#!/usr/bin/env bash

source common.sh

clearStore

lockFifo1=$TEST_ROOT/test1.fifo
mkfifo "$lockFifo1"

drvPath1=$(nix-instantiate gc-concurrent.nix -A test1 --argstr lockFifo "$lockFifo1")
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 "$drvPath1" &
pid1=$!

# Wait for the build of $drvPath1 to start
cat $lockFifo1

# Run the garbage collector while the build is running.
nix-collect-garbage

# Unlock the build of $drvPath1
echo "" > $lockFifo1
echo waiting for pid $pid1 to finish...
wait $pid1

# 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 the build build $drvPath2 succeeds.
# It should succeed because the derivation is a GC root.
nix-store -rvv "$drvPath2"
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)