niwinz

Enable native memory tracking in JVM by specifying the following flag

-XX:NativeMemoryTracking=detail

Know the <PID> of the java process

jps

To print ps based RSS

ps -p <PID> -o pcpu,rss,size,vsize

To print native memory tracking summary

niwinz

/**
 @class BroadcastChannel
 A simple BroadcastChannel polyfill that works with all major browsers.
 Please refer to the official MDN documentation of the Broadcast Channel API.
 @see <a href="https://developer.mozilla.org/en-US/docs/Web/API/Broadcast_Channel_API">Broadcast Channel API on MDN</a>
 @author Alessandro Piana
 @version 0.0.6
 */

/*

niwinz

#include <time.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <stdint.h>
#include <sys/random.h>

#define UUID_T_LENGTH (16)
#define UNIX_TS_LENGTH (6)

niwinz

#!/bin/bash

# Get temp dir
tmpdir=$(mktemp -d)

# Generate test
cat > ${tmpdir}/ListenToSignal.java <<EOF
import sun.misc.Signal;
import sun.misc.SignalHandler;
public class ListenToSignal {

niwinz

#!/bin/bash

# for use with cron, eg:
# 0 3 * * * postgres /var/db/db_backup.sh foo_db

if [[ -z "$1" ]]; then
    echo "Usage: $0 <db_name> [pg_dump args]"
    exit 1
fi

niwinz

#!/bin/bash
#
# PostgreSQL Backup Script Ver 1.0
# http://autopgsqlbackup.frozenpc.net
# Copyright (c) 2005 Aaron Axelsen <axelseaa@amadmax.com>
#
# This script is based of the AutoMySQLBackup Script Ver 2.2
# It can be found at http://sourceforge.net/projects/automysqlbackup/
#
# The PostgreSQL changes are based on a patch agaisnt AutoMySQLBackup 1.9

niwinz

(defn tree-seq-depth
  "Returns a lazy sequence of vectors of the nodes in a tree and their
  depth as [node depth], via a depth-first walk.  branch? must be a fn
  of one arg that returns true if passed a node that can have
  children (but may not).  children must be a fn of one arg that
  returns a sequence of the children. Will only be called on nodes for
  which branch? returns true. Root is the root node of the tree."
  [branch? children root]
  (let [walk (fn walk [depth node]
               (lazy-seq

niwinz

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Element

Box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
• elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
• elem.getClientRects(), elem.getBoundingClientRect()

niwinz

(require '[clojure.core.async.impl.protocols :as impl]
         '[clojure.core.async.impl.dispatch :as dispatch])

;;=> nil

(extend-type java.util.concurrent.CompletionStage
  impl/ReadPort
  (take! [this handler]
    (.whenCompleteAsync this
                        (reify

niwinz

(defn array-type
  "Return a string representing the type of an array with dims
  dimentions and an element of type klass.
  For primitives, use a klass like Integer/TYPE
  Useful for type hints of the form: ^#=(array-type String) my-str-array"
  ([klass] (array-type klass 1))
  ([klass dims]
     (.getName (class
                (apply make-array
                       (if (symbol? klass) (eval klass) klass)