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CK_RING_ENQUEUE_SPMC_... BSD Library Functions Manual CK_RING_ENQUEUE_SPMC_...

NAME
     ck_ring_enqueue_spmc_size -- enqueue pointer into bounded FIFO and return
     size of buffer

LIBRARY
     Concurrency Kit (libck, -lck)

SYNOPSIS
     #include <ck_ring.h>

     bool
     ck_ring_enqueue_spmc_size(ck_ring_t *ring, ck_ring_buffer_t *buffer,
         void *entry, unsigned int *length);

DESCRIPTION
     The ck_ring_enqueue_spmc(3) function enqueues the pointer entry into the
     bounded buffer pointed to by ring in FIFO fashion.  The buffer pointed to
     by buffer must be unique to ring and point to an array of ck_ring_buf-
     fer_t of sufficient length (according to the power-of-2 elements in the
     buffer).  The decoupling 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 entry.  This
     function is safe to call without locking for UINT_MAX concurrent invoca-
     tions of ck_ring_dequeue_spmc(3) or ck_ring_trydequeue_spmc(3).  This
     function provides wait-free progress guarantees for one active invoca-
     tion.

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
           enqueue(void)
           {
                   void *entry = some_object;
                   unsigned int length;

                   /* Attempt to enqueue pointer to some_object into buffer. */
                   if (ck_ring_enqueue_spmc_size(&ring, &buffer, &entry, &length) == false) {
                           /*
                            * The buffer was full and the enqueue operation
                            * has failed.
                            */
                           return;
                   }

                   /*
                    * If entry was the 101st or greater pointer in the buffer,
                    * do something.
                    */
                   if (length > 100) {
                           do_something;
                   }

                   return;
           }

RETURN VALUES
     The function returns true if the value of entry was successfully enqueued
     into ring.  The function will return false if the value of entry could
     not be enqueued which only occurs if ring was full. The number of entries
     in the buffer with respect to the point in time that entry is enqueued is
     stored in the integer pointed to by length.

SEE ALSO
     ck_ring_init(3), ck_ring_dequeue_spmc(3), ck_ring_trydequeue_spmc(3),
     ck_ring_enqueue_spmc(3), ck_ring_dequeue_spsc(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