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[uuid(ef194cab-3f86-4b61-b132-e5e96a79e5d1)]
10interface nsIThreadPoolListener : nsISupports
11{
12  /**
13   * Called when a new thread is created by the thread pool. The notification
14   * happens on the newly-created thread.
15   */
16  void onThreadCreated();
17
18  /**
19   * Called when a thread is about to be destroyed by the thread pool. The
20   * notification happens on the thread that is about to be destroyed.
21   */
22  void onThreadShuttingDown();
23};
24
25/**
26 * An interface to a thread pool.  A thread pool creates a limited number of
27 * anonymous (unnamed) worker threads.  An event dispatched to the thread pool
28 * will be run on the next available worker thread.
29 */
30[uuid(76ce99c9-8e43-489a-9789-f27cc4424965)]
31interface nsIThreadPool : nsIEventTarget
32{
33  /**
34   * Shutdown the thread pool.  This method may not be executed from any thread
35   * in the thread pool.  Instead, it is meant to be executed from another
36   * thread (usually the thread that created this thread pool).  When this
37   * function returns, the thread pool and all of its threads will be shutdown,
38   * and it will no longer be possible to dispatch tasks to the thread pool.
39   *
40   * As a side effect, events on the current thread will be processed.
41   */
42  void shutdown();
43
44  /**
45   * Shutdown the thread pool, but only wait for aTimeoutMs. After the timeout
46   * expires, any threads that have not shutdown yet are leaked and will not
47   * block shutdown.
48   *
49   * This method should only be used at during shutdown to cleanup threads that
50   * made blocking calls to code outside our control, and can't be safely
51   * terminated. We choose to leak them intentionally to avoid a shutdown hang.
52   */
53  [noscript] void shutdownWithTimeout(in long aTimeoutMs);
54
55  /**
56   * Get/set the maximum number of threads allowed at one time in this pool.
57   */
58  attribute unsigned long threadLimit;
59
60  /**
61   * Get/set the maximum number of idle threads kept alive.
62   */
63  attribute unsigned long idleThreadLimit;
64
65  /**
66   * Get/set the amount of time in milliseconds before an idle thread is
67   * destroyed.
68   */
69  attribute unsigned long idleThreadTimeout;
70
71  /**
72   * If set to true the idle timeout will be calculated as idleThreadTimeout
73   * divideded by the number of idle threads at the moment.  This may help
74   * save memory allocations but still keep reasonable amount of idle threads.
75   * Default is false, use |idleThreadTimeout| for all threads.
76   */
77  attribute boolean idleThreadTimeoutRegressive;
78
79  /**
80   * Get/set the number of bytes reserved for the stack of all threads in
81   * the pool. By default this is nsIThreadManager::DEFAULT_STACK_SIZE.
82   */
83  attribute unsigned long threadStackSize;
84
85  /**
86   * An optional listener that will be notified when a thread is created or
87   * destroyed in the course of the thread pool's operation.
88   *
89   * A listener will only receive notifications about threads created after the
90   * listener is set so it is recommended that the consumer set the listener
91   * before dispatching the first event. A listener that receives an
92   * onThreadCreated() notification is guaranteed to always receive the
93   * corresponding onThreadShuttingDown() notification.
94   *
95   * The thread pool takes ownership of the listener and releases it when the
96   * shutdown() method is called. Threads created after the listener is set will
97   * also take ownership of the listener so that the listener will be kept alive
98   * long enough to receive the guaranteed onThreadShuttingDown() notification.
99   */
100  attribute nsIThreadPoolListener listener;
101
102  /**
103   * Set the label for threads in the pool. All threads will be named
104   * "<aName> #<n>", where <n> is a serial number.
105   */
106  void setName(in ACString aName);
107};
108