Support for process-wide incidents in the safe browsing incident reporting service.

chrome/browser/safe_browsing/delayed_callback_runner.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_SAFE_BROWSING_DELAYED_CALLBACK_RUNNER_H_
+#define CHROME_BROWSER_SAFE_BROWSING_DELAYED_CALLBACK_RUNNER_H_
+
+#include <list>
+
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "base/task_runner.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+
+namespace safe_browsing {
+
+// Runs callbacks on a given task runner, waiting a certain amount of time
+// between each. The delay also applies to running the first callback (i.e.,
+// the first callback will be run some time after Start() is invoked. Callbacks
+// are deleted after they are run. Start() is idempotent: calling it while the
+// runner is doing it job has no effect.

[robertshield, 2014/08/04 01:35:12]

its

[grt (UTC plus 2), 2014/08/04 14:15:33]

Done.

+class DelayedCallbackRunner {

[robertshield, 2014/08/04 01:35:12]

May be worth mentioning in the class comment that this class is not thread-safe/

[grt (UTC plus 2), 2014/08/04 14:15:33]

Added enforcement via ThreadChecker.

+ public:
+  // Constructs an instance that runs tasks on |callback_runner|, waiting for
+  // |delay| time to pass before and between each callback.
+  DelayedCallbackRunner(base::TimeDelta delay,
+                        base::TaskRunner* task_runner);
+  ~DelayedCallbackRunner();
+
+  // Registers |callback| with the runner.
+  void RegisterCallback(const base::Closure& callback);

[robertshield, 2014/08/04 01:35:12]

Is it worth mentioning that a copy of the Closure is held for the lifetime of
the DelayedCallbackRunner instance?

[grt (UTC plus 2), 2014/08/04 14:15:33]

it should be held only until it is run. comment and code updated.

+
+  // Starts running the callbacks after the delay.
+  void Start();
+
+ private:
+  typedef std::list<base::Closure> CallbackList;
+
+  // A callback invoked by the timer to run the next callback. The timer is
+  // restarted to process the next callback if there is one.
+  void OnTimer();
+
+  base::TaskRunner* task_runner_;
+
+  CallbackList callbacks_;
+
+  // callbacks_.end() when no work is being done. Any other value otherwise.
+  CallbackList::iterator next_callback_;
+
+  // A timer upon the firing of which the next callback will be run.
+  base::DelayTimer<DelayedCallbackRunner> timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(DelayedCallbackRunner);
+};
+
+}  // namespace safe_browsing
+
+#endif  // CHROME_BROWSER_SAFE_BROWSING_DELAYED_CALLBACK_RUNNER_H_