jlblancoc

Run the following in the terminal:

Install the gcc-7 packages:

sudo apt-get install -y software-properties-common
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt install g++-7 -y

Set it up so the symbolic links gcc, g++ point to the newer version:

BillyONeal

#include <stddef.h>
#include <string_view>

#include <pmretvals.h>
#include <test_death.hpp>

using namespace std;

int test_case_operator_dereference_value_initalized_iterator() {
    string_view::iterator it; // note: for IDL to work correctly, default init and value init are equivalent

zachary822

/**
 * Sending a TCP SYN packet properly using the raw-socket package.
 */
var raw = require('raw-socket');
var crypto = require('crypto');

// create a raw socket using TCP
var s = raw.createSocket({
    protocol: raw.Protocol.TCP
});

arunk-s

1. Execute make first. This will result in a netlinkKernel.ko output among many others.
2. Execute $ gcc netlinkUser.c -o netlinkUser
3. Insert kernel module by :$ sudo insmod netlinkKernel.ko      
4. Run ./netlinkUser to see message and run dmesg to see debug messages
5. Remove module by : $ sudo rmmod netlinkKernel          
6. Finally make clean to remove output files.

metakeule

Latency Comparison Numbers
--------------------------
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
Send 1K bytes over 1 Gbps network        10,000   ns    0.01 ms
Read 4K randomly from SSD*              150,000   ns    0.15 ms

kputnam

Using dtruss on vim's :w

Ever wonder what happens when you save a file in vim? There's quite a lot more happening than open, write, and close. I found this out while working on some code to monitor changed files using the node.js fs.watch API, which abstracts (or obscures) Mac OS X's kqueue API.

To find out exactly what vim is doing when saving a file, we'll use a tool included with DTrace that reports on another process's system calls. We need the process ID of vim, which is already open and editing my file:

hellerbarde

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

jboner

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

lpereira

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <ucontext.h>

typedef struct coro_t_		coro_t;
typedef struct thread_t_	thread_t;
typedef int (*coro_function_t)(coro_t *coro);
typedef enum {
    CORO_NEW,