Unused druntime code: Barrier, ReadWriteMutex, Condition

[Richard (Rikki) Andrew Cattermole]

On 15/06/2026 9:41 PM, Denis Feklushkin wrote:
> On Monday, 15 June 2026 at 09:07:54 UTC, Richard (Rikki) Andrew 
> Cattermole wrote:
> 
>> There are enough primitives in FreeRTOS to build these other sync 
>> primitives.
> 
> Strictly, my question wasn't related to FreeRTOS.
> 
> I just want to understand why we keep such code that we don't use 
> directly in the druntime. This code complicates porting without 
> providing any benefit. Moving this code to Phobos allows us to put this 
> issue aside along with other similar ones (like std.file on systems 
> without filesystem)
> 
> One day we'll have to quickly port the language to something trendy. And 
> we won't be ready for it.
> 
>> There are enough primitives in FreeRTOS to build these other sync 
>> primitives.
> 
> Most likely, these primitives do not exist in any OS - they are too 
> high-level and can be implemented on the basis of "more primitive" 
> primitives. (Posix implementation just provides convient wrapper, I think)

They do.

Windows Internals 7th edition, part 2.

Page 205-206.

Reasoning mentioned is that it has performance benefits.

Its safe to assume some pthread implementations will have kernel backing 
as well.