Serialize Gradle and test runs

gradle-lock.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# Shared, process-safe lock for Gradle and IntelliJ platform test runs.
+# This file is sourced by jaigradle and jaitest; it is not a standalone command.
+
+JAI_GRADLE_LOCK_DIR="${JAI_GRADLE_LOCK_DIR:-.gradle-test.lock}"
+JAI_GRADLE_LOCK_PID_FILE="$JAI_GRADLE_LOCK_DIR/pid"
+
+jai_gradle_lock_acquire() {
+	if [[ "${JAI_GRADLE_LOCK_HELD:-0}" == "1" ]]; then
+		return 0
+	fi
+
+	local reported=0
+	while ! mkdir "$JAI_GRADLE_LOCK_DIR" 2>/dev/null; do
+		if [[ -f "$JAI_GRADLE_LOCK_PID_FILE" ]]; then
+			local owner
+			owner=$(<"$JAI_GRADLE_LOCK_PID_FILE")
+			if [[ "$owner" =~ ^[0-9]+$ ]] && ! kill -0 "$owner" 2>/dev/null; then
+				rm -rf "$JAI_GRADLE_LOCK_DIR"
+				continue
+			fi
+		else
+			# A process can be killed between mkdir and writing its PID. Give that
+			# tiny window a chance to finish, then reclaim the incomplete lock.
+			sleep 1
+			if [[ ! -f "$JAI_GRADLE_LOCK_PID_FILE" ]]; then
+				rm -rf "$JAI_GRADLE_LOCK_DIR"
+				continue
+			fi
+		fi
+
+		if ((reported == 0)); then
+			echo "Waiting for another Gradle/test run in this worktree..." >&2
+			reported=1
+		fi
+		sleep 1
+	done
+
+	printf '%s\n' "$$" >"$JAI_GRADLE_LOCK_PID_FILE"
+	JAI_GRADLE_LOCK_HELD=1
+	JAI_GRADLE_LOCK_OWNER_PID=$$
+	export JAI_GRADLE_LOCK_HELD JAI_GRADLE_LOCK_OWNER_PID
+}
+
+jai_gradle_lock_release() {
+	if [[ "${JAI_GRADLE_LOCK_OWNER_PID:-}" == "$$" ]]; then
+		rm -rf "$JAI_GRADLE_LOCK_DIR"
+		unset JAI_GRADLE_LOCK_OWNER_PID JAI_GRADLE_LOCK_HELD
+	fi
+}