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cg: more golint

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Vincent Batts 2016-11-29 11:38:04 -05:00
parent 727ac7a93b
commit 8d4b8d0ebb
1 changed files with 64 additions and 63 deletions
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127
cg.go
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@ -16,12 +16,26 @@ import (
"unsafe" "unsafe"
) )
// Init initializes libcgroup. Information about mounted hierarchies are
// examined and cached internally (just what's mounted where, not the groups
// themselves).
func Init() error {
return _err(C.cgroup_init())
}
// Cgroup is the structure describing one or more control groups. The structure // Cgroup is the structure describing one or more control groups. The structure
// is opaque to applications. // is opaque to applications.
type Cgroup struct { type Cgroup struct {
g *C.struct_cgroup g *C.struct_cgroup
} }
// NewCgroup allocates a new cgroup structure. This function itself does not create new
// control group in kernel, only new <tt>struct cgroup</tt> inside libcgroup!
// The caller would still need to Create() or similar to create this group in the kernel.
//
// @param name Path to the group, relative from root group. Use @c "/" or @c "."
// for the root group itself and @c "/foo/bar/baz" or @c "foo/bar/baz" for
// subgroups.
func NewCgroup(name string) Cgroup { func NewCgroup(name string) Cgroup {
cg := Cgroup{ cg := Cgroup{
C.cgroup_new_cgroup(C.CString(name)), C.cgroup_new_cgroup(C.CString(name)),
@ -30,33 +44,30 @@ func NewCgroup(name string) Cgroup {
return cg return cg
} }
func (cg *Cgroup) AddController(name string) Controller { // AddController attaches a new controller to cgroup. This function just
return Controller{ // modifies internal libcgroup structure, not the kernel control group.
func (cg *Cgroup) AddController(name string) *Controller {
return &Controller{
C.cgroup_add_controller(cg.g, C.CString(name)), C.cgroup_add_controller(cg.g, C.CString(name)),
} }
} }
func (cg Cgroup) GetController(name string) Controller {
return Controller{ // GetController returns appropriate controller from given group.
// The controller must be added before using AddController() or loaded
// from kernel using GetCgroup().
func (cg Cgroup) GetController(name string) *Controller {
return &Controller{
C.cgroup_get_controller(cg.g, C.CString(name)), C.cgroup_get_controller(cg.g, C.CString(name)),
} }
} }
func freeCgroupThings(cg *Cgroup) { func freeCgroupThings(cg *Cgroup) {
freeCgroup(*cg)
freeControllers(*cg)
}
func freeCgroup(cg Cgroup) {
C.cgroup_free(&cg.g) C.cgroup_free(&cg.g)
}
func freeControllers(cg Cgroup) {
C.cgroup_free_controllers(cg.g) C.cgroup_free_controllers(cg.g)
} }
/* /*
Physically create a control group in kernel. The group is created in all Create a control group in kernel. The group is created in all
hierarchies, which cover controllers added by Cgroup.AddController(). hierarchies, which cover controllers added by Cgroup.AddController().
TODO correct docs for golang implementation TODO correct docs for golang implementation
@ -67,24 +78,21 @@ permissions set by cgroup_set_permissions.
foo = cgroup.NewCgroup("foo) foo = cgroup.NewCgroup("foo)
foo.Create() foo.Create()
*/ */
func (cg Cgroup) Create() error { func (cg Cgroup) Create() error {
return _err(C.cgroup_create_cgroup(cg.g, C.int(0))) return _err(C.cgroup_create_cgroup(cg.g, C.int(0)))
} }
/* // CreateIgnoreOwnership is the same as Create(), but all errors are ignored
Same as Create(), but all errors are ignored when setting // when setting owner of the group and/or its tasks file.
owner of the group and/or its tasks file.
*/
func (cg Cgroup) CreateIgnoreOwnership() error { func (cg Cgroup) CreateIgnoreOwnership() error {
return _err(C.cgroup_create_cgroup(cg.g, C.int(1))) return _err(C.cgroup_create_cgroup(cg.g, C.int(1)))
} }
/* /*
Physically create new control group in kernel, with all parameters and values CreateFromParent creates new control group in kernel, with all parameters and
copied from its parent group. The group is created in all hierarchies, where values copied from its parent group. The group is created in all hierarchies,
the parent group exists. I.e. following code creates subgroup in all where the parent group exists. I.e. following code creates subgroup in all
hierarchies, because all of them have root (=parent) group. hierarchies, because all of them have root (=parent) group.
foo = cgroup.NewCgroup("foo) foo = cgroup.NewCgroup("foo)
@ -95,21 +103,17 @@ func (cg Cgroup) CreateFromParent() error {
return _err(C.cgroup_create_cgroup_from_parent(cg.g, C.int(0))) return _err(C.cgroup_create_cgroup_from_parent(cg.g, C.int(0)))
} }
/* // CreateFromParentIgnoreOwnership is the same as CreateFromParent(), but all
Same as CreateFromParent(), but all errors are ignored when setting // errors are ignored when setting owner of the group and/or its tasks file.
owner of the group and/or its tasks file.
*/
func (cg Cgroup) CreateFromParentIgnoreOwnership() error { func (cg Cgroup) CreateFromParentIgnoreOwnership() error {
return _err(C.cgroup_create_cgroup_from_parent(cg.g, C.int(1))) return _err(C.cgroup_create_cgroup_from_parent(cg.g, C.int(1)))
} }
/* // Modify a control group in kernel. All parameters added by cgroup_add_value_
Physically modify a control group in kernel. All parameters added by // or cgroup_set_value_ are written. Currently it's not possible to change and
cgroup_add_value_ or cgroup_set_value_ are written. // owner of a group.
Currently it's not possible to change and owner of a group. //
// TODO correct docs for golang implementation
TODO correct docs for golang implementation
*/
func (cg Cgroup) Modify() error { func (cg Cgroup) Modify() error {
return _err(C.cgroup_modify_cgroup(cg.g)) return _err(C.cgroup_modify_cgroup(cg.g))
} }
@ -129,18 +133,19 @@ func (cg Cgroup) Delete() error {
return _err(C.cgroup_delete_cgroup(cg.g, C.int(0))) return _err(C.cgroup_delete_cgroup(cg.g, C.int(0)))
} }
/* // DeleteIgnoreMigration is the same as Delete(), but ignores errors when
DeleteIgnoreMigration is the same as Delete(), but ignores errors when migrating. // migrating.
*/
func (cg Cgroup) DeleteIgnoreMigration() error { func (cg Cgroup) DeleteIgnoreMigration() error {
return _err(C.cgroup_delete_cgroup(cg.g, C.int(1))) return _err(C.cgroup_delete_cgroup(cg.g, C.int(1)))
} }
/* /*
DeleteExt removes a control group from kernel. DeleteExt removes a control group from kernel.
All tasks are automatically moved to parent group. All tasks are automatically moved to parent group.
If DeleteIgnoreMigration flag is used, the errors that occurred If DeleteIgnoreMigration flag is used, the errors that occurred
during the task movement are ignored. during the task movement are ignored.
DeleteRecursive flag specifies that all subgroups should be removed DeleteRecursive flag specifies that all subgroups should be removed
too. If root group is being removed with this flag specified, all subgroups too. If root group is being removed with this flag specified, all subgroups
are removed but the root group itself is left undeleted. are removed but the root group itself is left undeleted.
@ -167,7 +172,12 @@ func (cg Cgroup) Get() error {
} }
type ( type (
// UID is the user ID type.
// cgroup.UID(0)
UID C.uid_t UID C.uid_t
// GID is the group ID type.
// cgroup.GID(0)
GID C.gid_t GID C.gid_t
) )
@ -212,33 +222,34 @@ func (cg Cgroup) GetUIDGID() (tasksUID UID, tasksGID GID, controlUID UID, contro
} }
const ( const (
// Uninitialized file/directory permissions used for task/control files. // NoPerms is uninitialized file/directory permissions used for task/control files.
NO_PERMS = C.NO_PERMS NoPerms = C.NO_PERMS
// Uninitialized UID/GID used for task/control files. // NoUIDGID is uninitialized UID/GID used for task/control files.
NO_UID_GID = C.NO_UID_GID NoUIDGID = C.NO_UID_GID
) )
// Mode is the file permissions. Like used in SetPermissions()
type Mode C.mode_t type Mode C.mode_t
/* /*
SetPermissions stores given file permissions of the group's control and tasks files SetPermissions stores given file permissions of the group's control and tasks files
into the cgroup data structure. Use NO_PERMS if permissions shouldn't into the cgroup data structure. Use NoPerms if permissions shouldn't
be changed or a value which applicable to chmod(2). Please note that be changed or a value which applicable to chmod(2). Please note that
the given permissions are masked with the file owner's permissions. the given permissions are masked with the file owner's permissions.
For example if a control file has permissions 640 and control_fperm is For example if a control file has permissions 640 and controlFilePerm is
471 the result will be 460. 471 the result will be 460.
control_dperm Directory permission for the group. controlDirPerm Directory permission for the group.
control_fperm File permission for the control files. controlFilePerm File permission for the control files.
task_fperm File permissions for task file. taskFilePerm File permissions for task file.
g := cgroup.NewCgroup("foo") g := cgroup.NewCgroup("foo")
g.SetPermissions(cgroup.Mode(0777), cgroup.Mode(0777), cgroup.Mode(0777)) g.SetPermissions(cgroup.Mode(0777), cgroup.Mode(0777), cgroup.Mode(0777))
*/ */
func (cg Cgroup) SetPermissions(control_dperm, control_fperm, task_fperm Mode) { func (cg Cgroup) SetPermissions(controlDirPerm, controlFilePerm, taskFilePerm Mode) {
C.cgroup_set_permissions(cg.g, C.mode_t(control_dperm), C.cgroup_set_permissions(cg.g, C.mode_t(controlDirPerm),
C.mode_t(control_fperm), C.mode_t(task_fperm)) C.mode_t(controlFilePerm), C.mode_t(taskFilePerm))
} }
// CopyCgroup copies all controllers, parameters and their values. All existing // CopyCgroup copies all controllers, parameters and their values. All existing
@ -300,10 +311,8 @@ func (c Controller) GetValueBool(name string) (value bool, err error) {
return bool(v), err return bool(v), err
} }
/* // SetValueString sets a parameter value in @c libcgroup internal structures.
Set a parameter value in @c libcgroup internal structures. // Use Cgroup.Modify() or Cgroup.Create() to write it to kernel.
Use Cgroup.Modify() or Cgroup.Create() to write it to kernel.
*/
func (c Controller) SetValueString(name, value string) error { func (c Controller) SetValueString(name, value string) error {
return _err(C.cgroup_set_value_string(c.c, C.CString(name), C.CString(value))) return _err(C.cgroup_set_value_string(c.c, C.CString(name), C.CString(value)))
} }
@ -331,13 +340,6 @@ func CompareControllers(a, b Controller) error {
return _err(C.cgroup_compare_controllers(a.c, b.c)) return _err(C.cgroup_compare_controllers(a.c, b.c))
} }
// Init initializes libcgroup. Information about mounted hierarchies are
// examined and cached internally (just what's mounted where, not the groups
// themselves).
func Init() error {
return _err(C.cgroup_init())
}
// LoadConfig file and mount and create control groups described there. // LoadConfig file and mount and create control groups described there.
// See cgconfig.conf(5) man page for format of the file. // See cgconfig.conf(5) man page for format of the file.
func LoadConfig(filename string) error { func LoadConfig(filename string) error {
@ -385,8 +387,8 @@ cgroup_config_load_config() calls. If a config file contains a 'default {}'
section, the default permissions from the config file is then used. section, the default permissions from the config file is then used.
Use cgroup_new_cgroup() to create a dummy group and cgroup_set_uid_gid() and Use cgroup_new_cgroup() to create a dummy group and cgroup_set_uid_gid() and
cgroup_set_permissions() to set its permissions. Use NO_UID_GID instead of cgroup_set_permissions() to set its permissions. Use NoUIDGID instead of
GID/UID and NO_PERMS instead of file/directory permissions to let kernel GID/UID and NoPerms instead of file/directory permissions to let kernel
decide the default permissions where you don't want specific user and/or decide the default permissions where you don't want specific user and/or
permissions. Kernel then uses current user/group and permissions from umask permissions. Kernel then uses current user/group and permissions from umask
then. then.
@ -515,9 +517,8 @@ func GetAllControllers() (controllers []ControllerData, err error) {
} }
return controllers, err return controllers, err
} else {
controllers = append(controllers, fromCControllerData(cd))
} }
controllers = append(controllers, fromCControllerData(cd))
} }
return controllers, nil return controllers, nil
} }