Listings xii
Preface xvii
Chapter 1: Introduction 1
1.1 A (very) brief history of concurrency 1
1.2 Benefits of threads 3
1.3 Risks of threads 5
1.4 Threads are everywhere 9
Part I: Fundamentals 13
Chapter 2: Thread Safety 15
2.1 What is thread safety? 17
2.2 Atomicity 19
2.3 Locking 23
2.4 Guarding state with locks 27
2.5 Liveness and performance 29
Chapter 3: Sharing Objects 33
3.1 Visibility 33
3.2 Publication and escape 39
3.3 Thread confinement 42
3.4 Immutability 46
3.5 Safepublication 49
Chapter 4: Composing Objects 55
4.1 Designing a thread-safe class 55
4.2 Instance confinement 58
4.3 Delegating thread safety 62
4.4 Adding functionality to existing thread-safe classes 71
4.5 Documenting synchronization policies 74
Chapter 5: Building Blocks 79
5.1 Synchronized collections 79
5.2 Concurrent collections 84
5.3 Blocking queues and the producer-consumer pattern 87
5.4 Blocking and interruptible methods 92
5.5 Synchronizers 94
5.6 Building an efficient, scalable result cache 101
Part II: Structuring Concurrent Applications 111
Chapter 6: Task Execution 113
6.1 Executing tasks in threads 113
6.2 The Executor framework 117
6.3 Finding exploitable parallelism 123
Chapter 7: Cancellation and Shutdown 135
7.1 Task cancellation 135
7.2 Stopping a thread-based service 150
7.3 Handling abnormal thread termination 161
7.4 JVM shutdown 164
Chapter 8: Applying Thread Pools 167
8.1 Implicit couplings between tasks and execution policies 167
8.2 Sizing thread pools 170
8.3 Configuring ThreadPoolExecutor 171
8.4 Extending ThreadPoolExecutor 179
8.5 Parallelizing recursive algorithms 181
Chapter 9: GUI Applications 189
9.1 Why are GUIs single-threaded? 189
9.2 Short-running GUI tasks 192
9.3 Long-running GUI tasks 195
9.4 Shared data models 198
9.5 Other forms of single-threaded subsystems 202
Part III: Liveness, Performance, and Testing 203
Chapter 10: Avoiding Liveness Hazards 205
10.1 Deadlock 205
10.2 Avoiding and diagnosing deadlocks 215
10.3 Other liveness hazards 218
Chapter 11: Performance and Scalability 221
11.1 Thinking about performance 221
11.2 Amdahl's law 225
11.3 Costs introduced by threads 229
11.4 Reducing lock contention 232
11.5 Example: Comparing Map performance 242
11.6 Reducing context switch overhead 243
Chapter 12: Testing Concurrent Programs 247
12.1 Testing for correctness 248
12.2 Testing for performance 260
12.3 Avoiding performance testing pitfalls 266
12.4 Complementary testing approaches 270
Part IV: Advanced Topics 275
Chapter 13: Explicit Locks 277
13.1 Lock and ReentrantLock 277
13.2 Performance considerations 282
13.3 Fairness 283
13.4 Choosing between synchronized and ReentrantLock 285
13.5 Read-write locks 286
Chapter 14: Building Custom Synchronizers 291
14.1 Managing state dependence 291
14.2 Using condition queues 298
14.3 Explicit condition objects 306
14.4 Anatomy of a synchronizer 308
14.5 AbstractQueuedSynchronizer 311
14.6 AQS in java.util.concurrent synchronizer classes 314
Chapter15: Atomic Variables and Nonblocking Synchronization 319
15.1 Disadvantages of locking 319
15.2 Hardware support for concurrency 321
15.3 Atomic variable classes 324
15.4 Nonblocking algorithms 329
Chapter 16: The Java Memory Model 337
16.1 What is a memory model, and why would I want one? 337
16.2 Publication 344
16.3 Initialization safety 349
Appendix A: Annotations for Concurrency 353
A.1 Class annotations 353
A.2 Field andmethod annotations 353
Bibliography 355
Index 359