(* raw continuation *)
type ('a,'b) stack
perform : 'a eff -> 'a
resume : ('a,'b) stack -> ('c -> 'a) -> 'c -> 'b
delegate : 'a eff -> ('a,'b) stack -> 'b
The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.
In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.
This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.
args = "-c" & " -l " & """DISPLAY=:0 terminator""" | |
WScript.CreateObject("Shell.Application").ShellExecute "bash", args, "", "open", 0 |
This document was originally written several years ago. At the time I was working as an execution core verification engineer at Arm. The following points are coloured heavily by working in and around the execution cores of various processors. Apply a pinch of salt; points contain varying degrees of opinion.
It is still my opinion that RISC-V could be much better designed; though I will also say that if I was building a 32 or 64-bit CPU today I'd likely implement the architecture to benefit from the existing tooling.
Mostly based upon the RISC-V ISA spec v2.0. Some updates have been made for v2.2
The RISC-V ISA has pursued minimalism to a fault. There is a large emphasis on minimizing instruction count, normalizing encoding, etc. This pursuit of minimalism has resulted in false orthogonalities (such as reusing the same instruction for branches, calls and returns) and a requirement for superfluous instructions which impacts code density both in terms of size and
Using newer compiler versions and the optimizer gives gas optimizations and additional safety checks for free!
The advantages of versions 0.8.*
over <0.8.0
are:
- Safemath by default from
0.8.0
(can be more gas efficient than some library based safemath). - Low level inliner from
0.8.2
, leads to cheaper runtime gas. Especially relevant when the contract has small functions. For