1/* ==========================================================================
2 * setcpuaffinity.c - Linux/BSD setcpuaffinity.
3 * --------------------------------------------------------------------------
4 * Copyright (C) 2020 zhenwei pi
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sublicense, and/or sell copies of the Software, and to permit
11 * persons to whom the Software is furnished to do so, subject to the
12 * following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
20 * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
21 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
22 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
23 * USE OR OTHER DEALINGS IN THE SOFTWARE.
24 * ==========================================================================
25 */
26#ifndef _GNU_SOURCE
27#define _GNU_SOURCE
28#endif
29#include <stdlib.h>
30#include <string.h>
31#include <ctype.h>
32#ifdef __linux__
33#include <sched.h>
34#endif
35#ifdef __FreeBSD__
36#include <sys/param.h>
37#include <sys/cpuset.h>
38#endif
39#ifdef __DragonFly__
40#include <pthread.h>
41#include <pthread_np.h>
42#endif
43#ifdef __NetBSD__
44#include <pthread.h>
45#include <sched.h>
46#endif
47#include "config.h"
48
49#ifdef USE_SETCPUAFFINITY
50static const char *next_token(const char *q, int sep) {
51 if (q)
52 q = strchr(q, sep);
53 if (q)
54 q++;
55
56 return q;
57}
58
59static int next_num(const char *str, char **end, int *result) {
60 if (!str || *str == '\0' || !isdigit(*str))
61 return -1;
62
63 *result = strtoul(str, end, 10);
64 if (str == *end)
65 return -1;
66
67 return 0;
68}
69
70/* set current thread cpu affinity to cpu list, this function works like
71 * taskset command (actually cpulist parsing logic reference to util-linux).
72 * example of this function: "0,2,3", "0,2-3", "0-20:2". */
73void setcpuaffinity(const char *cpulist) {
74 const char *p, *q;
75 char *end = NULL;
76#ifdef __linux__
77 cpu_set_t cpuset;
78#endif
79#if defined (__FreeBSD__) || defined(__DragonFly__)
80 cpuset_t cpuset;
81#endif
82#ifdef __NetBSD__
83 cpuset_t *cpuset;
84#endif
85
86 if (!cpulist)
87 return;
88
89#ifndef __NetBSD__
90 CPU_ZERO(&cpuset);
91#else
92 cpuset = cpuset_create();
93#endif
94
95 q = cpulist;
96 while (p = q, q = next_token(q, ','), p) {
97 int a, b, s;
98 const char *c1, *c2;
99
100 if (next_num(p, &end, &a) != 0)
101 return;
102
103 b = a;
104 s = 1;
105 p = end;
106
107 c1 = next_token(p, '-');
108 c2 = next_token(p, ',');
109
110 if (c1 != NULL && (c2 == NULL || c1 < c2)) {
111 if (next_num(c1, &end, &b) != 0)
112 return;
113
114 c1 = end && *end ? next_token(end, ':') : NULL;
115 if (c1 != NULL && (c2 == NULL || c1 < c2)) {
116 if (next_num(c1, &end, &s) != 0)
117 return;
118
119 if (s == 0)
120 return;
121 }
122 }
123
124 if ((a > b))
125 return;
126
127 while (a <= b) {
128#ifndef __NetBSD__
129 CPU_SET(a, &cpuset);
130#else
131 cpuset_set(a, cpuset);
132#endif
133 a += s;
134 }
135 }
136
137 if (end && *end)
138 return;
139
140#ifdef __linux__
141 sched_setaffinity(0, sizeof(cpuset), &cpuset);
142#endif
143#ifdef __FreeBSD__
144 cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID, -1, sizeof(cpuset), &cpuset);
145#endif
146#ifdef __DragonFly__
147 pthread_setaffinity_np(pthread_self(), sizeof(cpuset), &cpuset);
148#endif
149#ifdef __NetBSD__
150 pthread_setaffinity_np(pthread_self(), cpuset_size(cpuset), cpuset);
151 cpuset_destroy(cpuset);
152#endif
153}
154
155#endif /* USE_SETCPUAFFINITY */
156