1 /*
2 * Copyright (C) 2015 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 "DisplayEventDispatcher"
18
19 #include <cinttypes>
20 #include <cstdint>
21
22 #include <gui/DisplayEventDispatcher.h>
23 #include <gui/DisplayEventReceiver.h>
24 #include <utils/Log.h>
25 #include <utils/Looper.h>
26
27 #include <utils/Timers.h>
28
29 namespace android {
30
31 // Number of events to read at a time from the DisplayEventDispatcher pipe.
32 // The value should be large enough that we can quickly drain the pipe
33 // using just a few large reads.
34 static const size_t EVENT_BUFFER_SIZE = 100;
35
DisplayEventDispatcher(const sp<Looper> & looper,ISurfaceComposer::VsyncSource vsyncSource,ISurfaceComposer::ConfigChanged configChanged)36 DisplayEventDispatcher::DisplayEventDispatcher(const sp<Looper>& looper,
37 ISurfaceComposer::VsyncSource vsyncSource,
38 ISurfaceComposer::ConfigChanged configChanged)
39 : mLooper(looper), mReceiver(vsyncSource, configChanged), mWaitingForVsync(false) {
40 ALOGV("dispatcher %p ~ Initializing display event dispatcher.", this);
41 }
42
initialize()43 status_t DisplayEventDispatcher::initialize() {
44 status_t result = mReceiver.initCheck();
45 if (result) {
46 ALOGW("Failed to initialize display event receiver, status=%d", result);
47 return result;
48 }
49
50 if (mLooper != nullptr) {
51 int rc = mLooper->addFd(mReceiver.getFd(), 0, Looper::EVENT_INPUT, this, NULL);
52 if (rc < 0) {
53 return UNKNOWN_ERROR;
54 }
55 }
56
57 return OK;
58 }
59
dispose()60 void DisplayEventDispatcher::dispose() {
61 ALOGV("dispatcher %p ~ Disposing display event dispatcher.", this);
62
63 if (!mReceiver.initCheck() && mLooper != nullptr) {
64 mLooper->removeFd(mReceiver.getFd());
65 }
66 }
67
scheduleVsync()68 status_t DisplayEventDispatcher::scheduleVsync() {
69 if (!mWaitingForVsync) {
70 ALOGV("dispatcher %p ~ Scheduling vsync.", this);
71
72 // Drain all pending events.
73 nsecs_t vsyncTimestamp;
74 PhysicalDisplayId vsyncDisplayId;
75 uint32_t vsyncCount;
76 if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) {
77 ALOGE("dispatcher %p ~ last event processed while scheduling was for %" PRId64 "", this,
78 ns2ms(static_cast<nsecs_t>(vsyncTimestamp)));
79 }
80
81 status_t status = mReceiver.requestNextVsync();
82 if (status) {
83 ALOGW("Failed to request next vsync, status=%d", status);
84 return status;
85 }
86
87 mWaitingForVsync = true;
88 }
89 return OK;
90 }
91
injectEvent(const DisplayEventReceiver::Event & event)92 void DisplayEventDispatcher::injectEvent(const DisplayEventReceiver::Event& event) {
93 mReceiver.sendEvents(&event, 1);
94 }
95
getFd() const96 int DisplayEventDispatcher::getFd() const {
97 return mReceiver.getFd();
98 }
99
handleEvent(int,int events,void *)100 int DisplayEventDispatcher::handleEvent(int, int events, void*) {
101 if (events & (Looper::EVENT_ERROR | Looper::EVENT_HANGUP)) {
102 ALOGE("Display event receiver pipe was closed or an error occurred. "
103 "events=0x%x",
104 events);
105 return 0; // remove the callback
106 }
107
108 if (!(events & Looper::EVENT_INPUT)) {
109 ALOGW("Received spurious callback for unhandled poll event. "
110 "events=0x%x",
111 events);
112 return 1; // keep the callback
113 }
114
115 // Drain all pending events, keep the last vsync.
116 nsecs_t vsyncTimestamp;
117 PhysicalDisplayId vsyncDisplayId;
118 uint32_t vsyncCount;
119 if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) {
120 ALOGV("dispatcher %p ~ Vsync pulse: timestamp=%" PRId64
121 ", displayId=%" ANDROID_PHYSICAL_DISPLAY_ID_FORMAT ", count=%d",
122 this, ns2ms(vsyncTimestamp), vsyncDisplayId, vsyncCount);
123 mWaitingForVsync = false;
124 dispatchVsync(vsyncTimestamp, vsyncDisplayId, vsyncCount);
125 }
126
127 return 1; // keep the callback
128 }
129
processPendingEvents(nsecs_t * outTimestamp,PhysicalDisplayId * outDisplayId,uint32_t * outCount)130 bool DisplayEventDispatcher::processPendingEvents(nsecs_t* outTimestamp,
131 PhysicalDisplayId* outDisplayId,
132 uint32_t* outCount) {
133 bool gotVsync = false;
134 DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE];
135 ssize_t n;
136 while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) {
137 ALOGV("dispatcher %p ~ Read %d events.", this, int(n));
138 for (ssize_t i = 0; i < n; i++) {
139 const DisplayEventReceiver::Event& ev = buf[i];
140 switch (ev.header.type) {
141 case DisplayEventReceiver::DISPLAY_EVENT_VSYNC:
142 // Later vsync events will just overwrite the info from earlier
143 // ones. That's fine, we only care about the most recent.
144 gotVsync = true;
145 *outTimestamp = ev.header.timestamp;
146 *outDisplayId = ev.header.displayId;
147 *outCount = ev.vsync.count;
148 break;
149 case DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG:
150 dispatchHotplug(ev.header.timestamp, ev.header.displayId, ev.hotplug.connected);
151 break;
152 case DisplayEventReceiver::DISPLAY_EVENT_CONFIG_CHANGED:
153 dispatchConfigChanged(ev.header.timestamp, ev.header.displayId,
154 ev.config.configId, ev.config.vsyncPeriod);
155 break;
156 case DisplayEventReceiver::DISPLAY_EVENT_NULL:
157 dispatchNullEvent(ev.header.timestamp, ev.header.displayId);
158 break;
159 default:
160 ALOGW("dispatcher %p ~ ignoring unknown event type %#x", this, ev.header.type);
161 break;
162 }
163 }
164 }
165 if (n < 0) {
166 ALOGW("Failed to get events from display event dispatcher, status=%d", status_t(n));
167 }
168 return gotVsync;
169 }
170
171 } // namespace android
172