## Semaphores

Question 1 |

Both 1 and 2 are true | |

1 is true but 2 is false | |

2 is true but 1 is false | |

Both 1 and 2 are false |

Question 1 Explanation:

P1 can be starves on P, then P2 loops forever.

P2 can be starves on P, then P1 loops forever.

Both statements (i) and (ii) are True.

P2 can be starves on P, then P1 loops forever.

Both statements (i) and (ii) are True.

Question 2 |

At a particular time of computation the value of a counting semaphore is 7. Then 20 P operations and 15 V operations were completed on this semaphore. The resulting value of the semaphore is:

42 | |

2 | |

7 | |

12 |

Question 2 Explanation:

Let the semaphore be S.

Initial value of S is 7.

So after 20P operations and 15V operations the value of semaphore S will be,

S = 7-20+15 = 2

Initial value of S is 7.

So after 20P operations and 15V operations the value of semaphore S will be,

S = 7-20+15 = 2

There are 2 questions to complete.