FD.io VPP  v18.07.1-19-g511ce25
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 SVM_FIFO_TRACE (0)
40 #define OOO_SEGMENT_INVALID_INDEX ((u32)~0)
41 
42 typedef struct
43 {
48 
49 typedef struct _svm_fifo
50 {
51  volatile u32 cursize; /**< current fifo size */
52  u32 nitems;
53  CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);
54 
55  volatile u32 has_event; /**< non-zero if deq event exists */
56 
57  /* Backpointers */
58  u32 master_session_index;
59  u32 client_session_index;
60  u8 master_thread_index;
61  u8 client_thread_index;
62  u32 segment_manager;
63  CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
64  u32 head;
65  CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);
66 
67  /* producer */
68  u32 tail;
69 
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 */
73  struct _svm_fifo *next; /**< next in freelist/active chain */
74  struct _svm_fifo *prev; /**< prev in active chain */
75 #if SVM_FIFO_TRACE
77 #endif
78  u32 freelist_index; /**< aka log2(allocated_size) - const. */
79  i8 refcnt; /**< reference count */
81 } svm_fifo_t;
82 
83 typedef enum
84 {
87 
88 #if SVM_FIFO_TRACE
89 #define svm_fifo_trace_add(_f, _s, _l, _t) \
90 { \
91  svm_fifo_trace_elem_t *trace_elt; \
92  vec_add2(_f->trace, trace_elt, 1); \
93  trace_elt->offset = _s; \
94  trace_elt->len = _l; \
95  trace_elt->action = _t; \
96 }
97 #else
98 #define svm_fifo_trace_add(_f, _s, _l, _t)
99 #endif
100 
101 u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
102 u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);
103 
104 static inline u32
106 {
107  return f->cursize;
108 }
109 
110 static inline u32
112 {
113  return f->nitems - svm_fifo_max_dequeue (f);
114 }
115 
116 static inline int
118 {
119  return f->has_event;
120 }
121 
122 static inline u8
124 {
125  return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
126 }
127 
128 /**
129  * Sets fifo event flag.
130  *
131  * @return 1 if flag was not set.
132  */
135 {
136  /* Probably doesn't need to be atomic. Still, better avoid surprises */
137  return __sync_lock_test_and_set (&f->has_event, 1) == 0;
138 }
139 
140 /**
141  * Unsets fifo event flag.
142  */
143 always_inline void
145 {
146  /* Probably doesn't need to be atomic. Still, better avoid surprises */
147  __sync_lock_release (&f->has_event);
148 }
149 
150 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
151 void svm_fifo_free (svm_fifo_t * f);
152 
153 int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
154  const u8 * copy_from_here);
156  u32 required_bytes, u8 * copy_from_here);
157 int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);
158 
159 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
160 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
164 void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);
165 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len);
166 
168 
171 {
172  if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
173  return 0;
174  return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
175 }
176 
177 always_inline void
179 {
180  f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
181 }
182 
183 /**
184  * Max contiguous chunk of data that can be read
185  */
188 {
189  return ((f->tail > f->head) ? (f->tail - f->head) : (f->nitems - f->head));
190 }
191 
192 /**
193  * Max contiguous chunk of data that can be written
194  */
197 {
198  return ((f->tail >= f->head) ? (f->nitems - f->tail) : (f->head - f->tail));
199 }
200 
201 /**
202  * Advance tail pointer
203  *
204  * Useful for moving tail pointer after external enqueue.
205  */
206 always_inline void
208 {
209  ASSERT (bytes <= svm_fifo_max_enqueue (f));
210  f->tail = (f->tail + bytes) % f->nitems;
211  f->cursize += bytes;
212 }
213 
216 {
217  return (f->data + f->head);
218 }
219 
222 {
223  return (f->data + f->tail);
224 }
225 
228 {
229  /* Ambiguous. Assumption is that ooo segments don't touch tail */
230  if (PREDICT_FALSE (pos == f->tail && f->tail == f->head))
231  return f->nitems;
232 
233  return (((f->nitems + pos) - f->tail) % f->nitems);
234 }
235 
238 {
239  return (((f->nitems + f->tail) - pos) % f->nitems);
240 }
241 
244 {
245  return ooo_segment_distance_from_tail (f, s->start);
246 }
247 
250 {
251  return ooo_segment_distance_from_tail (f, s->start) + s->length;
252 }
253 
256 {
257  return s->length;
258 }
259 
262 {
264  return 0;
265  return pool_elt_at_index (f->ooo_segments, s->prev);
266 }
267 
270 {
272  return 0;
273  return pool_elt_at_index (f->ooo_segments, s->next);
274 }
275 
276 #endif /* __included_ssvm_fifo_h__ */
277 
278 /*
279  * fd.io coding-style-patch-verification: ON
280  *
281  * Local Variables:
282  * eval: (c-set-style "gnu")
283  * End:
284  */
int svm_fifo_dequeue_drop(svm_fifo_t *f, u32 max_bytes)
Definition: svm_fifo.c:792
static vlib_cli_command_t trace
(constructor) VLIB_CLI_COMMAND (trace)
Definition: vlib_api_cli.c:862
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:63
format_function_t format_ooo_segment
Definition: svm_fifo.h:36
u8 * svm_fifo_replay(u8 *s, svm_fifo_t *f, u8 no_read, u8 verbose)
Definition: svm_fifo.c:90
static u8 svm_fifo_has_ooo_data(svm_fifo_t *f)
Definition: svm_fifo.h:123
format_function_t format_svm_fifo
Definition: svm_fifo.h:167
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:111
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
svm_fifo_t * svm_fifo_create(u32 data_size_in_bytes)
create an svm fifo, in the current heap.
Definition: svm_fifo.c:198
static u8 * svm_fifo_tail(svm_fifo_t *f)
Definition: svm_fifo.h:221
unsigned char u8
Definition: types.h:56
static u32 ooo_segment_distance_from_tail(svm_fifo_t *f, u32 pos)
Definition: svm_fifo.h:227
struct _svm_fifo svm_fifo_t
static void svm_fifo_enqueue_nocopy(svm_fifo_t *f, u32 bytes)
Advance tail pointer.
Definition: svm_fifo.h:207
static u32 ooo_segment_end_offset(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:249
#define always_inline
Definition: clib.h:92
static u32 svm_fifo_max_dequeue(svm_fifo_t *f)
Definition: svm_fifo.h:105
static u32 svm_fifo_max_write_chunk(svm_fifo_t *f)
Max contiguous chunk of data that can be written.
Definition: svm_fifo.h:196
static u32 ooo_segment_length(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:255
u8 * svm_fifo_dump_trace(u8 *s, svm_fifo_t *f)
Definition: svm_fifo.c:66
int svm_fifo_dequeue_nowait(svm_fifo_t *f, u32 max_bytes, u8 *copy_here)
Definition: svm_fifo.c:710
unsigned int u32
Definition: types.h:88
static u8 * svm_fifo_head(svm_fifo_t *f)
Definition: svm_fifo.h:215
static u32 svm_fifo_max_read_chunk(svm_fifo_t *f)
Max contiguous chunk of data that can be read.
Definition: svm_fifo.h:187
static void svm_fifo_newest_ooo_segment_reset(svm_fifo_t *f)
Definition: svm_fifo.h:178
void svm_fifo_overwrite_head(svm_fifo_t *f, u8 *data, u32 len)
Definition: svm_fifo.c:623
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:464
void svm_fifo_dequeue_drop_all(svm_fifo_t *f)
Definition: svm_fifo.c:832
static u32 ooo_segment_offset(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:243
#define PREDICT_FALSE(x)
Definition: clib.h:105
static ooo_segment_t * ooo_segment_next(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:269
static void svm_fifo_unset_event(svm_fifo_t *f)
Unsets fifo event flag.
Definition: svm_fifo.h:144
signed char i8
Definition: types.h:45
static ooo_segment_t * svm_fifo_newest_ooo_segment(svm_fifo_t *f)
Definition: svm_fifo.h:170
static u8 svm_fifo_set_event(svm_fifo_t *f)
Sets fifo event flag.
Definition: svm_fifo.h:134
format_function_t format_ooo_list
Definition: svm_fifo.h:37
int svm_fifo_enqueue_nowait(svm_fifo_t *f, u32 max_bytes, const u8 *copy_from_here)
Definition: svm_fifo.c:538
static ooo_segment_t * ooo_segment_get_prev(svm_fifo_t *f, ooo_segment_t *s)
Definition: svm_fifo.h:261
#define OOO_SEGMENT_INVALID_INDEX
Definition: svm_fifo.h:40
void svm_fifo_init_pointers(svm_fifo_t *f, u32 pointer)
Set fifo pointers to requested offset.
Definition: svm_fifo.c:854
#define ASSERT(truth)
void svm_fifo_free(svm_fifo_t *f)
Definition: svm_fifo.c:218
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:776
u32 svm_fifo_number_ooo_segments(svm_fifo_t *f)
Definition: svm_fifo.c:839
svm_fifo_err_t
Definition: svm_fifo.h:83
static int svm_fifo_has_event(svm_fifo_t *f)
Definition: svm_fifo.h:117
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:845
int svm_fifo_enqueue_with_offset(svm_fifo_t *f, u32 offset, u32 required_bytes, u8 *copy_from_here)
Definition: svm_fifo.c:614
CLIB vectors are ubiquitous dynamically resized arrays with by user defined "headers".
static u32 ooo_segment_distance_to_tail(svm_fifo_t *f, u32 pos)
Definition: svm_fifo.h:237