2 * Copyright (c) 2016 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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
15 #ifndef __included_ssvm_fifo_h__
16 #define __included_ssvm_fifo_h__
18 #include <vppinfra/clib.h>
19 #include <vppinfra/vec.h>
20 #include <vppinfra/mheap.h>
21 #include <vppinfra/heap.h>
22 #include <vppinfra/pool.h>
23 #include <vppinfra/format.h>
28 SVM_FIFO_TAG_NOT_HELD = 0,
33 /** Out-of-order segment */
36 u32 next; /**< Next linked-list element pool index */
37 u32 prev; /**< Previous linked-list element pool index */
39 u32 start; /**< Start of segment, normalized*/
40 u32 length; /**< Length of segment */
43 format_function_t format_ooo_segment;
44 format_function_t format_ooo_list;
46 #define OOO_SEGMENT_INVALID_INDEX ((u32)~0)
50 volatile u32 cursize; /**< current fifo size */
52 CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
54 volatile u8 has_event; /**< non-zero if deq event exists */
58 u32 server_session_index;
59 u32 client_session_index;
60 u8 server_thread_index;
61 u8 client_thread_index;
63 CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
65 CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
70 ooo_segment_t *ooo_segments; /**< Pool of ooo segments */
71 u32 ooos_list_head; /**< Head of out-of-order linked-list */
72 u32 ooos_newest; /**< Last segment to have been updated */
74 CLIB_CACHE_LINE_ALIGN_MARK (data);
78 svm_fifo_max_dequeue (svm_fifo_t * f)
84 svm_fifo_max_enqueue (svm_fifo_t * f)
86 return f->nitems - svm_fifo_max_dequeue (f);
90 svm_fifo_has_ooo_data (svm_fifo_t * f)
92 return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
96 * Sets fifo event flag.
98 * @return 1 if flag was not set.
101 svm_fifo_set_event (svm_fifo_t * f)
103 /* Probably doesn't need to be atomic. Still, better avoid surprises */
104 return __sync_lock_test_and_set (&f->has_event, 1) == 0;
108 * Unsets fifo event flag.
111 svm_fifo_unset_event (svm_fifo_t * f)
113 /* Probably doesn't need to be atomic. Still, better avoid surprises */
114 __sync_lock_test_and_set (&f->has_event, 0);
117 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
118 void svm_fifo_free (svm_fifo_t * f);
120 int svm_fifo_enqueue_nowait (svm_fifo_t * f, int pid, u32 max_bytes,
121 u8 * copy_from_here);
123 int svm_fifo_enqueue_with_offset (svm_fifo_t * f, int pid,
124 u32 offset, u32 required_bytes,
125 u8 * copy_from_here);
127 int svm_fifo_dequeue_nowait (svm_fifo_t * f, int pid, u32 max_bytes,
130 int svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes,
132 int svm_fifo_dequeue_drop (svm_fifo_t * f, int pid, u32 max_bytes);
133 u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
134 ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
136 format_function_t format_svm_fifo;
138 always_inline ooo_segment_t *
139 svm_fifo_newest_ooo_segment (svm_fifo_t * f)
141 return f->ooo_segments + f->ooos_newest;
145 ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s)
147 // return ((f->nitems + s->fifo_position - f->tail) % f->nitems);
152 ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s)
154 // return ((f->nitems + s->fifo_position + s->length - f->tail) % f->nitems);
155 return s->start + s->length;
158 always_inline ooo_segment_t *
159 ooo_segment_get_prev (svm_fifo_t * f, ooo_segment_t * s)
161 if (s->prev == OOO_SEGMENT_INVALID_INDEX)
163 return pool_elt_at_index (f->ooo_segments, s->prev);
166 #endif /* __included_ssvm_fifo_h__ */
169 * fd.io coding-style-patch-verification: ON
172 * eval: (c-set-style "gnu")