7 ms·

Without any intent to take away from how cool this is (seriously, it's awesome) I do wonder what kinds of applications need this sort of capability. Surviving

by mabbo 5y ago

Without any intent to take away from how cool this is (seriously, it's awesome) I do wonder what kinds of applications need this sort of capability. Surviving a reboot is a very specific capability. With no hyperbole intended, who needs it?

Asmod4n 5y ago
macOS does something kinda like it. For when your battery dies you just have to boot the machine and all running apps will sort of start in their previous state.
- paxys 5y ago
  That really depends on how well the app manages its own state and specifically handles restarts. No mainstream OS can restart without running apps even knowing it.
  - jonhohle 5y ago
    It’s possible with virtualization and containers. In those cases, to be fair, there applications are running in an environment that may not be aware it was restarted.
    - FredPret 5y ago
      What if we're a simulation unknowingly getting a restart every time Johhny the alien closes and opens his laptop?
  - zozbot234 5y ago
    A planned restart is just hibernation to disk, which is implemented in many OS's.
    - Asmod4n 5y ago
      If you got a Mac without a battery you can try to write something in pages and just yoink the power cable. Upon the next boot pages should open with your document and not lost anything.
  - adastra22 5y ago
    Isn’t this exactly what hibernation is?
- checker659 5y ago
  How is that any different from hibernation?
  - jonhohle 5y ago
    Memory isn’t snapshotted and dumped, then restored by the OS in a way that user space is largely unaware. macOS/iOS has adopted a model of giving apps an opportunity to persist their own state before being terminated (which may be eagerly to reduce memory pressure or power consumption, for example) and then have the application restore its own state in whatever way is appropriate. Outside of containers, hibernation almost needs to be a system-wide operation, which makes it inappropriate for OS updates, restoring from crashes (which, I suppose is what Phantom OS is trying to resolve), or hardware changes.
    - zozbot234 5y ago
      Note that "containers" is basically kernel-implemented namespaces, which is why a containerized app can be checkpointed and restored independently: they can preserve the semantics of kernel resources across runs. You could have just about any arbitrary app running in a "container" with it being none-the-wiser about it: it doesn't necessarily impact userspace support.
qmmmur 5y ago
Running a tiny embeddable computer in a highly contingent environment. Off the top of my head I know someone running such computers to measure biodiversity through audio recordings. They fail all the time due to extreme weather and in one instance a bear pissing on it. I imagine the security could be useful in such an instance
ModernMech 5y ago
I would flip it around and ask "Who wouldn't need this?" Think of it this way, operating systems like Windows have tons of vulnerabilities, which need to be patched, and applying those patches takes a reboot. But people push off those reboots so long because they mean closing all applications and interrupting work, to the point where the entire computing ecosystem is more vulnerable and less updated as a result. Microsoft started scheduling updates in the middle of the night just to find a time that was amenable to users, but that doesn't help when the machine is turned off! So I think that feature, if it were deployed everywhere, would be a net win for everyone, not specific at all.
- mgerdts 5y ago
  But if your application is just restored to its previous state, it is still using the buggy code that was patched on disk. If you page in new code from patched files, the program will not necessarily know that foo() now lives at a different address. Save/restore across shutdowns is much simpler when the code doesn’t change. When the code changes, you need some form of live patching (ala ksplice) in the mix as well. There are also concerns when the system interacts with external systems. Suppose the system state was saved just before the million dollar transfer was performed, the transfer was performed, then the cat tripped over the power cord without that being persisted. When the system starts back up, the app may make another million dollar transfer thinking it was the first one.
  - ModernMech 5y ago
    Sure, those are all complications, but I don't think it impacts the utility of the idea.
- glandium 5y ago
  Windows happily applies updates during the night on laptops even when the lid is closed. Then the next day, you open the lid and bam, nothing of what you left open the previous day is there anymore!
brightball 5y ago
Anywhere in regular danger of power failure would certainly benefit from it.
- 8n4vidtmkvmk 5y ago
  battery or ups solves that
watmough 5y ago
Back in late '80's out of St Andrews and Glasgow, there was a bunch of research into persistent object environments. Here's a paper: https://archive.cs.st-andrews.ac.uk/papers/download/MBC+88.pdf https://archive.cs.st-andrews.ac.uk/papers/download/MBC+88.p... In short imagine Java or C++ objects, but they can live in a soup in a persistent database. Imagine if your programming assignments at school, were "open this database then write a client to talk to the object retrieved." That's what we actually had in PS-Algol in 86. Super cool!
- jhgb 5y ago
  > In short imagine Java or C++ objects, but they can live in a soup in a persistent database. AllegroCache still exists today. So at least Lisp people don't have to imagine that. I wonder if that is one of the reasons why CL people in the 1980s came up with UPDATE-INSTANCE-FOR-REDEFINED-CLASS.
  - fiddlerwoaroof 5y ago
    Yeah, you could supposedly upgrade all the software on a lisp systems without having to restart anything (assuming the developers implemented the various redefinition protocols correctly.)
    - johnisgood 5y ago
      Ahh, how is StumpWM doing? The tiling window manager written in Common Lisp. You could hack it while it was running. I never got around to try. :(
    - jdougan 5y ago
      You can definitely do that in an image-based Smalltalk system, it is necessary to support the code browsers. I imagine the lispm devs had the same reason.
      - jhgb 5y ago
        What I had in mind was that this is also necessary to support an on-disk object database.
ianai 5y ago
Because persistent storage is about as fast as ram. (Not yet but eventually)
zuminator 5y ago
As to who would need the OS state surviving reboot, what comes to my mind is things like Mars rovers and other autonomous exploratory vehicles. Currently these use cases are filled by VxWorks[0] among others but a fresh approach might yield some advantages. [0] https://en.m.wikipedia.org/wiki/VxWorks#Aerospace_and_defense https://en.m.wikipedia.org/wiki/VxWorks#Aerospace_and_defens...
simne 5y ago
- imwillofficial 5y ago
  Wtf are you talking about?
  - simne 5y ago
    I say, this is road to nowhere. This efforts will not lead to anything real, only papers and pseudo-scientific talks. Nothing more. Oh, sorry, forgot about Russian national sport - extreme sized embezzlement of budgets, for which need super-duper fantastic projects, so in any case could say "they just suffer from budget cuts, just few additional billions could lead to success".
- nextaccountic 5y ago
  Are you sure you're commenting in the right thread? This isn't related to war
  - simne 5y ago
    - squarefoot 5y ago
      I just read some of your posts before replying. Assuming you really are Ukrainian, I'm very sorry about what you and other Ukrainians are going through, and of course I'm 100% on your side on this, but I have to warn you that this attitude is exactly what Russian leaders would like to see: people around the world hating everything Russian indiscriminately, so that they can play victim. You're not helping your cause at all this way.
      - johnisgood 5y ago
        I do not think that Russia wants to play the victim (completely different culturally for that). Plus, they have been the scapegoat for a really long time now. It became a meme. The Russians did it!
rco8786 5y ago
Imagine the user experience of closing the lid on your laptop and reopening it a few hours or a few days later, without using any battery life in between. You can also imagine it being useful in extremely low power solutions where battery life is critical. Space craft, etc
- marcellus23 5y ago
  > Imagine the user experience of closing the lid on your laptop and reopening it a few hours or a few days later, without using any battery life in between. MacBooks and probably other laptops (?) already do this. You might lose a couple percent over a few days.
  - glandium 5y ago
    Surprisingly, while my Intel-based MBP does that (and can remain sleeping unplugged for several months), my M1-based one doesn't (after a few weeks, there's barely any battery left).
    - hdjjhhvvhga 5y ago
      Interesting. Maybe there is something in M1 that draws power anyway.
    - marcellus23 5y ago
      Funnily enough I have the opposite experience! My M1 can stay closed for weeks without losing more than a few percent, while my Intel-based tends to drain about 10%-20% a day.
- spacexsucks 5y ago
  Lenovo S3 sleep state already does this. I have been using this for like 5 years atlesst. systemctl hibernate
  - nkoren 5y ago
    With what OS? My T14s running Windows 10 is unable to survive commanded sleep, much less just putting the lid down.
tomjen3 5y ago
I basically leave my MacBook on sleep all the time so that it is ready to pick up where I was. With this I could do the same with a desktop computer without having to lose power.

by mabbo 5y ago

Asmod4n 5y ago

macOS does something kinda like it. For when your battery dies you just have to boot the machine and all running apps will sort of start in their previous state.

paxys 5y ago
That really depends on how well the app manages its own state and specifically handles restarts. No mainstream OS can restart without running apps even knowing it.
- jonhohle 5y ago
  It’s possible with virtualization and containers. In those cases, to be fair, there applications are running in an environment that may not be aware it was restarted.
  - FredPret 5y ago
    What if we're a simulation unknowingly getting a restart every time Johhny the alien closes and opens his laptop?
- zozbot234 5y ago
  A planned restart is just hibernation to disk, which is implemented in many OS's.
  - Asmod4n 5y ago
    If you got a Mac without a battery you can try to write something in pages and just yoink the power cable. Upon the next boot pages should open with your document and not lost anything.
- adastra22 5y ago
  Isn’t this exactly what hibernation is?
checker659 5y ago
How is that any different from hibernation?
- jonhohle 5y ago
  Memory isn’t snapshotted and dumped, then restored by the OS in a way that user space is largely unaware. macOS/iOS has adopted a model of giving apps an opportunity to persist their own state before being terminated (which may be eagerly to reduce memory pressure or power consumption, for example) and then have the application restore its own state in whatever way is appropriate. Outside of containers, hibernation almost needs to be a system-wide operation, which makes it inappropriate for OS updates, restoring from crashes (which, I suppose is what Phantom OS is trying to resolve), or hardware changes.
  - zozbot234 5y ago
    Note that "containers" is basically kernel-implemented namespaces, which is why a containerized app can be checkpointed and restored independently: they can preserve the semantics of kernel resources across runs. You could have just about any arbitrary app running in a "container" with it being none-the-wiser about it: it doesn't necessarily impact userspace support.

qmmmur 5y ago

Running a tiny embeddable computer in a highly contingent environment. Off the top of my head I know someone running such computers to measure biodiversity through audio recordings. They fail all the time due to extreme weather and in one instance a bear pissing on it. I imagine the security could be useful in such an instance

ModernMech 5y ago

I would flip it around and ask "Who wouldn't need this?" Think of it this way, operating systems like Windows have tons of vulnerabilities, which need to be patched, and applying those patches takes a reboot. But people push off those reboots so long because they mean closing all applications and interrupting work, to the point where the entire computing ecosystem is more vulnerable and less updated as a result. Microsoft started scheduling updates in the middle of the night just to find a time that was amenable to users, but that doesn't help when the machine is turned off! So I think that feature, if it were deployed everywhere, would be a net win for everyone, not specific at all.

mgerdts 5y ago
But if your application is just restored to its previous state, it is still using the buggy code that was patched on disk. If you page in new code from patched files, the program will not necessarily know that foo() now lives at a different address. Save/restore across shutdowns is much simpler when the code doesn’t change. When the code changes, you need some form of live patching (ala ksplice) in the mix as well. There are also concerns when the system interacts with external systems. Suppose the system state was saved just before the million dollar transfer was performed, the transfer was performed, then the cat tripped over the power cord without that being persisted. When the system starts back up, the app may make another million dollar transfer thinking it was the first one.
- ModernMech 5y ago
  Sure, those are all complications, but I don't think it impacts the utility of the idea.
glandium 5y ago
Windows happily applies updates during the night on laptops even when the lid is closed. Then the next day, you open the lid and bam, nothing of what you left open the previous day is there anymore!

brightball 5y ago

Anywhere in regular danger of power failure would certainly benefit from it.

8n4vidtmkvmk 5y ago
battery or ups solves that

watmough 5y ago

Back in late '80's out of St Andrews and Glasgow, there was a bunch of research into persistent object environments. Here's a paper: https://archive.cs.st-andrews.ac.uk/papers/download/MBC+88.pdf https://archive.cs.st-andrews.ac.uk/papers/download/MBC+88.p... In short imagine Java or C++ objects, but they can live in a soup in a persistent database. Imagine if your programming assignments at school, were "open this database then write a client to talk to the object retrieved." That's what we actually had in PS-Algol in 86. Super cool!

jhgb 5y ago
> In short imagine Java or C++ objects, but they can live in a soup in a persistent database. AllegroCache still exists today. So at least Lisp people don't have to imagine that. I wonder if that is one of the reasons why CL people in the 1980s came up with UPDATE-INSTANCE-FOR-REDEFINED-CLASS.
- fiddlerwoaroof 5y ago
  Yeah, you could supposedly upgrade all the software on a lisp systems without having to restart anything (assuming the developers implemented the various redefinition protocols correctly.)
  - johnisgood 5y ago
    Ahh, how is StumpWM doing? The tiling window manager written in Common Lisp. You could hack it while it was running. I never got around to try. :(
  - jdougan 5y ago
    You can definitely do that in an image-based Smalltalk system, it is necessary to support the code browsers. I imagine the lispm devs had the same reason.
    - jhgb 5y ago
      What I had in mind was that this is also necessary to support an on-disk object database.

ianai 5y ago

Because persistent storage is about as fast as ram. (Not yet but eventually)

zuminator 5y ago

As to who would need the OS state surviving reboot, what comes to my mind is things like Mars rovers and other autonomous exploratory vehicles. Currently these use cases are filled by VxWorks[0] among others but a fresh approach might yield some advantages. [0] https://en.m.wikipedia.org/wiki/VxWorks#Aerospace_and_defense https://en.m.wikipedia.org/wiki/VxWorks#Aerospace_and_defens...

simne 5y ago

imwillofficial 5y ago
Wtf are you talking about?
- simne 5y ago
  I say, this is road to nowhere. This efforts will not lead to anything real, only papers and pseudo-scientific talks. Nothing more. Oh, sorry, forgot about Russian national sport - extreme sized embezzlement of budgets, for which need super-duper fantastic projects, so in any case could say "they just suffer from budget cuts, just few additional billions could lead to success".
nextaccountic 5y ago
Are you sure you're commenting in the right thread? This isn't related to war
- simne 5y ago
  - squarefoot 5y ago
    I just read some of your posts before replying. Assuming you really are Ukrainian, I'm very sorry about what you and other Ukrainians are going through, and of course I'm 100% on your side on this, but I have to warn you that this attitude is exactly what Russian leaders would like to see: people around the world hating everything Russian indiscriminately, so that they can play victim. You're not helping your cause at all this way.
    - johnisgood 5y ago
      I do not think that Russia wants to play the victim (completely different culturally for that). Plus, they have been the scapegoat for a really long time now. It became a meme. The Russians did it!

rco8786 5y ago

Imagine the user experience of closing the lid on your laptop and reopening it a few hours or a few days later, without using any battery life in between. You can also imagine it being useful in extremely low power solutions where battery life is critical. Space craft, etc

marcellus23 5y ago
> Imagine the user experience of closing the lid on your laptop and reopening it a few hours or a few days later, without using any battery life in between. MacBooks and probably other laptops (?) already do this. You might lose a couple percent over a few days.
- glandium 5y ago
  Surprisingly, while my Intel-based MBP does that (and can remain sleeping unplugged for several months), my M1-based one doesn't (after a few weeks, there's barely any battery left).
  - hdjjhhvvhga 5y ago
    Interesting. Maybe there is something in M1 that draws power anyway.
  - marcellus23 5y ago
    Funnily enough I have the opposite experience! My M1 can stay closed for weeks without losing more than a few percent, while my Intel-based tends to drain about 10%-20% a day.
spacexsucks 5y ago
Lenovo S3 sleep state already does this. I have been using this for like 5 years atlesst. systemctl hibernate
- nkoren 5y ago
  With what OS? My T14s running Windows 10 is unable to survive commanded sleep, much less just putting the lid down.

tomjen3 5y ago

I basically leave my MacBook on sleep all the time so that it is ready to pick up where I was. With this I could do the same with a desktop computer without having to lose power.