef() { 94 run("EventThread", PRIORITY_URGENT_DISPLAY + PRIORITY_MORE_FAVORABLE); 95 } 96 97 sp<EventThread::Connection> EventThread::createEventConnection() const { 98 return new Connection(const_cast<EventThread*>(this)); 99 } 100 101 status_t EventThread::registerDisplayEventConnection( 102 const sp<EventThread::Connection>& connection) { 103 Mutex::Autolock _l(mLock); 104 mDisplayEventConnections.add(connection); 105 mCondition.broadcast(); 106 return NO_ERROR; 107 } 108 109 void EventThread::removeDisplayEventConnection( 110 const wp<EventThread::Connection>& connection) { 111 Mutex::Autolock _l(mLock); 112 mDisplayEventConnections.remove(connection); 113 } 114 115 void EventThread::setVsyncRate(uint32_t count, 116 const sp<EventThread::Connection>& connection) { 117 if (int32_t(count) >= 0) { // server must protect against bad params 118 Mutex::Autolock _l(mLock); 119 const int32_t new_count = (count == 0) ? -1 : count; 120 if (connection->count != new_count) { 121 connection->count = new_count; 122 mCondition.broadcast(); 123 } 124 } 125 } 126 127 void EventThread::requestNextVsync( 128 const sp<EventThread::Connection>& connection) { 129 Mutex::Autolock _l(mLock); 130 131 mFlinger.resyncWithRateLimit(); 132 133 if (connection->count < 0) { 134 connection->count = 0; 135 mCondition.broadcast(); 136 } 137 } 138 139 void EventThread::onScreenReleased() { 140 Mutex::Autolock _l(mLock); 141 if (!mUseSoftwareVSync) { 142 // disable reliance on h/w vsync 143 mUseSoftwareVSync = true; 144 mCondition.broadcast(); 145 } 146 } 147 148 void EventThread::onScreenAcquired() { 149 Mutex::Autolock _l(mLock); 150 if (mUseSoftwareVSync) { 151 // resume use of h/w vsync 152 mUseSoftwareVSync = false; 153 mCondition.broadcast(); 154 } 155 } 156 157 void EventThread::onVSyncEvent(nsecs_t timestamp) { 158 Mutex::Autolock _l(mLock); 159 mVSyncEvent[0].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC; 160 mVSyncEvent[0].header.id = 0; 161 mVSyncEvent[0].header.timestamp = timestamp; 162 mVSyncEvent[0].vsync.count++; 163 mCondition.broadcast(); 164 } 165 166 void EventThread::onHotplugReceived(int type, bool connected) { 167 ALOGE_IF(type >= DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES, 168 "received hotplug event for an invalid display (id=%d)", type); 169 170 Mutex::Autolock _l(mLock); 171 if (type < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES) { 172 DisplayEventReceiver::Event event; 173 event.header.type = DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG; 174 event.header.id = type; 175 event.header.timestamp = systemTime(); 176 event.hotplug.connected = connected; 177 mPendingEvents.add(event); 178 mCondition.broadcast(); 179 } 180 } 181 182 bool EventThread::threadLoop() { 183 DisplayEventReceiver::Event event; 184 Vector< sp<EventThread::Connection> > signalConnections; 185 signalConnections = waitForEvent(&event); 186 187 // dispatch events to listeners... 188 const size_t count = signalConnections.size(); 189 for (size_t i=0 ; i<count ; i++) { 190 const sp<Connection>& conn(signalConnections[i]); 191 // now see if we still need to report this event 192 status_t err = conn->postEvent(event); 193 if (err == -EAGAIN || err == -EWOULDBLOCK) { 194 // The destination doesn't accept events anymore, it's probably 195 // full. For now, we just drop the events on the floor. 196 // FIXME: Note that some events cannot be dropped and would have 197 // to be re-sent later. 198 // Right-now we don't have the ability to do this. 199 ALOGW("EventThread: dropping event (%08x) for connection %p", 200 event.header.type, conn.get()); 201 } else if (err < 0) { 202 // handle any other error on the pipe as fatal. the only 203 // reasonable thing to do is to clean-up this connection. 204 // The most common error we'll get here is -EPIPE. 205 removeDisplayEventConnection(signalConnections[i]); 206 } 207 } 208 return true; 209 } 210 211 // This will return when (1) a vsync event has been received, and (2) there was 212 // at least one connection interested in receiving it when we started waiting. 213 Vector< sp<EventThread::Connection> > EventThread::waitForEvent( 214 DisplayEventReceiver::Event* event) 215 { 216 Mutex::Autolock _l(mLock); 217 Vector< sp<EventThread::Connection> > signalConnections; 218 219 do { 220 bool eventPending = false; 221 bool waitForVSync = false; 222 223 size_t vsyncCount = 0; 224 nsecs_t timestamp = 0; 225 for (int32_t i=0 ; i<DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES ; i++) { 226 timestamp = mVSyncEvent[i].header.timestamp; 227 if (timestamp) { 228 // we have a vsync event to dispatch 229 if (mInterceptVSyncs) { 230 mFlinger.mInterceptor.saveVSyncEvent(timestamp); 231 } 232 *event = mVSyncEvent[i]; 233 mVSyncEvent[i].header.timestamp = 0; 234 vsyncCount = mVSyncEvent[i].vsync.count; 235 break; 236 } 237 } 238 239 if (!timestamp) { 240 // no vsync event, see if there are some other event 241 eventPending = !mPendingEvents.isEmpty(); 242 if (eventPending) { 243 // we have some other event to dispatch 244 *event = mPendingEvents[0]; 245 mPendingEvents.removeAt(0); 246 } 247 } 248 249 // find out connections waiting for events 250 size_t count = mDisplayEventConnections.size(); 251 for (size_t i=0 ; i<count ; i++) { 252 sp<Connection> connection(mDisplayEventConnections[i].promote()); 253 if (connection != NULL) { 254 bool added = false; 255 if (connection->count >= 0) { 256 // we need vsync events because at least 257 // one connection is waiting for it 258 waitForVSync = true; 259 if (timestamp) { 260 // we consume the event only if it's time 261 // (ie: we received a vsync event) 262 if (connection->count == 0) { 263 // fired this time around 264 connection->count = -1; 265 signalConnections.add(connection); 266 added = true; 267 } else if (connection->count == 1 || 268 (vsyncCount % connection->count) == 0) { 269 // continuous event, and time to report it 270 signalConnections.add(connection); 271 added = true; 272 } 273 } 274 } 275 276 if (eventPending && !timestamp && !added) { 277 // we don't have a vsync event to process 278 // (timestamp==0), but we have some pending 279 // messages. 280 signalConnections.add(connection); 281 } 282 } else { 283 // we couldn't promote this reference, the connection has 284 // died, so clean-up! 285 mDisplayEventConnections.removeAt(i); 286 --i; --count; 287 } 288 } 289 290 // Here we figure out if we need to enable or disable vsyncs 291 if (timestamp && !waitForVSync) { 292 // we received a VSYNC but we have no clients 293 // don't report it, and disable VSYNC events 294 disableVSyncLocked(); 295 } else if (!timestamp && waitForVSync) { 296 // we have at least one client, so we want vsync enabled 297 // (TODO: this function is called right after we finish 298 // notifying clients of a vsync, so this call will be made 299 // at the vsync rate, e.g. 60fps. If we can accurately 300 // track the current state we could avoid making this call 301 // so often.) 302 enableVSyncLocked(); 303 } 304 305 // note: !timestamp implies signalConnections.isEmpty(), because we 306 // don't populate signalConnections if there's no vsync pending 307 if (!timestamp && !eventPending) { 308 // wait for something to happen 309 if (waitForVSync) { 310 // This is where we spend most of our time, waiting 311 // for vsync events and new client registrations. 312 // 313 // If the screen is off, we can't use h/w vsync, so we 314 // use a 16ms timeout instead. It doesn't need to be 315 // precise, we just need to keep feeding our clients. 316 // 317 // We don't want to stall if there's a driver bug, so we 318 // use a (long) timeout when waiting for h/w vsync, and 319 // generate fake events when necessary. 320 bool softwareSync = mUseSoftwareVSync; 321 nsecs_t timeout = softwareSync ? ms2ns(16) : ms2ns(1000); 322 if (mCondition.waitRelative(mLock, timeout) == TIMED_OUT) { 323 if (!softwareSync) { 324 ALOGW("Timed out waiting for hw vsync; faking it"); 325 } 326 // FIXME: how do we decide which display id the fake 327 // vsync came from ? 328 mVSyncEvent[0].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC; 329 mVSyncEvent[0].header.id = DisplayDevice::DISPLAY_PRIMARY; 330 mVSyncEvent[0].header.timestamp = systemTime(SYSTEM_TIME_MONOTONIC); 331 mVSyncEvent[0].vsync.count++; 332 } 333 } else { 334 // Nobody is interested in vsync, so we just want to sleep. 335 // h/w vsync should be disabled, so this will wait until we 336 // get a new connection, or an existing connection becomes 337 // interested in receiving vsync again. 338 mCondition.wait(mLock); 339 } 340 } 341 } while (signalConnections.isEmpty()); 342 343 // here we're guaranteed to have a timestamp and some connections to signal 344 // (The connections might have dropped out of mDisplayEventConnections 345 // while we were asleep, but we'll still have strong references to them.) 346 return signalConnections; 347 } 348 349 void EventThread::enableVSyncLocked() { 350 if (!mUseSoftwareVSync) { 351 // never enable h/w VSYNC when screen is off 352 if (!mVsyncEnabled) { 353 mVsyncEnabled = true; 354 mVSyncSource->setCallback(static_cast<VSyncSource::Callback*>(this)); 355 mVSyncSource->setVSyncEnabled(true); 356 } 357 } 358 mDebugVsyncEnabled = true; 359 sendVsyncHintOnLocked(); 360 } 361 362 void EventThread::disableVSyncLocked() { 363 if (mVsyncEnabled) { 364 mVsyncEnabled = false; 365 mVSyncSource->setVSyncEnabled(false); 366 mDebugVsyncEnabled = false; 367 } 368 } 369 370 void EventThread::dump(String8& result) const { 371 Mutex::Autolock _l(mLock); 372 result.appendFormat("VSYNC state: %s\n", 373 mDebugVsyncEnabled?"enabled":"disabled"); 374 result.appendFormat(" soft-vsync: %s\n", 375 mUseSoftwareVSync?"enabled":"disabled"); 376 result.appendFormat(" numListeners=%zu,\n events-delivered: %u\n", 377 mDisplayEventConnections.size(), 378 mVSyncEvent[DisplayDevice::DISPLAY_PRIMARY].vsync.count); 379 for (size_t i=0 ; i<mDisplayEventConnections.size() ; i++) { 380 sp<Connection> connection = 381 mDisplayEventConnections.itemAt(i).promote(); 382 result.appendFormat(" %p: count=%d\n", 383 connection.get(), connection!=NULL ? connection->count : 0); 384 } 385 } 386 387 // --------------------------------------------------------------------------- 388 389 EventThread::Connection::Connection( 390 const sp<EventThread>& eventThread) 391 : count(-1), mEventThread(eventThread), mChannel(gui::BitTube::DefaultSize) 392 { 393 } 394 395 EventThread::Connection::~Connection() { 396 // do nothing here -- clean-up will happen automatically 397 // when the main thread wakes up 398 } 399 400 void EventThread::Connection::onFirstRef() { 401 // NOTE: mEventThread doesn't hold a strong reference on us 402 mEventThread->registerDisplayEventConnection(this); 403 } 404 405 status_t EventThread::Connection::stealReceiveChannel(gui::BitTube* outChannel) { 406 outChannel->setReceiveFd(mChannel.moveReceiveFd()); 407 return NO_ERROR; 408 } 409 410 status_t EventThread::Connection::setVsyncRate(uint32_t count) { 411 mEventThread->setVsyncRate(count, this); 412 return NO_ERROR; 413 } 414 415 void EventThread::Connection::requestNextVsync() { 416 mEventThread->requestNextVsync(this); 417 } 418 419 status_t EventThread::Connection::postEvent( 420 const DisplayEventReceiver::Event& event) { 421 ssize_t size = DisplayEventReceiver::sendEvents(&mChannel, &event, 1); 422 return size < 0 ? status_t(size) : status_t(NO_ERROR); 423 } 424 425 // --------------------------------------------------------------------------- 426 427 }; // namespace android 428
