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_buffer_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  invocations  of  ck_ring_dequeue_spmc(3)  or ck_ring_trydequeue_spmc(3).  This
       function provides wait-free progress guarantees for one active invocation.

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                     CK_RING_ENQUEUE_SPMC_SIZE(3)