diff options
Diffstat (limited to 'vendor/golang.org/x/sys/unix/affinity_linux.go')
-rw-r--r-- | vendor/golang.org/x/sys/unix/affinity_linux.go | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/unix/affinity_linux.go b/vendor/golang.org/x/sys/unix/affinity_linux.go new file mode 100644 index 0000000..6e5c81a --- /dev/null +++ b/vendor/golang.org/x/sys/unix/affinity_linux.go | |||
@@ -0,0 +1,86 @@ | |||
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 | } | ||