1 // Copyright 2013 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 #include "content/browser/renderer_host/input/timeout_monitor.h" 6 7 using base::Time; 8 using base::TimeDelta; 9 10 namespace content { 11 12 TimeoutMonitor::TimeoutMonitor(const TimeoutHandler& timeout_handler) 13 : timeout_handler_(timeout_handler) { 14 DCHECK(!timeout_handler_.is_null()); 15 } 16 17 TimeoutMonitor::~TimeoutMonitor() {} 18 19 void TimeoutMonitor::Start(TimeDelta delay) { 20 // Set time_when_considered_timed_out_ if it's null. Also, update 21 // time_when_considered_timed_out_ if the caller's request is sooner than the 22 // existing one. This will have the side effect that the existing timeout will 23 // be forgotten. 24 Time requested_end_time = Time::Now() + delay; 25 if (time_when_considered_timed_out_.is_null() || 26 time_when_considered_timed_out_ > requested_end_time) 27 time_when_considered_timed_out_ = requested_end_time; 28 29 // If we already have a timer with the same or shorter duration, then we can 30 // wait for it to finish. 31 if (timeout_timer_.IsRunning() && timeout_timer_.GetCurrentDelay() <= delay) { 32 // If time_when_considered_timed_out_ was null, this timer may fire early. 33 // CheckTimedOut handles that that by calling Start with the remaining time. 34 // If time_when_considered_timed_out_ was non-null, it means we still 35 // haven't been stopped, so we leave time_when_considered_timed_out_ as is. 36 return; 37 } 38 39 // Either the timer is not yet running, or we need to adjust the timer to 40 // fire sooner. 41 time_when_considered_timed_out_ = requested_end_time; 42 timeout_timer_.Stop(); 43 timeout_timer_.Start(FROM_HERE, delay, this, &TimeoutMonitor::CheckTimedOut); 44 } 45 46 void TimeoutMonitor::Restart(TimeDelta delay) { 47 // Setting to null will cause StartTimeoutMonitor to restart the timer. 48 time_when_considered_timed_out_ = Time(); 49 Start(delay); 50 } 51 52 void TimeoutMonitor::Stop() { 53 // We do not bother to stop the timeout_timer_ here in case it will be 54 // started again shortly, which happens to be the common use case. 55 time_when_considered_timed_out_ = Time(); 56 } 57 58 void TimeoutMonitor::CheckTimedOut() { 59 // If we received a call to |Stop()|. 60 if (time_when_considered_timed_out_.is_null()) 61 return; 62 63 // If we have not waited long enough, then wait some more. 64 Time now = Time::Now(); 65 if (now < time_when_considered_timed_out_) { 66 Start(time_when_considered_timed_out_ - now); 67 return; 68 } 69 70 timeout_handler_.Run(); 71 } 72 73 bool TimeoutMonitor::IsRunning() const { 74 return timeout_timer_.IsRunning() && 75 !time_when_considered_timed_out_.is_null(); 76 } 77 78 } // namespace content 79
