Optimize EventHub to process events in big chunks.
When 10 fingers are down, reduces the CPU time spent by the InputReader
thread from ~30% to ~5% on Stingray.
Change-Id: Icdf7c91cd5d9039ac3beb38ba9021a05e7fabc80
diff --git a/services/input/EventHub.cpp b/services/input/EventHub.cpp
index b90571b..65bc1b9 100644
--- a/services/input/EventHub.cpp
+++ b/services/input/EventHub.cpp
@@ -127,9 +127,11 @@
mError(NO_INIT), mBuiltInKeyboardId(-1), mNextDeviceId(1),
mOpeningDevices(0), mClosingDevices(0),
mOpened(false), mNeedToSendFinishedDeviceScan(false),
- mInputBufferIndex(0), mInputBufferCount(0), mInputFdIndex(0) {
+ mInputFdIndex(1) {
acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_ID);
+
memset(mSwitches, 0, sizeof(mSwitches));
+ mNumCpus = sysconf(_SC_NPROCESSORS_ONLN);
}
EventHub::~EventHub(void) {
@@ -445,17 +447,10 @@
return NULL;
}
-bool EventHub::getEvent(int timeoutMillis, RawEvent* outEvent) {
- outEvent->deviceId = 0;
- outEvent->type = 0;
- outEvent->scanCode = 0;
- outEvent->keyCode = 0;
- outEvent->flags = 0;
- outEvent->value = 0;
- outEvent->when = 0;
-
- // Note that we only allow one caller to getEvent(), so don't need
+size_t EventHub::getEvents(int timeoutMillis, RawEvent* buffer, size_t bufferSize) {
+ // Note that we only allow one caller to getEvents(), so don't need
// to do locking here... only when adding/removing devices.
+ assert(bufferSize >= 1);
if (!mOpened) {
mError = openPlatformInput() ? NO_ERROR : UNKNOWN_ERROR;
@@ -463,99 +458,62 @@
mNeedToSendFinishedDeviceScan = true;
}
+ struct input_event readBuffer[bufferSize];
+
+ RawEvent* event = buffer;
+ size_t capacity = bufferSize;
for (;;) {
+ nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+
// Report any devices that had last been added/removed.
- if (mClosingDevices != NULL) {
+ while (mClosingDevices) {
Device* device = mClosingDevices;
LOGV("Reporting device closed: id=%d, name=%s\n",
device->id, device->path.string());
mClosingDevices = device->next;
- if (device->id == mBuiltInKeyboardId) {
- outEvent->deviceId = 0;
- } else {
- outEvent->deviceId = device->id;
- }
- outEvent->type = DEVICE_REMOVED;
- outEvent->when = systemTime(SYSTEM_TIME_MONOTONIC);
+ event->when = now;
+ event->deviceId = device->id == mBuiltInKeyboardId ? 0 : device->id;
+ event->type = DEVICE_REMOVED;
+ event += 1;
delete device;
mNeedToSendFinishedDeviceScan = true;
- return true;
+ if (--capacity == 0) {
+ break;
+ }
}
- if (mOpeningDevices != NULL) {
+ while (mOpeningDevices != NULL) {
Device* device = mOpeningDevices;
LOGV("Reporting device opened: id=%d, name=%s\n",
device->id, device->path.string());
mOpeningDevices = device->next;
- if (device->id == mBuiltInKeyboardId) {
- outEvent->deviceId = 0;
- } else {
- outEvent->deviceId = device->id;
- }
- outEvent->type = DEVICE_ADDED;
- outEvent->when = systemTime(SYSTEM_TIME_MONOTONIC);
+ event->when = now;
+ event->deviceId = device->id == mBuiltInKeyboardId ? 0 : device->id;
+ event->type = DEVICE_ADDED;
+ event += 1;
mNeedToSendFinishedDeviceScan = true;
- return true;
+ if (--capacity == 0) {
+ break;
+ }
}
if (mNeedToSendFinishedDeviceScan) {
mNeedToSendFinishedDeviceScan = false;
- outEvent->type = FINISHED_DEVICE_SCAN;
- outEvent->when = systemTime(SYSTEM_TIME_MONOTONIC);
- return true;
+ event->when = now;
+ event->type = FINISHED_DEVICE_SCAN;
+ event += 1;
+ if (--capacity == 0) {
+ break;
+ }
}
// Grab the next input event.
+ // mInputFdIndex is initially 1 because index 0 is used for inotify.
bool deviceWasRemoved = false;
- for (;;) {
- // Consume buffered input events, if any.
- if (mInputBufferIndex < mInputBufferCount) {
- const struct input_event& iev = mInputBufferData[mInputBufferIndex++];
- const Device* device = mDevices[mInputFdIndex];
-
- LOGV("%s got: t0=%d, t1=%d, type=%d, code=%d, v=%d", device->path.string(),
- (int) iev.time.tv_sec, (int) iev.time.tv_usec, iev.type, iev.code, iev.value);
- if (device->id == mBuiltInKeyboardId) {
- outEvent->deviceId = 0;
- } else {
- outEvent->deviceId = device->id;
- }
- outEvent->type = iev.type;
- outEvent->scanCode = iev.code;
- outEvent->flags = 0;
- if (iev.type == EV_KEY) {
- outEvent->keyCode = AKEYCODE_UNKNOWN;
- if (device->keyMap.haveKeyLayout()) {
- status_t err = device->keyMap.keyLayoutMap->mapKey(iev.code,
- &outEvent->keyCode, &outEvent->flags);
- LOGV("iev.code=%d keyCode=%d flags=0x%08x err=%d\n",
- iev.code, outEvent->keyCode, outEvent->flags, err);
- }
- } else {
- outEvent->keyCode = iev.code;
- }
- outEvent->value = iev.value;
-
- // Use an event timestamp in the same timebase as
- // java.lang.System.nanoTime() and android.os.SystemClock.uptimeMillis()
- // as expected by the rest of the system.
- outEvent->when = systemTime(SYSTEM_TIME_MONOTONIC);
- return true;
- }
-
- // Finish reading all events from devices identified in previous poll().
- // This code assumes that mInputDeviceIndex is initially 0 and that the
- // revents member of pollfd is initialized to 0 when the device is first added.
- // Since mFds[0] is used for inotify, we process regular events starting at index 1.
- mInputFdIndex += 1;
- if (mInputFdIndex >= mFds.size()) {
- break;
- }
-
+ while (mInputFdIndex < mFds.size()) {
const struct pollfd& pfd = mFds[mInputFdIndex];
if (pfd.revents & POLLIN) {
- int32_t readSize = read(pfd.fd, mInputBufferData,
- sizeof(struct input_event) * INPUT_BUFFER_SIZE);
+ int32_t readSize = read(pfd.fd, readBuffer, sizeof(struct input_event) * capacity);
if (readSize < 0) {
if (errno == ENODEV) {
deviceWasRemoved = true;
@@ -566,11 +524,43 @@
}
} else if ((readSize % sizeof(struct input_event)) != 0) {
LOGE("could not get event (wrong size: %d)", readSize);
+ } else if (readSize == 0) { // eof
+ deviceWasRemoved = true;
+ break;
} else {
- mInputBufferCount = size_t(readSize) / sizeof(struct input_event);
- mInputBufferIndex = 0;
+ const Device* device = mDevices[mInputFdIndex];
+ 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++) {
+ const struct input_event& iev = readBuffer[i];
+ LOGV("%s got: t0=%d, t1=%d, 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);
+
+ event->when = now;
+ event->deviceId = deviceId;
+ event->type = iev.type;
+ event->scanCode = iev.code;
+ event->value = iev.value;
+ event->keyCode = AKEYCODE_UNKNOWN;
+ event->flags = 0;
+ if (iev.type == EV_KEY && device->keyMap.haveKeyLayout()) {
+ status_t err = device->keyMap.keyLayoutMap->mapKey(iev.code,
+ &event->keyCode, &event->flags);
+ LOGV("iev.code=%d keyCode=%d flags=0x%08x err=%d\n",
+ iev.code, event->keyCode, event->flags, err);
+ }
+ event += 1;
+ }
+ capacity -= count;
+ if (capacity == 0) {
+ break;
+ }
}
}
+ mInputFdIndex += 1;
}
// Handle the case where a device has been removed but INotify has not yet noticed.
@@ -586,10 +576,16 @@
if(mFds[0].revents & POLLIN) {
readNotify(mFds[0].fd);
mFds.editItemAt(0).revents = 0;
+ mInputFdIndex = mFds.size();
continue; // report added or removed devices immediately
}
#endif
+ // Return now if we have collected any events, otherwise poll.
+ if (event != buffer) {
+ break;
+ }
+
// Poll for events. Mind the wake lock dance!
// We hold a wake lock at all times except during poll(). This works due to some
// subtle choreography. When a device driver has pending (unread) events, it acquires
@@ -608,19 +604,36 @@
acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_ID);
if (pollResult == 0) {
- // Timed out.
- return false;
+ break; // timed out
}
if (pollResult < 0) {
+ // Sleep after errors to avoid locking up the system.
+ // Hopefully the error is transient.
if (errno != EINTR) {
LOGW("poll failed (errno=%d)\n", errno);
usleep(100000);
}
+ } else {
+ // On an SMP system, it is possible for the framework to read input events
+ // faster than the kernel input device driver can produce a complete packet.
+ // Because poll() wakes up as soon as the first input event becomes available,
+ // the framework will often end up reading one event at a time until the
+ // packet is complete. Instead of one call to read() returning 71 events,
+ // it could take 71 calls to read() each returning 1 event.
+ //
+ // Sleep for a short period of time after waking up from the poll() to give
+ // the kernel time to finish writing the entire packet of input events.
+ if (mNumCpus > 1) {
+ usleep(250);
+ }
}
// Prepare to process all of the FDs we just polled.
- mInputFdIndex = 0;
+ mInputFdIndex = 1;
}
+
+ // All done, return the number of events we read.
+ return event - buffer;
}
/*
diff --git a/services/input/EventHub.h b/services/input/EventHub.h
index 1d287ac..4d26a95 100644
--- a/services/input/EventHub.h
+++ b/services/input/EventHub.h
@@ -157,6 +157,8 @@
// Sent when all added/removed devices from the most recent scan have been reported.
// This event is always sent at least once.
FINISHED_DEVICE_SCAN = 0x30000000,
+
+ FIRST_SYNTHETIC_EVENT = DEVICE_ADDED,
};
virtual uint32_t getDeviceClasses(int32_t deviceId) const = 0;
@@ -181,7 +183,7 @@
virtual void addExcludedDevice(const char* deviceName) = 0;
/*
- * Wait for the next event to become available and return it.
+ * Wait for events to become available and returns them.
* After returning, the EventHub holds onto a wake lock until the next call to getEvent.
* This ensures that the device will not go to sleep while the event is being processed.
* If the device needs to remain awake longer than that, then the caller is responsible
@@ -190,9 +192,9 @@
* The timeout is advisory only. If the device is asleep, it will not wake just to
* service the timeout.
*
- * Returns true if an event was obtained, false if the timeout expired.
+ * Returns the number of events obtained, or 0 if the timeout expired.
*/
- virtual bool getEvent(int timeoutMillis, RawEvent* outEvent) = 0;
+ virtual size_t getEvents(int timeoutMillis, RawEvent* buffer, size_t bufferSize) = 0;
/*
* Query current input state.
@@ -249,7 +251,7 @@
virtual bool markSupportedKeyCodes(int32_t deviceId, size_t numCodes,
const int32_t* keyCodes, uint8_t* outFlags) const;
- virtual bool getEvent(int timeoutMillis, RawEvent* outEvent);
+ virtual size_t getEvents(int timeoutMillis, RawEvent* buffer, size_t bufferSize);
virtual bool hasLed(int32_t deviceId, int32_t led) const;
virtual void setLedState(int32_t deviceId, int32_t led, bool on);
@@ -336,11 +338,11 @@
// device ids that report particular switches.
int32_t mSwitches[SW_MAX + 1];
- static const int INPUT_BUFFER_SIZE = 64;
- struct input_event mInputBufferData[INPUT_BUFFER_SIZE];
- size_t mInputBufferIndex;
- size_t mInputBufferCount;
+ // The index of the next file descriptor that needs to be read.
size_t mInputFdIndex;
+
+ // Set to the number of CPUs.
+ int32_t mNumCpus;
};
}; // namespace android
diff --git a/services/input/InputReader.cpp b/services/input/InputReader.cpp
index 182bd50..94753bf 100644
--- a/services/input/InputReader.cpp
+++ b/services/input/InputReader.cpp
@@ -250,15 +250,11 @@
timeoutMillis = toMillisecondTimeoutDelay(now, mNextTimeout);
}
- RawEvent rawEvent;
- if (mEventHub->getEvent(timeoutMillis, &rawEvent)) {
-#if DEBUG_RAW_EVENTS
- LOGD("Input event: device=%d type=0x%04x scancode=0x%04x keycode=0x%04x value=0x%04x",
- rawEvent.deviceId, rawEvent.type, rawEvent.scanCode, rawEvent.keyCode,
- rawEvent.value);
-#endif
- process(&rawEvent);
- } else {
+ size_t count = mEventHub->getEvents(timeoutMillis, mEventBuffer, EVENT_BUFFER_SIZE);
+ if (count) {
+ processEvents(mEventBuffer, count);
+ }
+ if (!count || timeoutMillis == 0) {
nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
#if DEBUG_RAW_EVENTS
LOGD("Timeout expired, latency=%0.3fms", (now - mNextTimeout) * 0.000001f);
@@ -268,23 +264,41 @@
}
}
-void InputReader::process(const RawEvent* rawEvent) {
- switch (rawEvent->type) {
- case EventHubInterface::DEVICE_ADDED:
- addDevice(rawEvent->deviceId);
- break;
-
- case EventHubInterface::DEVICE_REMOVED:
- removeDevice(rawEvent->deviceId);
- break;
-
- case EventHubInterface::FINISHED_DEVICE_SCAN:
- handleConfigurationChanged(rawEvent->when);
- break;
-
- default:
- consumeEvent(rawEvent);
- break;
+void InputReader::processEvents(const RawEvent* rawEvents, size_t count) {
+ for (const RawEvent* rawEvent = rawEvents; count;) {
+ int32_t type = rawEvent->type;
+ size_t batchSize = 1;
+ if (type < EventHubInterface::FIRST_SYNTHETIC_EVENT) {
+ int32_t deviceId = rawEvent->deviceId;
+ while (batchSize < count) {
+ if (rawEvent[batchSize].type >= EventHubInterface::FIRST_SYNTHETIC_EVENT
+ || rawEvent[batchSize].deviceId != deviceId) {
+ break;
+ }
+ batchSize += 1;
+ }
+#if DEBUG_RAW_EVENTS
+ LOGD("BatchSize: %d Count: %d", batchSize, count);
+#endif
+ processEventsForDevice(deviceId, rawEvent, batchSize);
+ } else {
+ switch (rawEvent->type) {
+ case EventHubInterface::DEVICE_ADDED:
+ addDevice(rawEvent->deviceId);
+ break;
+ case EventHubInterface::DEVICE_REMOVED:
+ removeDevice(rawEvent->deviceId);
+ break;
+ case EventHubInterface::FINISHED_DEVICE_SCAN:
+ handleConfigurationChanged(rawEvent->when);
+ break;
+ default:
+ assert(false); // can't happen
+ break;
+ }
+ }
+ count -= batchSize;
+ rawEvent += batchSize;
}
}
@@ -405,9 +419,8 @@
return device;
}
-void InputReader::consumeEvent(const RawEvent* rawEvent) {
- int32_t deviceId = rawEvent->deviceId;
-
+void InputReader::processEventsForDevice(int32_t deviceId,
+ const RawEvent* rawEvents, size_t count) {
{ // acquire device registry reader lock
RWLock::AutoRLock _rl(mDeviceRegistryLock);
@@ -423,7 +436,7 @@
return;
}
- device->process(rawEvent);
+ device->process(rawEvents, count);
} // release device registry reader lock
}
@@ -785,11 +798,25 @@
}
}
-void InputDevice::process(const RawEvent* rawEvent) {
+void InputDevice::process(const RawEvent* rawEvents, size_t count) {
+ // Process all of the events in order for each mapper.
+ // We cannot simply ask each mapper to process them in bulk because mappers may
+ // have side-effects that must be interleaved. For example, joystick movement events and
+ // gamepad button presses are handled by different mappers but they should be dispatched
+ // in the order received.
size_t numMappers = mMappers.size();
- for (size_t i = 0; i < numMappers; i++) {
- InputMapper* mapper = mMappers[i];
- mapper->process(rawEvent);
+ for (const RawEvent* rawEvent = rawEvents; count--; rawEvent++) {
+#if DEBUG_RAW_EVENTS
+ LOGD("Input event: device=%d type=0x%04x scancode=0x%04x "
+ "keycode=0x%04x value=0x%04x flags=0x%08x",
+ rawEvent->deviceId, rawEvent->type, rawEvent->scanCode, rawEvent->keyCode,
+ rawEvent->value, rawEvent->flags);
+#endif
+
+ for (size_t i = 0; i < numMappers; i++) {
+ InputMapper* mapper = mMappers[i];
+ mapper->process(rawEvent);
+ }
}
}
diff --git a/services/input/InputReader.h b/services/input/InputReader.h
index fdb4cfc..cf9b13d 100644
--- a/services/input/InputReader.h
+++ b/services/input/InputReader.h
@@ -216,6 +216,10 @@
virtual InputDispatcherInterface* getDispatcher() { return mDispatcher.get(); }
virtual EventHubInterface* getEventHub() { return mEventHub.get(); }
+ // The event queue.
+ static const int EVENT_BUFFER_SIZE = 256;
+ RawEvent mEventBuffer[EVENT_BUFFER_SIZE];
+
// This reader/writer lock guards the list of input devices.
// The writer lock must be held whenever the list of input devices is modified
// and then promptly released.
@@ -228,16 +232,15 @@
KeyedVector<int32_t, InputDevice*> mDevices;
// low-level input event decoding and device management
- void process(const RawEvent* rawEvent);
+ void processEvents(const RawEvent* rawEvents, size_t count);
void addDevice(int32_t deviceId);
void removeDevice(int32_t deviceId);
- void configureExcludedDevices();
-
- void consumeEvent(const RawEvent* rawEvent);
+ void processEventsForDevice(int32_t deviceId, const RawEvent* rawEvents, size_t count);
void timeoutExpired(nsecs_t when);
void handleConfigurationChanged(nsecs_t when);
+ void configureExcludedDevices();
// state management for all devices
Mutex mStateLock;
@@ -251,12 +254,12 @@
InputConfiguration mInputConfiguration;
void updateInputConfiguration();
- nsecs_t mDisableVirtualKeysTimeout;
+ nsecs_t mDisableVirtualKeysTimeout; // only accessed by reader thread
virtual void disableVirtualKeysUntil(nsecs_t time);
virtual bool shouldDropVirtualKey(nsecs_t now,
InputDevice* device, int32_t keyCode, int32_t scanCode);
- nsecs_t mNextTimeout;
+ nsecs_t mNextTimeout; // only accessed by reader thread
virtual void requestTimeoutAtTime(nsecs_t when);
// state queries
@@ -301,7 +304,7 @@
void addMapper(InputMapper* mapper);
void configure();
void reset();
- void process(const RawEvent* rawEvent);
+ void process(const RawEvent* rawEvents, size_t count);
void timeoutExpired(nsecs_t when);
void getDeviceInfo(InputDeviceInfo* outDeviceInfo);
diff --git a/services/input/tests/InputReader_test.cpp b/services/input/tests/InputReader_test.cpp
index 120951d..b9174bf 100644
--- a/services/input/tests/InputReader_test.cpp
+++ b/services/input/tests/InputReader_test.cpp
@@ -610,14 +610,14 @@
mExcludedDevices.add(String8(deviceName));
}
- virtual bool getEvent(int timeoutMillis, RawEvent* outEvent) {
+ virtual size_t getEvents(int timeoutMillis, RawEvent* buffer, size_t bufferSize) {
if (mEvents.empty()) {
- return false;
+ return 0;
}
- *outEvent = *mEvents.begin();
+ *buffer = *mEvents.begin();
mEvents.erase(mEvents.begin());
- return true;
+ return 1;
}
virtual int32_t getScanCodeState(int32_t deviceId, int32_t scanCode) const {
@@ -1433,7 +1433,7 @@
// Event handling.
RawEvent event;
- mDevice->process(&event);
+ mDevice->process(&event, 1);
ASSERT_NO_FATAL_FAILURE(mapper1->assertProcessWasCalled());
ASSERT_NO_FATAL_FAILURE(mapper2->assertProcessWasCalled());