proposal: os/signal: enhance NotifyContext() to return a context with cancel cause

[27149chen]

Proposal Details

Currently, NotifyContext returns a context without cancel cause

func NotifyContext(parent context.Context, signals ...os.Signal) (ctx context.Context, stop context.CancelFunc) {
    ctx, cancel := context.WithCancel(parent)
    ...
}

It is better to return a cause so that we can know it is canceled by a signal
Like that:

func NotifyContext(parent context.Context, signals ...os.Signal) (ctx context.Context, stop context.CancelFunc) {
    ctx, cancel := context.WithCancelCause(parent)
    ...
}

[DeedleFake]

The cause should be a custom error implementation that gives access to the os.Signal that caused the notification.

[mateusz834]

#60756 ?

[seankhliao]

Duplicate of #60756

[27149chen]

closed due to duplicated