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
