Merge "media.c2 : Change waitable object to be based on single fd" into main

This commit is contained in:
Treehugger Robot
2023-09-28 02:58:22 +00:00
committed by Gerrit Code Review
2 changed files with 16 additions and 29 deletions

View File

@@ -36,7 +36,7 @@ package android.hardware.media.c2;
interface IGraphicBufferAllocator {
android.hardware.media.c2.IGraphicBufferAllocator.Allocation allocate(in android.hardware.media.c2.IGraphicBufferAllocator.Description desc);
boolean deallocate(in long id);
android.hardware.media.c2.IGraphicBufferAllocator.WaitableFds getWaitableFds();
ParcelFileDescriptor getWaitableFd();
parcelable Allocation {
android.hardware.HardwareBuffer buffer;
ParcelFileDescriptor fence;
@@ -47,8 +47,4 @@ interface IGraphicBufferAllocator {
int format;
long usage;
}
parcelable WaitableFds {
ParcelFileDescriptor allocEvent;
ParcelFileDescriptor statusEvent;
}
}

View File

@@ -75,31 +75,22 @@ interface IGraphicBufferAllocator {
boolean deallocate(in long id);
/**
* Fds for waitable object events.
*
* Fds are created by eventfd() with semaphore mode.
* For allocEvent, An integer counter regarding dequeuable buffer count is maintained
* by client using read()/write() to the fd. The fd can be checked whether it is
* readable via poll(). When in readable status, the specified counter is positive
* so allocate/dequeue can happen.
*
* For statusEvent, the client can notify further allocation is not feasible.
* e.g.) life-cycle of the underlying allocator is ended.
*
* C2Fence object should be implemented based on this Fds. Thus, C2Fence can return
* either by allocation being ready or allocation being infeasible by the client status
* change.
*/
parcelable WaitableFds {
ParcelFileDescriptor allocEvent;
ParcelFileDescriptor statusEvent;
}
/**
* Gets waiable file descriptors.
* Gets a waitable file descriptor.
*
* Use this method once and cache it in order not to create unnecessary duplicated fds.
* The returned array will have two fds.
*
* Two file descriptors are created by pipe2(), and the reading end will be returned
* and shared by this method. Whenever a dequeuable buffer is ready a byte will be
* written to the writing end. Whenever a buffer is allocated(or dequeued) a byte will
* be read from the reading end.
*
* The returned file descriptor(the reading end) can be polled whether the read is ready
* via ::poll(). If no more allocate() can be fulfilled(by status change or etc.), the
* writing end will be closed. In the case, POLLHUP event can be retrieved via ::poll().
*
* C2Fence object should be implemented based on this Fd. Thus, C2Fence can return
* either by allocation being ready or allocation being infeasible by the client status
* change.
*
* If many waitable objects based on the same fd are competing, all watiable objects will be
* notified. After being notified, they should invoke allocate(). At least one of them can
@@ -110,5 +101,5 @@ interface IGraphicBufferAllocator {
* @return an fd array which will be wrapped to C2Fence and will be waited for
* until allocating is unblocked.
*/
WaitableFds getWaitableFds();
ParcelFileDescriptor getWaitableFd();
}