76 lines
2.8 KiB
Go
76 lines
2.8 KiB
Go
// Copyright 2018-2022 Tobias Klauser
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Package numcpus provides information about the number of CPUs in the system.
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//
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// It gets the number of CPUs (online, offline, present, possible or kernel
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// maximum) on Linux, Darwin, FreeBSD, NetBSD, OpenBSD, DragonflyBSD,
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// Solaris/Illumos or Windows systems.
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//
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// On Linux, the information is retrieved by reading the corresponding CPU
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// topology files in /sys/devices/system/cpu.
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//
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// On BSD systems, the information is retrieved using the hw.ncpu and
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// hw.ncpuonline sysctls, if supported.
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//
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// On Windows systems, the information is retrieved using the
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// GetActiveProcessorCount and GetMaximumProcessorCount functions, respectively.
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//
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// Not all functions are supported on Darwin, FreeBSD, NetBSD, OpenBSD,
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// DragonflyBSD, Solaris/Illumos and Windows. ErrNotSupported is returned in
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// case a function is not supported on a particular platform.
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package numcpus
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import "errors"
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// ErrNotSupported is the error returned when the function is not supported.
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var ErrNotSupported = errors.New("function not supported")
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// GetConfigured returns the number of CPUs configured on the system. This
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// function should return the same value as `getconf _SC_NPROCESSORS_CONF` on a
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// unix system.
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func GetConfigured() (int, error) {
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return getConfigured()
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}
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// GetKernelMax returns the maximum number of CPUs allowed by the kernel
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// configuration. This function is only supported on Linux and Windows systems.
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func GetKernelMax() (int, error) {
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return getKernelMax()
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}
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// GetOffline returns the number of offline CPUs, i.e. CPUs that are not online
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// because they have been hotplugged off or exceed the limit of CPUs allowed by
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// the kernel configuration (see GetKernelMax). This function is only supported
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// on Linux systems.
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func GetOffline() (int, error) {
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return getOffline()
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}
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// GetOnline returns the number of CPUs that are online and being scheduled.
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func GetOnline() (int, error) {
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return getOnline()
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}
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// GetPossible returns the number of possible CPUs, i.e. CPUs that
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// have been allocated resources and can be brought online if they are present.
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func GetPossible() (int, error) {
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return getPossible()
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}
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// GetPresent returns the number of CPUs present in the system.
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func GetPresent() (int, error) {
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return getPresent()
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}
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