3 ms·

Can you elaborate more? All of the parts that throw `InterruptedException` are handling the thread interrupt cancelation mechanism. There is also the example

by emccue 4y ago

Can you elaborate more? All of the parts that throw `InterruptedException` are handling the thread interrupt cancelation mechanism. There is also the example with the atomic boolean quit flag. I'm not convinced that Go has any unique mechanisms here. Just like Java you can't forcefully kill a thread without that thread's cooperation.

mperham 4y ago
Go provides a context package which allows in-flight cancellation of heavy operations spanning processes and even machines. https://pkg.go.dev/context https://pkg.go.dev/context
- emccue 4y ago
  Okay this is cool. I think mechanically the plans for ScopeLocals can be a part of implementing a scheme like that. Either way - I need to read this thoroughly in the morning.
- mkdirp 4y ago
  This is also part of how you could interrupt `time.Sleep`. > In Go there is less noise, but also there no way to interrupt Go's time.Sleep. The full piece would be something like: func sleepCtx(ctx context.Context, delay time.Duration) { select { case <-ctx.Done(): case <-time.After(delay): } } func main() { fmt.Printf("%v\n", time.Now()) ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond) defer cancel() sleepCtx(ctx, 1*time.Second) fmt.Printf("%v\n", time.Now()) } Runnable example on Go playground: https://go.dev/play/p/S5TY3CRmsYO https://go.dev/play/p/S5TY3CRmsYO
  - klabb3 4y ago
    Yep this is a utility function in sure thousands have written, including myself. It's not in std which is weird but go had been a bit inconsistent since context was a big api change. Fun fact: that func has a hidden bug, if one should be pedantic. Can you spot it?
    - eadmund 4y ago
      > Fun fact: that func has a hidden bug, if one should be pedantic. Can you spot it? Are you referring to the fact that the timer is still hanging around? Would this be the most-correct version? func sleepCtx(ctx context.Context, delay time.Duration) { t := time.NewTimer(delay) defer func() { if !t.Stop() { <-t.C } }() select { case <-ctx.Done(): case <-t.C: } }
      - klabb3 4y ago
        [Weird, I remember already replying to this comment.] Yes that's what I was thinking of :) I'm a bit unsure what's the value in draining the channel (which is internal to this func), given that Go should garbage collect channel (and in this case perhaps even some escape analysis). EDIT: Ah they aren't just closing the channel, but sending a time.Time. That makes sense, the timer wouldn't have anyone to send to if it's unbuffered.

by emccue 4y ago

mperham 4y ago

Go provides a context package which allows in-flight cancellation of heavy operations spanning processes and even machines. https://pkg.go.dev/context https://pkg.go.dev/context

emccue 4y ago
Okay this is cool. I think mechanically the plans for ScopeLocals can be a part of implementing a scheme like that. Either way - I need to read this thoroughly in the morning.
mkdirp 4y ago
This is also part of how you could interrupt `time.Sleep`. > In Go there is less noise, but also there no way to interrupt Go's time.Sleep. The full piece would be something like: func sleepCtx(ctx context.Context, delay time.Duration) { select { case <-ctx.Done(): case <-time.After(delay): } } func main() { fmt.Printf("%v\n", time.Now()) ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond) defer cancel() sleepCtx(ctx, 1*time.Second) fmt.Printf("%v\n", time.Now()) } Runnable example on Go playground: https://go.dev/play/p/S5TY3CRmsYO https://go.dev/play/p/S5TY3CRmsYO
- klabb3 4y ago
  Yep this is a utility function in sure thousands have written, including myself. It's not in std which is weird but go had been a bit inconsistent since context was a big api change. Fun fact: that func has a hidden bug, if one should be pedantic. Can you spot it?
  - eadmund 4y ago
    > Fun fact: that func has a hidden bug, if one should be pedantic. Can you spot it? Are you referring to the fact that the timer is still hanging around? Would this be the most-correct version? func sleepCtx(ctx context.Context, delay time.Duration) { t := time.NewTimer(delay) defer func() { if !t.Stop() { <-t.C } }() select { case <-ctx.Done(): case <-t.C: } }
    - klabb3 4y ago
      [Weird, I remember already replying to this comment.] Yes that's what I was thinking of :) I'm a bit unsure what's the value in draining the channel (which is internal to this func), given that Go should garbage collect channel (and in this case perhaps even some escape analysis). EDIT: Ah they aren't just closing the channel, but sending a time.Time. That makes sense, the timer wouldn't have anyone to send to if it's unbuffered.