Since the only construction and push_back() calls
to Bindings happen through the `BindingsBuilder` [1] we don't
need to keep `capacity` around on the heap anymore. This saves 8 bytes
(because of the member alignment padding)
per one Bindings allocation. This isn't that much, but it does
save significant memory.
This also shows that the Bindings don't necessarily have to
be mutable, which opens up opportunities for doing small bindings
optimization and storing a 1-element Bindings directly in Value.
For the following scenario:
nix-env --query --available --out-path --file ../nixpkgs --eval-system x86_64-linux
(nixpkgs revision: ddcddd7b09a417ca9a88899f4bd43a8edb72308d)
This patch results in reduction of `sets.bytes` 13115104016 -> 12653087640,
which amounts to 462 MB less bytes allocated for Bindings.
[1]: Not actually, `getBuiltins` does mutate bindings, but this is pretty
inconsequential and doesn't lead to problems.
This is relied upon (specifically the `local` store) by existing
tooling [1] and we broke this in 3e7879e6df (which
was first released in 2.31).
To lessen the scope of the breakage we should not normalize "auto" references
and explicitly specified references like "local" or "daemon". It also makes
sense to canonicalize local://,daemon:// to be more compatible with prior
behavior.
[1]: 05e1b3cba2/lib/NOM/Builds.hs (L60-L64)
Exactly why is is correct is a little subtle, because sometimes the
worker is owned by the worker. But the commit message in
e437b08250 explained the situation well
enough: I made that commit message part of the ABI docs, and now it
should be understandable to the next person.
Do this with a new `useHook` boolean we carefully make sure is set in
all cases. This change isn't really worthwhile by itself, but it allows
us to make further refactors (see later commits) which are
well-motivated.
When useMaster is true, startMaster() acquires the state lock, then
calls isMasterRunning(), which calls addCommonSSHOpts(), which tries
to acquire the state lock again, causing a deadlock.
The solution is to move tmpDir out of the state. It doesn't need to be
there in the first place because it never changes.
On macOS, poll() is fundamentally broken for HUP detection. It loses event
subscriptions when EVFILT_READ fires without matching the requested events
in the pollfd. This causes daemon processes to linger after client disconnect.
This commit replaces poll() with kqueue on macOS, which is what poll()
uses internally but without the bugs. The kqueue implementation uses
EVFILT_READ which works for both sockets and pipes, avoiding EVFILT_SOCK
which only works for sockets.
On Linux and other platforms, we continue using poll() with the standard
POSIX behavior where POLLHUP is always reported regardless of requested events.
Based on work from the Lix project (https://git.lix.systems/lix-project/lix)
commit 69ba3c92db3ecca468bcd5ff7849fa8e8e0fc6c0
Fixes: https://github.com/NixOS/nix/issues/13847
Related: https://git.lix.systems/lix-project/lix/issues/729
Apple bugs: rdar://37537852 (poll), FB17447257 (poll)
Co-authored-by: Jade Lovelace <jadel@mercury.com>
Now that Symbols are statically allocated at compile time with known IDs,
we can use switch statements instead of if-else chains for Symbol comparisons.
This provides better performance through compiler optimizations like jump tables.
Changes:
- Add public getId() method to Symbol class to access the internal ID
- Convert if-else chains comparing Symbol values to switch statements
in primops.cc's derivationStrictInternal function
- Simplify control flow by removing the 'handled' flag and moving the
default attribute handling into the switch's default case
The static and runtime Symbol IDs are guaranteed to match by the
copyIntoSymbolTable implementation which asserts this invariant.
Co-authored-by: John Ericson <git@JohnEricson.me>
In b70d22b `mkStringNoCopy()` was renamed to
`mkString()`, but this is a bit risky since in code like
vStringRegular.mkString("regular");
we want to be sure that the right overload is picked. (This is
especially problematic since the overload that takes an
`std::string_view` *does* allocate.) So let's be explicit.
(Rebased from https://github.com/NixOS/nix/pull/11551)
