Consider the following definition of semaphores: void semWait(s) { if (s.count > 0) { s.count--; } else
Question:
void semWait(s)
{
if (s.count > 0) {
s.count--;
}
else {
place this process in s.queue;
block;
}
}
void semSignal (s)
{
if (there is at least one process blocked on
semaphore s) {
remove a process P from s.queue;
place process P on ready list;
}
else
s.count++;
}
Compare this set of definitions with that of Figure 5.3. Note one difference: With the preceding definition, a semaphore can never take on a negative value. Is there any difference in the effect of the two sets of definitions when used in programs? That is, could you substitute one set for the other without altering the meaning of the program?
Fantastic news! We've Found the answer you've been seeking!
Step by Step Answer:
Related Book For
Operating Systems Internals and Design Principles
ISBN: 978-0133805918
8th edition
Authors: William Stallings
Question Posted: