gotosocial/vendor/codeberg.org/gruf/go-runners/context.go

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2022-01-03 16:37:09 +00:00
package runners
import (
"context"
"time"
)
// closedctx is an always closed context.
var closedctx = func() context.Context {
ctx := make(cancelctx)
close(ctx)
return ctx
}()
// Closed returns an always closed context.
func Closed() context.Context {
return closedctx
}
2022-01-03 16:37:09 +00:00
// ContextWithCancel returns a new context.Context impl with cancel.
func ContextWithCancel() (context.Context, context.CancelFunc) {
ctx := make(cancelctx)
return ctx, func() { close(ctx) }
}
// cancelctx is the simplest possible cancellable context.
type cancelctx (chan struct{})
func (cancelctx) Deadline() (time.Time, bool) {
return time.Time{}, false
}
func (ctx cancelctx) Done() <-chan struct{} {
return ctx
}
func (ctx cancelctx) Err() error {
select {
case <-ctx:
return context.Canceled
default:
return nil
}
}
func (cancelctx) Value(key interface{}) interface{} {
return nil
}
func (ctx cancelctx) String() string {
var state string
select {
case <-ctx:
state = "closed"
default:
state = "open"
}
return "cancelctx{state:" + state + "}"
}
func (ctx cancelctx) GoString() string {
return "runners." + ctx.String()
}