src/hotspot/share/services/attachListener.hpp

@@ -24,10 +24,12 @@
 
 #ifndef SHARE_SERVICES_ATTACHLISTENER_HPP
 #define SHARE_SERVICES_ATTACHLISTENER_HPP
 
 #include "memory/allocation.hpp"
+#include "metaprogramming/isRegisteredEnum.hpp"
+#include "runtime/atomic.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/macros.hpp"
 #include "utilities/ostream.hpp"
 

@@ -47,34 +49,64 @@
 struct AttachOperationFunctionInfo {
   const char* name;
   AttachOperationFunction func;
 };
 
+enum AttachListenerState {
+  AL_NOT_INITIALIZED,
+  AL_INITIALIZING,
+  AL_INITIALIZED
+};
+
+template<> struct IsRegisteredEnum<AttachListenerState> : public TrueType {};
+
 class AttachListener: AllStatic {
  public:
   static void vm_start() NOT_SERVICES_RETURN;
   static void init()  NOT_SERVICES_RETURN;
   static void abort() NOT_SERVICES_RETURN;
 
   // invoke to perform clean-up tasks when all clients detach
   static void detachall() NOT_SERVICES_RETURN;
 
+  // check unix domain socket file on filesystem
+  static bool check_socket_file() NOT_SERVICES_RETURN_(false);
+
   // indicates if the Attach Listener needs to be created at startup
   static bool init_at_startup() NOT_SERVICES_RETURN_(false);
 
   // indicates if we have a trigger to start the Attach Listener
   static bool is_init_trigger() NOT_SERVICES_RETURN_(false);
 
 #if !INCLUDE_SERVICES
   static bool is_attach_supported()             { return false; }
 #else
+
  private:
-  static volatile bool _initialized;
+  static volatile AttachListenerState _state;
 
  public:
-  static bool is_initialized()                  { return _initialized; }
-  static void set_initialized()                 { _initialized = true; }
+  static void set_state(AttachListenerState new_state) {
+    Atomic::store(new_state, &_state);
+  }
+
+  static AttachListenerState get_state() {
+    return Atomic::load(&_state);
+  }
+
+  static AttachListenerState transit_state(AttachListenerState new_state,
+                                           AttachListenerState cmp_state) {
+    return Atomic::cmpxchg(new_state, &_state, cmp_state);
+  }
+
+  static bool is_initialized() {
+    return Atomic::load(&_state) == AL_INITIALIZED;
+  }
+
+  static void set_initialized() {
+    Atomic::store(AL_INITIALIZED, &_state);
+  }
 
   // indicates if this VM supports attach-on-demand
   static bool is_attach_supported()             { return !DisableAttachMechanism; }
 
   // platform specific initialization