Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2018 Cisco and/or its affiliates.
       3             :  * Licensed under the Apache License, Version 2.0 (the "License");
       4             :  * you may not use this file except in compliance with the License.
       5             :  * You may obtain a copy of the License at:
       6             :  *
       7             :  *     http://www.apache.org/licenses/LICENSE-2.0
       8             :  *
       9             :  * Unless required by applicable law or agreed to in writing, software
      10             :  * distributed under the License is distributed on an "AS IS" BASIS,
      11             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             :  * See the License for the specific language governing permissions and
      13             :  * limitations under the License.
      14             :  */
      15             : 
      16             : #ifndef included_ring_h
      17             : #define included_ring_h
      18             : 
      19             : #include <vppinfra/error.h>
      20             : #include <vppinfra/format.h>
      21             : #include <vppinfra/vec.h>
      22             : #include <vppinfra/vector.h>
      23             : 
      24             : typedef struct
      25             : {
      26             :   u32 next, n_enq;
      27             : } clib_ring_header_t;
      28             : 
      29             : always_inline clib_ring_header_t *
      30           0 : clib_ring_header (void *v)
      31             : {
      32           0 :   return vec_header (v);
      33             : }
      34             : 
      35             : always_inline void
      36           0 : clib_ring_new_inline (void **p, u32 elt_bytes, u32 size, u32 align)
      37             : {
      38             :   void *v;
      39             :   clib_ring_header_t *h;
      40           0 :   vec_attr_t va = { .elt_sz = elt_bytes,
      41             :                     .hdr_sz = sizeof (clib_ring_header_t),
      42             :                     .align = align };
      43             : 
      44           0 :   v = _vec_alloc_internal (size, &va);
      45             : 
      46           0 :   h = clib_ring_header (v);
      47           0 :   h->next = 0;
      48           0 :   h->n_enq = 0;
      49           0 :   p[0] = v;
      50           0 : }
      51             : 
      52             : #define clib_ring_new_aligned(ring, size, align) \
      53             : { clib_ring_new_inline ((void **)&(ring), sizeof(ring[0]), size, align); }
      54             : 
      55             : #define clib_ring_new(ring, size) \
      56             : { clib_ring_new_inline ((void **)&(ring), sizeof(ring[0]), size, 0);}
      57             : 
      58             : #define clib_ring_free(f) vec_free ((f))
      59             : 
      60             : always_inline u32
      61             : clib_ring_n_enq (void *v)
      62             : {
      63             :   clib_ring_header_t *h = clib_ring_header (v);
      64             :   return h->n_enq;
      65             : }
      66             : 
      67             : always_inline void *
      68           0 : clib_ring_get_last_inline (void *v, u32 elt_bytes, int enqueue)
      69             : {
      70           0 :   clib_ring_header_t *h = clib_ring_header (v);
      71             :   u32 slot;
      72             : 
      73           0 :   if (enqueue)
      74             :     {
      75           0 :       if (h->n_enq == _vec_len (v))
      76           0 :         return 0;
      77           0 :       slot = h->next;
      78           0 :       h->n_enq++;
      79           0 :       h->next++;
      80           0 :       if (h->next == _vec_len (v))
      81           0 :         h->next = 0;
      82             :     }
      83             :   else
      84             :     {
      85           0 :       if (h->n_enq == 0)
      86           0 :         return 0;
      87           0 :       slot = h->next == 0 ? _vec_len (v) - 1 : h->next - 1;
      88             :     }
      89             : 
      90           0 :   return (void *) ((u8 *) v + elt_bytes * slot);
      91             : }
      92             : 
      93             : #define clib_ring_enq(ring) \
      94             : clib_ring_get_last_inline (ring, sizeof(ring[0]), 1)
      95             : 
      96             : #define clib_ring_get_last(ring) \
      97             : clib_ring_get_last_inline (ring, sizeof(ring[0]), 0)
      98             : 
      99             : always_inline void *
     100           0 : clib_ring_get_first_inline (void *v, u32 elt_bytes, int dequeue)
     101             : {
     102           0 :   clib_ring_header_t *h = clib_ring_header (v);
     103             :   u32 slot;
     104             : 
     105           0 :   if (h->n_enq == 0)
     106           0 :     return 0;
     107             : 
     108           0 :   if (h->n_enq > h->next)
     109           0 :     slot = _vec_len (v) + h->next - h->n_enq;
     110             :   else
     111           0 :     slot = h->next - h->n_enq;
     112             : 
     113           0 :   if (dequeue)
     114           0 :     h->n_enq--;
     115             : 
     116           0 :   return (void *) ((u8 *) v + elt_bytes * slot);
     117             : }
     118             : 
     119             : #define clib_ring_deq(ring) \
     120             : clib_ring_get_first_inline (ring, sizeof(ring[0]), 1)
     121             : 
     122             : #define clib_ring_get_first(ring) \
     123             : clib_ring_get_first_inline (ring, sizeof(ring[0]), 0)
     124             : 
     125             : #endif /* included_ring_h */
     126             : 
     127             : /*
     128             :  * fd.io coding-style-patch-verification: ON
     129             :  *
     130             :  * Local Variables:
     131             :  * eval: (c-set-style "gnu")
     132             :  * End:
     133             :  */