szegedi

Table of names of MemoryManagerMXBean and MemoryPoolMXBean instances under
different GC algorithms in Oracle HotSpot VM. Memory managers list the pools
they manage in square brackets; memory pools show their maximum sizes for -Xmx200M setting.

$ java -version
java version "1.6.0_24"
Java(TM) SE Runtime Environment (build 1.6.0_24-b07)
Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)

SerialGC:

szegedi

import java.util.Objects;

public class FunWithFloats {
    public static void main(String[] args) {
        float f1 = 0.7f;
        System.out.println(f1); // prints 0.7

        double d = f1;
        System.out.println(d); // prints 0.699999988079071

szegedi

                  Attila Szegedi Contributor Agreement

This Attila Szegedi Contributor Agreement (“ASzCA”) applies to any
contribution that you make to any product or project managed by me (the
“project”), and sets out the intellectual property rights you grant to
me in the contributed materials. The term “me” shall mean Attila 
Szegedi, born on November 14, 1974 in Osijek, Croatia. The term “you” 
shall mean the person or entity identified below. If you agree to be 
bound by these terms, fill in the information requested below and sign 
the ASzCA where indicated below. Read this agreement carefully before 

szegedi

Keybase proof

I hereby claim:

• I am szegedi on github.
• I am asz (https://keybase.io/asz) on keybase.
• I have a public key ASAFVgxsvW4XMH5ojizp_eBMIEX7iiRwCjz6ky6ki-k0Vwo

To claim this, I am signing this object:

szegedi

TL;DR: scalac apparently doesn't believe in exhaustiveness of value set (true, false) for a boolean, so pattern matching on a boolean in Scala emits a branch for "neither true nor false". (I won't even go into it emitting comparison to 1 and 0 instead of using ifeq or ifne instructions, or those gotos that jump to the very next instruction.)

This scala code:

final class X {
  final def foo(b: Boolean) = 
    b match {
      case true  => 10
      case false => 11
    }

szegedi

import javax.script.*;

public class X {
    public static void main(String[] args) throws ScriptException, NoSuchMethodException {
       ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
       ScriptEngine engine = scriptEngineManager.getEngineByName("nashorn");
       Compilable ce = (Compilable) engine;
       CompiledScript cs;
       try {
           String script = "function f1602838289254hw9b() {\n" +

szegedi

#!/bin/bash
# (C) Datadog, Inc. 2010-present
# All rights reserved
# Licensed under Apache-2.0 License (see LICENSE)
# Datadog Agent installation script: install and set up the Agent on supported Linux distributions
# using the package manager and Datadog repositories.

set -e

szegedi

Below is the lscpu output for the Amazon Fargate ECS spot instances that exhibited crashes when running code compiled with GCC 8 which chose to emit machine code on AArch64 that'd store/load pointers in/from floating-point registers.

See also GCC email discussion for more information as well as the latest message referencing this Gist.

Architecture:             aarch64
  CPU op-mode(s):         32-bit, 64-bit
  Byte Order:             Little Endian
CPU(s):                   2
  On-line CPU(s) list:    0,1

szegedi

1,4c1
< ASM_DD_CONFIG
< ASM_DD_MULTICONFIG
< ASM_DD_RULES
< DATADOG_DD_PROFILING_EXPERIMENTAL_ENDPOINT_COLLECTION_ENABLED
---
> DATADOG_API_KEY
7,8d3
< DD_ADMIN_PASSWORD
< DD_ADMIN_USERNAME