Logical processors
Logical processors
To be independent of hardware and thus allow concurrent programs to be portable, we say that P || Q means that each are given a logical processor. Each logical processor is a sequential machine which executes instructions one at a time from the processes that are allocated to it. We now consider P & Q to be processes that embody the statements we previously associated with them.
More than one logical processor may be implemented by a physical processor ie. by switching the CPU between them ( instruction interleaving).
No assumptions must be made about the speeds of operations of logical processors relative to one another.
No relationship exists between the speeds of operation of logical processors and our normal clocks for measuring “real” time. Logical processors do not necessarily proceed at a constant rate when measured in real-time units.
Consequently: