GNUnet 0.22.0
load.c
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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2010, 2013 GNUnet e.V.
4
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
9
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
14
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17
18 SPDX-License-Identifier: AGPL3.0-or-later
19 */
20
27#include "gnunet_load_lib.h"
28
29
30#define LOG(kind, ...) GNUNET_log_from (kind, "util-load", __VA_ARGS__)
31
36{
41
46
53
60
65
72
78 double load;
79};
80
81
82static void
84{
86 unsigned int n;
87
88 if (load->autodecline.rel_value_us ==
90 return;
92 if (delta.rel_value_us < load->autodecline.rel_value_us)
93 return;
94 if (0 == load->autodecline.rel_value_us)
95 {
96 load->runavg_delay = 0.0;
97 load->load = 0;
98 return;
99 }
100 n = delta.rel_value_us / load->autodecline.rel_value_us;
101 if (n > 16)
102 {
103 load->runavg_delay = 0.0;
104 load->load = 0;
105 return;
106 }
107 while (n > 0)
108 {
109 n--;
110 load->runavg_delay = (load->runavg_delay * 7.0) / 8.0;
111 }
112}
113
114
123struct GNUNET_LOAD_Value *
125{
126 struct GNUNET_LOAD_Value *ret;
127
129 ret->autodecline = autodecline;
130 ret->last_update = GNUNET_TIME_absolute_get ();
131 return ret;
132}
133
134
141void
144{
146 load->autodecline = autodecline;
147}
148
149
155static void
157{
158 double stddev;
159 double avgdel;
160 double sum_val_i;
161 double n;
162 double nm1;
163
164 if (load->cummulative_request_count <= 1)
165 return;
166 /* calculate std dev of latency; we have for n values of "i" that:
167 *
168 * avg = (sum val_i) / n
169 * stddev = (sum (val_i - avg)^2) / (n-1)
170 * = (sum (val_i^2 - 2 avg val_i + avg^2) / (n-1)
171 * = (sum (val_i^2) - 2 avg sum (val_i) + n * avg^2) / (n-1)
172 */sum_val_i = (double) load->cummulative_delay;
173 n = ((double) load->cummulative_request_count);
174 nm1 = n - 1.0;
175 avgdel = sum_val_i / n;
176 stddev =
177 (((double) load->cummulative_squared_delay) - 2.0 * avgdel * sum_val_i
178 + n * avgdel * avgdel) / nm1;
179 if (stddev <= 0)
180 stddev = 0.01; /* must have been rounding error or zero; prevent division by zero */
181 /* now calculate load based on how far out we are from
182 * std dev; or if we are below average, simply assume load zero */
183 if (load->runavg_delay < avgdel)
184 load->load = 0.0;
185 else
186 load->load = (load->runavg_delay - avgdel) / stddev;
187}
188
189
199double
201{
204 return load->load;
205}
206
207
214double
216{
217 double n;
218 double sum_val_i;
219
221 if (load->cummulative_request_count == 0)
222 return 0.0;
223 n = ((double) load->cummulative_request_count);
224 sum_val_i = (double) load->cummulative_delay;
225 return sum_val_i / n;
226}
227
228
235void
237{
238 uint32_t dv;
239
241 load->last_update = GNUNET_TIME_absolute_get ();
242 if (data > 64 * 1024)
243 {
244 /* very large */
245 load->load = 100.0;
246 return;
247 }
248 dv = (uint32_t) data;
249 load->cummulative_delay += dv;
250 load->cummulative_squared_delay += dv * dv;
251 load->cummulative_request_count++;
252 load->runavg_delay = ((load->runavg_delay * 7.0) + dv) / 8.0;
253}
254
255
256/* end of load.c */
static int ret
Final status code.
Definition: gnunet-arm.c:93
static char * data
The data to insert into the dht.
static void load()
Load persistent values from disk.
Functions related to load calculations.
void GNUNET_LOAD_value_set_decline(struct GNUNET_LOAD_Value *load, struct GNUNET_TIME_Relative autodecline)
Change the value by which the load automatically declines.
Definition: load.c:142
double GNUNET_LOAD_get_average(struct GNUNET_LOAD_Value *load)
Get the average value given to update so far.
Definition: load.c:215
struct GNUNET_LOAD_Value * GNUNET_LOAD_value_init(struct GNUNET_TIME_Relative autodecline)
Create a new load value.
Definition: load.c:124
void GNUNET_LOAD_update(struct GNUNET_LOAD_Value *load, uint64_t data)
Update the current load.
Definition: load.c:236
double GNUNET_LOAD_get_load(struct GNUNET_LOAD_Value *load)
Get the current load.
Definition: load.c:200
#define GNUNET_new(type)
Allocate a struct or union of the given type.
#define GNUNET_TIME_UNIT_FOREVER_REL
Constant used to specify "forever".
struct GNUNET_TIME_Relative GNUNET_TIME_absolute_get_duration(struct GNUNET_TIME_Absolute whence)
Get the duration of an operation as the difference of the current time and the given start time "henc...
Definition: time.c:438
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_get(void)
Get the current time.
Definition: time.c:111
static void internal_update(struct GNUNET_LOAD_Value *load)
Definition: load.c:83
static void calculate_load(struct GNUNET_LOAD_Value *load)
Recalculate our load value.
Definition: load.c:156
static struct GNUNET_TIME_Relative delta
Definition: speedup.c:36
Values we track for load calculations.
Definition: load.c:36
struct GNUNET_TIME_Relative autodecline
How fast should the load decline if no values are added?
Definition: load.c:40
uint64_t cummulative_request_count
Total number of requests included in the cumulative datastore delay values.
Definition: load.c:64
double runavg_delay
Current running average datastore delay.
Definition: load.c:71
struct GNUNET_TIME_Absolute last_update
Last time this load value was updated by an event.
Definition: load.c:45
uint64_t cummulative_squared_delay
Sum of squares of all datastore delays ever observed (in ms).
Definition: load.c:59
uint64_t cummulative_delay
Sum of all datastore delays ever observed (in ms).
Definition: load.c:52
double load
How high is the load? 0 for below average, otherwise the number of std.
Definition: load.c:78
Time for absolute times used by GNUnet, in microseconds.
Time for relative time used by GNUnet, in microseconds.
uint64_t rel_value_us
The actual value.