9017 Introduce taskq_empty()
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Yuri Pankov <yuripv@yuripv.net>

*** 21,30 ****
--- 21,31 ----
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   *
   * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
+  * Copyright 2018, Joyent, Inc.
   */
  
  #ifndef _SYS_TASKQ_H
  #define _SYS_TASKQ_H
  
*** 78,87 ****
--- 79,89 ----
      struct proc *, uint_t, uint_t);
  extern taskqid_t taskq_dispatch(taskq_t *, task_func_t, void *, uint_t);
  extern void     nulltask(void *);
  extern void     taskq_destroy(taskq_t *);
  extern void     taskq_wait(taskq_t *);
+ extern boolean_t taskq_empty(taskq_t *);
  extern void     taskq_suspend(taskq_t *);
  extern int      taskq_suspended(taskq_t *);
  extern void     taskq_resume(taskq_t *);
  extern int      taskq_member(taskq_t *, kthread_t *);