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Jim Shu cwshu

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@glacjay
glacjay / tun-ping-linux.py
Created September 18, 2010 04:49
Reading/writing Linux's TUN/TAP device using Python.
import fcntl
import os
import struct
import subprocess
# Some constants used to ioctl the device file. I got them by a simple C
# program.
TUNSETIFF = 0x400454ca
TUNSETOWNER = TUNSETIFF + 2
@jboner
jboner / latency.txt
Last active July 27, 2024 12:32
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@hellerbarde
hellerbarde / latency.markdown
Created May 31, 2012 13:16 — forked from jboner/latency.txt
Latency numbers every programmer should know

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

@MohamedAlaa
MohamedAlaa / tmux-cheatsheet.markdown
Last active July 27, 2024 16:01
tmux shortcuts & cheatsheet

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname
@mattmcd
mattmcd / Hello.g4
Last active April 19, 2024 08:04
Simple ANTLR4 grammar example
// define a grammar called Hello
grammar Hello;
r : 'hello' ID;
ID : [a-z]+ ;
WS : [ \t\r\n]+ -> skip ;
@hanksudo
hanksudo / Front-end-Developer-Interview-Questions-TC.md
Last active May 2, 2024 06:26
Front-end-Developer-Interview-Questions - 前端工程師面試問題集(繁體中文版)

前端工程師面試問題集

@版本 2.0.0

譯注:此翻譯版,主要給不能流利的讀英文的人看,相關專有名詞還是保留原文。翻譯不好地方請協助pull request.

此repository包含了一些前端開發的面試問題,來審查一個有潛力的面試者。這並不是建議你對同一個面試者問上所有的問 (那會花費好幾小時)。從列表中挑幾個題目,應該就夠幫助你審查面試者是否擁有你需要的技能。

Rebecca MurpheyBaseline For Front-End Developers 也是一篇很棒且值得讀的文章在你開始面試之前。

@DraTeots
DraTeots / ComPort over Network.md
Last active July 13, 2024 13:54
ComPort over Network
@ericclemmons
ericclemmons / example.md
Last active July 17, 2024 06:50
HTML5 <details> in GitHub

Using <details> in GitHub

Suppose you're opening an issue and there's a lot noisey logs that may be useful.

Rather than wrecking readability, wrap it in a <details> tag!

<details>
 Summary Goes Here
@Francesco149
Francesco149 / osu_on_linux_overhaul.md
Last active July 10, 2024 23:50
Ultimate guide to low-latency osu on linux