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comparison vendor/golang.org/x/sys/unix/affinity_linux.go @ 66:787b5ee0289d draft

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Use vendored modules Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>
author yakumo.izuru
date Sun, 23 Jul 2023 13:18:53 +0000
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65:6d985efa0f7a 66:787b5ee0289d
1 // Copyright 2018 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 // CPU affinity functions
6
7 package unix
8
9 import (
10 "math/bits"
11 "unsafe"
12 )
13
14 const cpuSetSize = _CPU_SETSIZE / _NCPUBITS
15
16 // CPUSet represents a CPU affinity mask.
17 type CPUSet [cpuSetSize]cpuMask
18
19 func schedAffinity(trap uintptr, pid int, set *CPUSet) error {
20 _, _, e := RawSyscall(trap, uintptr(pid), uintptr(unsafe.Sizeof(*set)), uintptr(unsafe.Pointer(set)))
21 if e != 0 {
22 return errnoErr(e)
23 }
24 return nil
25 }
26
27 // SchedGetaffinity gets the CPU affinity mask of the thread specified by pid.
28 // If pid is 0 the calling thread is used.
29 func SchedGetaffinity(pid int, set *CPUSet) error {
30 return schedAffinity(SYS_SCHED_GETAFFINITY, pid, set)
31 }
32
33 // SchedSetaffinity sets the CPU affinity mask of the thread specified by pid.
34 // If pid is 0 the calling thread is used.
35 func SchedSetaffinity(pid int, set *CPUSet) error {
36 return schedAffinity(SYS_SCHED_SETAFFINITY, pid, set)
37 }
38
39 // Zero clears the set s, so that it contains no CPUs.
40 func (s *CPUSet) Zero() {
41 for i := range s {
42 s[i] = 0
43 }
44 }
45
46 func cpuBitsIndex(cpu int) int {
47 return cpu / _NCPUBITS
48 }
49
50 func cpuBitsMask(cpu int) cpuMask {
51 return cpuMask(1 << (uint(cpu) % _NCPUBITS))
52 }
53
54 // Set adds cpu to the set s.
55 func (s *CPUSet) Set(cpu int) {
56 i := cpuBitsIndex(cpu)
57 if i < len(s) {
58 s[i] |= cpuBitsMask(cpu)
59 }
60 }
61
62 // Clear removes cpu from the set s.
63 func (s *CPUSet) Clear(cpu int) {
64 i := cpuBitsIndex(cpu)
65 if i < len(s) {
66 s[i] &^= cpuBitsMask(cpu)
67 }
68 }
69
70 // IsSet reports whether cpu is in the set s.
71 func (s *CPUSet) IsSet(cpu int) bool {
72 i := cpuBitsIndex(cpu)
73 if i < len(s) {
74 return s[i]&cpuBitsMask(cpu) != 0
75 }
76 return false
77 }
78
79 // Count returns the number of CPUs in the set s.
80 func (s *CPUSet) Count() int {
81 c := 0
82 for _, b := range s {
83 c += bits.OnesCount64(uint64(b))
84 }
85 return c
86 }