Concurrency in Go: Tools and Techniques for Developers

 Copyright....4 Table of Contents....7 Preface....9 Who Should Read This Book....10 Navigating This Book....10 Online Resources....11 Conventions Used in This Book....12 Using Code Examples....12 O’Reilly Safari....12 How to Contact Us....13 Acknowledgments....13 Chapter 1. An Introduction to Concurrency....15 Moore’s Law, Web Scale, and the Mess We’re In....16 Why Is Concurrency Hard?....18 Race Conditions....18 Atomicity....20 Memory Access Synchronization....22 Deadlocks, Livelocks, and Starvation....24 Determining Concurrency Safety....32 Simplicity in the Face of Complexity....34 Chapter 2. Modeling Your Code: Communicating Sequential Processes....37 The Difference Between Concurrency and Parallelism....37 What Is CSP?....40 How This Helps You....43 Go’s Philosophy on Concurrency....45 Chapter 3. Go’s Concurrency Building Blocks....51 Goroutines....51 The sync Package....61 WaitGroup....61 Mutex and RWMutex....63 Cond....66 Once....71 Pool....73 Channels....78 The select Statement....92 The GOMAXPROCS Lever....97 Conclusion....97 Chapter 4. Concurrency Patterns in Go....99 Confinement....99 The for-select Loop....103 Preventing Goroutine Leaks....104 The or-channel....108 Error Handling....111 Pipelines....114 Best Practices for Constructing Pipelines....118 Some Handy Generators....123 Fan-Out, Fan-In....128 The or-done-channel....133 The tee-channel....134 The bridge-channel....136 Queuing....138 The context Package....145 Summary....159 Chapter 5. Concurrency at Scale....161 Error Propagation....161 Timeouts and Cancellation....169 Heartbeats....175 Replicated Requests....186 Rate Limiting....188 Healing Unhealthy Goroutines....202 Summary....208 Chapter 6. Goroutines and the Go Runtime....211 Work Stealing....211 Stealing Tasks or Continuations?....218 Presenting All of This to the Developer....226 Conclusion....226 Appendix A. Appendix....227 Anatomy of a Goroutine Error....227 Race Detection....228 pprof....230 Index....233 About the Author....238 Colophon....238