OPERATING SYSTEM CONCEPTS 251
space’, this aspect is what makes a thread ‘lightweight’. When thread switching takes place,
there is no need to change the memory space, but the PC and stack do change.
Having multiple threads is like having many specialists at work on the same object—
only one of the specialists can work at one time, and each specialist does only one kind
of work on the object. us, a thread is one line of activity. Multiple threads act serially,
one after the other, doing separate activities. We can visualize a thread for reading a fi le,
and another one for writing. Each of these threads executes the low level instructions
needed for doing its assigned job.
e simplest process (task) is one which has just one thread. In general, ...