GoToSocial/vendor/github.com/godbus/dbus/v5/object.go
Daniele Sluijters acc333c40b
[feature] Inherit resource limits from cgroups (#1336)
When GTS is running in a container runtime which has configured CPU or
memory limits or under an init system that uses cgroups to impose CPU
and memory limits the values the Go runtime sees for GOMAXPROCS and
GOMEMLIMIT are still based on the host resources, not the cgroup.

At least for the throttling middlewares which use GOMAXPROCS to
configure their queue size, this can result in GTS running with values
too big compared to the resources that will actuall be available to it.

This introduces 2 dependencies which can pick up resource contraints
from the current cgroup and tune the Go runtime accordingly. This should
result in the different queues being appropriately sized and in general
more predictable performance. These dependencies are a no-op on
non-Linux systems or if running in a cgroup that doesn't set a limit on
CPU or memory.

The automatic tuning of GOMEMLIMIT can be disabled by either explicitly
setting GOMEMLIMIT yourself or by setting AUTOMEMLIMIT=off. The
automatic tuning of GOMAXPROCS can similarly be counteracted by setting
GOMAXPROCS yourself.
2023-01-17 20:59:04 +00:00

175 lines
5.9 KiB
Go

package dbus
import (
"context"
"errors"
"strings"
)
// BusObject is the interface of a remote object on which methods can be
// invoked.
type BusObject interface {
Call(method string, flags Flags, args ...interface{}) *Call
CallWithContext(ctx context.Context, method string, flags Flags, args ...interface{}) *Call
Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call
GoWithContext(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call
AddMatchSignal(iface, member string, options ...MatchOption) *Call
RemoveMatchSignal(iface, member string, options ...MatchOption) *Call
GetProperty(p string) (Variant, error)
StoreProperty(p string, value interface{}) error
SetProperty(p string, v interface{}) error
Destination() string
Path() ObjectPath
}
// Object represents a remote object on which methods can be invoked.
type Object struct {
conn *Conn
dest string
path ObjectPath
}
// Call calls a method with (*Object).Go and waits for its reply.
func (o *Object) Call(method string, flags Flags, args ...interface{}) *Call {
return <-o.createCall(context.Background(), method, flags, make(chan *Call, 1), args...).Done
}
// CallWithContext acts like Call but takes a context
func (o *Object) CallWithContext(ctx context.Context, method string, flags Flags, args ...interface{}) *Call {
return <-o.createCall(ctx, method, flags, make(chan *Call, 1), args...).Done
}
// AddMatchSignal subscribes BusObject to signals from specified interface,
// method (member). Additional filter rules can be added via WithMatch* option constructors.
// Note: To filter events by object path you have to specify this path via an option.
//
// Deprecated: use (*Conn) AddMatchSignal instead.
func (o *Object) AddMatchSignal(iface, member string, options ...MatchOption) *Call {
base := []MatchOption{
withMatchType("signal"),
WithMatchInterface(iface),
WithMatchMember(member),
}
options = append(base, options...)
return o.conn.BusObject().Call(
"org.freedesktop.DBus.AddMatch",
0,
formatMatchOptions(options),
)
}
// RemoveMatchSignal unsubscribes BusObject from signals from specified interface,
// method (member). Additional filter rules can be added via WithMatch* option constructors
//
// Deprecated: use (*Conn) RemoveMatchSignal instead.
func (o *Object) RemoveMatchSignal(iface, member string, options ...MatchOption) *Call {
base := []MatchOption{
withMatchType("signal"),
WithMatchInterface(iface),
WithMatchMember(member),
}
options = append(base, options...)
return o.conn.BusObject().Call(
"org.freedesktop.DBus.RemoveMatch",
0,
formatMatchOptions(options),
)
}
// Go calls a method with the given arguments asynchronously. It returns a
// Call structure representing this method call. The passed channel will
// return the same value once the call is done. If ch is nil, a new channel
// will be allocated. Otherwise, ch has to be buffered or Go will panic.
//
// If the flags include FlagNoReplyExpected, ch is ignored and a Call structure
// is returned with any error in Err and a closed channel in Done containing
// the returned Call as it's one entry.
//
// If the method parameter contains a dot ('.'), the part before the last dot
// specifies the interface on which the method is called.
func (o *Object) Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call {
return o.createCall(context.Background(), method, flags, ch, args...)
}
// GoWithContext acts like Go but takes a context
func (o *Object) GoWithContext(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call {
return o.createCall(ctx, method, flags, ch, args...)
}
func (o *Object) createCall(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call {
if ctx == nil {
panic("nil context")
}
iface := ""
i := strings.LastIndex(method, ".")
if i != -1 {
iface = method[:i]
}
method = method[i+1:]
msg := new(Message)
msg.Type = TypeMethodCall
msg.Flags = flags & (FlagNoAutoStart | FlagNoReplyExpected)
msg.Headers = make(map[HeaderField]Variant)
msg.Headers[FieldPath] = MakeVariant(o.path)
msg.Headers[FieldDestination] = MakeVariant(o.dest)
msg.Headers[FieldMember] = MakeVariant(method)
if iface != "" {
msg.Headers[FieldInterface] = MakeVariant(iface)
}
msg.Body = args
if len(args) > 0 {
msg.Headers[FieldSignature] = MakeVariant(SignatureOf(args...))
}
return o.conn.SendWithContext(ctx, msg, ch)
}
// GetProperty calls org.freedesktop.DBus.Properties.Get on the given
// object. The property name must be given in interface.member notation.
func (o *Object) GetProperty(p string) (Variant, error) {
var result Variant
err := o.StoreProperty(p, &result)
return result, err
}
// StoreProperty calls org.freedesktop.DBus.Properties.Get on the given
// object. The property name must be given in interface.member notation.
// It stores the returned property into the provided value.
func (o *Object) StoreProperty(p string, value interface{}) error {
idx := strings.LastIndex(p, ".")
if idx == -1 || idx+1 == len(p) {
return errors.New("dbus: invalid property " + p)
}
iface := p[:idx]
prop := p[idx+1:]
return o.Call("org.freedesktop.DBus.Properties.Get", 0, iface, prop).
Store(value)
}
// SetProperty calls org.freedesktop.DBus.Properties.Set on the given
// object. The property name must be given in interface.member notation.
func (o *Object) SetProperty(p string, v interface{}) error {
idx := strings.LastIndex(p, ".")
if idx == -1 || idx+1 == len(p) {
return errors.New("dbus: invalid property " + p)
}
iface := p[:idx]
prop := p[idx+1:]
return o.Call("org.freedesktop.DBus.Properties.Set", 0, iface, prop, v).Err
}
// Destination returns the destination that calls on (o *Object) are sent to.
func (o *Object) Destination() string {
return o.dest
}
// Path returns the path that calls on (o *Object") are sent to.
func (o *Object) Path() ObjectPath {
return o.path
}