Split BufferQueue into core + producer + consumer
Change-Id: Idc39f1e511d68ce4f02202d35425a419bc0bcd92
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