counter.h revision 58492a83
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/** Get the value of a simple counter
88    Scrapes the entire set of per-thread counters. Innacurate unless
89    worker threads which might increment the counter are
90    barrier-synchronized
91
92    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
93    @param index - (u32) index of the counter to fetch
94    @returns - (u64) current counter value
95*/
96always_inline counter_t
97vlib_get_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
98{
99  counter_t *my_counters;
100  counter_t v;
101  int i;
102
103  ASSERT (index < vlib_simple_counter_n_counters (cm));
104
105  v = 0;
106
107  for (i = 0; i < vec_len (cm->counters); i++)
108    {
109      my_counters = cm->counters[i];
110      v += my_counters[index];
111    }
112
113  return v;
114}
115
116/** Clear a simple counter
117    Clears the set of per-thread u16 counters, and the u64 counter
118
119    @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
120    @param index - (u32) index of the counter to clear
121*/
122always_inline void
123vlib_zero_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
124{
125  counter_t *my_counters;
126  int i;
127
128  ASSERT (index < vlib_simple_counter_n_counters (cm));
129
130  for (i = 0; i < vec_len (cm->counters); i++)
131    {
132      my_counters = cm->counters[i];
133      my_counters[index] = 0;
134    }
135}
136
137/** Add two combined counters, results in the first counter
138    @param [in,out] a - (vlib_counter_t *) dst counter
139    @param b - (vlib_counter_t *) src counter
140*/
141
142always_inline void
143vlib_counter_add (vlib_counter_t * a, vlib_counter_t * b)
144{
145  a->packets += b->packets;
146  a->bytes += b->bytes;
147}
148
149/** Subtract combined counters, results in the first counter
150    @param [in,out] a - (vlib_counter_t *) dst counter
151    @param b - (vlib_counter_t *) src counter
152*/
153always_inline void
154vlib_counter_sub (vlib_counter_t * a, vlib_counter_t * b)
155{
156  ASSERT (a->packets >= b->packets);
157  ASSERT (a->bytes >= b->bytes);
158  a->packets -= b->packets;
159  a->bytes -= b->bytes;
160}
161
162/** Clear a combined counter
163    @param a - (vlib_counter_t *) counter to clear
164*/
165always_inline void
166vlib_counter_zero (vlib_counter_t * a)
167{
168  a->packets = a->bytes = 0;
169}
170
171/** A collection of combined counters */
172typedef struct
173{
174  vlib_counter_t **counters;	/**< Per-thread u64 non-atomic counter pairs */
175  vlib_counter_t *value_at_last_serialize; /**< Counter values as of last serialize. */
176  u32 last_incremental_serialize_index;	/**< Last counter index serialized incrementally. */
177  char *name; /**< The counter collection's name. */
178  char *stat_segment_name;	/**< Name in stat segment directory */
179} vlib_combined_counter_main_t;
180
181/** The number of counters (not the number of per-thread counters) */
182u32 vlib_combined_counter_n_counters (const vlib_combined_counter_main_t *
183				      cm);
184
185/** Clear a collection of simple counters
186    @param cm - (vlib_simple_counter_main_t *) collection to clear
187*/
188void vlib_clear_simple_counters (vlib_simple_counter_main_t * cm);
189
190/** Clear a collection of combined counters
191    @param cm - (vlib_combined_counter_main_t *) collection to clear
192*/
193void vlib_clear_combined_counters (vlib_combined_counter_main_t * cm);
194
195/** Increment a combined counter
196    @param cm - (vlib_combined_counter_main_t *) comined counter main pointer
197    @param thread_index - (u32) the current cpu index
198    @param index - (u32) index of the counter to increment
199    @param packet_increment - (u64) number of packets to add to the counter
200    @param byte_increment - (u64) number of bytes to add to the counter
201*/
202
203always_inline void
204vlib_increment_combined_counter (vlib_combined_counter_main_t * cm,
205				 u32 thread_index,
206				 u32 index, u64 n_packets, u64 n_bytes)
207{
208  vlib_counter_t *my_counters;
209
210  /* Use this CPU's counter array */
211  my_counters = cm->counters[thread_index];
212
213  my_counters[index].packets += n_packets;
214  my_counters[index].bytes += n_bytes;
215}
216
217/** Pre-fetch a per-thread combined counter for the given object index */
218always_inline void
219vlib_prefetch_combined_counter (const vlib_combined_counter_main_t * cm,
220				u32 thread_index, u32 index)
221{
222  vlib_counter_t *cpu_counters;
223
224  /*
225   * This CPU's index is assumed to already be in cache
226   */
227  cpu_counters = cm->counters[thread_index];
228  CLIB_PREFETCH (cpu_counters + index, CLIB_CACHE_LINE_BYTES, STORE);
229}
230
231
232/** Get the value of a combined counter, never called in the speed path
233    Scrapes the entire set of per-thread counters. Innacurate unless
234    worker threads which might increment the counter are
235    barrier-synchronized
236
237    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
238    @param index - (u32) index of the combined counter to fetch
239    @param result [out] - (vlib_counter_t *) result stored here
240*/
241
242static inline void
243vlib_get_combined_counter (const vlib_combined_counter_main_t * cm,
244			   u32 index, vlib_counter_t * result)
245{
246  vlib_counter_t *my_counters, *counter;
247  int i;
248
249  result->packets = 0;
250  result->bytes = 0;
251
252  for (i = 0; i < vec_len (cm->counters); i++)
253    {
254      my_counters = cm->counters[i];
255
256      counter = vec_elt_at_index (my_counters, index);
257      result->packets += counter->packets;
258      result->bytes += counter->bytes;
259    }
260}
261
262/** Clear a combined counter
263    Clears the set of per-thread counters.
264
265    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
266    @param index - (u32) index of the counter to clear
267*/
268always_inline void
269vlib_zero_combined_counter (vlib_combined_counter_main_t * cm, u32 index)
270{
271  vlib_counter_t *my_counters, *counter;
272  int i;
273
274  for (i = 0; i < vec_len (cm->counters); i++)
275    {
276      my_counters = cm->counters[i];
277
278      counter = vec_elt_at_index (my_counters, index);
279      counter->packets = 0;
280      counter->bytes = 0;
281    }
282}
283
284/** validate a simple counter
285    @param cm - (vlib_simple_counter_main_t *) pointer to the counter collection
286    @param index - (u32) index of the counter to validate
287*/
288
289void vlib_validate_simple_counter (vlib_simple_counter_main_t * cm,
290				   u32 index);
291/** validate a combined counter
292    @param cm - (vlib_combined_counter_main_t *) pointer to the counter
293    collection
294    @param index - (u32) index of the counter to validate
295*/
296
297void vlib_validate_combined_counter (vlib_combined_counter_main_t * cm,
298				     u32 index);
299
300/** Obtain the number of simple or combined counters allocated.
301    A macro which reduces to to vec_len(cm->maxi), the answer in either
302    case.
303
304    @param cm - (vlib_simple_counter_main_t) or
305    (vlib_combined_counter_main_t) the counter collection to interrogate
306    @returns vec_len(cm->maxi)
307*/
308#define vlib_counter_len(cm) vec_len((cm)->maxi)
309
310serialize_function_t serialize_vlib_simple_counter_main,
311  unserialize_vlib_simple_counter_main;
312serialize_function_t serialize_vlib_combined_counter_main,
313  unserialize_vlib_combined_counter_main;
314
315#endif /* included_vlib_counter_h */
316
317/*
318 * fd.io coding-style-patch-verification: ON
319 *
320 * Local Variables:
321 * eval: (c-set-style "gnu")
322 * End:
323 */
324