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CK_RING_DEQUEUE_SPSC(3)	 BSD Library Functions Manual  CK_RING_DEQUEUE_SPSC(3)

NAME
     ck_ring_dequeue_spsc -- dequeue pointer from bounded FIFO

LIBRARY
     Concurrency Kit (libck, -lck)

SYNOPSIS
     #include <ck_ring.h>

     bool
     ck_ring_dequeue_spsc(ck_ring_t *ring, ck_ring_buffer_t *buffer,
	 void *result);

DESCRIPTION
     The ck_ring_dequeue_spsc(3) function dequeues a pointer from the bounded
     buffer pointed to by ring in FIFO fashion.	The pointer is stored in the
     pointer pointed to	by result.  The	buffer pointed to by buffer must be
     unique to ring and	point to an array of ck_ring_buffer_t of sufficient
     length (according to the power-of-2 elements in the buffer).  The decou-
     pling of the ring from the	buffer serves to address use-cases involving
     multiple address spaces and DMA, among others.  If	you are	on non-POSIX
     platforms or wish for strict compliance with C, then it is	recommended to
     pass a pointer of type void ** for	result.	 This function is safe to call
     without locking for one concurrent	invocation of ck_ring_dequeue_spsc(3)
     and up to one concurrent ck_ring_enqueue_spsc(3) invocation. This func-
     tion provides wait-free progress guarantees.

EXAMPLE
	   #include <ck_ring.h>

	   /* This ring	was previously initialized with	ck_ring_init. */
	   ck_ring_t ring;

	   /* The ring was initialized for 1023	elements. */
	   ck_ring_buffer_t buffer[1024];

	   void
	   dequeue(void)
	   {
		   void	*result;

		   /* Dequeue from ring	until it is empty. */
		   while (ck_ring_dequeue_spsc(&ring, &buffer, &result)	== true) {
			   /*
			    * Results contains the oldest pointer in ring
			    * since the	dequeue	operation returned true.
			    */
			   operation(result);
		   }

		   /* An empty ring was	encountered, leave. */
		   return;
	   }

RETURN VALUES
     The function returns true if the buffer was non-empty.  The result	of the
     dequeue operation is stored in the	value pointed to by result.  The func-
     tion will return false if the buffer was empty and	the value in result
     will be undefined.

SEE ALSO
     ck_ring_init(3), ck_ring_trydequeue_spmc(3), ck_ring_enqueue_spmc(3),
     ck_ring_enqueue_spmc_size(3), ck_ring_dequeue_spmc(3),
     ck_ring_enqueue_spsc(3), ck_ring_enqueue_spsc_size(3),
     ck_ring_capacity(3), ck_ring_size(3)

     Additional	information available at http://concurrencykit.org/

				April 20, 2013

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | EXAMPLE | RETURN VALUES | SEE ALSO

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