src/hotspot/os/linux/attachListener_linux.cpp

*** 1,7 ****
  /*
!  * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 67,87 ****
    static bool _has_path;
  
    // the file descriptor for the listening socket
    static int _listener;
  
!   static void set_path(char* path) {
!     if (path == NULL) {
!       _has_path = false;
!     } else {
!       strncpy(_path, path, UNIX_PATH_MAX);
!       _path[UNIX_PATH_MAX-1] = '\0';
!       _has_path = true;
!     }
!   }
! 
!   static void set_listener(int s)               { _listener = s; }
  
    // reads a request from the given connected socket
    static LinuxAttachOperation* read_request(int s);
  
   public:
--- 67,77 ----
    static bool _has_path;
  
    // the file descriptor for the listening socket
    static int _listener;
  
!   static bool _atexit_registered;
  
    // reads a request from the given connected socket
    static LinuxAttachOperation* read_request(int s);
  
   public:
*** 90,99 ****
--- 80,102 ----
    };
    enum {
      ATTACH_ERROR_BADVERSION     = 101           // error codes
    };
  
+   static void set_path(char* path) {
+     if (path == NULL) {
+       _path[0] = '\0';
+       _has_path = false;
+     } else {
+       strncpy(_path, path, UNIX_PATH_MAX);
+       _path[UNIX_PATH_MAX-1] = '\0';
+       _has_path = true;
+     }
+   }
+ 
+   static void set_listener(int s)               { _listener = s; }
+ 
    // initialize the listener, returns 0 if okay
    static int init();
  
    static char* path()                   { return _path; }
    static bool has_path()                { return _has_path; }
*** 123,132 ****
--- 126,136 ----
  
  // statics
  char LinuxAttachListener::_path[UNIX_PATH_MAX];
  bool LinuxAttachListener::_has_path;
  int LinuxAttachListener::_listener = -1;
+ bool LinuxAttachListener::_atexit_registered = false;
  
  // Supporting class to help split a buffer into individual components
  class ArgumentIterator : public StackObj {
   private:
    char* _pos;
*** 157,176 ****
  
  // atexit hook to stop listener and unlink the file that it is
  // bound too.
  extern "C" {
    static void listener_cleanup() {
-     static int cleanup_done;
-     if (!cleanup_done) {
-       cleanup_done = 1;
        int s = LinuxAttachListener::listener();
        if (s != -1) {
          ::close(s);
        }
        if (LinuxAttachListener::has_path()) {
          ::unlink(LinuxAttachListener::path());
!       }
      }
    }
  }
  
  // Initialization - create a listener socket and bind it to a file
--- 161,179 ----
  
  // atexit hook to stop listener and unlink the file that it is
  // bound too.
  extern "C" {
    static void listener_cleanup() {
      int s = LinuxAttachListener::listener();
      if (s != -1) {
+       LinuxAttachListener::set_listener(-1);
+       ::shutdown(s, SHUT_RDWR);
        ::close(s);
      }
      if (LinuxAttachListener::has_path()) {
        ::unlink(LinuxAttachListener::path());
!       LinuxAttachListener::set_path(NULL);
      }
    }
  }
  
  // Initialization - create a listener socket and bind it to a file
*** 179,189 ****
--- 182,195 ----
    char path[UNIX_PATH_MAX];          // socket file
    char initial_path[UNIX_PATH_MAX];  // socket file during setup
    int listener;                      // listener socket (file descriptor)
  
    // register function to cleanup
+   if (!_atexit_registered) {
+     _atexit_registered = true;
      ::atexit(listener_cleanup);
+   }
  
    int n = snprintf(path, UNIX_PATH_MAX, "%s/.java_pid%d",
                     os::get_temp_directory(), os::current_process_id());
    if (n < (int)UNIX_PATH_MAX) {
      n = snprintf(initial_path, UNIX_PATH_MAX, "%s.tmp", path);
*** 483,492 ****
--- 489,518 ----
    thread->check_and_wait_while_suspended();
  
    return ret_code;
  }
  
+ bool AttachListener::check_socket_file() {
+   int ret;
+   struct stat64 st;
+   ret = stat64(LinuxAttachListener::path(), &st);
+   if (ret == -1) { // need to restart attach listener.
+     log_debug(attach)("Socket file %s does not exist - Restart Attach Listener",
+                       LinuxAttachListener::path());
+ 
+     listener_cleanup();
+ 
+     // wait to terminate current attach listener instance...
+     while (AttachListener::transit_state(AL_INITIALIZING,
+                                          AL_NOT_INITIALIZED) != AL_NOT_INITIALIZED) {
+       os::naked_yield();
+     }
+     return is_init_trigger();
+   }
+   return false;
+ }
+ 
  // Attach Listener is started lazily except in the case when
  // +ReduseSignalUsage is used
  bool AttachListener::init_at_startup() {
    if (ReduceSignalUsage) {
      return true;