NEX-19665 Several door servers don't properly handle exiting threads
Review by: Gordon Ross <gordon.ross@nexenta.com>
Review by: Evan Layton <evan.layton@nexenta.com>

*** 19,28 ****
--- 19,29 ----
   * CDDL HEADER END
   */
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
+  * Copyright 2019 Nexenta Systems, Inc.
   */
  
  /*
   * Simple doors ldap cache daemon
   */
*** 223,239 ****
  
  /*ARGSUSED*/
  static void *
  server_tsd_bind(void *arg)
  {
!         static void     *value = 0;
  
          /*
           * disable cancellation to prevent hangs when server
           * threads disappear
           */
! 
          (void) thr_setspecific(server_key, value);
          (void) door_return(NULL, 0, NULL, 0);
  
          return (value);
  }
--- 224,240 ----
  
  /*ARGSUSED*/
  static void *
  server_tsd_bind(void *arg)
  {
!         static void *value = "NON-NULL TSD";
  
          /*
           * disable cancellation to prevent hangs when server
           * threads disappear
           */
!         (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
          (void) thr_setspecific(server_key, value);
          (void) door_return(NULL, 0, NULL, 0);
  
          return (value);
  }
*** 266,275 ****
--- 267,277 ----
  server_destroy(void *arg)
  {
          (void) mutex_lock(&create_lock);
          num_servers--;
          (void) mutex_unlock(&create_lock);
+         (void) thr_setspecific(server_key, NULL);
  }
  
  static void             client_killserver();
  
  int