diff options
Diffstat (limited to 'vendor/go.uber.org/automaxprocs/internal/cgroups')
7 files changed, 693 insertions, 0 deletions
diff --git a/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroup.go b/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroup.go new file mode 100644 index 000000000..fe4ecf561 --- /dev/null +++ b/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroup.go @@ -0,0 +1,79 @@ +// 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. + +//go:build linux +// +build linux + +package cgroups + +import ( + "bufio" + "io" + "os" + "path/filepath" + "strconv" +) + +// CGroup represents the data structure for a Linux control group. +type CGroup struct { + path string +} + +// NewCGroup returns a new *CGroup from a given path. +func NewCGroup(path string) *CGroup { + return &CGroup{path: path} +} + +// Path returns the path of the CGroup*. +func (cg *CGroup) Path() string { + return cg.path +} + +// ParamPath returns the path of the given cgroup param under itself. +func (cg *CGroup) ParamPath(param string) string { + return filepath.Join(cg.path, param) +} + +// readFirstLine reads the first line from a cgroup param file. +func (cg *CGroup) readFirstLine(param string) (string, error) { + paramFile, err := os.Open(cg.ParamPath(param)) + if err != nil { + return "", err + } + defer paramFile.Close() + + scanner := bufio.NewScanner(paramFile) + if scanner.Scan() { + return scanner.Text(), nil + } + if err := scanner.Err(); err != nil { + return "", err + } + return "", io.ErrUnexpectedEOF +} + +// readInt parses the first line from a cgroup param file as int. +func (cg *CGroup) readInt(param string) (int, error) { + text, err := cg.readFirstLine(param) + if err != nil { + return 0, err + } + return strconv.Atoi(text) +} diff --git a/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups.go b/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups.go new file mode 100644 index 000000000..e6c173197 --- /dev/null +++ b/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups.go @@ -0,0 +1,118 @@ +// 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. + +//go:build linux +// +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 +} diff --git a/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups2.go b/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups2.go new file mode 100644 index 000000000..66930d0ac --- /dev/null +++ b/vendor/go.uber.org/automaxprocs/internal/cgroups/cgroups2.go @@ -0,0 +1,151 @@ +// Copyright (c) 2022 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. + +//go:build linux +// +build linux + +package cgroups + +import ( + "bufio" + "errors" + "fmt" + "io" + "os" + "path" + "strconv" + "strings" +) + +const ( + // _cgroupv2CPUMax is the file name for the CGroup-V2 CPU max and period + // parameter. + _cgroupv2CPUMax = "cpu.max" + // _cgroupFSType is the Linux CGroup-V2 file system type used in + // `/proc/$PID/mountinfo`. + _cgroupv2FSType = "cgroup2" + + _cgroupv2MountPoint = "/sys/fs/cgroup" + + _cgroupV2CPUMaxDefaultPeriod = 100000 + _cgroupV2CPUMaxQuotaMax = "max" +) + +const ( + _cgroupv2CPUMaxQuotaIndex = iota + _cgroupv2CPUMaxPeriodIndex +) + +// ErrNotV2 indicates that the system is not using cgroups2. +var ErrNotV2 = errors.New("not using cgroups2") + +// CGroups2 provides access to cgroups data for systems using cgroups2. +type CGroups2 struct { + mountPoint string + cpuMaxFile string +} + +// NewCGroups2ForCurrentProcess builds a CGroups2 for the current process. +// +// This returns ErrNotV2 if the system is not using cgroups2. +func NewCGroups2ForCurrentProcess() (*CGroups2, error) { + return newCGroups2FromMountInfo(_procPathMountInfo) +} + +func newCGroups2FromMountInfo(mountInfoPath string) (*CGroups2, error) { + isV2, err := isCGroupV2(mountInfoPath) + if err != nil { + return nil, err + } + + if !isV2 { + return nil, ErrNotV2 + } + + return &CGroups2{ + mountPoint: _cgroupv2MountPoint, + cpuMaxFile: _cgroupv2CPUMax, + }, nil +} + +func isCGroupV2(procPathMountInfo string) (bool, error) { + var ( + isV2 bool + newMountPoint = func(mp *MountPoint) error { + isV2 = isV2 || (mp.FSType == _cgroupv2FSType && mp.MountPoint == _cgroupv2MountPoint) + return nil + } + ) + + if err := parseMountInfo(procPathMountInfo, newMountPoint); err != nil { + return false, err + } + + return isV2, nil +} + +// CPUQuota returns the CPU quota applied with the CPU cgroup2 controller. +// It is a result of reading cpu quota and period from cpu.max file. +// It will return `cpu.max / cpu.period`. If cpu.max is set to max, it returns +// (-1, false, nil) +func (cg *CGroups2) CPUQuota() (float64, bool, error) { + cpuMaxParams, err := os.Open(path.Join(cg.mountPoint, cg.cpuMaxFile)) + if err != nil { + if os.IsNotExist(err) { + return -1, false, nil + } + return -1, false, err + } + + scanner := bufio.NewScanner(cpuMaxParams) + if scanner.Scan() { + fields := strings.Fields(scanner.Text()) + if len(fields) == 0 || len(fields) > 2 { + return -1, false, fmt.Errorf("invalid format") + } + + if fields[_cgroupv2CPUMaxQuotaIndex] == _cgroupV2CPUMaxQuotaMax { + return -1, false, nil + } + + max, err := strconv.Atoi(fields[_cgroupv2CPUMaxQuotaIndex]) + if err != nil { + return -1, false, err + } + + var period int + if len(fields) == 1 { + period = _cgroupV2CPUMaxDefaultPeriod + } else { + period, err = strconv.Atoi(fields[_cgroupv2CPUMaxPeriodIndex]) + if err != nil { + return -1, false, err + } + } + + return float64(max) / float64(period), true, nil + } + + if err := scanner.Err(); err != nil { + return -1, false, err + } + + return 0, false, io.ErrUnexpectedEOF +} diff --git a/vendor/go.uber.org/automaxprocs/internal/cgroups/doc.go b/vendor/go.uber.org/automaxprocs/internal/cgroups/doc.go new file mode 100644 index 000000000..113555f63 --- /dev/null +++ b/vendor/go.uber.org/automaxprocs/internal/cgroups/doc.go @@ -0,0 +1,23 @@ +// 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. + +// Package cgroups provides utilities to access Linux control group (CGroups) +// parameters (CPU quota, for example) for a given process. +package cgroups diff --git a/vendor/go.uber.org/automaxprocs/internal/cgroups/errors.go b/vendor/go.uber.org/automaxprocs/internal/cgroups/errors.go new file mode 100644 index 000000000..94ac75a46 --- /dev/null +++ b/vendor/go.uber.org/automaxprocs/internal/cgroups/errors.go @@ -0,0 +1,52 @@ +// 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. + +//go:build linux +// +build linux + +package cgroups + +import "fmt" + +type cgroupSubsysFormatInvalidError struct { + line string +} + +type mountPointFormatInvalidError struct { + line string +} + +type pathNotExposedFromMountPointError struct { + mountPoint string + root string + path string +} + +func (err cgroupSubsysFormatInvalidError) Error() string { + return fmt.Sprintf("invalid format for CGroupSubsys: %q", err.line) +} + +func (err mountPointFormatInvalidError) Error() string { + return fmt.Sprintf("invalid format for MountPoint: %q", err.line) +} + +func (err pathNotExposedFromMountPointError) Error() string { + return fmt.Sprintf("path %q is not a descendant of mount point root %q and cannot be exposed from %q", err.path, err.root, err.mountPoint) +} diff --git a/vendor/go.uber.org/automaxprocs/internal/cgroups/mountpoint.go b/vendor/go.uber.org/automaxprocs/internal/cgroups/mountpoint.go new file mode 100644 index 000000000..2efde4c4b --- /dev/null +++ b/vendor/go.uber.org/automaxprocs/internal/cgroups/mountpoint.go @@ -0,0 +1,167 @@ +// 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. + +//go:build linux +// +build linux + +package cgroups + +import ( + "bufio" + "os" + "path/filepath" + "strconv" + "strings" +) + +const ( + _mountInfoSep = " " + _mountInfoOptsSep = "," + _mountInfoOptionalFieldsSep = "-" +) + +const ( + _miFieldIDMountID = iota + _miFieldIDParentID + _miFieldIDDeviceID + _miFieldIDRoot + _miFieldIDMountPoint + _miFieldIDOptions + _miFieldIDOptionalFields + + _miFieldCountFirstHalf +) + +const ( + _miFieldOffsetFSType = iota + _miFieldOffsetMountSource + _miFieldOffsetSuperOptions + + _miFieldCountSecondHalf +) + +const _miFieldCountMin = _miFieldCountFirstHalf + _miFieldCountSecondHalf + +// MountPoint is the data structure for the mount points in +// `/proc/$PID/mountinfo`. See also proc(5) for more information. +type MountPoint struct { + MountID int + ParentID int + DeviceID string + Root string + MountPoint string + Options []string + OptionalFields []string + FSType string + MountSource string + SuperOptions []string +} + +// NewMountPointFromLine parses a line read from `/proc/$PID/mountinfo` and +// returns a new *MountPoint. +func NewMountPointFromLine(line string) (*MountPoint, error) { + fields := strings.Split(line, _mountInfoSep) + + if len(fields) < _miFieldCountMin { + return nil, mountPointFormatInvalidError{line} + } + + mountID, err := strconv.Atoi(fields[_miFieldIDMountID]) + if err != nil { + return nil, err + } + + parentID, err := strconv.Atoi(fields[_miFieldIDParentID]) + if err != nil { + return nil, err + } + + for i, field := range fields[_miFieldIDOptionalFields:] { + if field == _mountInfoOptionalFieldsSep { + fsTypeStart := _miFieldIDOptionalFields + i + 1 + + if len(fields) != fsTypeStart+_miFieldCountSecondHalf { + return nil, mountPointFormatInvalidError{line} + } + + miFieldIDFSType := _miFieldOffsetFSType + fsTypeStart + miFieldIDMountSource := _miFieldOffsetMountSource + fsTypeStart + miFieldIDSuperOptions := _miFieldOffsetSuperOptions + fsTypeStart + + return &MountPoint{ + MountID: mountID, + ParentID: parentID, + DeviceID: fields[_miFieldIDDeviceID], + Root: fields[_miFieldIDRoot], + MountPoint: fields[_miFieldIDMountPoint], + Options: strings.Split(fields[_miFieldIDOptions], _mountInfoOptsSep), + OptionalFields: fields[_miFieldIDOptionalFields:(fsTypeStart - 1)], + FSType: fields[miFieldIDFSType], + MountSource: fields[miFieldIDMountSource], + SuperOptions: strings.Split(fields[miFieldIDSuperOptions], _mountInfoOptsSep), + }, nil + } + } + + return nil, mountPointFormatInvalidError{line} +} + +// Translate converts an absolute path inside the *MountPoint's file system to +// the host file system path in the mount namespace the *MountPoint belongs to. +func (mp *MountPoint) Translate(absPath string) (string, error) { + relPath, err := filepath.Rel(mp.Root, absPath) + + if err != nil { + return "", err + } + if relPath == ".." || strings.HasPrefix(relPath, "../") { + return "", pathNotExposedFromMountPointError{ + mountPoint: mp.MountPoint, + root: mp.Root, + path: absPath, + } + } + + return filepath.Join(mp.MountPoint, relPath), nil +} + +// parseMountInfo parses procPathMountInfo (usually at `/proc/$PID/mountinfo`) +// and yields parsed *MountPoint into newMountPoint. +func parseMountInfo(procPathMountInfo string, newMountPoint func(*MountPoint) error) error { + mountInfoFile, err := os.Open(procPathMountInfo) + if err != nil { + return err + } + defer mountInfoFile.Close() + + scanner := bufio.NewScanner(mountInfoFile) + + for scanner.Scan() { + mountPoint, err := NewMountPointFromLine(scanner.Text()) + if err != nil { + return err + } + if err := newMountPoint(mountPoint); err != nil { + return err + } + } + + return scanner.Err() +} diff --git a/vendor/go.uber.org/automaxprocs/internal/cgroups/subsys.go b/vendor/go.uber.org/automaxprocs/internal/cgroups/subsys.go new file mode 100644 index 000000000..cddc3eaec --- /dev/null +++ b/vendor/go.uber.org/automaxprocs/internal/cgroups/subsys.go @@ -0,0 +1,103 @@ +// 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. + +//go:build linux +// +build linux + +package cgroups + +import ( + "bufio" + "os" + "strconv" + "strings" +) + +const ( + _cgroupSep = ":" + _cgroupSubsysSep = "," +) + +const ( + _csFieldIDID = iota + _csFieldIDSubsystems + _csFieldIDName + _csFieldCount +) + +// CGroupSubsys represents the data structure for entities in +// `/proc/$PID/cgroup`. See also proc(5) for more information. +type CGroupSubsys struct { + ID int + Subsystems []string + Name string +} + +// NewCGroupSubsysFromLine returns a new *CGroupSubsys by parsing a string in +// the format of `/proc/$PID/cgroup` +func NewCGroupSubsysFromLine(line string) (*CGroupSubsys, error) { + fields := strings.SplitN(line, _cgroupSep, _csFieldCount) + + if len(fields) != _csFieldCount { + return nil, cgroupSubsysFormatInvalidError{line} + } + + id, err := strconv.Atoi(fields[_csFieldIDID]) + if err != nil { + return nil, err + } + + cgroup := &CGroupSubsys{ + ID: id, + Subsystems: strings.Split(fields[_csFieldIDSubsystems], _cgroupSubsysSep), + Name: fields[_csFieldIDName], + } + + return cgroup, nil +} + +// parseCGroupSubsystems parses procPathCGroup (usually at `/proc/$PID/cgroup`) +// and returns a new map[string]*CGroupSubsys. +func parseCGroupSubsystems(procPathCGroup string) (map[string]*CGroupSubsys, error) { + cgroupFile, err := os.Open(procPathCGroup) + if err != nil { + return nil, err + } + defer cgroupFile.Close() + + scanner := bufio.NewScanner(cgroupFile) + subsystems := make(map[string]*CGroupSubsys) + + for scanner.Scan() { + cgroup, err := NewCGroupSubsysFromLine(scanner.Text()) + if err != nil { + return nil, err + } + for _, subsys := range cgroup.Subsystems { + subsystems[subsys] = cgroup + } + } + + if err := scanner.Err(); err != nil { + return nil, err + } + + return subsystems, nil +} |