Agenda 1. Trading Platform, Latency 2. Queues Environment 3. Queues Requirement 4. Atomic hardware and C++ Atomic 5. Queues Classification 6. Queue creation, push, pop 7. Queue internals 8. Testing com/erez-strauss/lockfree_mpmc_queue template class QueueSchedulerIssue { std::atomic writeIndex; std::atomic readIndex; std::unique_ptr> elements; https://github.com/erez-strauss/lockfree_mpmc_queueC++ Atomic Operations / CPU instructions ● std::atomic - provides load / store / compare_exchange ● std::atomic::is_always_lock_free ● Load and Store

第三届中国Rust开发者大会 Rust Atomic Deep Dive Pu Wang @ DatenLord 2023/06/17 Rust原子操作高性能实践 What are atomic operations in Rust? What Why need atomic operations? Why How 01 02 03 Memory order in atomic operations Memory Memory Model The overhead of atomic operations Cache Coherence Summary 04 05 06 How to understand atomic operations? Atomic operation best practice Outline What are Atomic Operations in Rust? fn compare_exchange( Lock-free programming Why Atomic Operation? High Performance Lock - context switch Atomic - no context switch Shared Variable Access When Multi-threading 02 How to Understand Atomic Operations? Memory

How shared_ptr is implemented under the hood • Atomics and concurrency patterns • How existing atomic are implemented (the split reference count technique) • Deferred reclamation, i.e., You’ve heard of lock-free programming and know what a compare_exchange is • You know roughly what atomic does and what it is used for • You’ve heard of shared_ptr Things we won’t cover • Alias pointers How shared_ptr is implemented under the hood • Atomics and concurrency patterns • How existing atomic are implemented (the split reference count technique) • Deferred reclamation, i.e.,

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 Algorithms (P2500)C++26: Atomic Min/MaxC++26: Improving C++20 Concurrency primitives atomic min/max (P0493)Atomic min/max motivation (P0493) Long history - almost as old as atomic addition Multithreaded track the minimum or maximum value. Without atomic operations, race conditions can occur, leading to data corruption and unpredictable behavior. Atomic min/max operations provide a solution by ensuring

Expanded interoperability • Efficient acceleration by diverse backend acceleration APIs • SYCL atomic operations are now more closely aligned to standard C++ atomics • Enhances parallel programming and destructor are run 80atomic_ref 81atomic_ref ● C++11 std::atomic ○ Always defaults to seq_cst ■ Safety / easiest to reason about ○ Owns the data ○ Always requires atomic access ■ Over-constraint device 82 ● SYCL 1.2.1 cl::sycl::atomic ○ Modeled on std::atomic ■ Does not own its data ■ Defaults to relaxed ● Compatible with OpenCL ○ Deprecated in SYCL 2020atomic_ref ● C++11 ○ No notion of non-owning

. . . . . . . . . . . . . . . . . . . . 74 7.5 Atomic Operation and Memory Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Atomic Operation . . . . . . . . . . . . . . . . . . . cs[i] = std::thread(consumer); } p.join(); for (int i = 0; i < 2; ++i) { cs[i].join(); 75 7.5 Atomic Operation and Memory Model CHAPTER 07 PARALLELISM AND CONCURRENCY } return 0; } It is worth mentioning to produce content in a parallel consumer queue, and we still need a more granular approach. 7.5 Atomic Operation and Memory Model Careful readers may be tempted by the fact that the example of the producer-consumer

Concurrency Changes  Atomic Smart Pointers  Joining & Cancellable Threads  The C++20 Synchronization Library  Semaphores, efficient atomic waiting, latches, and barriers  std::atomic_ref  Designated Development on GitHub” -- Stephan T. Lavavej Tuesday, September 15 • 13:30Concurrency Changes35 Atomic Smart Pointers  Is shared_ptr thread safe?  Yes: control block manipulation thread safe  guarantees Use global non-member atomic operations, e.g. std::atomic_load(), atomic_store(), …  Error-prone, easy to accidently not use global non-member atomic operations  C++20: atomic>  Might

§39. Other Concurrency Synchronization Techniques - the sync standard package. §40. Atomic Operations - the sync/atomic standard package. §41. Memory Order Guarantees in Go §42. Common Concurrent Programming hand, those traditional concurrency synchronization techniques are provided in the sync and sync/atomic standard packages. Honestly, each concurrency synchronization technique has its own best use scenarios using channels, Go also supports several other common synchronization techniques, such as mutex and atomic operations. Please read the following articles to get how to do synchronizations with all kinds of

§39. Other Concurrency Synchronization Techniques - the sync standard package. §40. Atomic Operations - the sync/atomic standard package. §41. Memory Order Guarantees in Go §42. Common Concurrent Programming hand, those traditional concurrency synchronization techniques are provided in the sync and sync/atomic standard packages. Honestly, each concurrency synchronization technique has its own best use scenarios using channels, Go also supports several other common synchronization techniques, such as mutex and atomic operations. Please read the following articles to get how to do synchronizations with all kinds of

foreign key dependencies Querying Creating a new record Bulk inserts Updating existing records Atomic updates Deleting records Selecting a single record Create or get Selecting multiple records Filtering Example specifying the locking mode: db = SqliteDatabase('app.db') with db.atomic('EXCLUSIVE'): do_something() @db.atomic('IMMEDIATE') def some_other_function(): # This function is wrapped in an interfaces for working with transactions. The most general is the Database.atomic() method, which also supports nested transactions. atomic() blocks will be run in a transaction or savepoint, depending on the