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Software Transactional Memory in C++: pure functional approach (Tutorial)

In this article I’ll tell you about my pure functional library for Software Transactional Memory (STM) that I’ve built in C++. I adopted some advanced functional programming concepts that make it composable and convenient to use. Its implementation is rather small and robust, which differentiates the library from competitors. Let’s discuss what STM is and how to use it.

Links

• The cpp_stm_free library
• Dining Philosophers sample
• More STM samples
• C++ Russia 2018 talk slides (Eng)

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Why stack grows down

Any running process has several memory regions: code, read-only data, read-write data, et cetera. Some regions, such as code and read-only data, are static and do not change over time. Other regions are dynamic: they can expand and shrink. Usually there are two such regions: dynamic read-write data region, called heap, and a region called stack. Heap holds dynamic memory allocations, and stack is mostly used for keeping function frames.

Both stack and heap can grow. An OS doesn't know in advance whether stack or heap will be used predominantly. Therefore, an OS must layout these two memory regions in a way to guarantee maximum space for both. And here is the solution:

1. Layout static memory regions at the edges of process's virtual memory
2. Put heap and stack on edges too, and let them grow towards each other: one grows up, one grows down

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tl;dr Serokell is hiring Nix DevOps Engineers

Hi! We’re Serokell – a company with about 30 Haskellers working on a bunch of blockchain-related projects (like Cardano or TeachMePlease). We are hiring SREs and a Head of IT Operations that can work with Nix (yay Nix!) and know some Haskell. The job is fully remote.

A bit more about us

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How to setup Let's Encrypt for Nginx on Ubuntu 16.04 (including IPv6, HTTP/2 and A+ SLL rating)

There are two main modes to run the Let's Encrypt client (called Certbot):

• Standalone: replaces the webserver to respond to ACME challenges
• Webroot: needs your webserver to serve challenges from a known folder.

Webroot is better because it doesn't need to replace Nginx (to bind to port 80).

In the following, we're setting up mydomain.com. HTML is served from /var/www/mydomain, and challenges are served from /var/www/letsencrypt.

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Quick Tips for Fast Code on the JVM

I was talking to a coworker recently about general techniques that almost always form the core of any effort to write very fast, down-to-the-metal hot path code on the JVM, and they pointed out that there really isn't a particularly good place to go for this information. It occurred to me that, really, I had more or less picked up all of it by word of mouth and experience, and there just aren't any good reference sources on the topic. So… here's my word of mouth.

This is by no means a comprehensive gist. It's also important to understand that the techniques that I outline in here are not 100% absolute either. Performance on the JVM is an incredibly complicated subject, and while there are rules that almost always hold true, the "almost" remains very salient. Also, for many or even most applications, there will be other techniques that I'm not mentioning which will have a greater impact. JMH, Java Flight Recorder, and a good profiler are your very best friend! Mea

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Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

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-module(index).
-compile([export_all]).

% -export([get_file_contents/1,show_file_contents/1]).

% Used to read a file into a list of lines.
% Example files available in:
%   gettysburg-address.txt (short)
%   dickens-christmas.txt  (long)

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Hey! I saw this has been indexed by the search engines. It is a first draft of a post I ended up publishing on my blog at: Scaling PostgreSQL With Pgpool and PgBouncer

Thanks for stopping by!

PostgreSQL and Pgpool Architecture

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#!/boot/bzImage

# Linux kernel userspace initialization code, translated to bash
# (Minus floppy disk handling, because seriously, it's 2017.)
# Not 100% accurate, but gives you a good idea of how kernel init works
# GPLv2, Copyright 2017 Hector Martin <[email protected]>
# Based on Linux 4.10-rc2.

# Note: pretend chroot is a builtin and affects the current process
# Note: kernel actually uses major/minor device numbers instead of device name

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Git Cheat Sheet

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Commands

Getting Started

git init

or