cloudflared-mirror/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups.go

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// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// +build linux
package cgroups
const (
// _cgroupFSType is the Linux CGroup file system type used in
// `/proc/$PID/mountinfo`.
_cgroupFSType = "cgroup"
// _cgroupSubsysCPU is the CPU CGroup subsystem.
_cgroupSubsysCPU = "cpu"
// _cgroupSubsysCPUAcct is the CPU accounting CGroup subsystem.
_cgroupSubsysCPUAcct = "cpuacct"
// _cgroupSubsysCPUSet is the CPUSet CGroup subsystem.
_cgroupSubsysCPUSet = "cpuset"
// _cgroupSubsysMemory is the Memory CGroup subsystem.
_cgroupSubsysMemory = "memory"
// _cgroupCPUCFSQuotaUsParam is the file name for the CGroup CFS quota
// parameter.
_cgroupCPUCFSQuotaUsParam = "cpu.cfs_quota_us"
// _cgroupCPUCFSPeriodUsParam is the file name for the CGroup CFS period
// parameter.
_cgroupCPUCFSPeriodUsParam = "cpu.cfs_period_us"
)
const (
_procPathCGroup = "/proc/self/cgroup"
_procPathMountInfo = "/proc/self/mountinfo"
)
// CGroups is a map that associates each CGroup with its subsystem name.
type CGroups map[string]*CGroup
// NewCGroups returns a new *CGroups from given `mountinfo` and `cgroup` files
// under for some process under `/proc` file system (see also proc(5) for more
// information).
func NewCGroups(procPathMountInfo, procPathCGroup string) (CGroups, error) {
cgroupSubsystems, err := parseCGroupSubsystems(procPathCGroup)
if err != nil {
return nil, err
}
cgroups := make(CGroups)
newMountPoint := func(mp *MountPoint) error {
if mp.FSType != _cgroupFSType {
return nil
}
for _, opt := range mp.SuperOptions {
subsys, exists := cgroupSubsystems[opt]
if !exists {
continue
}
cgroupPath, err := mp.Translate(subsys.Name)
if err != nil {
return err
}
cgroups[opt] = NewCGroup(cgroupPath)
}
return nil
}
if err := parseMountInfo(procPathMountInfo, newMountPoint); err != nil {
return nil, err
}
return cgroups, nil
}
// NewCGroupsForCurrentProcess returns a new *CGroups instance for the current
// process.
func NewCGroupsForCurrentProcess() (CGroups, error) {
return NewCGroups(_procPathMountInfo, _procPathCGroup)
}
// CPUQuota returns the CPU quota applied with the CPU cgroup controller.
// It is a result of `cpu.cfs_quota_us / cpu.cfs_period_us`. If the value of
// `cpu.cfs_quota_us` was not set (-1), the method returns `(-1, nil)`.
func (cg CGroups) CPUQuota() (float64, bool, error) {
cpuCGroup, exists := cg[_cgroupSubsysCPU]
if !exists {
return -1, false, nil
}
cfsQuotaUs, err := cpuCGroup.readInt(_cgroupCPUCFSQuotaUsParam)
if defined := cfsQuotaUs > 0; err != nil || !defined {
return -1, defined, err
}
cfsPeriodUs, err := cpuCGroup.readInt(_cgroupCPUCFSPeriodUsParam)
if err != nil {
return -1, false, err
}
return float64(cfsQuotaUs) / float64(cfsPeriodUs), true, nil
}