67
value T,
68
err error,
70
>
// cannot directly set status to `ready`, to prevent data race in case multiple `Get` occurs
71
>
// instead set status to `setting` to prevent concurrent completion of this future
72
>
if !atomic.CompareAndSwapInt32(
73
>
&f.status,
74
>
pending,
75
>
setting,
76
>
) {
77
panic("future has already been completed")
78
}
79
81
>
f.err = err
82
>
atomic.CompareAndSwapInt32(&f.status, setting, ready)
83
>
close(f.readyCh)
84
}
85