The testbed to the package spsc. This package is like ringbuf.js but allows blocking communicatons. See the package for README.
Build the package and then build this website, and you should see the following output in console.
16:34:36.088 reader on message Object { sab: SharedArrayBuffer }
16:34:36.089 reader start 70.7
16:34:37.089 reader report: seq 5635 avg speed 5634.324 bps
16:34:38.093 reader report: seq 11095 avg speed 5438.247 bps
16:34:39.093 reader report: seq 16847 avg speed 5751.885 bps
16:34:40.100 reader report: seq 22887 avg speed 5998.729 bps
[...]
16:34:52.143 reader report: seq 94299 avg speed 5536.792 bps
16:34:53.048 producer finish writing and will close the pipe soon
16:34:54.054 closing writer's end
16:34:54.054 writer job is done!
16:34:54.055 reader got EOF
16:34:54.055 reader end, seq= 100000 ts= 18037.08
16:34:54.055 closing reader's end
16:34:54.055 reader job is done!