RE: [sv-ec] Semaphore Question - 2nd Request

My answers are embedded in blue below.

 

            Arturo

 

-----Original Message-----
From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of
Cliff Cummings
Sent: Wednesday, September 21, 2005 7:35 AM
To: sv-ec@eda.org
Subject: [sv-ec] Semaphore Question - 2nd Request

 

Semaphore Question:

 

An interesting question that I do not believe has been answered yet, nor

well documented (the FIFO description might be problematic here).

 

Question: What will happen if there are no keys, process-A requests two

keys (is put on the requesting FIFO) and later process-B requests one
key?

 

Is process-B put on the requesting FIFO behind process-A??

 

Yes. The semaphore queue is FIFO.

 

If one key is returned, does process-B come off the not-so-FIFO and
become

active??

 

No. Process A is in the queue ahead of process B, and it needs 2 keys.

 

If two keys are returned instead of one key, does process-A become
active

before process-B?

 

Yes. Process A becomes active before process B.

 

Regards - Cliff