Phantom OS

What is that this OS about?

Phantom is, usually, a digital machine (VM) working in a tall power digital reminiscence. Segment of the VM classes (some
classes, called ‘inner’) are implemented in kernel, giving VM code gain admission to to low level kernel providers. Power
digital reminiscence is entirely orthogonal to object dwelling and VM (no relation between, to illustrate, object boundary and
digital reminiscence page, and so on.) and is implemented in divulge that abrupt laptop failure or lack of energy leaves draw in coherent
teach. On the software program code (VM bytecode) level OS shutdown (either e book or induced by failure) is never any longer even ‘considered’ –
purposes and their recordsdata are ‘beneath no circumstances die’, they proceed their work after the following OS boot up as if no shutdown ever
came about.

code

Power reminiscence and snapshots

Phantom does typical snapshot of your entire digital reminiscence. Snapshots are finished asynchronously and without stopping the
world, nonetheless ensuing snapshot is synchronous – the general reminiscence is being snapped on the particular identical moment in OS’s
‘private’ time. It ability that snapshot teach is captured fancy if the general draw was stopped, dumped to disk and then
disappear as soon as more. Nonetheless without stopping.

Native code

Hi there-performance code (quantity-crunching, video or sound processing, and so on) requires precise
low-level gain admission to to the processor
and reminiscence. It is supposed that Phantom will seemingly be in a position to disappear native code in a completely different binary-object-sure thread.
One
binary object will provide code (CS teach material), others will seemingly be on hand as DS/SS and, most possible, ES/FS/GS (on completely different
architectures there objects will seemingly be merely mapped in thread deal with dwelling). This also can let Phantom to enact
highly-optimised native code.

It is supposed that to back some portability it’d be that you just furthermore could can imagine to create no longer exactly native, nonetheless LLVM-level
code
for this ambiance.

Digital machine

Phantom bytecode is outmoded stack-machine bytecode. It is very fancy Java bytecode, nonetheless there could be never any such thing as a difference
between constructed-in and user kinds on the manner boundary level. Any object (even integer) is class instance. There could be about a
particular back for integer calculations though, to speedup issues.

It is supposed that Phantom bytecode can signify any Java program, and Java to Phantom bytecode converter is being
written. Assorted languages are supposed to be brought through the Java bytecode or straight, by writing particular language
frontend.

C# (CLR) bytecode converter is deliberate, nonetheless no work is in progress yet.

Kernel verbal change

There could be set of (inner) classes, which ideas are implemented in kernel. These classes
offer kernel interface in
object ambiance. Not like Java, in Phantom the general class code is either inner (native, in Java phrases), or
bytecode-level.

Drivers

Currently drivers are written in C and dwell within the kernel entirely. Future releases could well contain likelihood to write
drivers in userland by offering required kernel frameworks. Userland driver will seemingly be restricted to check with
given (by kernel) set of hardware assets absolute top, and its interrupt-handling manner will seemingly be guaranteed to no longer to be
paged out.

POSIX ambiance

There could be (relatively straightforward) POSIX subsystem in Phantom. It is no longer power (yet?). As an illustration, Quake software program is
compiled for POSIX subsystem.