Memory Management

After reading the previous chapters, it should no longer come as a surprise that the way we handle memory can have a huge impact on the performance. The CPU spends a lot of time shuffling data between the CPU registers and the main memory (loading and storing data to and from the main memory). As shown in Chapter 4, Data Structures, the CPU uses memory caches to speed up the access of memory, and the programs need to be cache-friendly in order to run quickly. This chapter will reveal more aspects of how computers work with memory so that we know which things must be considered when tuning memory usage. We will discuss automatic memory allocation and dynamic memory management, and look at the life cycle of a C++ object. Sometimes there are hard memory limits that force us to keep our data representation compact, and sometimes we have plenty of memory available...