counter.h revision e51a9bbe
1/*
2 * Copyright (c) 2015 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 * counter.h: simple and packet/byte counters
17 *
18 * Copyright (c) 2008 Eliot Dresselhaus
19 *
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
27 *
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
30 *
31 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
38 */
39
40#ifndef included_vlib_counter_h
41#define included_vlib_counter_h
42
43#include <vlib/counter_types.h>
44
45/** \file
46
47    Optimized thread-safe counters.
48
49    Each vlib_[simple|combined]_counter_main_t consists of a per-thread
50    vector of per-object counters.
51
52    The idea is to drastically eliminate atomic operations.
53*/
54
55/** A collection of simple counters */
56
57typedef struct
58{
59  counter_t **counters;	 /**< Per-thread u64 non-atomic counters */
60  counter_t *value_at_last_serialize;	/**< Values as of last serialize. */
61  u32 last_incremental_serialize_index;	/**< Last counter index
62                                           serialized incrementally. */
63
64  char *name;			/**< The counter collection's name. */
65  char *stat_segment_name;    /**< Name in stat segment directory */
66} vlib_simple_counter_main_t;
67
68/** The number of counters (not the number of per-thread counters) */
69u32 vlib_simple_counter_n_counters (const vlib_simple_counter_main_t * cm);
70
71/** Increment a simple counter
72    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
73    @param thread_index - (u32) the current cpu index
74    @param index - (u32) index of the counter to increment
75    @param increment - (u64) quantitiy to add to the counter
76*/
77always_inline void
78vlib_increment_simple_counter (vlib_simple_counter_main_t * cm,
79			       u32 thread_index, u32 index, u64 increment)
80{
81  counter_t *my_counters;
82
83  my_counters = cm->counters[thread_index];
84  my_counters[index] += increment;
85}
86
87/** Set a simple counter
88    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
89    @param thread_index - (u32) the current cpu index
90    @param index - (u32) index of the counter to increment
91    @param value - (u64) quantitiy to set to the counter
92*/
93always_inline void
94vlib_set_simple_counter (vlib_simple_counter_main_t * cm,
95			 u32 thread_index, u32 index, u64 value)
96{
97  counter_t *my_counters;
98
99  my_counters = cm->counters[thread_index];
100  my_counters[index] = value;
101}
102
103/** Get the value of a simple counter
104    Scrapes the entire set of per-thread counters. Innacurate unless
105    worker threads which might increment the counter are
106    barrier-synchronized
107
108    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
109    @param index - (u32) index of the counter to fetch
110    @returns - (u64) current counter value
111*/
112always_inline counter_t
113vlib_get_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
114{
115  counter_t *my_counters;
116  counter_t v;
117  int i;
118
119  ASSERT (index < vlib_simple_counter_n_counters (cm));
120
121  v = 0;
122
123  for (i = 0; i < vec_len (cm->counters); i++)
124    {
125      my_counters = cm->counters[i];
126      v += my_counters[index];
127    }
128
129  return v;
130}
131
132/** Clear a simple counter
133    Clears the set of per-thread u16 counters, and the u64 counter
134
135    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
136    @param index - (u32) index of the counter to clear
137*/
138always_inline void
139vlib_zero_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
140{
141  counter_t *my_counters;
142  int i;
143
144  ASSERT (index < vlib_simple_counter_n_counters (cm));
145
146  for (i = 0; i < vec_len (cm->counters); i++)
147    {
148      my_counters = cm->counters[i];
149      my_counters[index] = 0;
150    }
151}
152
153/** Add two combined counters, results in the first counter
154    @param [in,out] a - (vlib_counter_t *) dst counter
155    @param b - (vlib_counter_t *) src counter
156*/
157
158always_inline void
159vlib_counter_add (vlib_counter_t * a, vlib_counter_t * b)
160{
161  a->packets += b->packets;
162  a->bytes += b->bytes;
163}
164
165/** Subtract combined counters, results in the first counter
166    @param [in,out] a - (vlib_counter_t *) dst counter
167    @param b - (vlib_counter_t *) src counter
168*/
169always_inline void
170vlib_counter_sub (vlib_counter_t * a, vlib_counter_t * b)
171{
172  ASSERT (a->packets >= b->packets);
173  ASSERT (a->bytes >= b->bytes);
174  a->packets -= b->packets;
175  a->bytes -= b->bytes;
176}
177
178/** Clear a combined counter
179    @param a - (vlib_counter_t *) counter to clear
180*/
181always_inline void
182vlib_counter_zero (vlib_counter_t * a)
183{
184  a->packets = a->bytes = 0;
185}
186
187/** A collection of combined counters */
188typedef struct
189{
190  vlib_counter_t **counters;	/**< Per-thread u64 non-atomic counter pairs */
191  vlib_counter_t *value_at_last_serialize; /**< Counter values as of last serialize. */
192  u32 last_incremental_serialize_index;	/**< Last counter index serialized incrementally. */
193  char *name; /**< The counter collection's name. */
194  char *stat_segment_name;	/**< Name in stat segment directory */
195} vlib_combined_counter_main_t;
196
197/** The number of counters (not the number of per-thread counters) */
198u32 vlib_combined_counter_n_counters (const vlib_combined_counter_main_t *
199				      cm);
200
201/** Clear a collection of simple counters
202    @param cm - (vlib_simple_counter_main_t *) collection to clear
203*/
204void vlib_clear_simple_counters (vlib_simple_counter_main_t * cm);
205
206/** Clear a collection of combined counters
207    @param cm - (vlib_combined_counter_main_t *) collection to clear
208*/
209void vlib_clear_combined_counters (vlib_combined_counter_main_t * cm);
210
211/** Increment a combined counter
212    @param cm - (vlib_combined_counter_main_t *) comined counter main pointer
213    @param thread_index - (u32) the current cpu index
214    @param index - (u32) index of the counter to increment
215    @param packet_increment - (u64) number of packets to add to the counter
216    @param byte_increment - (u64) number of bytes to add to the counter
217*/
218
219always_inline void
220vlib_increment_combined_counter (vlib_combined_counter_main_t * cm,
221				 u32 thread_index,
222				 u32 index, u64 n_packets, u64 n_bytes)
223{
224  vlib_counter_t *my_counters;
225
226  /* Use this CPU's counter array */
227  my_counters = cm->counters[thread_index];
228
229  my_counters[index].packets += n_packets;
230  my_counters[index].bytes += n_bytes;
231}
232
233/** Pre-fetch a per-thread combined counter for the given object index */
234always_inline void
235vlib_prefetch_combined_counter (const vlib_combined_counter_main_t * cm,
236				u32 thread_index, u32 index)
237{
238  vlib_counter_t *cpu_counters;
239
240  /*
241   * This CPU's index is assumed to already be in cache
242   */
243  cpu_counters = cm->counters[thread_index];
244  CLIB_PREFETCH (cpu_counters + index, CLIB_CACHE_LINE_BYTES, STORE);
245}
246
247
248/** Get the value of a combined counter, never called in the speed path
249    Scrapes the entire set of per-thread counters. Innacurate unless
250    worker threads which might increment the counter are
251    barrier-synchronized
252
253    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
254    @param index - (u32) index of the combined counter to fetch
255    @param result [out] - (vlib_counter_t *) result stored here
256*/
257
258static inline void
259vlib_get_combined_counter (const vlib_combined_counter_main_t * cm,
260			   u32 index, vlib_counter_t * result)
261{
262  vlib_counter_t *my_counters, *counter;
263  int i;
264
265  result->packets = 0;
266  result->bytes = 0;
267
268  for (i = 0; i < vec_len (cm->counters); i++)
269    {
270      my_counters = cm->counters[i];
271
272      counter = vec_elt_at_index (my_counters, index);
273      result->packets += counter->packets;
274      result->bytes += counter->bytes;
275    }
276}
277
278/** Clear a combined counter
279    Clears the set of per-thread counters.
280
281    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
282    @param index - (u32) index of the counter to clear
283*/
284always_inline void
285vlib_zero_combined_counter (vlib_combined_counter_main_t * cm, u32 index)
286{
287  vlib_counter_t *my_counters, *counter;
288  int i;
289
290  for (i = 0; i < vec_len (cm->counters); i++)
291    {
292      my_counters = cm->counters[i];
293
294      counter = vec_elt_at_index (my_counters, index);
295      counter->packets = 0;
296      counter->bytes = 0;
297    }
298}
299
300/** validate a simple counter
301    @param cm - (vlib_simple_counter_main_t *) pointer to the counter collection
302    @param index - (u32) index of the counter to validate
303*/
304
305void vlib_validate_simple_counter (vlib_simple_counter_main_t * cm,
306				   u32 index);
307/** validate a combined counter
308    @param cm - (vlib_combined_counter_main_t *) pointer to the counter
309    collection
310    @param index - (u32) index of the counter to validate
311*/
312
313void vlib_validate_combined_counter (vlib_combined_counter_main_t * cm,
314				     u32 index);
315
316/** Obtain the number of simple or combined counters allocated.
317    A macro which reduces to to vec_len(cm->maxi), the answer in either
318    case.
319
320    @param cm - (vlib_simple_counter_main_t) or
321    (vlib_combined_counter_main_t) the counter collection to interrogate
322    @returns vec_len(cm->maxi)
323*/
324#define vlib_counter_len(cm) vec_len((cm)->maxi)
325
326#endif /* included_vlib_counter_h */
327
328/*
329 * fd.io coding-style-patch-verification: ON
330 *
331 * Local Variables:
332 * eval: (c-set-style "gnu")
333 * End:
334 */
335