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.
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12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * counter.h: simple and packet/byte counters
18 * Copyright (c) 2008 Eliot Dresselhaus
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21 * a copy of this software and associated documentation files (the
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40 #ifndef included_vlib_counter_h
41 #define included_vlib_counter_h
45 Optimized thread-safe counters.
47 Each vlib_[simple|combined]_counter_main_t consists of a single
48 vector of thread-safe / atomically-updated u64 counters [the
49 "maxi" vector], and a (u16 **) per-thread vector [the "minis"
50 vector] of narrow, per-thread counters.
52 The idea is to drastically reduce the number of atomic operations.
53 In the case of packet counts, we divide the number of atomic ops
57 /** A collection of simple counters */
61 u16 **minis; /**< Per-thread u16 non-atomic counters */
62 u64 *maxi; /**< Shared wide counters */
63 u64 *value_at_last_clear; /**< Counter values as of last clear. */
64 u64 *value_at_last_serialize; /**< Values as of last serialize. */
65 u32 last_incremental_serialize_index; /**< Last counter index
66 serialized incrementally. */
68 char *name; /**< The counter collection's name. */
69 } vlib_simple_counter_main_t;
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 - (u32) quantitiy to add to the counter
78 vlib_increment_simple_counter (vlib_simple_counter_main_t * cm,
79 u32 cpu_index, u32 index, u32 increment)
85 my_minis = cm->minis[cpu_index];
86 mini = vec_elt_at_index (my_minis, index);
88 new = old + increment;
91 if (PREDICT_FALSE (mini[0] != new))
93 __sync_fetch_and_add (&cm->maxi[index], new);
98 /** Get the value of a simple counter
99 Scrapes the entire set of mini counters. Innacurate unless
100 worker threads which might increment the counter are
103 @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
104 @param index - (u32) index of the counter to fetch
105 @returns - (u64) current counter value
108 vlib_get_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
110 u16 *my_minis, *mini;
114 ASSERT (index < vec_len (cm->maxi));
118 for (i = 0; i < vec_len (cm->minis); i++)
120 my_minis = cm->minis[i];
121 mini = vec_elt_at_index (my_minis, index);
125 v += cm->maxi[index];
127 if (index < vec_len (cm->value_at_last_clear))
129 ASSERT (v >= cm->value_at_last_clear[index]);
130 v -= cm->value_at_last_clear[index];
136 /** Clear a simple counter
137 Clears the set of per-thread u16 counters, and the u64 counter
139 @param cm - (vlib_simple_counter_main_t *) simple counter main pointer
140 @param index - (u32) index of the counter to clear
143 vlib_zero_simple_counter (vlib_simple_counter_main_t * cm, u32 index)
148 ASSERT (index < vec_len (cm->maxi));
150 for (i = 0; i < vec_len (cm->minis); i++)
152 my_minis = cm->minis[i];
158 if (index < vec_len (cm->value_at_last_clear))
159 cm->value_at_last_clear[index] = 0;
162 /** Combined counter to hold both packets and byte differences.
166 u64 packets; /**< packet counter */
167 u64 bytes; /**< byte counter */
170 /** Add two combined counters, results in the first counter
171 @param [in,out] a - (vlib_counter_t *) dst counter
172 @param b - (vlib_counter_t *) src counter
176 vlib_counter_add (vlib_counter_t * a, vlib_counter_t * b)
178 a->packets += b->packets;
179 a->bytes += b->bytes;
182 /** Subtract combined counters, results in the first counter
183 @param [in,out] a - (vlib_counter_t *) dst counter
184 @param b - (vlib_counter_t *) src counter
187 vlib_counter_sub (vlib_counter_t * a, vlib_counter_t * b)
189 ASSERT (a->packets >= b->packets);
190 ASSERT (a->bytes >= b->bytes);
191 a->packets -= b->packets;
192 a->bytes -= b->bytes;
195 /** Clear a combined counter
196 @param a - (vlib_counter_t *) counter to clear
199 vlib_counter_zero (vlib_counter_t * a)
201 a->packets = a->bytes = 0;
204 /** Mini combined counter */
207 u16 packets; /**< Packet count */
208 i16 bytes; /**< Byte count */
209 } vlib_mini_counter_t;
211 /** A collection of combined counters */
214 vlib_mini_counter_t **minis; /**< Per-thread u16 non-atomic counter pairs */
215 vlib_counter_t *maxi; /**< Shared wide counter pairs */
216 vlib_counter_t *value_at_last_clear; /**< Counter values as of last clear. */
217 vlib_counter_t *value_at_last_serialize; /**< Counter values as of last serialize. */
218 u32 last_incremental_serialize_index; /**< Last counter index serialized incrementally. */
219 char *name; /**< The counter collection's name. */
220 } vlib_combined_counter_main_t;
222 /** Clear a collection of simple counters
223 @param cm - (vlib_simple_counter_main_t *) collection to clear
225 void vlib_clear_simple_counters (vlib_simple_counter_main_t * cm);
227 /** Clear a collection of combined counters
228 @param cm - (vlib_combined_counter_main_t *) collection to clear
230 void vlib_clear_combined_counters (vlib_combined_counter_main_t * cm);
232 /** Increment a combined counter
233 @param cm - (vlib_combined_counter_main_t *) comined counter main pointer
234 @param cpu_index - (u32) the current cpu index
235 @param index - (u32) index of the counter to increment
236 @param packet_increment - (u32) number of packets to add to the counter
237 @param byte_increment - (u32) number of bytes to add to the counter
241 vlib_increment_combined_counter (vlib_combined_counter_main_t * cm,
244 u32 packet_increment, u32 byte_increment)
246 vlib_mini_counter_t *my_minis, *mini;
247 u32 old_packets, new_packets;
248 i32 old_bytes, new_bytes;
250 /* Use this CPU's mini counter array */
251 my_minis = cm->minis[cpu_index];
253 mini = vec_elt_at_index (my_minis, index);
254 old_packets = mini->packets;
255 old_bytes = mini->bytes;
257 new_packets = old_packets + packet_increment;
258 new_bytes = old_bytes + byte_increment;
260 mini->packets = new_packets;
261 mini->bytes = new_bytes;
263 /* Bytes always overflow before packets.. */
264 if (PREDICT_FALSE (mini->bytes != new_bytes))
266 vlib_counter_t *maxi = vec_elt_at_index (cm->maxi, index);
268 __sync_fetch_and_add (&maxi->packets, new_packets);
269 __sync_fetch_and_add (&maxi->bytes, new_bytes);
276 /** Get the value of a combined counter, never called in the speed path
277 Scrapes the entire set of mini counters. Innacurate unless
278 worker threads which might increment the counter are
281 @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
282 @param index - (u32) index of the combined counter to fetch
283 @param result [out] - (vlib_counter_t *) result stored here
287 vlib_get_combined_counter (vlib_combined_counter_main_t * cm,
288 u32 index, vlib_counter_t * result)
290 vlib_mini_counter_t *my_minis, *mini;
291 vlib_counter_t *maxi;
297 for (i = 0; i < vec_len (cm->minis); i++)
299 my_minis = cm->minis[i];
301 mini = vec_elt_at_index (my_minis, index);
302 result->packets += mini->packets;
303 result->bytes += mini->bytes;
306 maxi = vec_elt_at_index (cm->maxi, index);
307 result->packets += maxi->packets;
308 result->bytes += maxi->bytes;
310 if (index < vec_len (cm->value_at_last_clear))
311 vlib_counter_sub (result, &cm->value_at_last_clear[index]);
314 /** Clear a combined counter
315 Clears the set of per-thread u16 counters, and the shared vlib_counter_t
317 @param cm - (vlib_combined_counter_main_t *) combined counter main pointer
318 @param index - (u32) index of the counter to clear
321 vlib_zero_combined_counter (vlib_combined_counter_main_t * cm, u32 index)
323 vlib_mini_counter_t *mini, *my_minis;
326 for (i = 0; i < vec_len (cm->minis); i++)
328 my_minis = cm->minis[i];
330 mini = vec_elt_at_index (my_minis, index);
335 vlib_counter_zero (&cm->maxi[index]);
336 if (index < vec_len (cm->value_at_last_clear))
337 vlib_counter_zero (&cm->value_at_last_clear[index]);
340 /** validate a simple counter
341 @param cm - (vlib_simple_counter_main_t *) pointer to the counter collection
342 @param index - (u32) index of the counter to validate
345 void vlib_validate_simple_counter (vlib_simple_counter_main_t * cm,
347 /** validate a combined counter
348 @param cm - (vlib_combined_counter_main_t *) pointer to the counter
350 @param index - (u32) index of the counter to validate
353 void vlib_validate_combined_counter (vlib_combined_counter_main_t * cm,
356 /** Obtain the number of simple or combined counters allocated.
357 A macro which reduces to to vec_len(cm->maxi), the answer in either
360 @param cm - (vlib_simple_counter_main_t) or
361 (vlib_combined_counter_main_t) the counter collection to interrogate
362 @returns vec_len(cm->maxi)
364 #define vlib_counter_len(cm) vec_len((cm)->maxi)
366 serialize_function_t serialize_vlib_simple_counter_main,
367 unserialize_vlib_simple_counter_main;
368 serialize_function_t serialize_vlib_combined_counter_main,
369 unserialize_vlib_combined_counter_main;
371 #endif /* included_vlib_counter_h */
374 * fd.io coding-style-patch-verification: ON
377 * eval: (c-set-style "gnu")