aboutsummaryrefslogtreecommitdiffstats
path: root/src/svm/svm_fifo.h
blob: a83cd858f833d5cd867281c88937431565588b93 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef __included_ssvm_fifo_h__
#define __included_ssvm_fifo_h__

#include <vppinfra/clib.h>
#include <vppinfra/vec.h>
#include <vppinfra/mheap.h>
#include <vppinfra/heap.h>
#include <vppinfra/pool.h>
#include <vppinfra/format.h>
#include <pthread.h>

/** Out-of-order segment */
typedef struct
{
  u32 next;	/**< Next linked-list element pool index */
  u32 prev;	/**< Previous linked-list element pool index */

  u32 start;	/**< Start of segment, normalized*/
  u32 length;	/**< Length of segment */
} ooo_segment_t;

format_function_t format_ooo_segment;
format_function_t format_ooo_list;

#define SVM_FIFO_TRACE (0)
#define OOO_SEGMENT_INVALID_INDEX ((u32)~0)

typedef struct
{
  u32 offset;
  u32 len;
  u32 action;
} svm_fifo_trace_elem_t;

typedef struct _svm_fifo
{
  volatile u32 cursize;		/**< current fifo size */
  u32 nitems;
    CLIB_CACHE_LINE_ALIGN_MARK (end_cursize);

  volatile u32 has_event;	/**< non-zero if deq event exists */

  /* Backpointers */
  u32 master_session_index;
  u32 client_session_index;
  u8 master_thread_index;
  u8 client_thread_index;
  u32 segment_manager;
    CLIB_CACHE_LINE_ALIGN_MARK (end_shared);
  u32 head;
    CLIB_CACHE_LINE_ALIGN_MARK (end_consumer);

  /* producer */
  u32 tail;

  ooo_segment_t *ooo_segments;	/**< Pool of ooo segments */
  u32 ooos_list_head;		/**< Head of out-of-order linked-list */
  u32 ooos_newest;		/**< Last segment to have been updated */
  struct _svm_fifo *next;	/**< next in freelist/active chain */
  struct _svm_fifo *prev;	/**< prev in active chain */
#if SVM_FIFO_TRACE
  svm_fifo_trace_elem_t *trace;
#endif
    CLIB_CACHE_LINE_ALIGN_MARK (data);
} svm_fifo_t;

#if SVM_FIFO_TRACE
#define svm_fifo_trace_add(_f, _s, _l, _t)		\
{							\
  svm_fifo_trace_elem_t *trace_elt;			\
  vec_add2(_f->trace, trace_elt, 1);			\
  trace_elt->offset = _s;				\
  trace_elt->len = _l;					\
  trace_elt->action = _t;				\
}
#else
#define svm_fifo_trace_add(_f, _s, _l, _t)
#endif

u8 *svm_fifo_dump_trace (u8 * s, svm_fifo_t * f);
u8 *svm_fifo_replay (u8 * s, svm_fifo_t * f, u8 no_read, u8 verbose);

static inline u32
svm_fifo_max_dequeue (svm_fifo_t * f)
{
  return f->cursize;
}

static inline u32
svm_fifo_max_enqueue (svm_fifo_t * f)
{
  return f->nitems - svm_fifo_max_dequeue (f);
}

static inline u8
svm_fifo_has_ooo_data (svm_fifo_t * f)
{
  return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
}

/**
 * Sets fifo event flag.
 *
 * @return 1 if flag was not set.
 */
always_inline u8
svm_fifo_set_event (svm_fifo_t * f)
{
  /* Probably doesn't need to be atomic. Still, better avoid surprises */
  return __sync_lock_test_and_set (&f->has_event, 1) == 0;
}

/**
 * Unsets fifo event flag.
 */
always_inline void
svm_fifo_unset_event (svm_fifo_t * f)
{
  /* Probably doesn't need to be atomic. Still, better avoid surprises */
  __sync_lock_release (&f->has_event);
}

svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
void svm_fifo_free (svm_fifo_t * f);

int svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
			     u8 * copy_from_here);
int svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset,
				  u32 required_bytes, u8 * copy_from_here);
int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);

int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
u32 svm_fifo_number_ooo_segments (svm_fifo_t * f);
ooo_segment_t *svm_fifo_first_ooo_segment (svm_fifo_t * f);
void svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer);

format_function_t format_svm_fifo;

always_inline ooo_segment_t *
svm_fifo_newest_ooo_segment (svm_fifo_t * f)
{
  if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
    return 0;
  return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
}

always_inline void
svm_fifo_newest_ooo_segment_reset (svm_fifo_t * f)
{
  f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
}

always_inline u32
ooo_segment_distance_from_tail (svm_fifo_t * f, u32 pos)
{
  /* Ambiguous. Assumption is that ooo segments don't touch tail */
  if (PREDICT_FALSE (pos == f->tail && f->tail == f->head))
    return f->nitems;

  return (((f->nitems + pos) - f->tail) % f->nitems);
}

always_inline u32
ooo_segment_distance_to_tail (svm_fifo_t * f, u32 pos)
{
  return (((f->nitems + f->tail) - pos) % f->nitems);
}

always_inline u32
ooo_segment_offset (svm_fifo_t * f, ooo_segment_t * s)
{
  return ooo_segment_distance_from_tail (f, s->start);
}

always_inline u32
ooo_segment_end_offset (svm_fifo_t * f, ooo_segment_t * s)
{
  return ooo_segment_distance_from_tail (f, s->start) + s->length;
}

always_inline u32
ooo_segment_length (svm_fifo_t * f, ooo_segment_t * s)
{
  return s->length;
}

always_inline ooo_segment_t *
ooo_segment_get_prev (svm_fifo_t * f, ooo_segment_t * s)
{
  if (s->prev == OOO_SEGMENT_INVALID_INDEX)
    return 0;
  return pool_elt_at_index (f->ooo_segments, s->prev);
}

always_inline ooo_segment_t *
ooo_segment_next (svm_fifo_t * f, ooo_segment_t * s)
{
  if (s->next == OOO_SEGMENT_INVALID_INDEX)
    return 0;
  return pool_elt_at_index (f->ooo_segments, s->next);
}

#endif /* __included_ssvm_fifo_h__ */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */