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Diffstat (limited to '')
-rw-r--r-- | dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/affinity_linux.go | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/affinity_linux.go b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/affinity_linux.go new file mode 100644 index 0000000..6e5c81a --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/sys@v0.1.0/unix/affinity_linux.go @@ -0,0 +1,86 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// CPU affinity functions + +package unix + +import ( + "math/bits" + "unsafe" +) + +const cpuSetSize = _CPU_SETSIZE / _NCPUBITS + +// CPUSet represents a CPU affinity mask. +type CPUSet [cpuSetSize]cpuMask + +func schedAffinity(trap uintptr, pid int, set *CPUSet) error { + _, _, e := RawSyscall(trap, uintptr(pid), uintptr(unsafe.Sizeof(*set)), uintptr(unsafe.Pointer(set))) + if e != 0 { + return errnoErr(e) + } + return nil +} + +// SchedGetaffinity gets the CPU affinity mask of the thread specified by pid. +// If pid is 0 the calling thread is used. +func SchedGetaffinity(pid int, set *CPUSet) error { + return schedAffinity(SYS_SCHED_GETAFFINITY, pid, set) +} + +// SchedSetaffinity sets the CPU affinity mask of the thread specified by pid. +// If pid is 0 the calling thread is used. +func SchedSetaffinity(pid int, set *CPUSet) error { + return schedAffinity(SYS_SCHED_SETAFFINITY, pid, set) +} + +// Zero clears the set s, so that it contains no CPUs. +func (s *CPUSet) Zero() { + for i := range s { + s[i] = 0 + } +} + +func cpuBitsIndex(cpu int) int { + return cpu / _NCPUBITS +} + +func cpuBitsMask(cpu int) cpuMask { + return cpuMask(1 << (uint(cpu) % _NCPUBITS)) +} + +// Set adds cpu to the set s. +func (s *CPUSet) Set(cpu int) { + i := cpuBitsIndex(cpu) + if i < len(s) { + s[i] |= cpuBitsMask(cpu) + } +} + +// Clear removes cpu from the set s. +func (s *CPUSet) Clear(cpu int) { + i := cpuBitsIndex(cpu) + if i < len(s) { + s[i] &^= cpuBitsMask(cpu) + } +} + +// IsSet reports whether cpu is in the set s. +func (s *CPUSet) IsSet(cpu int) bool { + i := cpuBitsIndex(cpu) + if i < len(s) { + return s[i]&cpuBitsMask(cpu) != 0 + } + return false +} + +// Count returns the number of CPUs in the set s. +func (s *CPUSet) Count() int { + c := 0 + for _, b := range s { + c += bits.OnesCount64(uint64(b)) + } + return c +} |