libgui: Remove RefBase from BitTube
Removes RefBase from BitTube, since because it is not a Binder object,
it doesn't need to be reference-counted in this way.
In the process, we rename IDisplayEventConnection::getDataChannel to
IDEC::stealReceiveChannel to make it clearer that this is a non-const
operation on the remote end that removes its access to the receive
channel.
This also adds a couple of methods for moving the receive file
descriptor out of one BitTube and into another, since this is the
essence of the IDisplayEventConnection::stealReceiveChannel method,
and now with C++11 move semantics, we can do this without needing to
return an sp<> from EventThread's implementation of stealReceiveChannel.
Test: m -j + manual testing
Change-Id: Ibaaca2a14fb6155052fe5434c14bc3e671b43743
diff --git a/include/gui/DisplayEventReceiver.h b/include/gui/DisplayEventReceiver.h
index 6d1ab5d..9557b4f 100644
--- a/include/gui/DisplayEventReceiver.h
+++ b/include/gui/DisplayEventReceiver.h
@@ -111,15 +111,13 @@
* should be destroyed and getEvents() shouldn't be called again.
*/
ssize_t getEvents(Event* events, size_t count);
- static ssize_t getEvents(const sp<gui::BitTube>& dataChannel,
- Event* events, size_t count);
+ static ssize_t getEvents(gui::BitTube* dataChannel, Event* events, size_t count);
/*
* sendEvents write events to the queue and returns how many events were
* written.
*/
- static ssize_t sendEvents(const sp<gui::BitTube>& dataChannel,
- Event const* events, size_t count);
+ static ssize_t sendEvents(gui::BitTube* dataChannel, Event const* events, size_t count);
/*
* setVsyncRate() sets the Event::VSync delivery rate. A value of
@@ -137,7 +135,7 @@
private:
sp<IDisplayEventConnection> mEventConnection;
- sp<gui::BitTube> mDataChannel;
+ std::unique_ptr<gui::BitTube> mDataChannel;
};
// ----------------------------------------------------------------------------
diff --git a/include/gui/IDisplayEventConnection.h b/include/gui/IDisplayEventConnection.h
index 21b53fe..0779448 100644
--- a/include/gui/IDisplayEventConnection.h
+++ b/include/gui/IDisplayEventConnection.h
@@ -34,9 +34,11 @@
DECLARE_META_INTERFACE(DisplayEventConnection)
/*
- * getDataChannel() returns a BitTube where to receive the events from
+ * stealReceiveChannel() returns a BitTube to receive events from. Only the receive file
+ * descriptor of outChannel will be initialized, and this effectively "steals" the receive
+ * channel from the remote end (such that the remote end can only use its send channel).
*/
- virtual status_t getDataChannel(sp<gui::BitTube>* outChannel) const = 0;
+ virtual status_t stealReceiveChannel(gui::BitTube* outChannel) = 0;
/*
* setVsyncRate() sets the vsync event delivery rate. A value of 1 returns every vsync event.
diff --git a/libs/gui/BitTube.cpp b/libs/gui/BitTube.cpp
index c023711..ef7a6f5 100644
--- a/libs/gui/BitTube.cpp
+++ b/libs/gui/BitTube.cpp
@@ -78,6 +78,14 @@
return mSendFd;
}
+base::unique_fd BitTube::moveReceiveFd() {
+ return std::move(mReceiveFd);
+}
+
+void BitTube::setReceiveFd(base::unique_fd&& receiveFd) {
+ mReceiveFd = std::move(receiveFd);
+}
+
ssize_t BitTube::write(void const* vaddr, size_t size) {
ssize_t err, len;
do {
@@ -121,8 +129,7 @@
return NO_ERROR;
}
-ssize_t BitTube::sendObjects(const sp<BitTube>& tube, void const* events, size_t count,
- size_t objSize) {
+ssize_t BitTube::sendObjects(BitTube* tube, void const* events, size_t count, size_t objSize) {
const char* vaddr = reinterpret_cast<const char*>(events);
ssize_t size = tube->write(vaddr, count * objSize);
@@ -136,7 +143,7 @@
return size < 0 ? size : size / static_cast<ssize_t>(objSize);
}
-ssize_t BitTube::recvObjects(const sp<BitTube>& tube, void* events, size_t count, size_t objSize) {
+ssize_t BitTube::recvObjects(BitTube* tube, void* events, size_t count, size_t objSize) {
char* vaddr = reinterpret_cast<char*>(events);
ssize_t size = tube->read(vaddr, count * objSize);
diff --git a/libs/gui/DisplayEventReceiver.cpp b/libs/gui/DisplayEventReceiver.cpp
index a3ae68c..1507d51 100644
--- a/libs/gui/DisplayEventReceiver.cpp
+++ b/libs/gui/DisplayEventReceiver.cpp
@@ -37,7 +37,8 @@
if (sf != NULL) {
mEventConnection = sf->createDisplayEventConnection();
if (mEventConnection != NULL) {
- mEventConnection->getDataChannel(&mDataChannel);
+ mDataChannel = std::make_unique<gui::BitTube>();
+ mEventConnection->stealReceiveChannel(mDataChannel.get());
}
}
}
@@ -80,16 +81,16 @@
ssize_t DisplayEventReceiver::getEvents(DisplayEventReceiver::Event* events,
size_t count) {
- return DisplayEventReceiver::getEvents(mDataChannel, events, count);
+ return DisplayEventReceiver::getEvents(mDataChannel.get(), events, count);
}
-ssize_t DisplayEventReceiver::getEvents(const sp<gui::BitTube>& dataChannel,
+ssize_t DisplayEventReceiver::getEvents(gui::BitTube* dataChannel,
Event* events, size_t count)
{
return gui::BitTube::recvObjects(dataChannel, events, count);
}
-ssize_t DisplayEventReceiver::sendEvents(const sp<gui::BitTube>& dataChannel,
+ssize_t DisplayEventReceiver::sendEvents(gui::BitTube* dataChannel,
Event const* events, size_t count)
{
return gui::BitTube::sendObjects(dataChannel, events, count);
diff --git a/libs/gui/IDisplayEventConnection.cpp b/libs/gui/IDisplayEventConnection.cpp
index d3ee39c..a197426 100644
--- a/libs/gui/IDisplayEventConnection.cpp
+++ b/libs/gui/IDisplayEventConnection.cpp
@@ -22,7 +22,11 @@
namespace android {
-enum { GET_DATA_CHANNEL = IBinder::FIRST_CALL_TRANSACTION, SET_VSYNC_RATE, REQUEST_NEXT_VSYNC };
+enum {
+ STEAL_RECEIVE_CHANNEL = IBinder::FIRST_CALL_TRANSACTION,
+ SET_VSYNC_RATE,
+ REQUEST_NEXT_VSYNC
+};
class BpDisplayEventConnection : public BpInterface<IDisplayEventConnection> {
public:
@@ -31,11 +35,11 @@
~BpDisplayEventConnection() override;
- status_t getDataChannel(sp<gui::BitTube>* outChannel) const override {
+ status_t stealReceiveChannel(gui::BitTube* outChannel) override {
Parcel data, reply;
data.writeInterfaceToken(IDisplayEventConnection::getInterfaceDescriptor());
- remote()->transact(GET_DATA_CHANNEL, data, &reply);
- *outChannel = new gui::BitTube(reply);
+ remote()->transact(STEAL_RECEIVE_CHANNEL, data, &reply);
+ outChannel->readFromParcel(&reply);
return NO_ERROR;
}
@@ -63,11 +67,11 @@
status_t BnDisplayEventConnection::onTransact(uint32_t code, const Parcel& data, Parcel* reply,
uint32_t flags) {
switch (code) {
- case GET_DATA_CHANNEL: {
+ case STEAL_RECEIVE_CHANNEL: {
CHECK_INTERFACE(IDisplayEventConnection, data, reply);
- sp<gui::BitTube> channel;
- getDataChannel(&channel);
- channel->writeToParcel(reply);
+ gui::BitTube channel;
+ stealReceiveChannel(&channel);
+ channel.writeToParcel(reply);
return NO_ERROR;
}
case SET_VSYNC_RATE: {
diff --git a/libs/gui/include/private/gui/BitTube.h b/libs/gui/include/private/gui/BitTube.h
index e93dc5f..13c0162 100644
--- a/libs/gui/include/private/gui/BitTube.h
+++ b/libs/gui/include/private/gui/BitTube.h
@@ -16,14 +16,9 @@
#pragma once
-#include <stdint.h>
-#include <sys/types.h>
-
-#include <android/log.h>
#include <android-base/unique_fd.h>
#include <binder/Parcelable.h>
#include <utils/Errors.h>
-#include <utils/RefBase.h>
namespace android {
@@ -31,7 +26,7 @@
namespace gui {
-class BitTube : public RefBase, public Parcelable {
+class BitTube : public Parcelable {
public:
// creates an uninitialized BitTube (to unparcel into)
BitTube() = default;
@@ -57,16 +52,22 @@
// get the send file-descriptor.
int getSendFd() const;
+ // moves the receive file descriptor out of this BitTube
+ base::unique_fd moveReceiveFd();
+
+ // resets this BitTube's receive file descriptor to receiveFd
+ void setReceiveFd(base::unique_fd&& receiveFd);
+
// send objects (sized blobs). All objects are guaranteed to be written or the call fails.
template <typename T>
- static ssize_t sendObjects(const sp<BitTube>& tube, T const* events, size_t count) {
+ static ssize_t sendObjects(BitTube* tube, T const* events, size_t count) {
return sendObjects(tube, events, count, sizeof(T));
}
// receive objects (sized blobs). If the receiving buffer isn't large enough, excess messages
// are silently discarded.
template <typename T>
- static ssize_t recvObjects(const sp<BitTube>& tube, T* events, size_t count) {
+ static ssize_t recvObjects(BitTube* tube, T* events, size_t count) {
return recvObjects(tube, events, count, sizeof(T));
}
@@ -87,10 +88,9 @@
base::unique_fd mSendFd;
mutable base::unique_fd mReceiveFd;
- static ssize_t sendObjects(const sp<BitTube>& tube, void const* events, size_t count,
- size_t objSize);
+ static ssize_t sendObjects(BitTube* tube, void const* events, size_t count, size_t objSize);
- static ssize_t recvObjects(const sp<BitTube>& tube, void* events, size_t count, size_t objSize);
+ static ssize_t recvObjects(BitTube* tube, void* events, size_t count, size_t objSize);
};
} // namespace gui
diff --git a/services/surfaceflinger/EventThread.cpp b/services/surfaceflinger/EventThread.cpp
index 2d3515e..a9bb2ba 100644
--- a/services/surfaceflinger/EventThread.cpp
+++ b/services/surfaceflinger/EventThread.cpp
@@ -21,7 +21,6 @@
#include <cutils/compiler.h>
-#include <private/gui/BitTube.h>
#include <gui/IDisplayEventConnection.h>
#include <gui/DisplayEventReceiver.h>
@@ -389,7 +388,7 @@
EventThread::Connection::Connection(
const sp<EventThread>& eventThread)
- : count(-1), mEventThread(eventThread), mChannel(new gui::BitTube(gui::BitTube::DefaultSize))
+ : count(-1), mEventThread(eventThread), mChannel(gui::BitTube::DefaultSize)
{
}
@@ -403,8 +402,8 @@
mEventThread->registerDisplayEventConnection(this);
}
-status_t EventThread::Connection::getDataChannel(sp<gui::BitTube>* outChannel) const {
- *outChannel = mChannel;
+status_t EventThread::Connection::stealReceiveChannel(gui::BitTube* outChannel) {
+ outChannel->setReceiveFd(mChannel.moveReceiveFd());
return NO_ERROR;
}
@@ -419,7 +418,7 @@
status_t EventThread::Connection::postEvent(
const DisplayEventReceiver::Event& event) {
- ssize_t size = DisplayEventReceiver::sendEvents(mChannel, &event, 1);
+ ssize_t size = DisplayEventReceiver::sendEvents(&mChannel, &event, 1);
return size < 0 ? status_t(size) : status_t(NO_ERROR);
}
diff --git a/services/surfaceflinger/EventThread.h b/services/surfaceflinger/EventThread.h
index 3e05749..6a59fbb 100644
--- a/services/surfaceflinger/EventThread.h
+++ b/services/surfaceflinger/EventThread.h
@@ -20,6 +20,7 @@
#include <stdint.h>
#include <sys/types.h>
+#include <private/gui/BitTube.h>
#include <gui/DisplayEventReceiver.h>
#include <gui/IDisplayEventConnection.h>
@@ -68,11 +69,11 @@
private:
virtual ~Connection();
virtual void onFirstRef();
- status_t getDataChannel(sp<gui::BitTube>* outChannel) const override;
+ status_t stealReceiveChannel(gui::BitTube* outChannel) override;
status_t setVsyncRate(uint32_t count) override;
void requestNextVsync() override; // asynchronous
sp<EventThread> const mEventThread;
- sp<gui::BitTube> const mChannel;
+ gui::BitTube mChannel;
};
public:
diff --git a/services/surfaceflinger/MessageQueue.cpp b/services/surfaceflinger/MessageQueue.cpp
index 6ef26fe..bca3430 100644
--- a/services/surfaceflinger/MessageQueue.cpp
+++ b/services/surfaceflinger/MessageQueue.cpp
@@ -25,7 +25,6 @@
#include <utils/Log.h>
#include <gui/IDisplayEventConnection.h>
-#include <private/gui/BitTube.h>
#include "MessageQueue.h"
#include "EventThread.h"
@@ -94,8 +93,8 @@
{
mEventThread = eventThread;
mEvents = eventThread->createEventConnection();
- mEvents->getDataChannel(&mEventTube);
- mLooper->addFd(mEventTube->getFd(), 0, Looper::EVENT_INPUT,
+ mEvents->stealReceiveChannel(&mEventTube);
+ mLooper->addFd(mEventTube.getFd(), 0, Looper::EVENT_INPUT,
MessageQueue::cb_eventReceiver, this);
}
@@ -150,7 +149,7 @@
int MessageQueue::eventReceiver(int /*fd*/, int /*events*/) {
ssize_t n;
DisplayEventReceiver::Event buffer[8];
- while ((n = DisplayEventReceiver::getEvents(mEventTube, buffer, 8)) > 0) {
+ while ((n = DisplayEventReceiver::getEvents(&mEventTube, buffer, 8)) > 0) {
for (int i=0 ; i<n ; i++) {
if (buffer[i].header.type == DisplayEventReceiver::DISPLAY_EVENT_VSYNC) {
mHandler->dispatchInvalidate();
diff --git a/services/surfaceflinger/MessageQueue.h b/services/surfaceflinger/MessageQueue.h
index 2bb5fa6..85a33c8 100644
--- a/services/surfaceflinger/MessageQueue.h
+++ b/services/surfaceflinger/MessageQueue.h
@@ -25,6 +25,7 @@
#include <utils/Timers.h>
#include <utils/Looper.h>
+#include <private/gui/BitTube.h>
#include <gui/DisplayEventReceiver.h>
#include "Barrier.h"
@@ -81,7 +82,7 @@
sp<Looper> mLooper;
sp<EventThread> mEventThread;
sp<IDisplayEventConnection> mEvents;
- sp<gui::BitTube> mEventTube;
+ gui::BitTube mEventTube;
sp<Handler> mHandler;