Re: [Help-smalltalk] Timeouts for BlockClosures

[Paolo Bonzini]

Almost there indeed, thanks for clarifying!

First comment: please move the TimeoutNotification under the Kernel 
namespace.

> +BlockClosure extend [
> +    timeout: seconds do: aBlock [

So what do you think about passing a delay here?  Or even making this 
method Delay>>#value:onTimeout:?  Do you know what other Smalltalks do?

> +<category: '*timeout-private'>
> +       "I will execute myself for up to seconds and if a timeout
> +       occurs I will invoke the aBlock. If the timeout occurs early
> +       not much of the block is executed yet. I also have some issues
> +       with Delays and not breaking these properly.

Is the comment still accurate?

> +        [[
> +
> +            "Start a process to wait in and then signal"
> +            [| delay |
> +                delay := Delay forSeconds: seconds.
> +
> +                "Wait and see if it is timed out. If so send a signal."
> +                (delay timedWaitOn: sem) ifTrue: [
> +                   proc signalInterrupt: (TimeoutNotification on: self).
> +                ].
> +            ] fork.
> +
> +            value := self value.
> +        ] ensure: [sem signal]

This can be written in a lighter way:

        [

            "Start a process to wait in and then signal"
            [| delay |
                delay := Delay forSeconds: seconds.

                "Wait and see if it is timed out. If so send a signal."
                (delay timedWaitOn: sem) ifTrue: [
                   proc signalInterrupt: (TimeoutNotification on: self)]
            ] fork.

            value := self ensure: [sem signal]

> +        ] on: TimeoutNotification do: [:e |
> +            e block = self
> +                ifTrue:  [timeout := true]
> +                ifFalse: [e pass].
> +        ].
> +
> +        "Make sure we call the ensure's first."
> +        ^ timeout
> +            ifTrue:  [^aBlock value]
> +            ifFalse: [^value].

No returns within ifTrue/ifFalse blocks.

> +    ]
> +]

> +            ] timeout: 1 do: [events add: 'timeout'].

Larger timeout, please (1s for example).

Thanks!

Paolo