Split BufferQueue into core + producer + consumer
Change-Id: Idc39f1e511d68ce4f02202d35425a419bc0bcd92
diff --git a/include/gui/BufferItem.h b/include/gui/BufferItem.h
new file mode 100644
index 0000000..5effd10
--- /dev/null
+++ b/include/gui/BufferItem.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright 2014 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_GUI_BUFFERITEM_H
+#define ANDROID_GUI_BUFFERITEM_H
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include <gui/IGraphicBufferConsumer.h>
+
+#include <ui/Rect.h>
+
+#include <utils/Flattenable.h>
+#include <utils/StrongPointer.h>
+
+namespace android {
+
+class Fence;
+class GraphicBuffer;
+
+class BufferItem : public Flattenable<BufferItem> {
+ friend class Flattenable<BufferItem>;
+ size_t getPodSize() const;
+ size_t getFlattenedSize() const;
+ size_t getFdCount() const;
+ status_t flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const;
+ status_t unflatten(void const*& buffer, size_t& size, int const*& fds, size_t& count);
+
+ public:
+ // The default value of mBuf, used to indicate this doesn't correspond to a slot.
+ enum { INVALID_BUFFER_SLOT = -1 };
+ BufferItem();
+ operator IGraphicBufferConsumer::BufferItem() const;
+
+ static const char* scalingModeName(uint32_t scalingMode);
+
+ // mGraphicBuffer points to the buffer allocated for this slot, or is NULL
+ // if the buffer in this slot has been acquired in the past (see
+ // BufferSlot.mAcquireCalled).
+ sp<GraphicBuffer> mGraphicBuffer;
+
+ // mFence is a fence that will signal when the buffer is idle.
+ sp<Fence> mFence;
+
+ // mCrop is the current crop rectangle for this buffer slot.
+ Rect mCrop;
+
+ // mTransform is the current transform flags for this buffer slot.
+ // refer to NATIVE_WINDOW_TRANSFORM_* in <window.h>
+ uint32_t mTransform;
+
+ // mScalingMode is the current scaling mode for this buffer slot.
+ // refer to NATIVE_WINDOW_SCALING_* in <window.h>
+ uint32_t mScalingMode;
+
+ // mTimestamp is the current timestamp for this buffer slot. This gets
+ // to set by queueBuffer each time this slot is queued. This value
+ // is guaranteed to be monotonically increasing for each newly
+ // acquired buffer.
+ int64_t mTimestamp;
+
+ // mIsAutoTimestamp indicates whether mTimestamp was generated
+ // automatically when the buffer was queued.
+ bool mIsAutoTimestamp;
+
+ // mFrameNumber is the number of the queued frame for this slot.
+ uint64_t mFrameNumber;
+
+ // mSlot is the slot index of this buffer (default INVALID_BUFFER_SLOT).
+ int mSlot;
+
+ // mIsDroppable whether this buffer was queued with the
+ // property that it can be replaced by a new buffer for the purpose of
+ // making sure dequeueBuffer() won't block.
+ // i.e.: was the BufferQueue in "mDequeueBufferCannotBlock" when this buffer
+ // was queued.
+ bool mIsDroppable;
+
+ // Indicates whether this buffer has been seen by a consumer yet
+ bool mAcquireCalled;
+
+ // Indicates this buffer must be transformed by the inverse transform of the screen
+ // it is displayed onto. This is applied after mTransform.
+ bool mTransformToDisplayInverse;
+};
+
+} // namespace android
+
+#endif
diff --git a/include/gui/BufferQueueConsumer.h b/include/gui/BufferQueueConsumer.h
new file mode 100644
index 0000000..0980ebb
--- /dev/null
+++ b/include/gui/BufferQueueConsumer.h
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2014 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_GUI_BUFFERQUEUECONSUMER_H
+#define ANDROID_GUI_BUFFERQUEUECONSUMER_H
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include <gui/BufferQueueCore.h>
+#include <gui/IGraphicBufferConsumer.h>
+
+namespace android {
+
+class BufferQueueCore;
+
+class BufferQueueConsumer : public BnGraphicBufferConsumer {
+
+public:
+ BufferQueueConsumer(const sp<BufferQueueCore>& core);
+ virtual ~BufferQueueConsumer();
+
+ // acquireBuffer attempts to acquire ownership of the next pending buffer in
+ // the BufferQueue. If no buffer is pending then it returns
+ // NO_BUFFER_AVAILABLE. If a buffer is successfully acquired, the
+ // information about the buffer is returned in BufferItem. If the buffer
+ // returned had previously been acquired then the BufferItem::mGraphicBuffer
+ // field of buffer is set to NULL and it is assumed that the consumer still
+ // holds a reference to the buffer.
+ //
+ // If expectedPresent is nonzero, it indicates the time when the buffer
+ // will be displayed on screen. If the buffer's timestamp is farther in the
+ // future, the buffer won't be acquired, and PRESENT_LATER will be
+ // returned. The presentation time is in nanoseconds, and the time base
+ // is CLOCK_MONOTONIC.
+ virtual status_t acquireBuffer(BufferItem* outBuffer,
+ nsecs_t expectedPresent);
+
+ // releaseBuffer releases a buffer slot from the consumer back to the
+ // BufferQueue. This may be done while the buffer's contents are still
+ // being accessed. The fence will signal when the buffer is no longer
+ // in use. frameNumber is used to indentify the exact buffer returned.
+ //
+ // If releaseBuffer returns STALE_BUFFER_SLOT, then the consumer must free
+ // any references to the just-released buffer that it might have, as if it
+ // had received a onBuffersReleased() call with a mask set for the released
+ // buffer.
+ //
+ // Note that the dependencies on EGL will be removed once we switch to using
+ // the Android HW Sync HAL.
+ virtual status_t releaseBuffer(int slot, uint64_t frameNumber,
+ const sp<Fence>& releaseFence, EGLDisplay display,
+ EGLSyncKHR fence);
+
+ // connect connects a consumer to the BufferQueue. Only one
+ // consumer may be connected, and when that consumer disconnects the
+ // BufferQueue is placed into the "abandoned" state, causing most
+ // interactions with the BufferQueue by the producer to fail.
+ // controlledByApp indicates whether the consumer is controlled by
+ // the application.
+ //
+ // consumerListener may not be NULL.
+ virtual status_t connect(const sp<IConsumerListener>& consumerListener,
+ bool controlledByApp);
+
+ // disconnect disconnects a consumer from the BufferQueue. All
+ // buffers will be freed and the BufferQueue is placed in the "abandoned"
+ // state, causing most interactions with the BufferQueue by the producer to
+ // fail.
+ virtual status_t disconnect();
+
+ // getReleasedBuffers sets the value pointed to by outSlotMask to a bit mask
+ // indicating which buffer slots have been released by the BufferQueue
+ // but have not yet been released by the consumer.
+ //
+ // This should be called from the onBuffersReleased() callback.
+ virtual status_t getReleasedBuffers(uint32_t* outSlotMask);
+
+ // setDefaultBufferSize is used to set the size of buffers returned by
+ // dequeueBuffer when a width and height of zero is requested. Default
+ // is 1x1.
+ virtual status_t setDefaultBufferSize(uint32_t width, uint32_t height);
+
+ // setDefaultMaxBufferCount sets the default value for the maximum buffer
+ // count (the initial default is 2). If the producer has requested a
+ // buffer count using setBufferCount, the default buffer count will only
+ // take effect if the producer sets the count back to zero.
+ //
+ // The count must be between 2 and NUM_BUFFER_SLOTS, inclusive.
+ virtual status_t setDefaultMaxBufferCount(int bufferCount);
+
+ // disableAsyncBuffer disables the extra buffer used in async mode
+ // (when both producer and consumer have set their "isControlledByApp"
+ // flag) and has dequeueBuffer() return WOULD_BLOCK instead.
+ //
+ // This can only be called before connect().
+ virtual status_t disableAsyncBuffer();
+
+ // setMaxAcquiredBufferCount sets the maximum number of buffers that can
+ // be acquired by the consumer at one time (default 1). This call will
+ // fail if a producer is connected to the BufferQueue.
+ virtual status_t setMaxAcquiredBufferCount(int maxAcquiredBuffers);
+
+ // setConsumerName sets the name used in logging
+ virtual void setConsumerName(const String8& name);
+
+ // setDefaultBufferFormat allows the BufferQueue to create
+ // GraphicBuffers of a defaultFormat if no format is specified
+ // in dequeueBuffer. Formats are enumerated in graphics.h; the
+ // initial default is HAL_PIXEL_FORMAT_RGBA_8888.
+ virtual status_t setDefaultBufferFormat(uint32_t defaultFormat);
+
+ // setConsumerUsageBits will turn on additional usage bits for dequeueBuffer.
+ // These are merged with the bits passed to dequeueBuffer. The values are
+ // enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER; the default is 0.
+ virtual status_t setConsumerUsageBits(uint32_t usage);
+
+ // setTransformHint bakes in rotation to buffers so overlays can be used.
+ // The values are enumerated in window.h, e.g.
+ // NATIVE_WINDOW_TRANSFORM_ROT_90. The default is 0 (no transform).
+ virtual status_t setTransformHint(uint32_t hint);
+
+ // dump our state in a String
+ virtual void dump(String8& result, const char* prefix) const;
+
+private:
+ sp<BufferQueueCore> mCore;
+ BufferQueueCore::SlotsType& mSlots;
+ String8 mConsumerName; // Cached from mCore. Updated on setConsumerName.
+
+}; // class BufferQueueConsumer
+
+} // namespace android
+
+#endif
diff --git a/include/gui/BufferQueueCore.h b/include/gui/BufferQueueCore.h
new file mode 100644
index 0000000..ef11c61
--- /dev/null
+++ b/include/gui/BufferQueueCore.h
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2014 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_GUI_BUFFERQUEUECORE_H
+#define ANDROID_GUI_BUFFERQUEUECORE_H
+
+#include <gui/BufferSlot.h>
+
+#include <utils/Condition.h>
+#include <utils/Mutex.h>
+#include <utils/RefBase.h>
+#include <utils/String8.h>
+#include <utils/StrongPointer.h>
+#include <utils/Trace.h>
+#include <utils/Vector.h>
+
+#define BQ_LOGV(x, ...) ALOGV("[%s] "x, mConsumerName.string(), ##__VA_ARGS__)
+#define BQ_LOGD(x, ...) ALOGD("[%s] "x, mConsumerName.string(), ##__VA_ARGS__)
+#define BQ_LOGI(x, ...) ALOGI("[%s] "x, mConsumerName.string(), ##__VA_ARGS__)
+#define BQ_LOGW(x, ...) ALOGW("[%s] "x, mConsumerName.string(), ##__VA_ARGS__)
+#define BQ_LOGE(x, ...) ALOGE("[%s] "x, mConsumerName.string(), ##__VA_ARGS__)
+
+#define ATRACE_BUFFER_INDEX(index) \
+ if (ATRACE_ENABLED()) { \
+ char ___traceBuf[1024]; \
+ snprintf(___traceBuf, 1024, "%s: %d", \
+ mCore->mConsumerName.string(), (index)); \
+ android::ScopedTrace ___bufTracer(ATRACE_TAG, ___traceBuf); \
+ }
+
+namespace android {
+
+class BufferItem;
+class IBinder;
+class IConsumerListener;
+class IGraphicBufferAlloc;
+
+class BufferQueueCore : public virtual RefBase {
+
+ friend class BufferQueueProducer;
+ friend class BufferQueueConsumer;
+
+public:
+ // BufferQueue will keep track of at most this value of buffers. Attempts
+ // at runtime to increase the number of buffers past this will fail.
+ enum { NUM_BUFFER_SLOTS = 32 };
+
+ // Used as a placeholder slot number when the value isn't pointing to an
+ // existing buffer.
+ enum { INVALID_BUFFER_SLOT = -1 }; // TODO: Extract from IGBC::BufferItem
+
+ // We reserve two slots in order to guarantee that the producer and
+ // consumer can run asynchronously.
+ enum { MAX_MAX_ACQUIRED_BUFFERS = NUM_BUFFER_SLOTS - 2 };
+
+ // The default API number used to indicate that no producer is connected
+ enum { NO_CONNECTED_API = 0 };
+
+ typedef BufferSlot SlotsType[NUM_BUFFER_SLOTS];
+ typedef Vector<BufferItem> Fifo;
+
+ // BufferQueueCore manages a pool of gralloc memory slots to be used by
+ // producers and consumers. allocator is used to allocate all the needed
+ // gralloc buffers.
+ BufferQueueCore(const sp<IGraphicBufferAlloc>& allocator = NULL);
+ virtual ~BufferQueueCore();
+
+private:
+ void dump(String8& result, const char* prefix) const;
+
+ int getMinUndequeuedBufferCountLocked(bool async) const;
+ int getMinMaxBufferCountLocked(bool async) const;
+ int getMaxBufferCountLocked(bool async) const;
+ status_t setDefaultMaxBufferCountLocked(int count);
+ void freeBufferLocked(int slot);
+ void freeAllBuffersLocked();
+ bool stillTracking(const BufferItem* item) const;
+
+ const sp<IGraphicBufferAlloc>& mAllocator;
+ mutable Mutex mMutex;
+ bool mIsAbandoned;
+ bool mConsumerControlledByApp;
+ String8 mConsumerName;
+ sp<IConsumerListener> mConsumerListener;
+ uint32_t mConsumerUsageBits;
+ int mConnectedApi;
+ sp<IBinder> mConnectedProducerToken;
+ BufferSlot mSlots[NUM_BUFFER_SLOTS];
+ Fifo mQueue;
+ int mOverrideMaxBufferCount;
+ mutable Condition mDequeueCondition;
+ bool mUseAsyncBuffer;
+ bool mDequeueBufferCannotBlock;
+ uint32_t mDefaultBufferFormat;
+ int mDefaultWidth;
+ int mDefaultHeight;
+ int mDefaultMaxBufferCount;
+ int mMaxAcquiredBufferCount;
+ bool mBufferHasBeenQueued;
+ uint64_t mFrameCounter;
+ uint32_t mTransformHint;
+
+}; // class BufferQueueCore
+
+} // namespace android
+
+#endif
diff --git a/include/gui/BufferQueueProducer.h b/include/gui/BufferQueueProducer.h
new file mode 100644
index 0000000..7f063aa
--- /dev/null
+++ b/include/gui/BufferQueueProducer.h
@@ -0,0 +1,165 @@
+/*
+ * Copyright 2014 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_GUI_BUFFERQUEUEPRODUCER_H
+#define ANDROID_GUI_BUFFERQUEUEPRODUCER_H
+
+#include <gui/BufferQueueCore.h>
+#include <gui/IGraphicBufferProducer.h>
+
+namespace android {
+
+class BufferSlot;
+
+class BufferQueueProducer : public BnGraphicBufferProducer,
+ private IBinder::DeathRecipient {
+
+public:
+ BufferQueueProducer(const sp<BufferQueueCore>& core);
+ virtual ~BufferQueueProducer();
+
+ // requestBuffer returns the GraphicBuffer for slot N.
+ //
+ // In normal operation, this is called the first time slot N is returned
+ // by dequeueBuffer. It must be called again if dequeueBuffer returns
+ // flags indicating that previously-returned buffers are no longer valid.
+ virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* buf);
+
+ // setBufferCount updates the number of available buffer slots. If this
+ // method succeeds, buffer slots will be both unallocated and owned by
+ // the BufferQueue object (i.e. they are not owned by the producer or
+ // consumer).
+ //
+ // This will fail if the producer has dequeued any buffers, or if
+ // bufferCount is invalid. bufferCount must generally be a value
+ // between the minimum undequeued buffer count (exclusive) and NUM_BUFFER_SLOTS
+ // (inclusive). It may also be set to zero (the default) to indicate
+ // that the producer does not wish to set a value. The minimum value
+ // can be obtained by calling query(NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS,
+ // ...).
+ //
+ // This may only be called by the producer. The consumer will be told
+ // to discard buffers through the onBuffersReleased callback.
+ virtual status_t setBufferCount(int bufferCount);
+
+ // dequeueBuffer gets the next buffer slot index for the producer to use.
+ // If a buffer slot is available then that slot index is written to the
+ // location pointed to by the buf argument and a status of OK is returned.
+ // If no slot is available then a status of -EBUSY is returned and buf is
+ // unmodified.
+ //
+ // The outFence parameter will be updated to hold the fence associated with
+ // the buffer. The contents of the buffer must not be overwritten until the
+ // fence signals. If the fence is Fence::NO_FENCE, the buffer may be
+ // written immediately.
+ //
+ // The width and height parameters must be no greater than the minimum of
+ // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv).
+ // An error due to invalid dimensions might not be reported until
+ // updateTexImage() is called. If width and height are both zero, the
+ // default values specified by setDefaultBufferSize() are used instead.
+ //
+ // The pixel formats are enumerated in graphics.h, e.g.
+ // HAL_PIXEL_FORMAT_RGBA_8888. If the format is 0, the default format
+ // will be used.
+ //
+ // The usage argument specifies gralloc buffer usage flags. The values
+ // are enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER. These
+ // will be merged with the usage flags specified by setConsumerUsageBits.
+ //
+ // The return value may be a negative error value or a non-negative
+ // collection of flags. If the flags are set, the return values are
+ // valid, but additional actions must be performed.
+ //
+ // If IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION is set, the
+ // producer must discard cached GraphicBuffer references for the slot
+ // returned in buf.
+ // If IGraphicBufferProducer::RELEASE_ALL_BUFFERS is set, the producer
+ // must discard cached GraphicBuffer references for all slots.
+ //
+ // In both cases, the producer will need to call requestBuffer to get a
+ // GraphicBuffer handle for the returned slot.
+ virtual status_t dequeueBuffer(int *outSlot, sp<Fence>* outFence, bool async,
+ uint32_t width, uint32_t height, uint32_t format, uint32_t usage);
+
+ // queueBuffer returns a filled buffer to the BufferQueue.
+ //
+ // Additional data is provided in the QueueBufferInput struct. Notably,
+ // a timestamp must be provided for the buffer. The timestamp is in
+ // nanoseconds, and must be monotonically increasing. Its other semantics
+ // (zero point, etc) are producer-specific and should be documented by the
+ // producer.
+ //
+ // The caller may provide a fence that signals when all rendering
+ // operations have completed. Alternatively, NO_FENCE may be used,
+ // indicating that the buffer is ready immediately.
+ //
+ // Some values are returned in the output struct: the current settings
+ // for default width and height, the current transform hint, and the
+ // number of queued buffers.
+ virtual status_t queueBuffer(int slot,
+ const QueueBufferInput& input, QueueBufferOutput* output);
+
+ // cancelBuffer returns a dequeued buffer to the BufferQueue, but doesn't
+ // queue it for use by the consumer.
+ //
+ // The buffer will not be overwritten until the fence signals. The fence
+ // will usually be the one obtained from dequeueBuffer.
+ virtual void cancelBuffer(int slot, const sp<Fence>& fence);
+
+ // Query native window attributes. The "what" values are enumerated in
+ // window.h (e.g. NATIVE_WINDOW_FORMAT).
+ virtual int query(int what, int* outValue);
+
+ // connect attempts to connect a producer API to the BufferQueue. This
+ // must be called before any other IGraphicBufferProducer methods are
+ // called except for getAllocator. A consumer must already be connected.
+ //
+ // This method will fail if connect was previously called on the
+ // BufferQueue and no corresponding disconnect call was made (i.e. if
+ // it's still connected to a producer).
+ //
+ // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU).
+ virtual status_t connect(const sp<IBinder>& token,
+ int api, bool producerControlledByApp, QueueBufferOutput* output);
+
+ // disconnect attempts to disconnect a producer API from the BufferQueue.
+ // Calling this method will cause any subsequent calls to other
+ // IGraphicBufferProducer methods to fail except for getAllocator and connect.
+ // Successfully calling connect after this will allow the other methods to
+ // succeed again.
+ //
+ // This method will fail if the the BufferQueue is not currently
+ // connected to the specified producer API.
+ virtual status_t disconnect(int api);
+
+private:
+ // This is required by the IBinder::DeathRecipient interface
+ virtual void binderDied(const wp<IBinder>& who);
+
+ sp<BufferQueueCore> mCore;
+ BufferQueueCore::SlotsType& mSlots;
+
+ // This is a cached copy of the name stored in the BufferQueueCore.
+ // It's updated during connect and dequeueBuffer (which should catch
+ // most updates).
+ String8 mConsumerName;
+
+}; // class BufferQueueProducer
+
+} // namespace android
+
+#endif
diff --git a/include/gui/BufferSlot.h b/include/gui/BufferSlot.h
new file mode 100644
index 0000000..2c4b43f
--- /dev/null
+++ b/include/gui/BufferSlot.h
@@ -0,0 +1,136 @@
+/*
+ * Copyright 2014 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_GUI_BUFFERSLOT_H
+#define ANDROID_GUI_BUFFERSLOT_H
+
+#include <ui/Fence.h>
+#include <ui/GraphicBuffer.h>
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include <utils/StrongPointer.h>
+
+namespace android {
+
+class Fence;
+
+struct BufferSlot {
+
+ BufferSlot()
+ : mEglDisplay(EGL_NO_DISPLAY),
+ mBufferState(BufferSlot::FREE),
+ mRequestBufferCalled(false),
+ mFrameNumber(0),
+ mEglFence(EGL_NO_SYNC_KHR),
+ mAcquireCalled(false),
+ mNeedsCleanupOnRelease(false) {
+ }
+
+ // mGraphicBuffer points to the buffer allocated for this slot or is NULL
+ // if no buffer has been allocated.
+ sp<GraphicBuffer> mGraphicBuffer;
+
+ // mEglDisplay is the EGLDisplay used to create EGLSyncKHR objects.
+ EGLDisplay mEglDisplay;
+
+ // BufferState represents the different states in which a buffer slot
+ // can be. All slots are initially FREE.
+ enum BufferState {
+ // FREE indicates that the buffer is available to be dequeued
+ // by the producer. The buffer may be in use by the consumer for
+ // a finite time, so the buffer must not be modified until the
+ // associated fence is signaled.
+ //
+ // The slot is "owned" by BufferQueue. It transitions to DEQUEUED
+ // when dequeueBuffer is called.
+ FREE = 0,
+
+ // DEQUEUED indicates that the buffer has been dequeued by the
+ // producer, but has not yet been queued or canceled. The
+ // producer may modify the buffer's contents as soon as the
+ // associated ready fence is signaled.
+ //
+ // The slot is "owned" by the producer. It can transition to
+ // QUEUED (via queueBuffer) or back to FREE (via cancelBuffer).
+ DEQUEUED = 1,
+
+ // QUEUED indicates that the buffer has been filled by the
+ // producer and queued for use by the consumer. The buffer
+ // contents may continue to be modified for a finite time, so
+ // the contents must not be accessed until the associated fence
+ // is signaled.
+ //
+ // The slot is "owned" by BufferQueue. It can transition to
+ // ACQUIRED (via acquireBuffer) or to FREE (if another buffer is
+ // queued in asynchronous mode).
+ QUEUED = 2,
+
+ // ACQUIRED indicates that the buffer has been acquired by the
+ // consumer. As with QUEUED, the contents must not be accessed
+ // by the consumer until the fence is signaled.
+ //
+ // The slot is "owned" by the consumer. It transitions to FREE
+ // when releaseBuffer is called.
+ ACQUIRED = 3
+ };
+
+ static const char* bufferStateName(BufferState state);
+
+ // mBufferState is the current state of this buffer slot.
+ BufferState mBufferState;
+
+ // mRequestBufferCalled is used for validating that the producer did
+ // call requestBuffer() when told to do so. Technically this is not
+ // needed but useful for debugging and catching producer bugs.
+ bool mRequestBufferCalled;
+
+ // mFrameNumber is the number of the queued frame for this slot. This
+ // is used to dequeue buffers in LRU order (useful because buffers
+ // may be released before their release fence is signaled).
+ uint64_t mFrameNumber;
+
+ // mEglFence is the EGL sync object that must signal before the buffer
+ // associated with this buffer slot may be dequeued. It is initialized
+ // to EGL_NO_SYNC_KHR when the buffer is created and may be set to a
+ // new sync object in releaseBuffer. (This is deprecated in favor of
+ // mFence, below.)
+ EGLSyncKHR mEglFence;
+
+ // mFence is a fence which will signal when work initiated by the
+ // previous owner of the buffer is finished. When the buffer is FREE,
+ // the fence indicates when the consumer has finished reading
+ // from the buffer, or when the producer has finished writing if it
+ // called cancelBuffer after queueing some writes. When the buffer is
+ // QUEUED, it indicates when the producer has finished filling the
+ // buffer. When the buffer is DEQUEUED or ACQUIRED, the fence has been
+ // passed to the consumer or producer along with ownership of the
+ // buffer, and mFence is set to NO_FENCE.
+ sp<Fence> mFence;
+
+ // Indicates whether this buffer has been seen by a consumer yet
+ bool mAcquireCalled;
+
+ // Indicates whether this buffer needs to be cleaned up by the
+ // consumer. This is set when a buffer in ACQUIRED state is freed.
+ // It causes releaseBuffer to return STALE_BUFFER_SLOT.
+ bool mNeedsCleanupOnRelease;
+};
+
+} // namespace android
+
+#endif