replicant-frameworks_native/services/surfaceflinger/EventThread.h
Mathias Agopian 10125f00a5 Fix deadlock in SF.
problem was that we were acquiring a strong reference
on Connection object with a lock held, when those
got out of scope (lock still held) their dtor
could be called if all other refs had dropped,
the dtor would acquire the lock again to
remove the Connection from the main list. boom.

we rearange the code so this doesn't happen.

Bug: 6942208

Change-Id: I0a0ebabce2842d29d60d645b64aac2f26640e59b
2012-08-17 18:48:56 -07:00

118 lines
3.6 KiB
C++

/*
* Copyright (C) 2011 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.
*/
#ifndef ANDROID_SURFACE_FLINGER_EVENT_THREAD_H
#define ANDROID_SURFACE_FLINGER_EVENT_THREAD_H
#include <stdint.h>
#include <sys/types.h>
#include <gui/DisplayEventReceiver.h>
#include <gui/IDisplayEventConnection.h>
#include <utils/Errors.h>
#include <utils/threads.h>
#include <utils/SortedVector.h>
#include "DisplayHardware/PowerHAL.h"
// ---------------------------------------------------------------------------
namespace android {
// ---------------------------------------------------------------------------
class SurfaceFlinger;
class String8;
// ---------------------------------------------------------------------------
class EventThread : public Thread {
class Connection : public BnDisplayEventConnection {
public:
Connection(const sp<EventThread>& eventThread);
status_t postEvent(const DisplayEventReceiver::Event& event);
// count >= 1 : continuous event. count is the vsync rate
// count == 0 : one-shot event that has not fired
// count ==-1 : one-shot event that fired this round / disabled
// count ==-2 : one-shot event that fired the round before
int32_t count;
private:
virtual ~Connection();
virtual void onFirstRef();
virtual sp<BitTube> getDataChannel() const;
virtual void setVsyncRate(uint32_t count);
virtual void requestNextVsync(); // asynchronous
sp<EventThread> const mEventThread;
sp<BitTube> const mChannel;
};
public:
EventThread(const sp<SurfaceFlinger>& flinger);
sp<Connection> createEventConnection() const;
status_t registerDisplayEventConnection(const sp<Connection>& connection);
status_t unregisterDisplayEventConnection(const wp<Connection>& connection);
void setVsyncRate(uint32_t count, const sp<Connection>& connection);
void requestNextVsync(const sp<Connection>& connection);
// called before the screen is turned off from main thread
void onScreenReleased();
// called after the screen is turned on from main thread
void onScreenAcquired();
// called when receiving a vsync event
void onVSyncReceived(int display, nsecs_t timestamp);
void dump(String8& result, char* buffer, size_t SIZE) const;
private:
virtual bool threadLoop();
virtual status_t readyToRun();
virtual void onFirstRef();
void removeDisplayEventConnection(const wp<Connection>& connection);
void enableVSyncLocked();
void disableVSyncLocked();
// constants
sp<SurfaceFlinger> mFlinger;
PowerHAL mPowerHAL;
mutable Mutex mLock;
mutable Condition mCondition;
// protected by mLock
SortedVector< wp<Connection> > mDisplayEventConnections;
nsecs_t mVSyncTimestamp;
bool mUseSoftwareVSync;
size_t mVSyncCount;
// for debugging
bool mDebugVsyncEnabled;
};
// ---------------------------------------------------------------------------
}; // namespace android
// ---------------------------------------------------------------------------
#endif /* ANDROID_SURFACE_FLINGER_EVENT_THREAD_H */