this change introduces R/W locks in the right places.
on the server-side, it guarantees that setBufferCount()
is synchronized with "retire" and "resize".
on the client-side, it guarantees that setBufferCount()
is synchronized with "dequeue", "lockbuffer" and "queue"
First, the window manager tells us when a surface is no longer needed. At this point, several things happen:
- the surface is removed from the active/visible list
- it is added to a purgatory list, where it waits for all clients to release their reference
- it destroys all data/state that can be spared
Later, when all clients are done, the remains of the Surface are disposed off: it is removed from the purgatory and destroyed.
In particular its gralloc buffers are destroyed at that point (when we're sure nobody is using them anymore).