Re: [boost] [Interprocess::Semaphore] Deadlock on more producers - one consumer problem

Subject: Re: [boost] [Interprocess::Semaphore] Deadlock on more producers - one consumer problem
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2009-06-18 10:50:40

Cosimo Calabrese wrote:
> Is there a way to unlock all the producers with the 
> boost::interprocess::semaphore? Or I have mistaken the approach of the 
> problem?

If a semaphore count represents free resources, shouldn't post be 
performed by the producer to signal available resources? You can try this:

http://en.wikipedia.org/wiki/Producer-consumer_problem#Using_semaphores

semaphore fillCount = 0
semaphore emptyCount = BUFFER_SIZE

procedure producer() {
     while (true) {
         item = produceItem()
         down(emptyCount)
         putItemIntoBuffer(item)
         up(fillCount)
     }
  }

procedure consumer() {
     while (true) {
         down(fillCount)
         item = removeItemFromBuffer()
         up(emptyCount)
         consumeItem(item)
     }
}

where down is "wait" and up is "post".

Best,

Ion