Isolate CLI workers and module serialization

scripts/test_server_arguments.sh

@@ -38,7 +38,8 @@ socket_inode=$(stat -c %i "$socket_path")
 invoke() {
 	local output="$1"
 	shift
-	timeout --signal=TERM --kill-after=1s 2s unshare --mount --fork \
+	local timeout_seconds="${INVOKE_TIMEOUT_SECONDS:-2}"
+	timeout --signal=TERM --kill-after=1s "$timeout_seconds" unshare --mount --fork \
 		bash -c 'mount --bind "$1" /etc/uce/settings.cfg; exec "$2" "${@:3}"' \
 		_ "$cfg" "$binary" "$@" >"$output.stdout" 2>"$output.stderr"
 }
@@ -47,10 +48,11 @@ for option in --help -h; do
 	invoke "$root/help" "$option"
 	grep -q '^Usage: uce_fastcgi' "$root/help.stdout"
 	grep -q -- '--precompile' "$root/help.stdout"
+	grep -q -- '--serialize-module' "$root/help.stdout"
 	[[ ! -s "$root/help.stderr" ]]
 done
 
-for arguments in '--unknown' '--precompile extra' '--help extra'; do
+for arguments in '--unknown' '--precompile extra' '--serialize-module' '--help extra'; do
 	read -r -a argv <<<"$arguments"
 	set +e
 	invoke "$root/invalid" "${argv[@]}"
@@ -62,6 +64,36 @@ for arguments in '--unknown' '--precompile extra' '--help extra'; do
 	[[ ! -s "$root/invalid.stdout" ]]
 done
 
+cp bin/wasm/core.wasm "$root/serialize.wasm"
+INVOKE_TIMEOUT_SECONDS=30 invoke "$root/serialize" --serialize-module "$root/serialize.wasm"
+[[ -s "$root/serialize.cwasm" ]]
+[[ ! -s "$root/serialize.stderr" ]]
+
+# Serialization shares the unit compile lock. If the wasm path is replaced
+# while the serializer is waiting, it must read the replacement and must not
+# publish a stale native artifact for the old inode.
+cp bin/wasm/core.wasm "$root/race.wasm"
+exec 8>"$root/race.wasm.lock"
+flock 8
+INVOKE_TIMEOUT_SECONDS=30 invoke "$root/race" --serialize-module "$root/race.wasm" &
+race_pid=$!
+sleep 0.1
+kill -0 "$race_pid"
+printf 'not wasm\n' >"$root/race.wasm.next"
+mv "$root/race.wasm.next" "$root/race.wasm"
+flock -u 8
+set +e
+wait "$race_pid"
+race_rc=$?
+set -e
+[[ $race_rc -eq 1 ]]
+grep -Eqi 'wasm|magic|WebAssembly|compile' "$root/race.stderr"
+[[ ! -e "$root/race.cwasm" ]]
+if compgen -G "$root/race.cwasm.*.tmp" >/dev/null; then
+	echo "failed serialization left a temporary artifact" >&2
+	exit 1
+fi
+
 [[ -S "$socket_path" ]]
 [[ "$(stat -c %i "$socket_path")" == "$socket_inode" ]]
 kill -0 "$listener_pid"