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 <androidfw/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)36 DisplayEventDispatcher::DisplayEventDispatcher(const sp<Looper>& looper,
37 ISurfaceComposer::VsyncSource vsyncSource) :
38 mLooper(looper), mReceiver(vsyncSource), mWaitingForVsync(false) {
39 ALOGV("dispatcher %p ~ Initializing display event dispatcher.", this);
40 }
41
initialize()42 status_t DisplayEventDispatcher::initialize() {
43 status_t result = mReceiver.initCheck();
44 if (result) {
45 ALOGW("Failed to initialize display event receiver, status=%d", result);
46 return result;
47 }
48
49 int rc = mLooper->addFd(mReceiver.getFd(), 0, Looper::EVENT_INPUT,
50 this, NULL);
51 if (rc < 0) {
52 return UNKNOWN_ERROR;
53 }
54 return OK;
55 }
56
dispose()57 void DisplayEventDispatcher::dispose() {
58 ALOGV("dispatcher %p ~ Disposing display event dispatcher.", this);
59
60 if (!mReceiver.initCheck()) {
61 mLooper->removeFd(mReceiver.getFd());
62 }
63 }
64
scheduleVsync()65 status_t DisplayEventDispatcher::scheduleVsync() {
66 if (!mWaitingForVsync) {
67 ALOGV("dispatcher %p ~ Scheduling vsync.", this);
68
69 // Drain all pending events.
70 nsecs_t vsyncTimestamp;
71 PhysicalDisplayId vsyncDisplayId;
72 uint32_t vsyncCount;
73 if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) {
74 ALOGE("dispatcher %p ~ last event processed while scheduling was for %" PRId64 "",
75 this, ns2ms(static_cast<nsecs_t>(vsyncTimestamp)));
76 }
77
78 status_t status = mReceiver.requestNextVsync();
79 if (status) {
80 ALOGW("Failed to request next vsync, status=%d", status);
81 return status;
82 }
83
84 mWaitingForVsync = true;
85 }
86 return OK;
87 }
88
handleEvent(int,int events,void *)89 int DisplayEventDispatcher::handleEvent(int, int events, void*) {
90 if (events & (Looper::EVENT_ERROR | Looper::EVENT_HANGUP)) {
91 ALOGE("Display event receiver pipe was closed or an error occurred. "
92 "events=0x%x", events);
93 return 0; // remove the callback
94 }
95
96 if (!(events & Looper::EVENT_INPUT)) {
97 ALOGW("Received spurious callback for unhandled poll event. "
98 "events=0x%x", events);
99 return 1; // keep the callback
100 }
101
102 // Drain all pending events, keep the last vsync.
103 nsecs_t vsyncTimestamp;
104 PhysicalDisplayId vsyncDisplayId;
105 uint32_t vsyncCount;
106 if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) {
107 ALOGV("dispatcher %p ~ Vsync pulse: timestamp=%" PRId64 ", displayId=%"
108 ANDROID_PHYSICAL_DISPLAY_ID_FORMAT ", count=%d",
109 this, ns2ms(vsyncTimestamp), vsyncDisplayId, vsyncCount);
110 mWaitingForVsync = false;
111 dispatchVsync(vsyncTimestamp, vsyncDisplayId, vsyncCount);
112 }
113
114 return 1; // keep the callback
115 }
116
processPendingEvents(nsecs_t * outTimestamp,PhysicalDisplayId * outDisplayId,uint32_t * outCount)117 bool DisplayEventDispatcher::processPendingEvents(
118 nsecs_t* outTimestamp, PhysicalDisplayId* outDisplayId, uint32_t* outCount) {
119 bool gotVsync = false;
120 DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE];
121 ssize_t n;
122 while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) {
123 ALOGV("dispatcher %p ~ Read %d events.", this, int(n));
124 for (ssize_t i = 0; i < n; i++) {
125 const DisplayEventReceiver::Event& ev = buf[i];
126 switch (ev.header.type) {
127 case DisplayEventReceiver::DISPLAY_EVENT_VSYNC:
128 // Later vsync events will just overwrite the info from earlier
129 // ones. That's fine, we only care about the most recent.
130 gotVsync = true;
131 *outTimestamp = ev.header.timestamp;
132 *outDisplayId = ev.header.displayId;
133 *outCount = ev.vsync.count;
134 break;
135 case DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG:
136 dispatchHotplug(ev.header.timestamp, ev.header.displayId, ev.hotplug.connected);
137 break;
138 case DisplayEventReceiver::DISPLAY_EVENT_CONFIG_CHANGED:
139 dispatchConfigChanged(ev.header.timestamp, ev.header.displayId, ev.config.configId);
140 break;
141 default:
142 ALOGW("dispatcher %p ~ ignoring unknown event type %#x", this, ev.header.type);
143 break;
144 }
145 }
146 }
147 if (n < 0) {
148 ALOGW("Failed to get events from display event dispatcher, status=%d", status_t(n));
149 }
150 return gotVsync;
151 }
152 }
153