Memory Model C++11 – C++23About Me: alex.dathskovsky@speedata.io www.linkedin.com/in/alexdathskovsky https://www.cppnext.comAlex Dathskovsky | alex.dathskovsky@speedata.io | www.linkedin.com/in/a hazards • an instruction can be executed when its operands have been calculated or loaded from memory • an instruction stalls if operands are not availableAlex Dathskovsky | alex.dathskovsky@speedata com/in/alexdathskovsky Reordering Types • Data dependencies must be honored • C++ compiler may reorder any memory access under the as-if rule • Different processors have different reordering guarantiesAlex

Perspective Security Beyond Memory Safety Using Modern C++ to Avoid Vulnerabilities by DesignMax Hoffmann Security Beyond Memory Safety CppCon 2024 2 Security Beyond Memory Safety Using Modern C++ to Security Beyond Memory Safety CppCon 2024 3 FIFTY SHADES OF SHOOTING YOURSELF IN THE FOOT WITH A RAILGUNMax Hoffmann Security Beyond Memory Safety CppCon 2024 4Max Hoffmann Security Beyond Memory Safety CppCon Security Beyond Memory Safety CppCon 2024 6Max Hoffmann Security Beyond Memory Safety CppCon 2024 7Max Hoffmann Security Beyond Memory Safety CppCon 2024 8Max Hoffmann Security Beyond Memory Safety CppCon

A Relaxed Guide to memory_order_relaxed Hans Boehm Paul E. McKenney Google Facebook CPPCON 2020std::atomic/std::atomic_ref and memory_order_relaxed ● C++ atomic sacrificing the simple threads-as-interleaving semantics ● by passing memory_order enum values to explicit atomic operations. ● In particular, memory_order_relaxed allows arbitrary visibility reordering with respect About memory_order_relaxed? ● Just a load, just a store: Full control, excellent efficiency and scalability! ○ Assuming aligned machine-sized atomic objects, that is…What is Not to Like About memory_order_relaxed

© 2019 Apex.AI, Inc. Safe and certified software for autonomous mobility TM Practical memory pool based allocators for Modern C++ by Misha Shalem misha.shalem@apex.ai © 2020 Apex.AI, Inc.● CppCon Andreas Pasternak ● Quote: “Memory pools and allocators are only one piece of the solution” Today we going to talk about this one piece in (more) depth © 2020 Apex.AI, Inc.Memory allocations in real-time practically for C++ memory allocations? We asked an independent 3rd party safety assessor and the answer was “It should comply to Autosar C++ 14 Coding Guidelines regarding memory allocations” © 2020

Bar std::string Bar std::string Bar std::stringObject Introspection (OI) Goals • Byte level memory footprint analysis for objects • Complete object type hierarchies • Dynamic allocations and containers hierarchy from a given root type • Understand the layout in memory of the entire hierarchy • Understand how to interpret data at memory offsets • Understand containers • Compiler generated debug Object Introspection Measurement Code Code GenerationApplied Example 1 • Unused container memory: Unused Sz = (C.capacity() - C.size()) * sizeof(element) Name TypeName Number ElemStatSz Length

Systems - NUMA regions: - 4+ GPUs - 2+ CPUs - Systems becoming more hierarchical: even more memory domains - Software needed to reduce complexity CPU NIC GPU Tile 1 Tile 0 GPU Tile 1 Tile 0 Random access: access any element at random in constant time - Contiguous: a contiguous block of memory begin end begin end Contiguous Range begin end Range Random Access Range begin + 4Distributed to remote memory Node 0 Node 1 Write 12 -> 0x8f Communication Mechanisms- Message Passing - processes issue matching send and receive calls - RDMA - directly read/write to remote memory Node 0

Java 内存模型 Java 程序内存运行分析 Java 内存管理建议 JVM 内存溢出和参数调优  当遇到 OutOfMemoryError 时该如何做？ ▶ 常见的 OOM（Out Of Memory）内存溢出异常，就是堆内 存空间不足以存放新对象实例时导致。 ▶ 永久区内存溢出相对少见，一般是由于需要加载海量的 Class 数据，超过了非堆内存的容量导致。 ▶ 栈内存也会溢出，但是更加少见。 Java 内存模型 Java 程序内存运行分析 Java 内存管理建议 JVM 内存溢出和参数调优  当遇到 OutOfMemoryError 时该如何做？ ▶ 常见的 OOM（Out Of Memory）内存溢出异常，就是堆内 存空间不足以存放新对象实例时导致。 ▶ 永久区内存溢出相对少见，一般是由于需要加载海量的 Class 数据，超过了非堆内存的容量导致。 ▶ 栈内存也会溢出，但是更加少见。 Java 内存模型 Java 程序内存运行分析 Java 内存管理建议 JVM 内存溢出和参数调优  当遇到 OutOfMemoryError 时该如何做？ ▶ 常见的 OOM（Out Of Memory）内存溢出异常，就是堆内 存空间不足以存放新对象实例时导致。 ▶ 永久区内存溢出相对少见，一般是由于需要加载海量的 Class 数据，超过了非堆内存的容量导致。 ▶ 栈内存也会溢出，但是更加少见。

Installing with git Running tests Optional dependencies Skip Compilation of SQLite Extensions Quickstart Model Definition Storing data Retrieving Data Closing the database Working with existing databases What example Diving into the code More examples Contributing Patches Bugs Questions Query Examples Model Definitions Schema Creation Basic Exercises Joins and Subqueries Modifying Data Aggregation Recursion queries Adding a new Database Driver Models and Fields Fields Field-naming conflicts Creating model tables Model options and table metadata Indexes and Constraints Non-integer Primary Keys, Composite Keys

document presents a brief, high-level overview of Peewee’s primary features. This guide will cover: • Model Definition 4 Chapter 1. Contents: peewee Documentation, Release 3.4.0 • Storing data • Retrieving 1.2.1 Model Definition Model classes, fields and model instances all map to database concepts: Object Corresponds to. . . Model class Database table Field instance Column on a table Model instance typically best to begin with your data model, by defining one or more Model classes: from peewee import * db = SqliteDatabase('people.db') class Person(Model): name = CharField() birthday = DateField()