there's no reason to have the worker set information on goals that the
goals themselves return from their entry point. doing this in the goal
`work()` function is much cleaner, and a prerequisite to removing more
implicit strong shared references to goals that are currently running.
Change-Id: Ibb3e953ab8482a6a21ce2ed659d5023a991e7923
this simplifies the worker loop, and lets us remove it entirely later.
note that ideally only one promise waiting for interrupts should exist
in the entire system. not one per event loop, one per *process*. extra
interrupt waiters make interrupt response nondeterministic and as such
aren't great for user experience. if anything wants to react to aborts
caused by explicit interruptions, or anything else, those things would
be much better served using RAII guards such as Finally (or KJ_DEFER).
Change-Id: I41d035ff40172d536e098153c7375b0972110d51
this was a triumph. i'm making a note here: huge success. it's hard to
overstate my satisfaction! i'm not even angry. i'm being so sincere ri
actually, no. we *are* angry. this was one dumbass odyssey. nobody has
asked for this. but not doing it would have locked us into old, broken
protocols forever or (possibly worse) forced us to write our own async
framework building on the old did-you-mean-continuations in Worker. if
we had done that we'd be locked into ever more, and ever more complex,
manual state management all over the place. this just could not stand.
Change-Id: I43a6de1035febff59d2eff83be9ad52af4659871
due to event loop scheduling behavior it's possible for a derivation
goal to fully finish (having seen all paths it was asked to create),
but to not notify the worker of this in time to prevent another goal
asking the recently-finished goal for more outputs. if this happened
the finished goal would ignore the request for more outputs since it
considered itself fully done, and the delayed result reporting would
cause the requesting goal to assume its request had been honored. if
the requested goal had finished *properly* the worker would recreate
it instead of asking for more outputs, and this would succeed. it is
thus safe to always recreate goals once they are done, so we now do.
Change-Id: Ifedd69ca153372c623abe9a9b49cd1523588814f
This splits `ignoreException` into `ignoreExceptionExceptInterrupt`
(which ignores all exceptions except `Interrupt`, which indicates a
SIGINT/CTRL-C) and `ignoreExceptionInDestructor` (which ignores all
exceptions, so that destructors do not throw exceptions).
This prevents many cases where Nix ignores CTRL-C entirely.
See: https://github.com/NixOS/nix/issues/7245
Upstream-PR: https://github.com/NixOS/nix/pull/11618
Change-Id: Ie7d2467eedbe840d1b9fa2e88a4e88e4ab26a87b
we'll now loop to update displayed statistics, and use this loop to
limit the update rate to 50 times per second. we could have updated
much more frequently before this (once per iteration of `runImpl`),
much faster than would ever be useful in practice. aggressive stats
updates can even impede progress due to terminal or network delays.
Change-Id: Ifba755a2569f73c919b1fbb06a142c0951395d6d
Worker::run() is now entirely based on the kj event loop and promises,
so we need not handle awakeness of goals manually any more. every goal
can instead, once it has finished a partial work call, defer itself to
being called again in the next iteration of the loop. same end effect.
Change-Id: I320eee2fa60bcebaabd74d1323fa96d1402c1d15
notably we will check whether we want to do GC at all only once during
startup, and we'll only attempt GC every ten seconds rather than every
time a goal has finished a partial work call. this shouldn't cause any
problems in practice since relying on auto-gc is not deterministic and
stores in which builds can fill all remaining free space in merely ten
seconds are severely troubled even when gargage collection runs a lot.
Change-Id: I1175a56bf7f4e531f8be90157ad88750ff2ddec4
Revert submission 1946
Reason for revert: regression in building (found via bisection)
Reported by users:
> error: path '/nix/store/04ca5xwvasz6s3jg0k7njz6rzi0d225w-jq-1.7.1-dev' does not exist in the store
Reverted changes: /q/submissionid:1946
Change-Id: I6f1a4b2f7d7ef5ca430e477fc32bca62fd97036b
nothing needs to signal being still active but not actively pollable,
only that immediate polling for the next goal work phase is in order.
Change-Id: Ia43c1015e94ba4f5f6b9cb92943da608c4a01555
this was immensely inefficient on large caches, as can exist when many
derivations are buildable simultaneously. since we have smart pointers
to goals we can do cache maintenance in goal deleters instead, and use
the exact iterators instead of doing a linear search. this *does* rely
on goals being deleted to remove them from the cache, which isn't true
for toplevel goals. those would have previously been removed when done
in all cases, removing the cache entry when keep-going is set. this is
arguably incorrect since it might result in those goals being retried,
although that could only happen with dynamic derivations or the likes.
(luckily dynamic derivations not complete enough to allow this at all)
Change-Id: I8e750b868393588c33e4829333d370f2c509ce99
makeDerivationGoalCommon had the right idea, but it didn't quite go far
enough. let's do the rest and remove the remaining factory duplication.
Change-Id: I1fe32446bdfb501e81df56226fd962f85720725b
this was a debugging aid from day one that should not have any impact on
build semantics, and if it *does* have an impact on build semantics then
build semantics are seriously broken. keeping the order imposed by these
keys will be impossible once we let a real event loop schedule our jobs.
Change-Id: I5c313324e1f213ab6453d82f41ae5e59de809a5b
without circular references we do not need weak goal pointers except for
caches, which should not prevent goal destructors running. caches though
cannot create circular references even when they keep strong references.
if we removed goals from caches when their work() is fully finished, not
when their destructors are run, we could keep strong pointers in caches.
since we do not gain much from this we keep those pointers weak for now.
Change-Id: I1d4a6850ff5e264443c90eb4531da89f5e97a3a0
have DerivationGoal and its subclasses produce a wrapper promise for
their intermediate results instead, and return this wrapper promise.
Worker already handles promises that do not complete immediately, so
we do not have to duplicate this into an entire result type variant.
Change-Id: Iae8dbf63cfc742afda4d415922a29ac5a3f39348
the new event loop could very occasionally notice that a dependency of
some goal has failed, process the failure, cause the depending goal to
fail accordingly, and in the doing of the latter two steps let further
dependencies that previously have not been reported as failed do their
reporting anyway. in such cases a goal could fail with "1 dependencies
failed", but more than one dependency failure message was shown. we'll
now report the correct number of failed dependency goals in all cases.
Change-Id: I5aa95dcb2db4de4fd5fee8acbf5db833531d81a8
these can be unique rather than shared because shared_ptr has a
converting constructor. preparatory refactor for something else
and not necessary on its own, and the extra allocations we must
do for shared_ptr control blocks isn't usually relevant anyway.
Change-Id: I5391715545240c6ec8e83a031206edafdfc6462f
also gets rid of explicit strong references to dependencies of any goal,
and weak references to dependers as well. those are now only held within
promises representing goal completion and thus independent of the goal's
relation to each other. the weak references to dependers was only needed
for notifications, and that's much better handled entirely by kj itself.
Change-Id: I00d06df9090f8d6336ee4bb0c1313a7052fb016b
now that we have an event loop in the worker we can use it and its
magical execution suspending properties to replace the slot counts
we managed explicitly with semaphores and raii tokens. technically
this would not have needed an event loop base to be doable, but it
is a whole lot easier to wait for a token to be available if there
is a callback mechanism ready for use that doesn't require a whole
damn dedicated abstract method in Goal to work, and specific calls
to that dedicated method strewn all over the worker implementation
Change-Id: I1da7cf386d94e2bbf2dba9b53ff51dbce6a0cff7
with waitForAWhile turned into promised the core functionality of
waitForInput is now merely to let gc run every so often if needed
Change-Id: I68da342bbc1d67653901cf4502dabfa5bc947628
this simplifies waitForInput quite a lot, and at the same time makes
polling less thundering-herd-y. it even fixes early polling wakeups!
Change-Id: I6dfa62ce91729b8880342117d71af5ae33366414
this removes the rather janky did-you-mean-async poll loop we had so
far. sadly kj does not play well with pty file descriptors, so we do
have to add our own async input stream that does not eat pty EIO and
turns it into an exception. that's still a *lot* better than the old
code, and using a real even loop makes everything else easier later.
Change-Id: Idd7e0428c59758602cc530bcad224cd2fed4c15e
Without this, verifying TLS certificates would fail on macOS, as well
as any system that doesn't have a certificate file at /etc/ssl/certs/ca-certificates.crt,
which includes e.g. Fedora.
Change-Id: Iaa2e0e9db3747645b5482c82e3e0e4e8f229f5f9
using a proper event loop basis we no longer have to worry about most of
the intricacies of poll(), or platform-dependent replacements for it. we
may even be able to use the event loop and its promise system for all of
our scheduling in the future. we don't do any real async processing yet,
this is just preparation to separate the first such change from the huge
api design difference with the async framework we chose (kj from capnp):
kj::Promise, unlike std::future, doesn't return exceptions unmangled. it
instead wraps any non-kj exception into a kj exception, erasing all type
information and preserving mostly the what() string in the process. this
makes sense in the capnp rpc use case where unrestricted exception types
can't be transferred, and since it moves error handling styles closer to
a world we'd actually like there's no harm in doing it only here for now
Change-Id: I20f888de74d525fb2db36ca30ebba4bcfe9cc838
it just makes sense to have it too, rather than just the pass/fail
information we keep so far. once we turn goals into something more
promise-shaped it'll also help detangle the current data flow mess
Change-Id: I915cf04d177cad849ea7a5833215d795326f1946
it doesn't have a purpose except cache priming, which is largely
irrelevant by default (since another code path already runs this
exact query). our store implementations do not benefit that much
from this either, and the more bursty load may indeed harm them.
Change-Id: I1cc12f8c21cede42524317736d5987f1e43fc9c9
updating statistics *immediately* when any counter changes declutters
things somewhat and makes useful status reports less dependent on the
current worker main loop. using callbacks will make it easier to move
the worker loop into kj entirely, using only promises for scheduling.
Change-Id: I695dfa83111b1ec09b1a54cff268f3c1d7743ed6
there's no reason to go through the event loop in these cases. returning
ContinueImmediately here is just a very convoluted way of jumping to the
state we've just set after unwinding one frame of the stack, which never
matters in the cases changed here because there are no live RAII guards.
Change-Id: I7c00948c22e3caf35e934c1a14ffd2d40efc5547
this is not ideal, but it's better than having this stuck in the worker
loop itself. setting ex on all failing goals is not problematic because
only toplevel goals can ever be observable, all the others are ignored.
notably only derivation goals ever set `ex`, substitution goals do not.
Change-Id: I02e2164487b2955df053fef3c8e774d557aa638a
this doesn't serve a great purpose yet except to confine construction of
goals to the stack frame of Worker::run() and its child frames. we don't
need this yet (and the goal constructors remain fully visible), but in a
future change that fully removes the current worker loop we'll need some
way of knowing which goals are top-level goals without passing the goals
themselves around. once that's possible we can remove visible goals as a
concept and rely on build result futures and a scheduler built upon them
Change-Id: Ia73cdeffcfb9ba1ce9d69b702dc0bc637a4c4ce6
whether goal errors are reported via the `ex` member or just printed to
the log depends on whether the goal is a toplevel goal or a dependency.
if goals are aware of this themselves we can move error printing out of
the worker loop, and since a running worker can only be used by running
goals it's totally sufficient to keep a `Worker::running` flag for this
Change-Id: I6b5cbe6eccee1afa5fde80653c4b968554ddd16f
this makes WorkResult copyable, and just all around easier to deal with.
in the future we'll need this to let Goal::work() return a promise for a
WorkResult (or even just a Finished) that can be awaited by other goals.
Change-Id: Ic5a1ce04c5a0f8e683bd00a2ed2b77a2e28989c1
this should be done where we're actually trying to build something, not
in the main worker loop that shouldn't have to be aware of such details
Change-Id: I07276740c0e2e5591a8ce4828a4bfc705396527e
This caused an absolute saga which I would not like anyone else to have
to experience. Let's put in a laser targeted error message that
diagnoses this exact problem.
Fixes: https://git.lix.systems/lix-project/lix/issues/484
Change-Id: I2a79f04aeb4a1b67c10115e5e39501d958836298
this can be a proper WorkResult now. childTerminated is unfortunately a
lot more stubborn and won't be made private for quite a while yet. once
we can get rid of the Worker poll loop that *should* be possible though
Change-Id: I2218df202da5cb84e852f6a37e4c20367495b617
we'll need this once we want to pass extra information out of accepting
replies, such as fd sets or possibly even async output reader promises.
Change-Id: I5e2f18cdb80b0d2faf3067703cc18bd263329b3f
don't keep fds open we're not using. currently this does not cause any
problems, but it does increase the size of our fd table needlessly and
in the future, when we have proper async processing, having builderOut
open in the daemon once the hook has been fully started is problematic
Change-Id: I6e7fb773b280b042873103638d3e04272ca1e4fc
this is useless to do on the face of it, but it'll make it easier to
convert the entire output handling to use async io and promises soon
Change-Id: I2d1eb62c4bbf8f57bd558b9599c08710a389b1a8
eldritch horrors