counter.h revision 048a4e5a
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/** \file
44
45    Optimized thread-safe counters.
46
47    Each vlib_[simple|combined]_counter_main_t consists of a per-thread
48    vector of per-object counters.
49
50    The idea is to drastically eliminate atomic operations.
51*/
52
53/** 64bit counters */
54typedef u64 counter_t;
55
56/** A collection of simple counters */
57
58typedef struct
59{
60  counter_t **counters;	 /**< Per-thread u64 non-atomic counters */
61  counter_t *value_at_last_serialize;	/**< Values as of last serialize. */
62  u32 last_incremental_serialize_index;	/**< Last counter index
63                                           serialized incrementally. */
64
65  char *name;			/**< The counter collection's name. */
66  char *stat_segment_name;    /**< Name in stat segment directory */
67} vlib_simple_counter_main_t;
68
69/** The number of counters (not the number of per-thread counters) */
70u32 vlib_simple_counter_n_counters (const vlib_simple_counter_main_t * cm);
71
72/** Increment a simple counter
73    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
74    @param thread_index - (u32) the current cpu index
75    @param index - (u32) index of the counter to increment
76    @param increment - (u64) quantitiy to add to the counter
77*/
78always_inline void
79vlib_increment_simple_counter (vlib_simple_counter_main_t * cm,
80			       u32 thread_index, u32 index, u64 increment)
81{
82  counter_t *my_counters;
83
84  my_counters = cm->counters[thread_index];
85  my_counters[index] += increment;
86}
87
88/** Get the value of a simple counter
89    Scrapes the entire set of per-thread counters. Innacurate unless
90    worker threads which might increment the counter are
91    barrier-synchronized
92
93    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
94    @param index - (u32) index of the counter to fetch
95    @returns - (u64) current counter value
96*/
97always_inline counter_t
98vlib_get_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
99{
100  counter_t *my_counters;
101  counter_t v;
102  int i;
103
104  ASSERT (index < vlib_simple_counter_n_counters (cm));
105
106  v = 0;
107
108  for (i = 0; i < vec_len (cm->counters); i++)
109    {
110      my_counters = cm->counters[i];
111      v += my_counters[index];
112    }
113
114  return v;
115}
116
117/** Clear a simple counter
118    Clears the set of per-thread u16 counters, and the u64 counter
119
120    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
121    @param index - (u32) index of the counter to clear
122*/
123always_inline void
124vlib_zero_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
125{
126  counter_t *my_counters;
127  int i;
128
129  ASSERT (index < vlib_simple_counter_n_counters (cm));
130
131  for (i = 0; i < vec_len (cm->counters); i++)
132    {
133      my_counters = cm->counters[i];
134      my_counters[index] = 0;
135    }
136}
137
138/** Combined counter to hold both packets and byte differences.
139 */
140typedef struct
141{
142  counter_t packets;			/**< packet counter */
143  counter_t bytes;			/**< byte counter  */
144} vlib_counter_t;
145
146/** Add two combined counters, results in the first counter
147    @param [in,out] a - (vlib_counter_t *) dst counter
148    @param b - (vlib_counter_t *) src counter
149*/
150
151always_inline void
152vlib_counter_add (vlib_counter_t * a, vlib_counter_t * b)
153{
154  a->packets += b->packets;
155  a->bytes += b->bytes;
156}
157
158/** Subtract combined counters, results in the first counter
159    @param [in,out] a - (vlib_counter_t *) dst counter
160    @param b - (vlib_counter_t *) src counter
161*/
162always_inline void
163vlib_counter_sub (vlib_counter_t * a, vlib_counter_t * b)
164{
165  ASSERT (a->packets >= b->packets);
166  ASSERT (a->bytes >= b->bytes);
167  a->packets -= b->packets;
168  a->bytes -= b->bytes;
169}
170
171/** Clear a combined counter
172    @param a - (vlib_counter_t *) counter to clear
173*/
174always_inline void
175vlib_counter_zero (vlib_counter_t * a)
176{
177  a->packets = a->bytes = 0;
178}
179
180/** A collection of combined counters */
181typedef struct
182{
183  vlib_counter_t **counters;	/**< Per-thread u64 non-atomic counter pairs */
184  vlib_counter_t *value_at_last_serialize; /**< Counter values as of last serialize. */
185  u32 last_incremental_serialize_index;	/**< Last counter index serialized incrementally. */
186  char *name; /**< The counter collection's name. */
187  char *stat_segment_name;	/**< Name in stat segment directory */
188} vlib_combined_counter_main_t;
189
190/** The number of counters (not the number of per-thread counters) */
191u32 vlib_combined_counter_n_counters (const vlib_combined_counter_main_t *
192				      cm);
193
194/** Clear a collection of simple counters
195    @param cm - (vlib_simple_counter_main_t *) collection to clear
196*/
197void vlib_clear_simple_counters (vlib_simple_counter_main_t * cm);
198
199/** Clear a collection of combined counters
200    @param cm - (vlib_combined_counter_main_t *) collection to clear
201*/
202void vlib_clear_combined_counters (vlib_combined_counter_main_t * cm);
203
204/** Increment a combined counter
205    @param cm - (vlib_combined_counter_main_t *) comined counter main pointer
206    @param thread_index - (u32) the current cpu index
207    @param index - (u32) index of the counter to increment
208    @param packet_increment - (u64) number of packets to add to the counter
209    @param byte_increment - (u64) number of bytes to add to the counter
210*/
211
212always_inline void
213vlib_increment_combined_counter (vlib_combined_counter_main_t * cm,
214				 u32 thread_index,
215				 u32 index, u64 n_packets, u64 n_bytes)
216{
217  vlib_counter_t *my_counters;
218
219  /* Use this CPU's counter array */
220  my_counters = cm->counters[thread_index];
221
222  my_counters[index].packets += n_packets;
223  my_counters[index].bytes += n_bytes;
224}
225
226/** Pre-fetch a per-thread combined counter for the given object index */
227always_inline void
228vlib_prefetch_combined_counter (const vlib_combined_counter_main_t * cm,
229				u32 thread_index, u32 index)
230{
231  vlib_counter_t *cpu_counters;
232
233  /*
234   * This CPU's index is assumed to already be in cache
235   */
236  cpu_counters = cm->counters[thread_index];
237  CLIB_PREFETCH (cpu_counters + index, CLIB_CACHE_LINE_BYTES, STORE);
238}
239
240
241/** Get the value of a combined counter, never called in the speed path
242    Scrapes the entire set of per-thread counters. Innacurate unless
243    worker threads which might increment the counter are
244    barrier-synchronized
245
246    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
247    @param index - (u32) index of the combined counter to fetch
248    @param result [out] - (vlib_counter_t *) result stored here
249*/
250
251static inline void
252vlib_get_combined_counter (const vlib_combined_counter_main_t * cm,
253			   u32 index, vlib_counter_t * result)
254{
255  vlib_counter_t *my_counters, *counter;
256  int i;
257
258  result->packets = 0;
259  result->bytes = 0;
260
261  for (i = 0; i < vec_len (cm->counters); i++)
262    {
263      my_counters = cm->counters[i];
264
265      counter = vec_elt_at_index (my_counters, index);
266      result->packets += counter->packets;
267      result->bytes += counter->bytes;
268    }
269}
270
271/** Clear a combined counter
272    Clears the set of per-thread counters.
273
274    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
275    @param index - (u32) index of the counter to clear
276*/
277always_inline void
278vlib_zero_combined_counter (vlib_combined_counter_main_t * cm, u32 index)
279{
280  vlib_counter_t *my_counters, *counter;
281  int i;
282
283  for (i = 0; i < vec_len (cm->counters); i++)
284    {
285      my_counters = cm->counters[i];
286
287      counter = vec_elt_at_index (my_counters, index);
288      counter->packets = 0;
289      counter->bytes = 0;
290    }
291}
292
293/** validate a simple counter
294    @param cm - (vlib_simple_counter_main_t *) pointer to the counter collection
295    @param index - (u32) index of the counter to validate
296*/
297
298void vlib_validate_simple_counter (vlib_simple_counter_main_t * cm,
299				   u32 index);
300/** validate a combined counter
301    @param cm - (vlib_combined_counter_main_t *) pointer to the counter
302    collection
303    @param index - (u32) index of the counter to validate
304*/
305
306void vlib_validate_combined_counter (vlib_combined_counter_main_t * cm,
307				     u32 index);
308
309/** Obtain the number of simple or combined counters allocated.
310    A macro which reduces to to vec_len(cm->maxi), the answer in either
311    case.
312
313    @param cm - (vlib_simple_counter_main_t) or
314    (vlib_combined_counter_main_t) the counter collection to interrogate
315    @returns vec_len(cm->maxi)
316*/
317#define vlib_counter_len(cm) vec_len((cm)->maxi)
318
319serialize_function_t serialize_vlib_simple_counter_main,
320  unserialize_vlib_simple_counter_main;
321serialize_function_t serialize_vlib_combined_counter_main,
322  unserialize_vlib_combined_counter_main;
323
324#endif /* included_vlib_counter_h */
325
326/*
327 * fd.io coding-style-patch-verification: ON
328 *
329 * Local Variables:
330 * eval: (c-set-style "gnu")
331 * End:
332 */
333