Re: [PATCH v2 3/4] gdbsupport: add async parallel_for_each version

[Simon Marchi <simon.marchi@polymtl.ca>]

On 9/18/25 3:16 PM, Tom Tromey wrote:
>>>>>> "Simon" == simon marchi <simon.marchi@polymtl.ca> writes:
> 
> Simon> From: Simon Marchi <simon.marchi@polymtl.ca>
> Simon> New in v2: make the global variable constexpr.
> 
> Simon> I would like to use gdb::parallel_for_each to implement the parallelism
> Simon> of the DWARF unit indexing.  However, the existing implementation of
> Simon> gdb::parallel_for_each is blocking, which doesn't work with the model
> Simon> used by the DWARF indexer, which is asynchronous and callback-based.
> Simon> Add an asynchronouys version of gdb::parallel_for_each that will be
> Simon> suitable for this task.
> 
> Simon> This new version accepts a callback that is invoked when the parallel
> Simon> for each is complete.
> 
> This looks good to me.
> 
> Simon> +	  const auto [batch_first, batch_last] = state->queue.pop_batch ();
> Simon> +
> Simon> +	  if (batch_first == batch_last)
> Simon> +	    break;
> 
> If this was using iterator_range, it'd be easy enough to add an 'empty'
> method to that object.

I did that.  I also changed the interface so that the workers receive an
iterator_range, I'll include that in v3.

Simon