ios/chrome/app/deferred_initialization_runner.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef IOS_CHROME_APP_DEFERRED_INITIALIZATION_RUNNER_H_
   6 #define IOS_CHROME_APP_DEFERRED_INITIALIZATION_RUNNER_H_
   7
   8 #import <Foundation/Foundation.h>
   9
  10 #include "base/ios/block_types.h"
  11
  12 // A singleton object to run initialization code asynchronously. Blocks are
  13 // scheduled to be run after a delay. The block is named when added to the
  14 // singleton so that other code can force a deferred block to be run
  15 // synchronously if necessary.
  16 @interface DeferredInitializationRunner : NSObject
  17
  18 // Returns singleton instance.
  19 + (DeferredInitializationRunner*)sharedInstance;
  20
  21 // Schedules |block| to be run after |delaySeconds| on the current queue.
  22 // This |block| is stored as |name| so code can force this initialization to
  23 // be run synchronously if necessary. This method may be called more than
  24 // once with the same |name| parameter. Any block with the same |name|
  25 // cancels a previously scheduled block of the same |name| if the block has
  26 // not been run yet.
  27 - (void)runBlockNamed:(NSString*)name
  28                 after:(NSTimeInterval)delaySeconds
  29                 block:(ProceduralBlock)block;
  30
  31 // Looks up a previously scheduled block of |name|. If block has not been
  32 // run yet, run it synchronously now.
  33 - (void)runBlockIfNecessary:(NSString*)name;
  34
  35 // Cancels a previously scheduled block of |name|. This is a no-op if the
  36 // block has already been executed.
  37 - (void)cancelBlockNamed:(NSString*)name;
  38
  39 // Number of blocks that have been registered but not executed yet.
  40 // Exposed for testing.
  41 @property(nonatomic, readonly) NSUInteger numberOfBlocksRemaining;
  42
  43 @end
  44
  45 #endif  // IOS_CHROME_APP_DEFERRED_INITIALIZATION_RUNNER_H_