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#Create bitbucket branch

##Create local branch

$ git checkout -b sync
Switched to a new branch 'sync'
$ git branch
  master
* sync

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Distributed Read-Write Mutex in Go

The default Go implementation of sync.RWMutex does not scale well to multiple cores, as all readers contend on the same memory location when they all try to atomically increment it. This gist explores an n-way RWMutex, also known as a "big reader" lock, which gives each CPU core its own RWMutex. Readers take only a read lock local to their core, whereas writers must take all locks in order.

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Persistent "pipes" in Linux

In a project I'm working on I ran into the requirement of having some sort of persistent FIFO buffer or pipe in Linux, i.e. something file-like that could accept writes from a process and persist it to disk until a second process reads (and acknowledges) it. The persistence should be both across process restarts as well as OS restarts.

AFAICT unfortunately in the Linux world such a primitive does not exist (named pipes/FIFOs do not persist

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#include <stdint.h>

/*
 
  Fast 64bit integer log10
  WARNING: calling ilog10c(0) yields undefined behaviour!

  On x64 this compiles down to:

  pushq	%rbp

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from flask import after_this_request, request
from cStringIO import StringIO as IO
import gzip
import functools

def gzipped(f):
    @functools.wraps(f)
    def view_func(*args, **kwargs):
        @after_this_request
        def zipper(response):

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import brotli

def main(request, response):
    if "content" in request.GET:
        output = request.GET["content"]
    else:
        output = request.body
    output = brotli.compress(output)

    headers = [("Content-type", "text/plain"),

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./mach cargo-update -p brotli --precise 0.3.17


components/servo
thread '<main>' panicked at 'index 0 and/or 8 in `0.3.17` do not lie on character boundary', ../src/libcore/str/mod.rs:1284

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#include <stdio.h>

#define STR2(x) #x
#define STR(x) STR2(x)

#define INCBIN(name, file) \
    __asm__(".section .rodata\n" \
            ".global incbin_" STR(name) "_start\n" \
            ".type incbin_" STR(name) "_start, @object\n" \
            ".balign 16\n" \

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Keybase proof

I hereby claim:

• I am nxnfufunezn on github.
• I am nxnfufunezn (https://keybase.io/nxnfufunezn) on keybase.
• I have a public key whose fingerprint is 9369 D7F4 0F45 BBB3 6C27 C45A AFC9 CF33 B178 6FD6

To claim this, I am signing this object:

nxnfufunezn

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