Drumroll please!
For implementers, backpressure adds complexity without providing guarantees. The machinery to track queue sizes, compute desiredSize, and invoke pull() at the right times must all be implemented correctly. However, since these signals are advisory, all that work doesn't actually prevent the problems backpressure is supposed to solve.
，这一点在heLLoword翻译官方下载中也有详细论述
Employees can ask Patty how to make various menu items or tell Patty to remove items from digital menus if they’ve run out of ingredients.
But that’s a lot of resetting! We can save a bunch of bandwidth by instead tracking the current foreground and background color in our renderer and only emitting a new color escape sequence when our desired color changes. This is an annoying amount of bookkeeping but it substantially cuts down on the amount of escape codes emitted.