cspinetta

#!/usr/bin/env bash

cat /proc/net/tcp* | awk '
{
	TOTAL += $7;
	COUNT++;
}
END {
	printf "rate_retr %.3f\n", TOTAL/COUNT
}

cspinetta

version: "3.6"

services:
  promtail:
    image: grafana/promtail:1.4.0
    container_name: promtail
    command: [ "-config.file=/etc/promtail/local-config.yaml" ]
    volumes:
      - './promtail.yml:/etc/promtail/local-config.yaml:ro'
      - '__path_to_logs_directory__:/app/log:ro'

cspinetta

Object locking implementation in the Java HotSpot VM

The most synchronization idiom in Java is using the synchronized keyword.

The JVM supports synchronization of both methods and sequences of instructions within a method using a single synchronization construct - synchronized - which is built around an internal entity known as the intrinsic lock or monitor lock (The API specification often refers to this entity simply as a "monitor"). Intrinsic locks play a role in both aspects of synchronization: enforcing exclusive access to an object's state and establishing happens-before relationships to ensure a correct visibility amoung threads.

At bytecode level, the JVM supplies the monitorenter and monitorexit instructions to support such constructs.

At runtime level, in the Java HotSpot VM, every object has a built-in monitor (the so called intrinsic lock or monitor lock) that can be acquired by any thread.

cspinetta

package main

import (
	"fmt"
	"io"
)

func main() {
	r := NewDataGenerator(1000)