The CPU meter shows the problem. One core is running at 100 percent, but all the other cores are idle. Your application is CPU-bound, but you are using only a fraction of the computing power of your multicore system. What next? The answer, in a nutshell, is parallel programming. Where you once would have written the kind of sequential code that is familiar to all programmers, you now find that this no longer meets your performance goals. To use your system’s CPU resources efficiently, you need to split your application into pieces that can run at the same time. This is easier said than done. Parallel programming has a reputation for being the domain of experts and a minefield of subtle, hard-to-reproduce software defects. Everyone seems to have a favorite story about a parallel program that did not behave as expected because of a mysterious bug. These stories should inspire a healthy respect for the difficulty of the problems you face in writing your own parallel programs. Fortunately, help has arrived. Microsoft Visual Studio® 2010 introduces a new programming model for parallelism that significantly simplifies the job. Behind the scenes are supporting libraries with sophisticated algorithms that dynamically distribute computations on multicore architectures. Proven design patterns are another source of help. A Guide to Parallel Programming introduces you to the most important and frequently used patterns of parallel programming and gives executable code samples for them, using the Task Parallel Library (TPL) and Parallel LINQ (PLINQ). Contents......Page 6 Foreword......Page 12 Who This Book Is For......Page 14 What You Need to Use the Code......Page 15 How to Use This Book......Page 16 Goals......Page 19 Acknowledgments......Page 20 1. Introduction......Page 22 The Importance of Potential Parallelism......Page 23 Decomposition, Coordination, and Scalable Sharing......Page 24 A Word About Terminology......Page 28 The Limits of Parallelism......Page 29 A Few Tips......Page 31 For More Information......Page 32 2. Parallel Loops......Page 34 The Basics......Page 35 An Example......Page 39 Variations......Page 42 Anti-Patterns......Page 53 Design Notes......Page 55 Related Patterns......Page 56 Further Reading......Page 58 3. Parallel Tasks......Page 60 The Basics......Page 61 An Example......Page 62 Variations......Page 64 Anti-Patterns......Page 72 Design Notes......Page 74 The Default Task Scheduler......Page 77 Exercises......Page 85 Further Reading......Page 86 4. Parallel Aggregation......Page 88 The Basics......Page 89 An Example......Page 90 Variations......Page 94 Design Notes......Page 101 Exercises......Page 103 Further Reading......Page 104 5. Futures......Page 106 The Basics......Page 107 Example: The Adatum Financial Dashboard......Page 110 Variations......Page 118 Design Notes......Page 120 Related Patterns......Page 121 Further Reading......Page 122 The Basics......Page 124 An Example......Page 126 Variations......Page 128 Design Notes......Page 130 Further Reading......Page 131 The Basics......Page 134 An Example......Page 138 Variations......Page 143 Anti-Patterns......Page 150 Related Patterns......Page 152 Further Reading......Page 153 Structural Patterns......Page 154 Singletons and Service Locators......Page 160 Model-View-ViewModel......Page 163 Immutable Types......Page 169 Shared Data Classes......Page 174 Iterators......Page 175 Lists and Enumerables......Page 176 Further Reading......Page 177 The Parallel Tasks and Parallel Stacks Windows......Page 180 The Concurrency Visualizer......Page 183 Visual Patterns......Page 188 Further Reading......Page 193 Appendix C. Technology Overview......Page 194 Further Reading......Page 196 Glossary......Page 198 References......Page 208 Other Online Sources......Page 210 A......Page 212 F......Page 213 N......Page 214 P......Page 215 S......Page 216 W......Page 217
