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