tree dbaf30368442533597bc0b2413e5fec2cc9e33b1
parent face176394e0a28bd7b7b8bed13b4696e79668a2
author Tianyu <tianyuj@google.com> 1539210872 -0700
committer Tianyu Jiang <tianyuj@google.com> 1543863340 -0800

Change the definition of buffer state and client state bits.

Please refer to go/bufferhub-buffer-state-redesign for more information.

In this change:
1. Every clients takes up two bits in the buffer_state.
One from the higher 32 bits, one from the lower 32 bits. For details:
go/bufferhub-buffer-state-redesign

2. Upon the creation of a new buffer, the buffer is in released state.
Previously, only producer creates buffer, and upon creation, the buffer
was in gained state. Now, producer needs to specifically gain the buffer
before trying to produce and post it.

3. If there is no other clients when a client post a buffer, the buffer
will actually be in released state instead of posted state. This is
because the posted buffer does not have readers and can be reused
immediately.

4. If a new client is added to the buffer when the buffer is in acquired
or posted state, the buffer state of the new client will be set to posted
state and able to acquire the same buffer content as posted.

In the next change:
variables of type std::atomic<uint64_t> in metadata header in shared memory
will be replaced by std::atomic<uint32_t>

Test: marlin-eng passing AHardwareBufferTest BufferHubBuffer_test
BufferHubMetadata_test buffer_hub_binder_service-test
buffer_hub_queue_producer-test dvr_api-test libgui_test
libsensor_test vrflinger_test buffer_hub-test
dvr_buffer_queue-test dvr_display-test buffer_hub_queue-test

Test: smartphone VR works on blueline-eng

Test: vega_xr passing AHardwareBufferTest BufferHubBuffer_test
BufferHubMetadata_test buffer_hub_queue_producer-test buffer_hub-test
buffer_hub_queue-test dvr_buffer_queue-test dvr_api-test

Cherrypicking this changelist to oc-dr1-daydream-dev branch requires
ag/5514563 to be merged at the same time to make Vega actually work.

Bug: 112007999
Change-Id: I86393818ad922a91c709fe22f8e99b0667d2e9ef