| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * tc_core.c TC core library. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <math.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <string.h> |
| |
| #include "utils.h" |
| #include "tc_core.h" |
| |
| int tc_setup_estimator(unsigned int A, unsigned int time_const, struct tc_estimator *est) |
| { |
| for (est->interval = 0; est->interval <= 5; est->interval++) { |
| if (A <= (1<<est->interval)*(TIME_UNITS_PER_SEC/4)) |
| break; |
| } |
| if (est->interval > 5) |
| return -1; |
| est->interval -= 2; |
| for (est->ewma_log = 1; est->ewma_log < 32; est->ewma_log++) { |
| double w = 1.0 - 1.0/(1<<est->ewma_log); |
| |
| if (A/(-log(w)) > time_const) |
| break; |
| } |
| est->ewma_log--; |
| if (est->ewma_log == 0 || est->ewma_log >= 31) |
| return -1; |
| return 0; |
| } |