input key and Touch
Android 输入事件的一般流程
EventHub
- EventHub 事件枢纽，可以多路复用监听/dev/input/目录 文件的变化；
- getEvents步骤：
(1) . 开始循环执行，直至已经收集了任何事件，或者我们被显式地唤醒，现在返回。
a. Reopen input devices if needed.
b. Report any devices that had last been added/removed.
c. scan devices if Needed, add devices / remove devices.
d. product adding devices event if needed.
e. product finishing scan devices event if needed.
f. start grab the next input event really. //多路复用监听fd,
g. readNotify()将修改设备列表，因此必须在处理所有其他事件之后完 成，以确保在关闭设备之前读取所有剩余事件。
h. 若上一个动作g执行,Report added or removed devices immediately.
i. 如果我们已经收集了任何事件，或者我们被显式地唤醒，现在返回。
多路复用监听事件补充：
/*
man help:
EPOLLIN 连接到达；有数据来临；
The associated file is available for read(2) operations.
EPOLLOUT 有数据要写
The associated file is available for write(2) operations.
EPOLLRDHUP 表示读关闭。
如果有EPOLLRDHUP，检测它就可以直到是对方关闭；否则就用上面方法。
EPOLLHUP 表示读写都关闭。
*/
if (eventItem.events & EPOLLIN) {
...
} else if (eventItem.events & EPOLLHUP) {
ALOGI("Removing device %s due to epoll hang-up event.",
device->identifier.name.string());
deviceChanged = true;
closeDeviceLocked(device);
} else {
ALOGW("Received unexpected epoll event 0x%08x for device %s.",
eventItem.events, device->identifier.name.string());
}
EventHub getEvents 函数：
size_t EventHub::getEvents(int timeoutMillis, RawEvent* buffer, size_t bufferSize) {
ALOG_ASSERT(bufferSize >= 1);
AutoMutex _l(mLock);
struct input_event readBuffer[bufferSize];
RawEvent* event = buffer;
size_t capacity = bufferSize;
bool awoken = false;
for (;;) {
nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
// Reopen input devices if needed.
if (mNeedToReopenDevices) {
mNeedToReopenDevices = false;
ALOGI("Reopening all input devices due to a configuration change.");
closeAllDevicesLocked();
mNeedToScanDevices = true;
break; // return to the caller before we actually rescan
}
// Report any devices that had last been added/removed.
while (mClosingDevices) {
Device* device = mClosingDevices;
ALOGV("Reporting device closed: id=%d, name=%s\n",
device->id, device->path.string());
mClosingDevices = device->next;
event->when = now;
event->deviceId = device->id == mBuiltInKeyboardId ? BUILT_IN_KEYBOARD_ID : device->id;
event->type = DEVICE_REMOVED;
event += 1;
delete device;
mNeedToSendFinishedDeviceScan = true;
if (--capacity == 0) {
break;
}
}
if (mNeedToScanDevices) {
mNeedToScanDevices = false;
scanDevicesLocked();
mNeedToSendFinishedDeviceScan = true;
}
while (mOpeningDevices != NULL) {
Device* device = mOpeningDevices;
ALOGV("Reporting device opened: id=%d, name=%s\n",
device->id, device->path.string());
mOpeningDevices = device->next;
event->when = now;
event->deviceId = device->id == mBuiltInKeyboardId ? 0 : device->id;
event->type = DEVICE_ADDED;
event += 1;
mNeedToSendFinishedDeviceScan = true;
if (--capacity == 0) {
break;
}
}
if (mNeedToSendFinishedDeviceScan) {
mNeedToSendFinishedDeviceScan = false;
event->when = now;
event->type = FINISHED_DEVICE_SCAN;
event += 1;
if (--capacity == 0) {
break;
}
}
// Grab the next input event.
bool deviceChanged = false;
while (mPendingEventIndex < mPendingEventCount) {
const struct epoll_event& eventItem = mPendingEventItems[mPendingEventIndex++];
if (eventItem.data.u32 == EPOLL_ID_INOTIFY) {
if (eventItem.events & EPOLLIN) {
mPendingINotify = true;
} else {
ALOGW("Received unexpected epoll event 0x%08x for INotify.", eventItem.events);
}
continue;
}
if (eventItem.data.u32 == EPOLL_ID_WAKE) {
if (eventItem.events & EPOLLIN) {
ALOGV("awoken after wake()");
awoken = true;
char buffer[16];
ssize_t nRead;
do {
nRead = read(mWakeReadPipeFd, buffer, sizeof(buffer));
} while ((nRead == -1 && errno == EINTR) || nRead == sizeof(buffer));
} else {
ALOGW("Received unexpected epoll event 0x%08x for wake read pipe.",
eventItem.events);
}
continue;
}
ssize_t deviceIndex = mDevices.indexOfKey(eventItem.data.u32);
if (deviceIndex < 0) {
ALOGW("Received unexpected epoll event 0x%08x for unknown device id %d.",
eventItem.events, eventItem.data.u32);
continue;
}
Device* device = mDevices.valueAt(deviceIndex);
if (eventItem.events & EPOLLIN) {
int32_t readSize = read(device->fd, readBuffer,
sizeof(struct input_event) * capacity);
if (readSize == 0 || (readSize < 0 && errno == ENODEV)) {
// Device was removed before INotify noticed.
ALOGW("could not get event, removed? (fd: %d size: %" PRId32
" bufferSize: %zu capacity: %zu errno: %d)\n",
device->fd, readSize, bufferSize, capacity, errno);
deviceChanged = true;
closeDeviceLocked(device);
} else if (readSize < 0) {
if (errno != EAGAIN && errno != EINTR) {
ALOGW("could not get event (errno=%d)", errno);
}
} else if ((readSize % sizeof(struct input_event)) != 0) {
ALOGE("could not get event (wrong size: %d)", readSize);
} else {
int32_t deviceId = device->id == mBuiltInKeyboardId ? 0 : device->id;
size_t count = size_t(readSize) / sizeof(struct input_event);
for (size_t i = 0; i < count; i++) {
struct input_event& iev = readBuffer[i];
ALOGV("%s got: time=%d.%06d, type=%d, code=%d, value=%d",
device->path.string(),
(int) iev.time.tv_sec, (int) iev.time.tv_usec,
iev.type, iev.code, iev.value);
// Some input devices may have a better concept of the time
// when an input event was actually generated than the kernel
// which simply timestamps all events on entry to evdev.
// This is a custom Android extension of the input protocol
// mainly intended for use with uinput based device drivers.
if (iev.type == EV_MSC) {
if (iev.code == MSC_ANDROID_TIME_SEC) {
device->timestampOverrideSec = iev.value;
continue;
} else if (iev.code == MSC_ANDROID_TIME_USEC) {
device->timestampOverrideUsec = iev.value;
continue;
}
}
if (device->timestampOverrideSec || device->timestampOverrideUsec) {
iev.time.tv_sec = device->timestampOverrideSec;
iev.time.tv_usec = device->timestampOverrideUsec;
if (iev.type == EV_SYN && iev.code == SYN_REPORT) {
device->timestampOverrideSec = 0;
device->timestampOverrideUsec = 0;
}
ALOGV("applied override time %d.%06d",
int(iev.time.tv_sec), int(iev.time.tv_usec));
}
// Use the time specified in the event instead of the current time
// so that downstream code can get more accurate estimates of
// event dispatch latency from the time the event is enqueued onto
// the evdev client buffer.
//
// The event's timestamp fortuitously uses the same monotonic clock
// time base as the rest of Android. The kernel event device driver
// (drivers/input/evdev.c) obtains timestamps using ktime_get_ts().
// The systemTime(SYSTEM_TIME_MONOTONIC) function we use everywhere
// calls clock_gettime(CLOCK_MONOTONIC) which is implemented as a
// system call that also queries ktime_get_ts().
event->when = nsecs_t(iev.time.tv_sec) * 1000000000LL
+ nsecs_t(iev.time.tv_usec) * 1000LL;
ALOGV("event time %" PRId64 ", now %" PRId64, event->when, now);
// Bug 7291243: Add a guard in case the kernel generates timestamps
// that appear to be far into the future because they were generated
// using the wrong clock source.
//
// This can happen because when the input device is initially opened
// it has a default clock source of CLOCK_REALTIME. Any input events
// enqueued right after the device is opened will have timestamps
// generated using CLOCK_REALTIME. We later set the clock source
// to CLOCK_MONOTONIC but it is already too late.
//
// Invalid input event timestamps can result in ANRs, crashes and
// and other issues that are hard to track down. We must not let them
// propagate through the system.
//
// Log a warning so that we notice the problem and recover gracefully.
if (event->when >= now + 10 * 1000000000LL) {
// Double-check. Time may have moved on.
nsecs_t time = systemTime(SYSTEM_TIME_MONOTONIC);
if (event->when > time) {
ALOGW("An input event from %s has a timestamp that appears to "
"have been generated using the wrong clock source "
"(expected CLOCK_MONOTONIC): "
"event time %" PRId64 ", current time %" PRId64
", call time %" PRId64 ". "
"Using current time instead.",
device->path.string(), event->when, time, now);
event->when = time;
} else {
ALOGV("Event time is ok but failed the fast path and required "
"an extra call to systemTime: "
"event time %" PRId64 ", current time %" PRId64
", call time %" PRId64 ".",
event->when, time, now);
}
}
event->deviceId = deviceId;
event->type = iev.type;
event->code = iev.code;
event->value = iev.value;
event += 1;
capacity -= 1;
}
if (capacity == 0) {
// The result buffer is full. Reset the pending event index
// so we will try to read the device again on the next iteration.
mPendingEventIndex -= 1;
break;
}
}
} else if (eventItem.events & EPOLLHUP) {
ALOGI("Removing device %s due to epoll hang-up event.",
device->identifier.name.string());
deviceChanged = true;
closeDeviceLocked(device);
} else {
ALOGW("Received unexpected epoll event 0x%08x for device %s.",
eventItem.events, device->identifier.name.string());
}
}
// readNotify() will modify the list of devices so this must be done after
// processing all other events to ensure that we read all remaining events
// before closing the devices.
if (mPendingINotify && mPendingEventIndex >= mPendingEventCount) {
mPendingINotify = false;
readNotifyLocked();
deviceChanged = true;
}
// Report added or removed devices immediately.
if (deviceChanged) {
continue;
}
// Return now if we have collected any events or if we were explicitly awoken.
if (event != buffer || awoken) {
break;
}
// Poll for events. Mind the wake lock dance!
// We hold a wake lock at all times except during epoll_wait(). This works due to some
// subtle choreography. When a device driver has pending (unread) events, it acquires
// a kernel wake lock. However, once the last pending event has been read, the device
// driver will release the kernel wake lock. To prevent the system from going to sleep
// when this happens, the EventHub holds onto its own user wake lock while the client
// is processing events. Thus the system can only sleep if there are no events
// pending or currently being processed.
//
// The timeout is advisory only. If the device is asleep, it will not wake just to
// service the timeout.
mPendingEventIndex = 0;
mLock.unlock(); // release lock before poll, must be before release_wake_lock
release_wake_lock(WAKE_LOCK_ID);
int pollResult = epoll_wait(mEpollFd, mPendingEventItems, EPOLL_MAX_EVENTS, timeoutMillis);
acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_ID);
mLock.lock(); // reacquire lock after poll, must be after acquire_wake_lock
if (pollResult == 0) {
// Timed out.
mPendingEventCount = 0;
break;
}
if (pollResult < 0) {
// An error occurred.
mPendingEventCount = 0;
// Sleep after errors to avoid locking up the system.
// Hopefully the error is transient.
if (errno != EINTR) {
ALOGW("poll failed (errno=%d)\n", errno);
usleep(100000);
}
} else {
// Some events occurred.
mPendingEventCount = size_t(pollResult);
}
}
// All done, return the number of events we read.
return event - buffer;
}
InputRead
- InputManager 启动的一个线程主要用于循环去通过EventHub监听事件
InputDispatcher
- inputManager 启动的一个线程主要用于循环的派发事件；
InputManager
- 主要用来管理InputReader 和 InputDispatcher;
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "InputManager"
//#define LOG_NDEBUG 0
#include "InputManager.h"
#include <cutils/log.h>
namespace android {
InputManager::InputManager(
const sp<EventHubInterface>& eventHub,
const sp<InputReaderPolicyInterface>& readerPolicy,
const sp<InputDispatcherPolicyInterface>& dispatcherPolicy) {
mDispatcher = new InputDispatcher(dispatcherPolicy);
mReader = new InputReader(eventHub, readerPolicy, mDispatcher);
initialize();
}
InputManager::InputManager(
const sp<InputReaderInterface>& reader,
const sp<InputDispatcherInterface>& dispatcher) :
mReader(reader),
mDispatcher(dispatcher) {
initialize();
}
InputManager::~InputManager() {
stop();
}
void InputManager::initialize() {
mReaderThread = new InputReaderThread(mReader);
mDispatcherThread = new InputDispatcherThread(mDispatcher);
}
status_t InputManager::start() {
status_t result = mDispatcherThread->run("InputDispatcher", PRIORITY_URGENT_DISPLAY);
if (result) {
ALOGE("Could not start InputDispatcher thread due to error %d.", result);
return result;
}
result = mReaderThread->run("InputReader", PRIORITY_URGENT_DISPLAY);
if (result) {
ALOGE("Could not start InputReader thread due to error %d.", result);
mDispatcherThread->requestExit();
return result;
}
return OK;
}
status_t InputManager::stop() {
status_t result = mReaderThread->requestExitAndWait();
if (result) {
ALOGW("Could not stop InputReader thread due to error %d.", result);
}
result = mDispatcherThread->requestExitAndWait();
if (result) {
ALOGW("Could not stop InputDispatcher thread due to error %d.", result);
}
return OK;
}
sp<InputReaderInterface> InputManager::getReader() {
return mReader;
}
sp<InputDispatcherInterface> InputManager::getDispatcher() {
return mDispatcher;
}
} // namespace android
Key
常见debug 工具 或 命令
- input 自动化测试常用(命令每次重新执行通过app_process是用来调用java代码的，耗时1到2s ，可以做优化)
- dumpsys input 调试常用，可以查看当前按键和触屏情况；
- 打开开发者选项的命令：
settings put secure user_setup_complete 1
settings put global device_provisioned 1
am start -n com.android.launcher/com.android.launcher2.Launcher - 控制log的相关命令：
关闭所有log: setprop persist.log.tag S
打开指定TAG的log： setprop persist.log.tag.TAG V - kill -3 PID命令获取java应用堆栈信息,一般可以用来调查APP无法接受按键和触屏事件的内部原因
Android 框架Key原理
dumpsys input:
Event Hub State:
BuiltInKeyboardId: 5
Devices:
-1: Virtual
Classes: 0x40000023
Path: <virtual>
Enabled: true
Descriptor: a718a782d34bc767f4689c232d64d527998ea7fd
Location:
ControllerNumber: 0
UniqueId: <virtual>
Identifier: bus=0x0000, vendor=0x0000, product=0x0000, version=0x0000
KeyLayoutFile: /system/usr/keylayout/Generic.kl
KeyCharacterMapFile: /system/usr/keychars/Virtual.kcm
ConfigurationFile:
HaveKeyboardLayoutOverlay: false
Input Reader State:
Device -1: Virtual
Generation: 2
IsExternal: false
HasMic: false
Sources: 0x00000301
KeyboardType: 2
Keyboard Input Mapper:
Parameters:
HasAssociatedDisplay: false
OrientationAware: false
HandlesKeyRepeat: false
KeyboardType: 2
Orientation: 0
KeyDowns: 0 keys currently down
MetaState: 0x0
DownTime: 0
根据个人的项目经验， KeyLayoutFile条目中看到加载的按键映射文件，都是根据厂商ID和产品ID匹配对应文件的，例如vendor为0x3697，product 为0x0001，那么对应的配置文件为/system/usr/keylayout/Vendor_3697_Product_0001.kl.
常见需求
Touch
常见debug 工具
Android 框架Touch原理
常见需求
来源：oschina
链接：https://my.oschina.net/u/4303989/blog/4480015