tclementdev

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

• You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

• Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

katlogic

#include <sys/epoll.h>
#include <sys/socket.h>
#include <stdio.h>
int main()
{
  struct epoll_event ev = {
    .data.fd = 1
  };
  int efd = epoll_create(1);
  ev.events = EPOLLIN|EPOLLET;

a-dma

#!/bin/bash

# Bash script for setting or clearing touch requirements for
# cryptographic operations the OpenPGP application on a YubiKey 4.
#
# Author: Alessio Di Mauro <alessio@yubico.com>

GCA=$(which gpg-connect-agent)
DO=0
UIF=0

daurnimator

hkp-cacert ~/.gnupg/sks-keyservers.netCA.pem

lukego

Prototype code for quickly reading the values of all CPU Performance Monitoring Counters from Lua.

Uses dynasm to generate the routine at runtime based on the capabilities of the running CPU.

dynasm: https://github.com/luapower/dynasm/blob/master/dynasm.md

jhass

python/
*.log

daurnimator

#pragma warning(push, 3)

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <Winternl.h>
#pragma comment(lib, "Ntdll.lib")

#pragma warning(pop)

#include "afd.h"

daurnimator

// ==UserScript==
// @name         Better dimensions for Glowing Bear
// @namespace    http://daurnimator.com
// @version      0.1
// @description  Glowing Bear sidebar dimensions
// @author       Daurnimator
// @match        http://www.glowing-bear.org/
// @grant        GM_addStyle
// ==/UserScript==

daurnimator

local ffi = require "ffi"
local S = require "syscall"
local c = S.c
local t = S.types.t
local util = S.util
local nr = require "syscall.linux.nr"
local lfs = require "syscall.lfs"

-- Returns an iterator over open fds
local function open_fds(pid)

insin

function new_(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z, A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z) {
  switch (arguments.length) {
    case 0:  return new this
    case 1:  return new this(a)
    case 2:  return new this(a, b)
    case 3:  return new this(a, b, c)
    case 4:  return new this(a, b, c, d)
    case 5:  return new this(a, b, c, d, e)
    case 6:  return new this(a, b, c, d, e, f)
    case 7:  return new this(a, b, c, d, e, f, g)