xpcom/threads/nsIThread.idl

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsIEventTarget.idl"
   8
   9 [ptr] native PRThread(PRThread);
  10
  11 /**
  12  * This interface provides a high-level abstraction for an operating system
  13  * thread.
  14  *
  15  * Threads have a built-in event queue, and a thread is an event target that
  16  * can receive nsIRunnable objects (events) to be processed on the thread.
  17  *
  18  * See nsIThreadManager for the API used to create and locate threads.
  19  */
  20 [scriptable, uuid(9c889946-a73a-4af3-ae9a-ea64f7d4e3ca)]
  21 interface nsIThread : nsIEventTarget
  22 {
  23   /**
  24    * @returns
  25    *   The NSPR thread object corresponding to this nsIThread.
  26    */
  27   [noscript] readonly attribute PRThread PRThread;
  28
  29   /**
  30    * Shutdown the thread.  This method prevents further dispatch of events to
  31    * the thread, and it causes any pending events to run to completion before
  32    * the thread joins (see PR_JoinThread) with the current thread.  During this
  33    * method call, events for the current thread may be processed.
  34    *
  35    * This method MAY NOT be executed from the thread itself.  Instead, it is
  36    * meant to be executed from another thread (usually the thread that created
  37    * this thread or the main application thread).  When this function returns,
  38    * the thread will be shutdown, and it will no longer be possible to dispatch
  39    * events to the thread.
  40    *
  41    * @throws NS_ERROR_UNEXPECTED
  42    *   Indicates that this method was erroneously called when this thread was
  43    *   the current thread, that this thread was not created with a call to
  44    *   nsIThreadManager::NewThread, or if this method was called more than once
  45    *   on the thread object.
  46    */
  47   void shutdown();
  48
  49   /**
  50    * This method may be called to determine if there are any events ready to be
  51    * processed.  It may only be called when this thread is the current thread.
  52    *
  53    * Because events may be added to this thread by another thread, a "false"
  54    * result does not mean that this thread has no pending events.  It only
  55    * means that there were no pending events when this method was called.
  56    *
  57    * @returns
  58    *   A boolean value that if "true" indicates that this thread has one or
  59    *   more pending events.
  60    *
  61    * @throws NS_ERROR_UNEXPECTED
  62    *   Indicates that this method was erroneously called when this thread was
  63    *   not the current thread.
  64    */
  65   boolean hasPendingEvents();
  66
  67   /**
  68    * Process the next event.  If there are no pending events, then this method
  69    * may wait -- depending on the value of the mayWait parameter -- until an
  70    * event is dispatched to this thread.  This method is re-entrant but may
  71    * only be called if this thread is the current thread.
  72    *
  73    * @param mayWait
  74    *   A boolean parameter that if "true" indicates that the method may block
  75    *   the calling thread to wait for a pending event.
  76    *
  77    * @returns
  78    *   A boolean value that if "true" indicates that an event was processed.
  79    *
  80    * @throws NS_ERROR_UNEXPECTED
  81    *   Indicates that this method was erroneously called when this thread was
  82    *   not the current thread.
  83    */
  84   boolean processNextEvent(in boolean mayWait);
  85 };