On Saturday, 9 May 2015 at 16:59:35 UTC, Jens Bauer wrote:
... "System calls" will need to access the peripherals in some
way, in order to send data to for instance a printer or
harddisk. If the way it's done is using a memory location, then
it's necessary to tell the compiler that this is not ordinary
memory, but I/O-memory AKA hardware address space.
Userland code still uses system calls and not global variables,
whatever is expressed in read(2) signature tells the compiler
enough to pass data via buffer.
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.
In other words, it's the oposite of 'static' ?
Whether data is shared or not is not tied to its storage class,
that's why its shared nature is expressed in its type and storage
class can be anything; for the same reason shared type qualifier
is transitive.
