Add 'third_party/nix/' from commit 'be66c7a6b24e3c3c6157fd37b86c7203d14acf10'

git-subtree-dir: third_party/nix
git-subtree-mainline: cf8cd640c1
git-subtree-split: be66c7a6b24e3c3c6157fd37b86c7203d14acf10

third_party/nix/tests/gc-concurrent.sh

@@ -0,0 +1,58 @@
+source common.sh
+
+clearStore
+
+drvPath1=$(nix-instantiate gc-concurrent.nix -A test1)
+outPath1=$(nix-store -q $drvPath1)
+
+drvPath2=$(nix-instantiate gc-concurrent.nix -A test2)
+outPath2=$(nix-store -q $drvPath2)
+
+drvPath3=$(nix-instantiate simple.nix)
+outPath3=$(nix-store -r $drvPath3)
+
+(! test -e $outPath3.lock)
+touch $outPath3.lock
+
+rm -f "$NIX_STATE_DIR"/gcroots/foo*
+ln -s $drvPath2 "$NIX_STATE_DIR"/gcroots/foo
+ln -s $outPath3 "$NIX_STATE_DIR"/gcroots/foo2
+
+# Start build #1 in the background.  It starts immediately.
+nix-store -rvv "$drvPath1" &
+pid1=$!
+
+# Start build #2 in the background after 10 seconds.
+(sleep 10 && nix-store -rvv "$drvPath2") &
+pid2=$!
+
+# Run the garbage collector while the build is running.
+sleep 6
+nix-collect-garbage
+
+# Wait for build #1/#2 to finish.
+echo waiting for pid $pid1 to finish...
+wait $pid1
+echo waiting for pid $pid2 to finish...
+wait $pid2
+
+# Check that the root of build #1 and its dependencies haven't been
+# deleted.  The should not be deleted by the GC because they were
+# being built during the GC.
+cat $outPath1/foobar
+cat $outPath1/input-2/bar
+
+# Check that build #2 has succeeded.  It should succeed because the
+# derivation is a GC root.
+cat $outPath2/foobar
+
+rm -f "$NIX_STATE_DIR"/gcroots/foo*
+
+# The collector should have deleted lock files for paths that have
+# been built previously.
+(! test -e $outPath3.lock)
+
+# If we run the collector now, it should delete outPath1/2.
+nix-collect-garbage
+(! test -e $outPath1)
+(! test -e $outPath2)