How to "pause" the evaluation (aka breakpoint)?

[AlmogBaku]

Hi,
I'm wondering if/how it's possible to add some mechanism for breakpoints?

I saw that there are a few lines there is a "preparation" for hooking up a debugging breakpoint, but I couldn't find any way to hook there...

a. Is it possible today?
b. If that's not possible, I suggest adding a callback function in the thread or in a thread's local. If that is accepted, I'd be happy to do a PR. (The interface can be something simple like func(thread *Thread, typ BreakpointType)

[AlmogBaku]

PS, might be related to #304

[AlmogBaku]

@alandonovan WDYT? should I write a PR as described?

[pivotaljohn]

I think the now "proper" mention for Alan is: @adonovan.

[adonovan]

I saw that there are a few lines there is a "preparation" for hooking up a debugging breakpoint, but I couldn't find any way to hook there...

The 'vmdebug' logic is just an internal logging statement used when debugging changes to the interpreter. It's not a feature.

There is no breakpoint (debugger) feature today. The request to add this feature is #304, but there has been no progress towards that.

[AlmogBaku]

@adonovan are you against my proposed solution?
If that's acceptable, I'd be happy to write a PR

Edit: I meant to add this "hook" everywhere we have this vmdebug