1 Basic Hazard Pointer Algorithm read pointer A from SRC remove A from SRC 1 5 4 Safe to use pointer A SRC A hazard pointer is a single-writer multi-reader pointer. set HP to A if SRC == A clear ACCESS If a hazard pointer points to an object before its removal, then the object will not be reclaimed as long as the hazard pointer remains unchanged unchanged. *A Hazard Pointer Synchronous Reclamation Beyond Concurrency TS2 – Maged Michael Protector Remover / Reclaimer Hazard pointers protect access to objects that may be removed concurrently. SAFE RECLAMATION

Firebird Null Guide NULL behaviour and pitfalls in Firebird SQL Paul Vinkenoog Version 1.2, 30 June 2020 Table of Contents 1. What is NULL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. NULL as a default state. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. NULL support in Firebird 1. Disallowing NULL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2. Testing for NULL . . . . . . .

Guide Firebird et NULL Comportement et précautions au sujet de NULL dans Firebird SQL Paul Vinkenoog Traduction en français: Philippe Makowski 04 mai 2005 - Document version 0.2.1-fr 2 Table des matières ............ 3 Qu'est ce que NULL? .............................................................................................................................. 3 NULL dans les expressions ......... .............. 3 Expressions retournant NULL .......................................................................................................... 4 NULL dans des expressions booléennes ........

Guía de NULL en Firebird Comportamiento y dificultades de NULL en Firebird Paul Vinkenoog 22 de julio de 2005 - Versión de documento 0.2-es-2 Traducción al castellano: Víctor Zaragoza 2 Tabla de ............... 3 ¿Qué es NULL? ...................................................................................................................................... 3 NULL en expresiones ........... ............... 3 Expresiones que devuelven NULL ................................................................................................... 4 NULL en expresiones booleanas ..................

NULL в СУБД Firebird Подводные камни и поведение NULL в СУБД Firebird Paul Vinkenoog 19 октября 2006 – Версия документа 0.2-ru Перевод документа на русский язык: Сергей Ковалёв 2 Содержание Введение ............... 3 Что такое NULL? ................................................................................................................................... 3 NULL в выражениях .............. .................. 3 Выражения, возвращающие NULL ................................................................................................ 4 NULL в логических выражениях .....................

Nulls and other C# stories from the future Chapter One Herding nulls Every reference type allows null! Code must be defensive about it C# shares this with most object oriented languages Not all languages { get; set; } public string LastName { get; set; } } J 1. Protect non-null types from nulls 2. Protect nulls from dereference Must be optional Turn it on when you’re ready to know Can’t affect semantics job with existing code Can’t force you to rewrite good code Recognize existing ways of ensuring null safety (checks and assignments) Can’t be exhaustive Tradeoff between completeness and convenience

pointers and the C++ language. In this talk, we will discuss the low level foundations of what a raw pointer is--a variable that stores an address. We will then see some examples of raw pointers for creating leave understanding how we can use pointers in a safe manner through the standard library smart pointer abstractions. 4 The abstract that you read and enticed you to join me is here!Code for the talk and more on: www.mshah.io 6One of my fondest programming memories was... 7... when I used a pointer correctly on the first try 8 ● And maybe as a C or C++ programmer you have a similar memory or

empty spot somewhere in the heap that is big enough, marks it as being in use, and returns to us a pointer to that location. This process is called allocating on the heap, and sometimes we abbreviate the considered allocating. Because the pointer is a known, fixed size, we 81 can store the pointer on the stack, but when we want the actual data, we have to follow the pointer. Think of being seated at a restaurant Accessing data in the heap is slower than accessing data on the stack because we have to follow a pointer to get there. Contemporary processors are faster if they jump around less in memory. Continuing the

can't appear at the left of :=. These items include qualified identifiers, container elements, pointer dereferences and struct field selectors. Pure assignments have no such limit. About the terminology the multiplication binary operator * can also be used as pointer dereference operator, and the bitwise-and operator & can also be used as pointer address operator. Please read pointers in Go (§15) for details // +1.000000e-001 println(y) // +1.500000e-001 } More Operators Same as C/C++, there are two pointer related operators, * and &. Yes the same operator symbols as the multiplication and bitwise-and operators

can't appear at the left of :=. These items include qualified identifiers, container elements, pointer dereferences and struct field selectors. Pure assignments have no such limit. About the terminology the multiplication binary operator * can also be used as pointer dereference operator, and the bitwise-and operator & can also be used as pointer address operator. Please read pointers in Go (§15) for details 000000e-001 8| println(y) // +1.500000e-001 9| } More Operators Same as C/C++, there are two pointer related operators, * and &. Yes the same operator symbols as the multiplication and bitwise-and