Fix systemd misjudging by sending heartbeats.

.idea/compiler.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="TypeScriptCompiler">
+    <option name="useService" value="false" />
+  </component>
+</project>

main.rb

@@ -24,6 +24,7 @@ end
 
 require_relative 'method_executor' # 日志系统在此时初始化
 require_relative 'server_status_detector'
+require_relative 'systemd_notifier' # 心跳系统在此时初始化
 
 MethodExecutor.record("info", "mainloop", "MineSentinel started, entering mainloop.")
 
@@ -58,9 +59,13 @@ def main
         MethodExecutor.record("info", "mainloop", "Action: ForceResetServerProcess triggered.")
         MethodExecutor.reset_minecraft_server
         # 重启后等待服务器启动（MC服务器启动通常需要30秒~2分钟）
-        cooldown = 200 # 200秒冷却期
+        cooldown_duration = 200 # 200秒冷却期
+        cooldown_beg = Time.now
         MethodExecutor.record("info", "mainloop", "Cooling down #{cooldown}s for server startup...")
-        sleep cooldown
+        while Time.now < cooldown_beg + cooldown_duration
+          sleep 1
+          SystemdNotifier.notify("WATCHDOG=1")
+        end
         MethodExecutor.record("info", "mainloop", "Cooldown finished, resuming monitoring.")
       end
     end
@@ -70,5 +75,6 @@ end
 
 while true
   sleep 1.5
+  SystemdNotifier.notify("WATCHDOG=1")
   main
 end

method_executor.rb

@@ -121,4 +121,5 @@ class MethodExecutor
 
 
   end
-  end
+
+end

systemd_notifier.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+class SystemdNotifier
+  require_relative 'method_executor'
+  public
+
+  @notify_socket = ENV["NOTIFY_SOCKET"]
+  @watchdog_usec = (ENV["WATCHDOG_USEC"] || '0').to_i
+
+  unless @notify_socket && File.socket?(@notify_socket)
+    MethodExecutor.record("error", "heartbeat", "NOTIFY_SOCKET is not set or is not a socket, am I a service?")
+    @enable_heartbeat = false
+  else
+    @enable_heartbeat = true
+    @socket = UNIXSocket.new(@notify_socket)
+  end
+
+  def enabled?
+    @enable_heartbeat
+  end
+
+  def notify_heartbeat(message)
+    return unless @enable_heartbeat
+
+    begin
+      @socket.send(message, 0)
+    rescue => e
+      MethodExecutor.error("heartbeat", "Failed to send heartbeat: #{e}")
+      @enable_heartbeat = false
+    end
+  end
+
+  def self.notify(message)
+    MethodExecutor.record("info", "systemd", message)
+  end
+end