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 | } | ||