Dare I ... another volatile discussion ?

[Kagamin via Digitalmars-d]

On Thursday, 7 May 2015 at 16:04:56 UTC, Jens Bauer wrote:
> Regarding (1), because marking a variable 'shared' is not 
> enough (it allows instructions to be moved around), Johannes 
> already made a volatileLoad and volatileStore, which will be 
> usable for microcontrollers, though for convenience, it 
> requires writing additional code.
> -But this solution ... I do not know if it would work, when 
> writing a driver for Debian running on a i586 platform or 
> PowerMac G3 for instance.

System calls on sufficiently smart processors like x86 use C-like 
ABI good practices: registers and buffers to pass data instead of 
global variables, because multithreaded programs will have race 
condition on accessing the global variables. See read(2) syscall 
as an example of such API 
http://man7.org/linux/man-pages/man2/read.2.html

On Thursday, 7 May 2015 at 18:18:02 UTC, Johannes Pfau wrote:
> Not sure about shared (I don't think anybody knows what exactly 
> shared is supposed to do)

Shared is supposed to prevent the programmer from accidentally 
putting unshared data in a shared context. Expectedly people 
wanted it to be a silver bullet for concurrency, instead 
std.concurrency provides high-level concurrency safety.