Currently, the main memory management code is one of the remaining
places where we have global state. The next series of changes will aim
to rectify this.
This change simply introduces the main skeleton of the class that will
contain all the necessary state.
This only encourages the use of the global system instance (which will
be phased out long-term). Instead, we use the direct system function
call directly to remove the appealing but discouraged short-hand.
Migrates the HLE service code off the use of directly accessing the
global system instance where trivially able to do so.
This removes all usages of Core::CurrentProcess from the service code,
only 8 occurrences of this function exist elsewhere. There's still quite
a bit of "System::GetInstance()" being used, however this was able to
replace a few instances.
Gets rid of the largest set of mutable global state within the core.
This also paves a way for eliminating usages of GetInstance() on the
System class as a follow-up.
Note that no behavioral changes have been made, and this simply extracts
the functionality into a class. This also has the benefit of making
dependencies on the core timing functionality explicit within the
relevant interfaces.
This is a function that definitely doesn't always have a non-modifying
behavior across all implementations, so this should be made non-const.
This gets rid of the need to mark data members as mutable to work around
the fact mutating data members needs to occur.
Many of the Current<Thing> getters (as well as a few others) were
missing const qualified variants, which makes it a pain to retrieve
certain things from const qualified references to System.
There's no real need to use a shared pointer in these cases, and only
makes object management more fragile in terms of how easy it would be to
introduce cycles. Instead, just do the simple thing of using a regular
pointer. Much of this is just a hold-over from citra anyways.
It also doesn't make sense from a behavioral point of view for a
process' thread to prolong the lifetime of the process itself (the
process is supposed to own the thread, not the other way around).
Given we now have the kernel as a class, it doesn't make sense to keep
the current process pointer within the System class, as processes are
related to the kernel.
This also gets rid of a subtle case where memory wouldn't be freed on
core shutdown, as the current_process pointer would never be reset,
causing the pointed to contents to continue to live.
