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| 1 // Copyright 2015 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/renderer/scheduler/resource_dispatch_throttler.h" | |
| 6 | |
| 7 #include "base/auto_reset.h" | |
| 8 #include "base/trace_event/trace_event.h" | |
| 9 #include "content/common/resource_messages.h" | |
| 10 #include "content/renderer/scheduler/renderer_scheduler.h" | |
| 11 #include "ipc/ipc_message_macros.h" | |
| 12 | |
| 13 namespace content { | |
| 14 namespace { | |
| 15 | |
| 16 bool IsResourceRequest(const IPC::Message& msg) { | |
| 17 return msg.type() == ResourceHostMsg_RequestResource::ID; | |
| 18 } | |
| 19 | |
| 20 } // namespace | |
| 21 | |
| 22 ResourceDispatchThrottler::ResourceDispatchThrottler( | |
| 23 IPC::Sender* proxied_sender, | |
| 24 RendererScheduler* scheduler, | |
| 25 base::TimeDelta flush_period, | |
| 26 uint32 max_requests_per_flush) | |
| 27 : proxied_sender_(proxied_sender), | |
| 28 scheduler_(scheduler), | |
| 29 flush_period_(flush_period), | |
| 30 max_requests_per_flush_(max_requests_per_flush), | |
| 31 flush_timer_( | |
| 32 FROM_HERE, | |
| 33 flush_period_, | |
| 34 base::Bind(&ResourceDispatchThrottler::Flush, base::Unretained(this)), | |
| 35 false /* is_repeating */), | |
| 36 sent_requests_since_last_flush_(0) { | |
| 37 DCHECK(proxied_sender); | |
| 38 DCHECK(scheduler); | |
| 39 DCHECK_NE(flush_period_, base::TimeDelta()); | |
| 40 DCHECK(max_requests_per_flush_); | |
| 41 flush_timer_.SetTaskRunner(scheduler->LoadingTaskRunner()); | |
| 42 } | |
| 43 | |
| 44 ResourceDispatchThrottler::~ResourceDispatchThrottler() { | |
| 45 FlushAll(); | |
| 46 } | |
| 47 | |
| 48 bool ResourceDispatchThrottler::Send(IPC::Message* msg) { | |
| 49 DCHECK(thread_checker_.CalledOnValidThread()); | |
| 50 if (msg->is_sync()) { | |
| 51 // Flush any pending requests, preserving dispatch order between async and | |
| 52 // sync requests. | |
| 53 FlushAll(); | |
| 54 return ForwardMessage(msg); | |
| 55 } | |
| 56 | |
| 57 // Always defer message forwarding if there are pending messages, ensuring | |
| 58 // message dispatch ordering consistency. | |
| 59 if (!throttled_messages_.empty()) { | |
| 60 TRACE_EVENT_INSTANT0("loader", "ResourceDispatchThrottler::ThrottleMessage", | |
| 61 TRACE_EVENT_SCOPE_THREAD); | |
| 62 throttled_messages_.push_back(msg); | |
| 63 return true; | |
| 64 } | |
| 65 | |
| 66 if (!IsResourceRequest(*msg)) | |
| 67 return ForwardMessage(msg); | |
| 68 | |
| 69 if (!scheduler_->IsHighPriorityWorkAnticipated()) | |
| 70 return ForwardMessage(msg); | |
| 71 | |
| 72 if (Now() > (last_sent_request_time_ + flush_period_)) { | |
| 73 // If sufficient time has passed since the previous send, we can effectively | |
| 74 // mark the pipeline as flushed. | |
| 75 sent_requests_since_last_flush_ = 0; | |
| 76 return ForwardMessage(msg); | |
| 77 } | |
| 78 | |
| 79 if (sent_requests_since_last_flush_ < max_requests_per_flush_) | |
| 80 return ForwardMessage(msg); | |
| 81 | |
| 82 TRACE_EVENT_INSTANT0("loader", "ResourceDispatchThrottler::ThrottleRequest", | |
| 83 TRACE_EVENT_SCOPE_THREAD); | |
| 84 throttled_messages_.push_back(msg); | |
| 85 ScheduleFlush(); | |
| 86 return true; | |
| 87 } | |
| 88 | |
| 89 base::TimeTicks ResourceDispatchThrottler::Now() const { | |
| 90 return base::TimeTicks::Now(); | |
| 91 } | |
| 92 | |
| 93 void ResourceDispatchThrottler::ScheduleFlush() { | |
| 94 DCHECK(!flush_timer_.IsRunning()); | |
| 95 flush_timer_.Reset(); | |
| 96 } | |
| 97 | |
| 98 void ResourceDispatchThrottler::Flush() { | |
| 99 DCHECK(thread_checker_.CalledOnValidThread()); | |
| 100 TRACE_EVENT1("loader", "ResourceDispatchThrottler::Flush", | |
| 101 "total_throttled_messages", throttled_messages_.size()); | |
| 102 sent_requests_since_last_flush_ = 0; | |
| 103 | |
| 104 // If high-priority work is no longer anticipated, dispatch can be safely | |
| 105 // accelerated. Avoid completely flushing in such case in the event that | |
| 106 // a large number of requests have been throttled. | |
| 107 uint32 max_requests = scheduler_->IsHighPriorityWorkAnticipated() | |
| 108 ? max_requests_per_flush_ | |
| 109 : max_requests_per_flush_ * 2; | |
| 110 | |
| 111 while (!throttled_messages_.empty() && | |
| 112 (sent_requests_since_last_flush_ < max_requests || | |
| 113 !IsResourceRequest(*throttled_messages_.front()))) { | |
| 114 IPC::Message* msg = throttled_messages_.front(); | |
| 115 throttled_messages_.pop_front(); | |
| 116 ForwardMessage(msg); | |
| 117 } | |
| 118 | |
| 119 if (!throttled_messages_.empty()) | |
| 120 ScheduleFlush(); | |
| 121 } | |
| 122 | |
| 123 void ResourceDispatchThrottler::FlushAll() { | |
| 124 if (throttled_messages_.empty()) | |
| 125 return; | |
| 126 | |
| 127 TRACE_EVENT1("loader", "ResourceDispatchThrottler::FlushAll", | |
| 128 "total_throttled_messages", throttled_messages_.size()); | |
| 129 std::deque<IPC::Message*> throttled_messages; | |
| 130 throttled_messages.swap(throttled_messages_); | |
| 131 for (auto& message : throttled_messages) | |
| 132 ForwardMessage(message); | |
| 133 // There shouldn't be re-entrancy issues when forwarding an IPC, but validate | |
| 134 // as a safeguard. | |
| 135 DCHECK(throttled_messages_.empty()); | |
| 136 } | |
| 137 | |
| 138 bool ResourceDispatchThrottler::ForwardMessage(IPC::Message* msg) { | |
| 139 if (IsResourceRequest(*msg)) { | |
| 140 last_sent_request_time_ = Now(); | |
| 141 ++sent_requests_since_last_flush_; | |
| 142 } | |
| 143 return proxied_sender_->Send(msg); | |
| 144 } | |
| 145 | |
| 146 } // namespace content | |
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Chromium Code Reviews
Issue 897223002:
Revert of Throttle resource message requests during user interaction (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master