"How are concurrent threads executed on machines with only a single CPU core?" you might ask. The answer is time slicing. It is the same mechanism that is being used by the operating system to support concurrent execution of processes. In order to understand time slicing, let's assume we have two separate sequences of instructions that should be executed concurrently, as shown in the following figure:
Two separate sequences of instructions executed in two threads labeled T1 and T2
The numbered boxes represent instructions. Each sequence of instructions is executed in separate threads labeled T1 and T2. The operating system will ...
