binary semaphore

Question

Say I have a Binary Semaphore S initialized to 1.

Consider V() as Signal and P() as Wait. If I now invoke V(S), will it wait for S to become 0? Or will it go on with further execution without making any changes to S?

Comments

the below pseudo-code of V(S) should be answer for your qsn,

V(S)
{
    if(wait queue is empty)
    {
        S=1;
    }
    else
    {
        select the process 'P' from wait queue and wake it;
    }
}

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you mean V(S), right?

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typo!!

yes.

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thank you :)

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Please provide book name, where pseudocode of binary semaphore present.

Thankyou in advance.

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From where you took this. Please clarify.

@joshi_nitish

Thankyou in advance.

Answer 1

When we perform any operation on a binary semaphore untill that operation is performed completely the process will wait untill a value is encountered on which the given semaphore operation can be performed . In the given question in the binary semaphore S untill it becomes 0 the signal operation can't be done and unless that statement is executed the control will not move on to the following statement.

Comments

The comment says otherwise.