counter.h revision 1bd01099
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} 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 cpu_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 cpu_index, u32 index, u64 increment)
80{
81  counter_t *my_counters;
82
83  my_counters = cm->counters[cpu_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/** Combined counter to hold both packets and byte differences.
138 */
139typedef struct
140{
141  counter_t packets;			/**< packet counter */
142  counter_t bytes;			/**< byte counter  */
143} vlib_counter_t;
144
145/** Add two combined counters, results in the first counter
146    @param [in,out] a - (vlib_counter_t *) dst counter
147    @param b - (vlib_counter_t *) src counter
148*/
149
150always_inline void
151vlib_counter_add (vlib_counter_t * a, vlib_counter_t * b)
152{
153  a->packets += b->packets;
154  a->bytes += b->bytes;
155}
156
157/** Subtract combined counters, results in the first counter
158    @param [in,out] a - (vlib_counter_t *) dst counter
159    @param b - (vlib_counter_t *) src counter
160*/
161always_inline void
162vlib_counter_sub (vlib_counter_t * a, vlib_counter_t * b)
163{
164  ASSERT (a->packets >= b->packets);
165  ASSERT (a->bytes >= b->bytes);
166  a->packets -= b->packets;
167  a->bytes -= b->bytes;
168}
169
170/** Clear a combined counter
171    @param a - (vlib_counter_t *) counter to clear
172*/
173always_inline void
174vlib_counter_zero (vlib_counter_t * a)
175{
176  a->packets = a->bytes = 0;
177}
178
179/** A collection of combined counters */
180typedef struct
181{
182  vlib_counter_t **counters;	/**< Per-thread u64 non-atomic counter pairs */
183  vlib_counter_t *value_at_last_serialize; /**< Counter values as of last serialize. */
184  u32 last_incremental_serialize_index;	/**< Last counter index serialized incrementally. */
185  char *name; /**< The counter collection's name. */
186} vlib_combined_counter_main_t;
187
188/** The number of counters (not the number of per-thread counters) */
189u32 vlib_combined_counter_n_counters (const vlib_combined_counter_main_t *
190				      cm);
191
192/** Clear a collection of simple counters
193    @param cm - (vlib_simple_counter_main_t *) collection to clear
194*/
195void vlib_clear_simple_counters (vlib_simple_counter_main_t * cm);
196
197/** Clear a collection of combined counters
198    @param cm - (vlib_combined_counter_main_t *) collection to clear
199*/
200void vlib_clear_combined_counters (vlib_combined_counter_main_t * cm);
201
202/** Increment a combined counter
203    @param cm - (vlib_combined_counter_main_t *) comined counter main pointer
204    @param cpu_index - (u32) the current cpu index
205    @param index - (u32) index of the counter to increment
206    @param packet_increment - (u64) number of packets to add to the counter
207    @param byte_increment - (u64) number of bytes to add to the counter
208*/
209
210always_inline void
211vlib_increment_combined_counter (vlib_combined_counter_main_t * cm,
212				 u32 cpu_index,
213				 u32 index, u64 n_packets, u64 n_bytes)
214{
215  vlib_counter_t *my_counters;
216
217  /* Use this CPU's counter array */
218  my_counters = cm->counters[cpu_index];
219
220  my_counters[index].packets += n_packets;
221  my_counters[index].bytes += n_bytes;
222}
223
224/** Pre-fetch a per-thread combined counter for the given object index */
225always_inline void
226vlib_prefetch_combined_counter (const vlib_combined_counter_main_t * cm,
227				u32 cpu_index, u32 index)
228{
229  vlib_counter_t *cpu_counters;
230
231  /*
232   * This CPU's index is assumed to already be in cache
233   */
234  cpu_counters = cm->counters[cpu_index];
235  CLIB_PREFETCH (cpu_counters + index, CLIB_CACHE_LINE_BYTES, STORE);
236}
237
238
239/** Get the value of a combined counter, never called in the speed path
240    Scrapes the entire set of per-thread counters. Innacurate unless
241    worker threads which might increment the counter are
242    barrier-synchronized
243
244    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
245    @param index - (u32) index of the combined counter to fetch
246    @param result [out] - (vlib_counter_t *) result stored here
247*/
248
249static inline void
250vlib_get_combined_counter (const vlib_combined_counter_main_t * cm,
251			   u32 index, vlib_counter_t * result)
252{
253  vlib_counter_t *my_counters, *counter;
254  int i;
255
256  result->packets = 0;
257  result->bytes = 0;
258
259  for (i = 0; i < vec_len (cm->counters); i++)
260    {
261      my_counters = cm->counters[i];
262
263      counter = vec_elt_at_index (my_counters, index);
264      result->packets += counter->packets;
265      result->bytes += counter->bytes;
266    }
267}
268
269/** Clear a combined counter
270    Clears the set of per-thread counters.
271
272    @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
273    @param index - (u32) index of the counter to clear
274*/
275always_inline void
276vlib_zero_combined_counter (vlib_combined_counter_main_t * cm, u32 index)
277{
278  vlib_counter_t *my_counters, *counter;
279  int i;
280
281  for (i = 0; i < vec_len (cm->counters); i++)
282    {
283      my_counters = cm->counters[i];
284
285      counter = vec_elt_at_index (my_counters, index);
286      counter->packets = 0;
287      counter->bytes = 0;
288    }
289}
290
291/** validate a simple counter
292    @param cm - (vlib_simple_counter_main_t *) pointer to the counter collection
293    @param index - (u32) index of the counter to validate
294*/
295
296void vlib_validate_simple_counter (vlib_simple_counter_main_t * cm,
297				   u32 index);
298/** validate a combined counter
299    @param cm - (vlib_combined_counter_main_t *) pointer to the counter
300    collection
301    @param index - (u32) index of the counter to validate
302*/
303
304void vlib_validate_combined_counter (vlib_combined_counter_main_t * cm,
305				     u32 index);
306
307/** Obtain the number of simple or combined counters allocated.
308    A macro which reduces to to vec_len(cm->maxi), the answer in either
309    case.
310
311    @param cm - (vlib_simple_counter_main_t) or
312    (vlib_combined_counter_main_t) the counter collection to interrogate
313    @returns vec_len(cm->maxi)
314*/
315#define vlib_counter_len(cm) vec_len((cm)->maxi)
316
317serialize_function_t serialize_vlib_simple_counter_main,
318  unserialize_vlib_simple_counter_main;
319serialize_function_t serialize_vlib_combined_counter_main,
320  unserialize_vlib_combined_counter_main;
321
322#endif /* included_vlib_counter_h */
323
324/*
325 * fd.io coding-style-patch-verification: ON
326 *
327 * Local Variables:
328 * eval: (c-set-style "gnu")
329 * End:
330 */
331