2 * Copyright (C) 2015 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #define LOG_TAG "DisplayEventDispatcher"
22 #include <androidfw/DisplayEventDispatcher.h>
23 #include <gui/DisplayEventReceiver.h>
24 #include <utils/Log.h>
25 #include <utils/Looper.h>
27 #include <utils/Timers.h>
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;
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);
42 status_t DisplayEventDispatcher::initialize() {
43 status_t result = mReceiver.initCheck();
45 ALOGW("Failed to initialize display event receiver, status=%d", result);
49 int rc = mLooper->addFd(mReceiver.getFd(), 0, Looper::EVENT_INPUT,
57 void DisplayEventDispatcher::dispose() {
58 ALOGV("dispatcher %p ~ Disposing display event dispatcher.", this);
60 if (!mReceiver.initCheck()) {
61 mLooper->removeFd(mReceiver.getFd());
65 status_t DisplayEventDispatcher::scheduleVsync() {
66 if (!mWaitingForVsync) {
67 ALOGV("dispatcher %p ~ Scheduling vsync.", this);
69 // Drain all pending events.
70 nsecs_t vsyncTimestamp;
71 int32_t vsyncDisplayId;
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)));
78 status_t status = mReceiver.requestNextVsync();
80 ALOGW("Failed to request next vsync, status=%d", status);
84 mWaitingForVsync = true;
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
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
102 // Drain all pending events, keep the last vsync.
103 nsecs_t vsyncTimestamp;
104 int32_t vsyncDisplayId;
106 if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) {
107 ALOGV("dispatcher %p ~ Vsync pulse: timestamp=%" PRId64 ", id=%d, count=%d",
108 this, ns2ms(vsyncTimestamp), vsyncDisplayId, vsyncCount);
109 mWaitingForVsync = false;
110 dispatchVsync(vsyncTimestamp, vsyncDisplayId, vsyncCount);
113 return 1; // keep the callback
116 bool DisplayEventDispatcher::processPendingEvents(
117 nsecs_t* outTimestamp, int32_t* outId, uint32_t* outCount) {
118 bool gotVsync = false;
119 DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE];
121 while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) {
122 ALOGV("dispatcher %p ~ Read %d events.", this, int(n));
123 for (ssize_t i = 0; i < n; i++) {
124 const DisplayEventReceiver::Event& ev = buf[i];
125 switch (ev.header.type) {
126 case DisplayEventReceiver::DISPLAY_EVENT_VSYNC:
127 // Later vsync events will just overwrite the info from earlier
128 // ones. That's fine, we only care about the most recent.
130 *outTimestamp = ev.header.timestamp;
131 *outId = ev.header.id;
132 *outCount = ev.vsync.count;
134 case DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG:
135 dispatchHotplug(ev.header.timestamp, ev.header.id, ev.hotplug.connected);
138 ALOGW("dispatcher %p ~ ignoring unknown event type %#x", this, ev.header.type);
144 ALOGW("Failed to get events from display event dispatcher, status=%d", status_t(n));