Re: Concurrency support in iostream mapped_file_source

From: Niall Douglas (s_sourceforge_at_[hidden])
Date: 2020-07-03 09:34:50

On 03/07/2020 07:01, Lloyd via Boost-users wrote:

> Does boost iostream mapped_file_source support concurrent read from
> multiple threads? What is the best way to implement concurrent read on a
> performance sensitive application?
> 
> The file is a read only one and its size is in gigabytes/terabytes

For memory mapped files in general, reads served from kernel cache will
parallelise at CPU concurrency level, whereas reads served from the
storage layer will parallelise at device concurrency level. This means
that i/o which is not served from cache will synchronise CPUs during i/o
submission and completion.

Niall