Buffering is there for a reason and this approach will lead to weird failure modes and fragility in scripts. The core issue is that any stream producer might go slower than any given consumer. Even a momentary hiccup will totally mess up the pipe unless there is adequate buffering, and the amount needed is system-dependent.
It is different from a pipe - instead of using read/write to copy data from/to a kernel buffer, it gives user space a mapped buffer object and they need to take care to use it properly (using atomic operations on the head/tail and such).
If you own the code for the reader and writer, it's like using shared memory for a buffer. The proposal is about standardizing an interface.
What makes this any different than other buffer implementations that have a max size? Buffer fills, writes block. What failure mode are you worried about that can't occur with pipes which are also
bounded?
