replicant-frameworks_native/include/private/surfaceflinger/SharedBufferStack.h
Mathias Agopian 19957553cb fix [2835280] Add support for cancelling buffers to ANativeWindow
There is a new ANativeWindow::cancelBuffer() API that can be used to
cancel any dequeued buffer, BEFORE it's been enqueued. The buffer is
returned to the list of availlable buffers. dequeue and cancel are not
mutually thread safe, they must be called from the same thread or
external synchronization must be used.

Change-Id: I86cc7985bace8b6a93ad2c75d2bef5c3c2cb4d61
2010-10-04 20:10:11 -07:00

401 lines
12 KiB
C++

/*
* Copyright (C) 2007 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_SF_SHARED_BUFFER_STACK_H
#define ANDROID_SF_SHARED_BUFFER_STACK_H
#include <stdint.h>
#include <sys/types.h>
#include <cutils/compiler.h>
#include <utils/Debug.h>
#include <utils/threads.h>
#include <utils/String8.h>
#include <ui/Rect.h>
namespace android {
// ---------------------------------------------------------------------------
/*
* These classes manage a stack of buffers in shared memory.
*
* SharedClient: represents a client with several stacks
* SharedBufferStack: represents a stack of buffers
* SharedBufferClient: manipulates the SharedBufferStack from the client side
* SharedBufferServer: manipulates the SharedBufferStack from the server side
*
* Buffers can be dequeued until there are none available, they can be locked
* unless they are in use by the server, which is only the case for the last
* dequeue-able buffer. When these various conditions are not met, the caller
* waits until the condition is met.
*
*/
// ----------------------------------------------------------------------------
class Region;
class SharedBufferStack;
class SharedClient;
// ----------------------------------------------------------------------------
class SharedBufferStack
{
friend class SharedClient;
friend class SharedBufferBase;
friend class SharedBufferClient;
friend class SharedBufferServer;
public:
// When changing these values, the COMPILE_TIME_ASSERT at the end of this
// file need to be updated.
static const unsigned int NUM_LAYERS_MAX = 31;
static const unsigned int NUM_BUFFER_MAX = 16;
static const unsigned int NUM_BUFFER_MIN = 2;
static const unsigned int NUM_DISPLAY_MAX = 4;
struct Statistics { // 4 longs
typedef int32_t usecs_t;
usecs_t totalTime;
usecs_t reserved[3];
};
struct SmallRect {
uint16_t l, t, r, b;
};
struct FlatRegion { // 52 bytes = 4 * (1 + 2*N)
static const unsigned int NUM_RECT_MAX = 5;
uint32_t count;
SmallRect rects[NUM_RECT_MAX];
};
struct BufferData {
FlatRegion dirtyRegion;
SmallRect crop;
uint8_t transform;
uint8_t reserved[3];
};
SharedBufferStack();
void init(int32_t identity);
status_t setDirtyRegion(int buffer, const Region& reg);
status_t setCrop(int buffer, const Rect& reg);
status_t setTransform(int buffer, uint8_t transform);
Region getDirtyRegion(int buffer) const;
Rect getCrop(int buffer) const;
uint32_t getTransform(int buffer) const;
// these attributes are part of the conditions/updates
volatile int32_t head; // server's current front buffer
volatile int32_t available; // number of dequeue-able buffers
volatile int32_t queued; // number of buffers waiting for post
volatile int32_t inUse; // buffer currently in use by SF
volatile status_t status; // surface's status code
// not part of the conditions
volatile int32_t reallocMask;
volatile int8_t index[NUM_BUFFER_MAX];
int32_t identity; // surface's identity (const)
int32_t token; // surface's token (for debugging)
Statistics stats;
int8_t headBuf; // last retired buffer
uint8_t reservedBytes[3];
int32_t reserved;
BufferData buffers[NUM_BUFFER_MAX]; // 1024 bytes
};
// ----------------------------------------------------------------------------
// 32 KB max
class SharedClient
{
public:
SharedClient();
~SharedClient();
status_t validate(size_t token) const;
private:
friend class SharedBufferBase;
friend class SharedBufferClient;
friend class SharedBufferServer;
// FIXME: this should be replaced by a lock-less primitive
Mutex lock;
Condition cv;
SharedBufferStack surfaces[ SharedBufferStack::NUM_LAYERS_MAX ];
};
// ============================================================================
class SharedBufferBase
{
public:
SharedBufferBase(SharedClient* sharedClient, int surface,
int32_t identity);
~SharedBufferBase();
status_t getStatus() const;
int32_t getIdentity() const;
String8 dump(char const* prefix) const;
protected:
SharedClient* const mSharedClient;
SharedBufferStack* const mSharedStack;
const int mIdentity;
friend struct Update;
friend struct QueueUpdate;
struct ConditionBase {
SharedBufferStack& stack;
inline ConditionBase(SharedBufferBase* sbc)
: stack(*sbc->mSharedStack) { }
virtual ~ConditionBase() { };
virtual bool operator()() const = 0;
virtual const char* name() const = 0;
};
status_t waitForCondition(const ConditionBase& condition);
struct UpdateBase {
SharedBufferStack& stack;
inline UpdateBase(SharedBufferBase* sbb)
: stack(*sbb->mSharedStack) { }
};
template <typename T>
status_t updateCondition(T update);
};
template <typename T>
status_t SharedBufferBase::updateCondition(T update) {
SharedClient& client( *mSharedClient );
Mutex::Autolock _l(client.lock);
ssize_t result = update();
client.cv.broadcast();
return result;
}
// ----------------------------------------------------------------------------
class SharedBufferClient : public SharedBufferBase
{
public:
SharedBufferClient(SharedClient* sharedClient, int surface, int num,
int32_t identity);
ssize_t dequeue();
status_t undoDequeue(int buf);
status_t lock(int buf);
status_t cancel(int buf);
status_t queue(int buf);
bool needNewBuffer(int buffer) const;
status_t setDirtyRegion(int buffer, const Region& reg);
status_t setCrop(int buffer, const Rect& reg);
status_t setTransform(int buffer, uint32_t transform);
class SetBufferCountCallback {
friend class SharedBufferClient;
virtual status_t operator()(int bufferCount) const = 0;
protected:
virtual ~SetBufferCountCallback() { }
};
status_t setBufferCount(int bufferCount, const SetBufferCountCallback& ipc);
private:
friend struct Condition;
friend struct DequeueCondition;
friend struct LockCondition;
struct QueueUpdate : public UpdateBase {
inline QueueUpdate(SharedBufferBase* sbb);
inline ssize_t operator()();
};
struct DequeueUpdate : public UpdateBase {
inline DequeueUpdate(SharedBufferBase* sbb);
inline ssize_t operator()();
};
struct CancelUpdate : public UpdateBase {
int tail, buf;
inline CancelUpdate(SharedBufferBase* sbb, int tail, int buf);
inline ssize_t operator()();
};
// --
struct DequeueCondition : public ConditionBase {
inline DequeueCondition(SharedBufferClient* sbc);
inline bool operator()() const;
inline const char* name() const { return "DequeueCondition"; }
};
struct LockCondition : public ConditionBase {
int buf;
inline LockCondition(SharedBufferClient* sbc, int buf);
inline bool operator()() const;
inline const char* name() const { return "LockCondition"; }
};
int32_t computeTail() const;
mutable RWLock mLock;
int mNumBuffers;
int32_t tail;
int32_t queued_head;
// statistics...
nsecs_t mDequeueTime[SharedBufferStack::NUM_BUFFER_MAX];
};
// ----------------------------------------------------------------------------
class SharedBufferServer
: public SharedBufferBase,
public LightRefBase<SharedBufferServer>
{
public:
SharedBufferServer(SharedClient* sharedClient, int surface, int num,
int32_t identity);
ssize_t retireAndLock();
status_t unlock(int buffer);
void setStatus(status_t status);
status_t reallocateAll();
status_t reallocateAllExcept(int buffer);
int32_t getQueuedCount() const;
Region getDirtyRegion(int buffer) const;
Rect getCrop(int buffer) const;
uint32_t getTransform(int buffer) const;
status_t resize(int newNumBuffers);
SharedBufferStack::Statistics getStats() const;
private:
friend class LightRefBase<SharedBufferServer>;
~SharedBufferServer();
/*
* BufferList is basically a fixed-capacity sorted-vector of
* unsigned 5-bits ints using a 32-bits int as storage.
* it has efficient iterators to find items in the list and not in the list.
*/
class BufferList {
size_t mCapacity;
uint32_t mList;
public:
BufferList(size_t c = SharedBufferStack::NUM_BUFFER_MAX)
: mCapacity(c), mList(0) { }
status_t add(int value);
status_t remove(int value);
uint32_t getMask() const { return mList; }
class const_iterator {
friend class BufferList;
uint32_t mask, curr;
const_iterator(uint32_t mask) :
mask(mask), curr(__builtin_clz(mask)) {
}
public:
inline bool operator == (const const_iterator& rhs) const {
return mask == rhs.mask;
}
inline bool operator != (const const_iterator& rhs) const {
return mask != rhs.mask;
}
inline int operator *() const { return curr; }
inline const const_iterator& operator ++() {
mask &= ~(1<<(31-curr));
curr = __builtin_clz(mask);
return *this;
}
};
inline const_iterator begin() const {
return const_iterator(mList);
}
inline const_iterator end() const {
return const_iterator(0);
}
inline const_iterator free_begin() const {
uint32_t mask = (1 << (32-mCapacity)) - 1;
return const_iterator( ~(mList | mask) );
}
};
// this protects mNumBuffers and mBufferList
mutable RWLock mLock;
int mNumBuffers;
BufferList mBufferList;
struct UnlockUpdate : public UpdateBase {
const int lockedBuffer;
inline UnlockUpdate(SharedBufferBase* sbb, int lockedBuffer);
inline ssize_t operator()();
};
struct RetireUpdate : public UpdateBase {
const int numBuffers;
inline RetireUpdate(SharedBufferBase* sbb, int numBuffers);
inline ssize_t operator()();
};
struct StatusUpdate : public UpdateBase {
const status_t status;
inline StatusUpdate(SharedBufferBase* sbb, status_t status);
inline ssize_t operator()();
};
};
// ===========================================================================
struct display_cblk_t
{
uint16_t w;
uint16_t h;
uint8_t format;
uint8_t orientation;
uint8_t reserved[2];
float fps;
float density;
float xdpi;
float ydpi;
uint32_t pad[2];
};
struct surface_flinger_cblk_t // 4KB max
{
uint8_t connected;
uint8_t reserved[3];
uint32_t pad[7];
display_cblk_t displays[SharedBufferStack::NUM_DISPLAY_MAX];
};
// ---------------------------------------------------------------------------
COMPILE_TIME_ASSERT(sizeof(SharedClient) <= 32768)
COMPILE_TIME_ASSERT(sizeof(surface_flinger_cblk_t) <= 4096)
// ---------------------------------------------------------------------------
}; // namespace android
#endif /* ANDROID_SF_SHARED_BUFFER_STACK_H */