xpcom/threads/nsIThreadPool.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 #include "nsIThread.idl"
   9
  10 [uuid(ef194cab-3f86-4b61-b132-e5e96a79e5d1)]
  11 interface nsIThreadPoolListener : nsISupports
  12 {
  13   /**
  14    * Called when a new thread is created by the thread pool. The notification
  15    * happens on the newly-created thread.
  16    */
  17   void onThreadCreated();
  18
  19   /**
  20    * Called when a thread is about to be destroyed by the thread pool. The
  21    * notification happens on the thread that is about to be destroyed.
  22    */
  23   void onThreadShuttingDown();
  24 };
  25
  26 /**
  27  * An interface to a thread pool.  A thread pool creates a limited number of
  28  * anonymous (unnamed) worker threads.  An event dispatched to the thread pool
  29  * will be run on the next available worker thread.
  30  */
  31 [rust_sync, uuid(76ce99c9-8e43-489a-9789-f27cc4424965)]
  32 interface nsIThreadPool : nsIEventTarget
  33 {
  34   /**
  35    * Set the entire pool's QoS priority. If the priority has not changed, do nothing.
  36    * Existing threads will update their QoS priority the next time they become
  37    * active, and newly created threads will set this QoS priority upon creation.
  38    */
  39    [noscript] void setQoSForThreads(in nsIThread_QoSPriority aPriority);
  40
  41   /**
  42    * Shutdown the thread pool.  This method may not be executed from any thread
  43    * in the thread pool.  Instead, it is meant to be executed from another
  44    * thread (usually the thread that created this thread pool).  When this
  45    * function returns, the thread pool and all of its threads will be shutdown,
  46    * and it will no longer be possible to dispatch tasks to the thread pool.
  47    *
  48    * As a side effect, events on the current thread will be processed.
  49    */
  50   void shutdown();
  51
  52   /**
  53    * Shutdown the thread pool, but only wait for aTimeoutMs. After the timeout
  54    * expires, any threads that have not shutdown yet are leaked and will not
  55    * block shutdown.
  56    *
  57    * This method should only be used at during shutdown to cleanup threads that
  58    * made blocking calls to code outside our control, and can't be safely
  59    * terminated. We choose to leak them intentionally to avoid a shutdown hang.
  60    */
  61   [noscript] void shutdownWithTimeout(in long aTimeoutMs);
  62
  63   /**
  64    * Get/set the maximum number of threads allowed at one time in this pool.
  65    */
  66   attribute unsigned long threadLimit;
  67
  68   /**
  69    * Get/set the maximum number of idle threads kept alive.
  70    */
  71   attribute unsigned long idleThreadLimit;
  72
  73   /**
  74    * Get/set the amount of time in milliseconds before an idle thread is
  75    * destroyed.
  76    */
  77   attribute unsigned long idleThreadTimeout;
  78
  79   /**
  80    * If set to true the idle timeout will be calculated as idleThreadTimeout
  81    * divideded by the number of idle threads at the moment.  This may help
  82    * save memory allocations but still keep reasonable amount of idle threads.
  83    * Default is false, use |idleThreadTimeout| for all threads.
  84    */
  85   attribute boolean idleThreadTimeoutRegressive;
  86
  87   /**
  88    * Get/set the number of bytes reserved for the stack of all threads in
  89    * the pool. By default this is nsIThreadManager::DEFAULT_STACK_SIZE.
  90    */
  91   attribute unsigned long threadStackSize;
  92
  93   /**
  94    * An optional listener that will be notified when a thread is created or
  95    * destroyed in the course of the thread pool's operation.
  96    *
  97    * A listener will only receive notifications about threads created after the
  98    * listener is set so it is recommended that the consumer set the listener
  99    * before dispatching the first event. A listener that receives an
 100    * onThreadCreated() notification is guaranteed to always receive the
 101    * corresponding onThreadShuttingDown() notification.
 102    *
 103    * The thread pool takes ownership of the listener and releases it when the
 104    * shutdown() method is called. Threads created after the listener is set will
 105    * also take ownership of the listener so that the listener will be kept alive
 106    * long enough to receive the guaranteed onThreadShuttingDown() notification.
 107    */
 108   attribute nsIThreadPoolListener listener;
 109
 110   /**
 111    * Set the label for threads in the pool. All threads will be named
 112    * "<aName> #<n>", where <n> is a serial number.
 113    */
 114   void setName(in ACString aName);
 115 };