gc-non-blocking.sh: Add explanation

Also name the _NIX_TEST_GC_SYNC environment variables logically.
This commit is contained in:
Eelco Dolstra 2024-01-12 12:38:55 +01:00
parent 5703c31325
commit 3e23759834
2 changed files with 19 additions and 11 deletions

View file

@ -511,7 +511,7 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
/* Synchronisation point to test ENOENT handling in
addTempRoot(), see tests/gc-non-blocking.sh. */
if (auto p = getEnv("_NIX_TEST_GC_SYNC_2"))
if (auto p = getEnv("_NIX_TEST_GC_SYNC_1"))
readFile(*p);
/* Start the server for receiving new roots. */
@ -637,6 +637,10 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
roots.insert(root.first);
}
/* Synchronisation point for testing, see tests/functional/gc-non-blocking.sh. */
if (auto p = getEnv("_NIX_TEST_GC_SYNC_2"))
readFile(*p);
/* Helper function that deletes a path from the store and throws
GCLimitReached if we've deleted enough garbage. */
auto deleteFromStore = [&](std::string_view baseName)
@ -783,10 +787,6 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
}
};
/* Synchronisation point for testing, see tests/functional/gc-non-blocking.sh. */
if (auto p = getEnv("_NIX_TEST_GC_SYNC"))
readFile(*p);
/* Either delete all garbage paths, or just the specified
paths (for gcDeleteSpecific). */
if (options.action == GCOptions::gcDeleteSpecific) {

View file

@ -6,10 +6,14 @@ needLocalStore "the GC test needs a synchronisation point"
clearStore
fifo=$TEST_ROOT/test.fifo
mkfifo "$fifo"
# This FIFO is read just after the global GC lock has been acquired,
# but before the root server is started.
fifo1=$TEST_ROOT/test2.fifo
mkfifo "$fifo1"
fifo2=$TEST_ROOT/test2.fifo
# This FIFO is read just after the roots have been read, but before
# the actual GC starts.
fifo2=$TEST_ROOT/test.fifo
mkfifo "$fifo2"
dummy=$(nix store add-path ./simple.nix)
@ -17,19 +21,23 @@ dummy=$(nix store add-path ./simple.nix)
running=$TEST_ROOT/running
touch $running
(_NIX_TEST_GC_SYNC=$fifo _NIX_TEST_GC_SYNC_2=$fifo2 nix-store --gc -vvvvv; rm $running) &
# Start GC.
(_NIX_TEST_GC_SYNC_1=$fifo1 _NIX_TEST_GC_SYNC_2=$fifo2 nix-store --gc -vvvvv; rm $running) &
pid=$!
sleep 2
(sleep 1; echo > $fifo2) &
# Delay the start of the root server to check that the build below
# correctly handles ENOENT when connecting to the root server.
(sleep 1; echo > $fifo1) &
pid2=$!
# Start a build. This should not be blocked by the GC in progress.
outPath=$(nix-build --max-silent-time 60 -o "$TEST_ROOT/result" -E "
with import ./config.nix;
mkDerivation {
name = \"non-blocking\";
buildCommand = \"set -x; test -e $running; mkdir \$out; echo > $fifo\";
buildCommand = \"set -x; test -e $running; mkdir \$out; echo > $fifo2\";
}")
wait $pid