H1 2015 Priorities and Bare-Metal Programming

[Mike via Digitalmars-d]

On Sunday, 1 February 2015 at 21:58:19 UTC, Walter Bright wrote:

> There's nothing inherent to D or druntime that requires a 
> multithreaded operating system. After all, a single threaded OS 
> is a multithreaded operating system that simply returns an 
> error when a call to create a new thread is initiated.

Agreed, but in the current druntime implementation, by the time 
the program reaches main, 2 threads have already been initiated.  
There is also some runtime and code-size overhead with TLS, even 
if one is building a single-threaded executable.  I need to look 
into this in more detail though before I start spouting ideas.  
But I certainly welcome the dialogue.

>> IIRC he also proposed moving more of TypeInfo implementation 
>> to the
>> runtime so TypeInfo layout can be modified by the runtime or 
>> even
>> completely avoided by not implementing it in the runtime. The 
>> main
>> response was that it complicates compiler code too much for 
>> little
>> benefit. Obviously bare-metal programmers might disagree on 
>> the little
>> benefit part and as Mike points out rust seems to do similar 
>> things.
>
> We did something similar with the GC info, i.e. RTinfo. I think 
> the same technique could be use for TypeInfo.

I think Adam may have it right with Issue 12270 [1].  But I 
reject the notion that TypeInfo is a baked-in feature of the 
language, and if one want to eat the oatmeal cookie, they have to 
eat the raisins too.

Mike

[1] -  Move TypeInfo to the D Runtime - 
https://issues.dlang.org/show_bug.cgi?id=12270