Move 'super-long post delayed task' warning to IncomingTaskQueue.

base/message_loop/incoming_task_queue.cc

 // Copyright 2013 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.
 
 #include "base/message_loop/incoming_task_queue.h"
 
+#include <limits>
+
 #include "base/location.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/time/time.h"
 
 namespace base {
 namespace internal {
 
 namespace {
 
+// Delays larger than this many microseconds are often bogus, and a warning
+// should be emitted in debug builds to warn developers.
+// http://crbug.com/450045
+const int kTaskDelayWarningThresholdInMicroseconds =
+    std::numeric_limits<int>::max() / 2;  // A little less than 18 minutes.
+
 // Returns true if MessagePump::ScheduleWork() must be called one
 // time for every task that is added to the MessageLoop incoming queue.
 bool AlwaysNotifyPump(MessageLoop::Type type) {
 #if defined(OS_ANDROID)
   // The Android UI message loop needs to get notified each time a task is
   // added
   // to the incoming queue.
   return type == MessageLoop::TYPE_UI || type == MessageLoop::TYPE_JAVA;
 #else
   return false;
 #endif
 }
 
 }  // namespace
 
 IncomingTaskQueue::IncomingTaskQueue(MessageLoop* message_loop)
     : high_res_task_count_(0),
       message_loop_(message_loop),
       next_sequence_num_(0),
       message_loop_scheduled_(false),
       always_schedule_work_(AlwaysNotifyPump(message_loop_->type())) {
 }
 
 bool IncomingTaskQueue::AddToIncomingQueue(
     const tracked_objects::Location& from_here,
     const Closure& task,
     TimeDelta delay,
     bool nestable) {
+  DLOG_IF(WARNING,
+          delay.InMicroseconds() > kTaskDelayWarningThresholdInMicroseconds)
+      << "Requesting super-long task delay period of " << delay.InMicroseconds()
+      << " usec from here: " << from_here.ToString();
+
   AutoLock locked(incoming_queue_lock_);
   PendingTask pending_task(
       from_here, task, CalculateDelayedRuntime(delay), nestable);
 #if defined(OS_WIN)
   // We consider the task needs a high resolution timer if the delay is
   // more than 0 and less than 32ms. This caps the relative error to
   // less than 50% : a 33ms wait can wake at 48ms since the default
   // resolution on Windows is between 10 and 15ms.
   if (delay > TimeDelta() &&
       delay.InMilliseconds() < (2 * Time::kMinLowResolutionThresholdMs)) {
@@ skipping 87 matching lines @@
     // reload from the incoming queue before waiting again so we clear this flag
     // in ReloadWorkQueue().
     message_loop_scheduled_ = true;
   }
 
   return true;
 }
 
 }  // namespace internal
 }  // namespace base