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authorEelco Dolstra <e.dolstra@tudelft.nl>2005-02-01T12·36+0000
committerEelco Dolstra <e.dolstra@tudelft.nl>2005-02-01T12·36+0000
commitdcc37c236c66ba463bd61fec23d046485d8a412f (patch)
treeb1a34feaf2a9a0ca0e0bad89c1671289de9e19d2 /src/libmain/shared.hh
parenta6b65fd5e107416588a6572a88518d8816abcb12 (diff)
* nix-store, nix-instantiate: added an option `--add-root' to
  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.

Diffstat (limited to 'src/libmain/shared.hh')
-rw-r--r--src/libmain/shared.hh4
1 files changed, 4 insertions, 0 deletions
diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index 76b639e3785d..82da7550626f 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -17,6 +17,10 @@ void run(Strings args);
 /* Should print a help message to stdout and return. */
 void printHelp();
 
+/* Ugh.  No better place to put this. */
+Path makeRootName(const Path & gcRoot, int & counter);
+void printGCWarning();
+
 
 extern string programId;