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

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

FpMMap (201) option: Ignored. MAP_EXECUTABLE = $1000 FpMMap (201) option: Ignored. MAP_FAILED = pointer(- 1) Memory mapping failed error code MAP_FIXED = $10 FpMMap (201) map type: Interpret addr exactly off_t Offset type. PBlkCnt = ^Blkcnt_t pointer to TBlkCnt (175) type. PBlkSize = ^Blksize_t Pointer to TBlkSize (175) type. pcbool = UnixType.pcbool Pointer to boolean type cbool (165) pcchar = UnixType UnixType.pcdouble Pointer to cdouble (165) type. pcfloat = UnixType.pcfloat Pointer to cfloat (165) type. pcint = UnixType.pcint 168 CHAPTER 1. REFERENCE FOR UNIT ’BASEUNIX’ Pointer to cInt (165) type

polymorphic mechanisms, • Member Data Pointers, • Member Function Pointers, • * Stack Frame / Base Pointer mechanics • * Construction/Destruction order, • * Running code before and after main(), 3About DestructedC++ Under the Hood ‘C’ Pointer types int * Pointer to Data int(*)(int) Pointer to Function Member Pointer types int Foo::* Pointer to Member Data int(Foo::*)(int) Pointer to Member Function 65C++ Pointers - Pointer to Data(aka object) 66 godbolt.org/z/rKzdTsejzC++ Under the Hood ‘C’ Pointer types int * Pointer to Data int(*)(int) Pointer to Function Member Pointer types int Foo::* Pointer to Member

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

unsigned __int128 unsigned 128-bit integer isize intptr_t signed pointer sized integer usize uintptr_t , size_t unsigned pointer sized integer. Also see #5185 c_char char for ABI compatibility with b are compile-time known. const mem = @imp const pattern = mem.eql(u8, patt Pointer Dereference a.* Pointers Pointer dereference. const x: u32 = 1 const ptr = &x; ptr.* == 1234 Address Of &a All size of an array comptime { assert(message.len == 5); } // A string literal is a single-item pointer to an array. const same_message = "hello"; comptime { assert(mem.eql(u8, &message, same_message));

Agenda 1. Improving C++20 Atomic Min/Max(P0493; Michael) 2. Hazard pointer extensions (P3135; Maged) 3. Pointer tagging (P3125; Maged) 4. Parallel Range algorithms (P3179; Michael), may be Parallel capabilities Significant performance benefits Additional functions for more specific needsHazard Pointer Extensions beyond C++26Hazard Pointers in C++26 -- Background Hazard pointers protect dynamic objects class hazard_pointer_obj_base { void retire(D d = D()) noexcept; }; class hazard_pointer { hazard_pointer() noexcept; // construct empty hazard_pointer hazard_pointer(hazard_pointer&&) noexcept;

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

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 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

already have a Concurrency TS? • Why do we need a new one? • implementation status 2.TS2 Hazard Pointer • how I learn to love C++ tricks 3.TS2 RCU • From C to C++ in 2500 days 3 3 © 2021. 4 Concurrency protect access to objects that may be concurrently removed. A hazard pointer is a single-writer multi-reader pointer. If a hazard pointer points to an object before its removal, then as long as the hazard pointer remains unchanged Features: • Fast and scalable protection • Supports arbitrarily long protection 18 Protect object A Set a hazard pointer to point to A if A is not removed