xpcom/threads/nsIThread.idl

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   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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  22  * Contributor(s):
  23  *  Darin Fisher <darin@meer.net>
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  38
  39 #include "nsIEventTarget.idl"
  40
  41 [ptr] native PRThread(PRThread);
  42
  43 /**
  44  * This interface provides a high-level abstraction for an operating system
  45  * thread.
  46  *
  47  * Threads have a built-in event queue, and a thread is an event target that
  48  * can receive nsIRunnable objects (events) to be processed on the thread.
  49  *
  50  * See nsIThreadManager for the API used to create and locate threads.
  51  */
  52 [scriptable, uuid(9c889946-a73a-4af3-ae9a-ea64f7d4e3ca)]
  53 interface nsIThread : nsIEventTarget
  54 {
  55   /**
  56    * @returns
  57    *   The NSPR thread object corresponding to this nsIThread.
  58    */
  59   [noscript] readonly attribute PRThread PRThread;
  60
  61   /**
  62    * Shutdown the thread.  This method prevents further dispatch of events to
  63    * the thread, and it causes any pending events to run to completion before
  64    * the thread joins (see PR_JoinThread) with the current thread.  During this
  65    * method call, events for the current thread may be processed.
  66    *
  67    * This method MAY NOT be executed from the thread itself.  Instead, it is
  68    * meant to be executed from another thread (usually the thread that created
  69    * this thread or the main application thread).  When this function returns,
  70    * the thread will be shutdown, and it will no longer be possible to dispatch
  71    * events to the thread.
  72    *
  73    * @throws NS_ERROR_UNEXPECTED
  74    *   Indicates that this method was erroneously called when this thread was
  75    *   the current thread, that this thread was not created with a call to
  76    *   nsIThreadManager::NewThread, or if this method was called more than once
  77    *   on the thread object.
  78    */
  79   void shutdown();
  80
  81   /**
  82    * This method may be called to determine if there are any events ready to be
  83    * processed.  It may only be called when this thread is the current thread.
  84    *
  85    * Because events may be added to this thread by another thread, a "false"
  86    * result does not mean that this thread has no pending events.  It only
  87    * means that there were no pending events when this method was called.
  88    *
  89    * @returns
  90    *   A boolean value that if "true" indicates that this thread has one or
  91    *   more pending events.
  92    *
  93    * @throws NS_ERROR_UNEXPECTED
  94    *   Indicates that this method was erroneously called when this thread was
  95    *   not the current thread.
  96    */
  97   boolean hasPendingEvents();
  98
  99   /**
 100    * Process the next event.  If there are no pending events, then this method
 101    * may wait -- depending on the value of the mayWait parameter -- until an
 102    * event is dispatched to this thread.  This method is re-entrant but may
 103    * only be called if this thread is the current thread.
 104    *
 105    * @param mayWait
 106    *   A boolean parameter that if "true" indicates that the method may block
 107    *   the calling thread to wait for a pending event.
 108    *
 109    * @returns
 110    *   A boolean value that if "true" indicates that an event was processed.
 111    *
 112    * @throws NS_ERROR_UNEXPECTED
 113    *   Indicates that this method was erroneously called when this thread was
 114    *   not the current thread.
 115    */
 116   boolean processNextEvent(in boolean mayWait);
 117 };