depot - monorepo for the virus lounge

Age	Commit message (Collapse)	Author	Files	Lines
2005-02-01	* Move root finding from `nix-collect-garbage' to `nix-store --gc'.	Eelco Dolstra	1	-5/+54
	This was necessary becase root finding must be done after acquisition of the global GC lock. This makes `nix-collect-garbage' obsolete; it is now just a wrapper around `nix-store --gc'. * Automatically remove stale GC roots (i.e., indirect GC roots that point to non-existent paths).
2005-02-01	* nix-build: use an indirection scheme to make it easier for users to	Eelco Dolstra	1	-19/+42
	get rid of GC roots. Nix-build places a symlink `result' in the current directory. Previously, removing that symlink would not remove the store path being linked to as a GC root. Now, the GC root created by nix-build is actually a symlink in `/nix/var/nix/gcroots/auto' to `result'. So if that symlink is removed the GC root automatically becomes invalid (since it can no longer be resolved). The root itself is not automatically removed - the garbage collector should delete dangling roots.
2005-02-01	* nix-store, nix-instantiate: added an option `--add-root' to	Eelco Dolstra	1	-0/+46
	immediately add the result as a permanent GC root. This is the only way to prevent a race with the garbage collector. For instance, the old style ln -s $(nix-store -r $(nix-instantiate foo.nix)) \ /nix/var/nix/gcroots/result has two time windows in which the garbage collector can interfere (by GC'ing the derivation and the output, respectively). On the other hand, nix-store --add-root /nix/var/nix/gcroots/result -r \ $(nix-instantiate --add-root /nix/var/nix/gcroots/drv \ foo.nix) is safe. * nix-build: use `--add-root' to prevent GC races.
2005-01-31	* Acquire a global GC lock to prevent new temporary root files from	Eelco Dolstra	1	-15/+29
	being created after the garbage collector has read the temproots directory. This blocks the creation of new processes, but the garbage collector could periodically release the GC lock to allow them to run.
2005-01-31	* Add a test for a more subtle race: a process starting after the	Eelco Dolstra	1	-2/+20
	temporary root files have been read but creating outputs before the store directory has been read.
2005-01-31	* Automatically remove temporary root files.	Eelco Dolstra	1	-1/+11

2005-01-31	* Topologically sort paths under the references relation to ensure	Eelco Dolstra	1	-35/+77
	that they are deleted in an order that maintains the closure invariant. * Presence of a path in a temporary roots file does not imply that all paths in its closure are also present, so add the closure.
2005-01-31	* Don't delete active lock files.	Eelco Dolstra	1	-0/+26

2005-01-31	* Start of concurrent garbage collection. Processes write temporary	Eelco Dolstra	1	-97/+148
	roots to a per-process temporary file in /nix/var/nix/temproots while holding a write lock on that file. The garbage collector acquires read locks on all those files, thus blocking further progress in other Nix processes, and reads the sets of temporary roots.
2005-01-27	* Fix and simplify the garbage collector (it's still not concurrent,	Eelco Dolstra	1	-1/+57
	though). In particular it's now much easier to register a GC root. Just place a symlink to whatever store path it is that you want to keep in /nix/var/nix/gcroots.
2005-01-19	* Renamed `normalise.cc' -> `build.cc', `storeexprs.cc' ->	Eelco Dolstra	1	-1/+1
	`derivations.cc', etc. * Store the SHA-256 content hash of store paths in the database after they have been built/added. This is so that we can check whether the store has been messed with (a la `rpm --verify'). * When registering path validity, verify that the closure property holds.
2005-01-19	* Started removing closure store expressions, i.e., the explicit	Eelco Dolstra	1	-0/+2
	representation of closures as ATerms in the Nix store. Instead, the file system pointer graph is now stored in the Nix database. This has many advantages: - It greatly simplifies the implementation (we can drop the notion of `successors', and so on). - It makes registering roots for the garbage collector much easier. Instead of specifying the closure expression as a root, you can simply specify the store path that must be retained as a root. This could not be done previously, since there was no way to find the closure store expression containing a given store path. - Better traceability: it is now possible to query what paths are referenced by a path, and what paths refer to a path.
2004-08-25	* `--min-age' flag in nix-store and nix-collect-garbage to only delete	Eelco Dolstra	1	-1/+16
	unreachable paths that haven't been used for N hours. For instance, `nix-collect-garbage --min-age 168' only deletes paths that haven't been accessed in the last week. This is useful for instance in the build farm where many derivations can be shared between consecutive builds, and we wouldn't want a garbage collect to throw them all away. We could of course register them as roots, but then we'd to unregister them at some point, which would be a pain to manage. The `--min-age' flag gives us a sort of MRU caching scheme. BUG: this really shouldn't be in gc.cc since that violates mechanism/policy separation.
2004-08-25	* Put the garbage collector in nix-store: operation `--gc',	Eelco Dolstra	1	-0/+83
	suboperations `--print-live', `--print-dead', and `--delete'. The roots are not determined by nix-store; they are read from standard input. This is to make it easy to customise what the roots are. The collector now no longer fails when store expressions are missing (which legally happens when using substitutes). It never tries to fetch paths through substitutes. TODO: acquire a global lock on the store while garbage collecting. * Removed `nix-store --delete'.