Pointers  Is shared_ptr thread safe?  Yes: control block manipulation thread safe  guarantees object is deleted exactly once  No: accessing pointer not thread-safe, one thread could be reading pointer pointer, while another thread could be storing new pointer  Make it thread-safe?  Manually use mutex to protect access to smart pointer  Use global non-member atomic operations, e.g. std::atomic_load() format text in C++:  I/O streams  Safe and extensible  Hard to read, hard to localize  No separation of format string and arguments  printf()  Not safe, not extensible  Easier to read, no

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 HP 2 3 6 if HP != A HP Safe to delete A A 7 8 SAFE ACCESS If a hazard Protector Remover / Reclaimer Hazard pointers protect access to objects that may be removed concurrently. SAFE RECLAMATION Concurrency TS2 Essential Hazard Pointer Interface Base class for protectable objects  Working Draft, Extensions to C++ for Concurrency Version 2 (wg21.link/n4895).  Hazard Pointers: Safe Memory Reclamation for Lock-Free Objects, IEEE Transactions on Parallel and Distributed Systems. 15

Cross platform - Performance - Thread Safe - Memory Safe - Love 利用 Rust 重塑移动应用开发 Rust 在移动应用 开发中的应用 Why Rust? - Cross platform - Performance - Memory Safe - Love 利用 Rust 重塑移动应用开发 PhoTto / image

the common virtualization components which implements a Rust-based VMM. • Written in Rust: Memory-safe language • Secure: Minimal hardware emulation • Flexible: Easy to customize to fit various network programming Rust is a multi-paradigm programming language focused on performance and safety, especially safe concurrency. empty • vmm-vcpu: a hypervisor-agnostic abstraction for Virtual CPUs (vCPUs). rust-vmm chain. crates.io • kvm-bindings: Rust FFI bindings to KVM generated using bindgen. • kvm-ioctls: Safe wrappers over the KVM API. • vfio-bindings: Rust FFI bindings for using the VFIO framework. • virtio-bindings:

Embark), even it has paid contributors! Tokio is good enough Tokio Tokio's APIs are memory-safe, thread-safe, and misuse-resistant. This helps prevent common bugs, such as unbounded queues, buffer overflows

danielanderson.net std::atomic How many lines does it take to implement a lock-free & memory-safe stack? template struct Stack { struct Node { T t; shared_ptr next; }; danielanderson.net std::atomic How many lines does it take to implement a lock-free & memory-safe stack? Since GCC-12 Since MSVC v19.30 Not lock free Not lock free atomic Lock free

my::shared_ptr(block); } // FixMe: What about alignment? // ToDo: Are these reinterpret_casts safe? // CheckThis: What if T() throws? // Why am I manipulating bytes? // This was supposed to be

Logic • Separation Logic Background ERC Project "RustBelt" 2015-2021 Unlike C/C++, Rust is a safe language But, like C/C++, Rust is also an unsafe language There are guaranteed memory safety, thread

int i = co_await compute_helper_async(data); /* ... */ } Because of the nested scopes, it’s safe to pass locals by reference to callees... … no dynamic allocation or reference counting

不接受参数，仅仅作为同步用， 不传递任何实际的值。 第 3 章：互斥量 多线程打架案例 • 两个线程试图往同一个数组里推数据。 • 奔溃了！为什么？ • vector 不是多线程安全（ MT-safe ）的容 器。 • 多个线程同时访问同一个 vector 会出现 数据竞争（ data-race ）现象。 std::mutex ：上锁，防止多个线程同时进入某一代码段 • 调用 std::mutex