FD.io VPP  v17.07-30-g839fa73
Vector Packet Processing
svm_fifo.h
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1 /*
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:
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 #ifndef __included_ssvm_fifo_h__
16 #define __included_ssvm_fifo_h__
17 
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>
24 #include <pthread.h>
25 
26 /** Out-of-order segment */
27 typedef struct
28 {
29  u32 next; /**< Next linked-list element pool index */
30  u32 prev; /**< Previous linked-list element pool index */
31 
32  u32 start; /**< Start of segment, normalized*/
33  u32 length; /**< Length of segment */
35 
38 
39 #define OOO_SEGMENT_INVALID_INDEX ((u32)~0)
40 
41 typedef struct _svm_fifo
42 {
43  volatile u32 cursize; /**< current fifo size */
44  u32 nitems;
45  CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
46 
47  volatile u32 has_event; /**< non-zero if deq event exists */
48 
49  /* Backpointers */
50  u32 master_session_index;
51  u32 client_session_index;
52  u8 master_thread_index;
53  u8 client_thread_index;
54  u32 segment_manager;
55  CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
56  u32 head;
57  CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
58 
59  /* producer */
60  u32 tail;
61 
62  ooo_segment_t *ooo_segments; /**< Pool of ooo segments */
63  u32 ooos_list_head; /**< Head of out-of-order linked-list */
64  u32 ooos_newest; /**< Last segment to have been updated */
65  struct _svm_fifo *next; /**< next in freelist/active chain */
66  struct _svm_fifo *prev; /**< prev in active chain */
68 } svm_fifo_t;
69 
70 static inline u32
72 {
73  return f->cursize;
74 }
75 
76 static inline u32
78 {
79  return f->nitems - svm_fifo_max_dequeue (f);
80 }
81 
82 static inline u8
84 {
85  return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
86 }
87 
88 /**
89  * Sets fifo event flag.
90  *
91  * @return 1 if flag was not set.
92  */
95 {
96  /* Probably doesn't need to be atomic. Still, better avoid surprises */
97  return __sync_lock_test_and_set (&f->has_event, 1) == 0;
98 }
99 
100 /**
101  * Unsets fifo event flag.
102  */
103 always_inline void
105 {
106  /* Probably doesn't need to be atomic. Still, better avoid surprises */
107  __sync_lock_release (&f->has_event);
108 }
109 
110 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
111 void svm_fifo_free (svm_fifo_t * f);
112 
113 int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
114  u8 * copy_from_here);
116  u32 required_bytes, u8 * copy_from_here);
117 int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);
118 
119 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
120 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
123 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
124 
126 
129 {
130  if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
131  return 0;
132  return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
133 }
134 
137 {
138  /* Ambiguous. Assumption is that ooo segments don't touch tail */
139  if (a == f->tail && f->tail == f->head)
140  return f->nitems;
141 
142  return ((f->nitems + a - f->tail) % f->nitems);
143 }
144 
147 {
148  return ooo_segment_distance_to_tail (f, s->start);
149 }
150 
153 {
154  return ooo_segment_distance_to_tail (f, s->start) + s->length;
155 }
156 
159 {
160  return s->length;
161 }
162 
165 {
167  return 0;
168  return pool_elt_at_index (f->ooo_segments, s->prev);
169 }
170 
171 #endif /* __included_ssvm_fifo_h__ */
172 
173 /*
174  * fd.io coding-style-patch-verification: ON
175  *
176  * Local Variables:
177  * eval: (c-set-style "gnu")
178  * End:
179  */
int svm_fifo_dequeue_drop(svm_fifo_t *f, u32 max_bytes)
Definition: svm_fifo.c:675
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:68
a
Definition: bitmap.h:516
format_function_t format_ooo_segment
Definition: svm_fifo.h:36
static u8 svm_fifo_has_ooo_data(svm_fifo_t *f)
Definition: svm_fifo.h:83
format_function_t format_svm_fifo
Definition: svm_fifo.h:125
Fixed length block allocator.
u32 prev
Previous linked-list element pool index.
Definition: svm_fifo.h:30
static u32 svm_fifo_max_enqueue(svm_fifo_t *f)
Definition: svm_fifo.h:77
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
int svm_fifo_enqueue_nowait(svm_fifo_t *f, u32 max_bytes, u8 *copy_from_here)
Definition: svm_fifo.c:441
svm_fifo_t * svm_fifo_create(u32 data_size_in_bytes)
create an svm fifo, in the current heap.
Definition: svm_fifo.c:107
struct _svm_fifo svm_fifo_t
static u32 ooo_segment_end_offset(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:152
#define always_inline
Definition: clib.h:84
static u32 svm_fifo_max_dequeue(svm_fifo_t *f)
Definition: svm_fifo.h:71
static u32 ooo_segment_length(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:158
int svm_fifo_dequeue_nowait(svm_fifo_t *f, u32 max_bytes, u8 *copy_here)
Definition: svm_fifo.c:593
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:397
static u32 ooo_segment_offset(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:146
static void svm_fifo_unset_event(svm_fifo_t *f)
Unsets fifo event flag.
Definition: svm_fifo.h:104
static ooo_segment_t * svm_fifo_newest_ooo_segment(svm_fifo_t *f)
Definition: svm_fifo.h:128
static u8 svm_fifo_set_event(svm_fifo_t *f)
Sets fifo event flag.
Definition: svm_fifo.h:94
format_function_t format_ooo_list
Definition: svm_fifo.h:37
static ooo_segment_t * ooo_segment_get_prev(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:164
#define OOO_SEGMENT_INVALID_INDEX
Definition: svm_fifo.h:39
void svm_fifo_init_pointers(svm_fifo_t *f, u32 pointer)
Set fifo pointers to requested offset.
Definition: svm_fifo.c:726
unsigned int u32
Definition: types.h:88
void svm_fifo_free(svm_fifo_t *f)
Definition: svm_fifo.c:124
Out-of-order segment.
Definition: svm_fifo.h:27
u32 length
Length of segment.
Definition: svm_fifo.h:33
u32 next
Next linked-list element pool index.
Definition: svm_fifo.h:29
template key/value backing page structure
Definition: bihash_doc.h:44
int svm_fifo_peek(svm_fifo_t *f, u32 offset, u32 max_bytes, u8 *copy_here)
Definition: svm_fifo.c:659
unsigned char u8
Definition: types.h:56
u32 svm_fifo_number_ooo_segments(svm_fifo_t *f)
Definition: svm_fifo.c:711
u32 start
Start of segment, normalized.
Definition: svm_fifo.h:32
ooo_segment_t * svm_fifo_first_ooo_segment(svm_fifo_t *f)
Definition: svm_fifo.c:717
static u32 ooo_segment_distance_to_tail(svm_fifo_t *f, u32 a)
Definition: svm_fifo.h:136
int svm_fifo_enqueue_with_offset(svm_fifo_t *f, u32 offset, u32 required_bytes, u8 *copy_from_here)
Definition: svm_fifo.c:514
CLIB vectors are ubiquitous dynamically resized arrays with by user defined "headers".