1 files changed, 40 insertions, 0 deletions
diff --git a/xpcom/threads/nsICancelableRunnable.h b/xpcom/threads/nsICancelableRunnable.h
new file mode 100644
index 0000000000..7aa98c86b6
--- /dev/null
+++ b/xpcom/threads/nsICancelableRunnable.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsICancelableRunnable_h__
+#define nsICancelableRunnable_h__
+
+#include "nsISupports.h"
+
+#define NS_ICANCELABLERUNNABLE_IID                   \
+  {                                                  \
+    0xde93dc4c, 0x5eea, 0x4eb7, {                    \
+      0xb6, 0xd1, 0xdb, 0xf1, 0xe0, 0xce, 0xf6, 0x5c \
+    }                                                \
+  }
+
+class nsICancelableRunnable : public nsISupports {
+ public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_ICANCELABLERUNNABLE_IID)
+
+  /*
+   * Cancels a pending task, so that calling run() on the task is a no-op.
+   * Calling cancel after the task execution has begun will be a no-op.
+   * Calling this method twice is considered an error.
+   *
+   * @throws NS_ERROR_UNEXPECTED
+   *   Indicates that the runnable has already been canceled.
+   */
+  virtual nsresult Cancel() = 0;
+
+ protected:
+  nsICancelableRunnable() = default;
+  virtual ~nsICancelableRunnable() = default;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsICancelableRunnable, NS_ICANCELABLERUNNABLE_IID)
+
+#endif  // nsICancelableRunnable_h__