Preface

I encountered the concept of multithreaded code while working at my first job after I left college. We were writing a data processing application that had to populate a database with incoming data records. There was a lot of data, but each record was independent and required a reasonable amount of processing before it could be inserted into the database. To take full advantage of the power of our 10-CPU UltraSPARC, we ran the code in multiple threads, each thread processing its own set of incoming records. We wrote the code in C++, using POSIX threads, and made a fair number of mistakes—multithreading was new to all of us—but we got there in the end. It was also while working on this project that I first became aware of the C++ Standards Committee and the freshly published C++ Standard.

I have had a keen interest in multithreading and concurrency ever since. Where others saw it as difficult, complex, and a source of problems, I saw it as a powerful tool that could enable your code to take advantage of the available hardware to run faster. Later on I would learn how it could be used to improve the responsiveness and performance of applications even on single-core hardware, by using multiple threads to hide the latency of time-consuming operations such as I/O. I also learned how it worked at the OS level and how Intel CPUs handled task switching.