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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "content/browser/loader/resource_scheduler.h" | 5 #include "content/browser/loader/resource_scheduler.h" |
6 | 6 |
7 #include "base/stl_util.h" | 7 #include "base/stl_util.h" |
8 #include "content/common/resource_messages.h" | 8 #include "content/common/resource_messages.h" |
9 #include "content/browser/loader/resource_message_delegate.h" | 9 #include "content/browser/loader/resource_message_delegate.h" |
10 #include "content/public/browser/resource_controller.h" | 10 #include "content/public/browser/resource_controller.h" |
11 #include "content/public/browser/resource_request_info.h" | |
11 #include "content/public/browser/resource_throttle.h" | 12 #include "content/public/browser/resource_throttle.h" |
12 #include "ipc/ipc_message_macros.h" | 13 #include "ipc/ipc_message_macros.h" |
13 #include "net/base/load_flags.h" | 14 #include "net/base/load_flags.h" |
14 #include "net/base/request_priority.h" | 15 #include "net/base/request_priority.h" |
15 #include "net/url_request/url_request.h" | 16 #include "net/url_request/url_request.h" |
16 | 17 |
17 namespace content { | 18 namespace content { |
18 | 19 |
20 static const int kMaxNumLowPriorityRequestsPerClient = 10; | |
21 | |
22 // Each client represents a tab. | |
23 struct ResourceScheduler::Client { | |
24 Client() : has_body(false) {} | |
25 ~Client() {} | |
26 | |
27 bool has_body; | |
28 RequestQueue pending_requests; | |
29 RequestSet in_flight_requests; | |
30 }; | |
31 | |
32 // A thin wrapper around net::PriorityQueue that deals with | |
33 // ScheduledResourceRequests instead of PriorityQueue::Pointers. | |
34 class ResourceScheduler::RequestQueue { | |
35 public: | |
36 RequestQueue() : queue_(net::NUM_PRIORITIES) {} | |
37 ~RequestQueue() {} | |
38 | |
39 // Adds |request| to the queue with given |priority|. | |
40 void Insert(ScheduledResourceRequest* request, | |
41 net::RequestPriority priority) { | |
42 DCHECK(!ContainsKey(pointers_, request)); | |
43 NetQueue::Pointer pointer = queue_.Insert(request, priority); | |
44 pointers_[request] = pointer; | |
45 } | |
46 | |
47 // Removes |request| from the queue. | |
48 void Erase(ScheduledResourceRequest* request) { | |
49 PointerMap::iterator it = pointers_.find(request); | |
50 DCHECK(it != pointers_.end()); | |
51 queue_.Erase(it->second); | |
52 pointers_.erase(it); | |
53 } | |
54 | |
55 // Returns the highest priority request that's queued, or NULL if none are. | |
56 ScheduledResourceRequest* FirstMax() { | |
57 return queue_.FirstMax().value(); | |
58 } | |
59 | |
60 // Returns true if |request| is queued. | |
61 bool IsQueued(ScheduledResourceRequest* request) const { | |
62 return ContainsKey(pointers_, request); | |
63 } | |
64 | |
65 // Returns true if no requests are queued. | |
66 bool IsEmpty() const { return queue_.size() == 0; } | |
67 | |
68 private: | |
69 typedef net::PriorityQueue<ScheduledResourceRequest*> NetQueue; | |
70 typedef std::map<ScheduledResourceRequest*, NetQueue::Pointer> PointerMap; | |
71 | |
72 NetQueue queue_; | |
73 PointerMap pointers_; | |
74 }; | |
75 | |
76 // This is the handle we return to the ResourceDispatcherHostImpl so it can | |
77 // interact with the request. | |
19 class ResourceScheduler::ScheduledResourceRequest | 78 class ResourceScheduler::ScheduledResourceRequest |
20 : public ResourceMessageDelegate, | 79 : public ResourceMessageDelegate, |
21 public ResourceThrottle { | 80 public ResourceThrottle { |
22 public: | 81 public: |
23 ScheduledResourceRequest(const ClientId& client_id, | 82 ScheduledResourceRequest(const ClientId& client_id, |
24 net::URLRequest* request, | 83 net::URLRequest* request, |
25 ResourceScheduler* scheduler) | 84 ResourceScheduler* scheduler) |
26 : ResourceMessageDelegate(request), | 85 : ResourceMessageDelegate(request), |
27 client_id_(client_id), | 86 client_id_(client_id), |
28 request_(request), | 87 request_(request), |
29 ready_(false), | 88 ready_(false), |
30 deferred_(false), | 89 deferred_(false), |
31 scheduler_(scheduler) { | 90 scheduler_(scheduler) { |
32 } | 91 } |
33 | 92 |
34 virtual ~ScheduledResourceRequest() { | 93 virtual ~ScheduledResourceRequest() { |
35 scheduler_->RemoveRequest(this); | 94 scheduler_->RemoveRequest(this); |
36 } | 95 } |
37 | 96 |
38 void Start() { | 97 void Start() { |
39 ready_ = true; | 98 ready_ = true; |
40 if (deferred_ && request_->status().is_success()) { | 99 if (deferred_ && request_->status().is_success()) { |
41 deferred_ = false; | 100 deferred_ = false; |
42 controller()->Resume(); | 101 controller()->Resume(); |
43 } | 102 } |
44 } | 103 } |
45 | 104 |
46 const ClientId& client_id() const { return client_id_; } | 105 const ClientId& client_id() const { return client_id_; } |
47 const net::URLRequest& url_request() const { return *request_; } | 106 net::URLRequest* url_request() { return request_; } |
107 const net::URLRequest* url_request() const { return request_; } | |
48 | 108 |
49 private: | 109 private: |
50 // ResourceMessageDelegate interface: | 110 // ResourceMessageDelegate interface: |
51 virtual bool OnMessageReceived(const IPC::Message& message, | 111 virtual bool OnMessageReceived(const IPC::Message& message, |
52 bool* message_was_ok) OVERRIDE { | 112 bool* message_was_ok) OVERRIDE { |
53 bool handled = true; | 113 bool handled = true; |
54 IPC_BEGIN_MESSAGE_MAP_EX(ScheduledResourceRequest, message, *message_was_ok) | 114 IPC_BEGIN_MESSAGE_MAP_EX(ScheduledResourceRequest, message, *message_was_ok) |
55 IPC_MESSAGE_HANDLER(ResourceHostMsg_DidChangePriority, DidChangePriority) | 115 IPC_MESSAGE_HANDLER(ResourceHostMsg_DidChangePriority, DidChangePriority) |
56 IPC_MESSAGE_UNHANDLED(handled = false) | 116 IPC_MESSAGE_UNHANDLED(handled = false) |
57 IPC_END_MESSAGE_MAP_EX() | 117 IPC_END_MESSAGE_MAP_EX() |
58 return handled; | 118 return handled; |
59 } | 119 } |
60 | 120 |
61 // ResourceThrottle interface: | 121 // ResourceThrottle interface: |
62 virtual void WillStartRequest(bool* defer) OVERRIDE { | 122 virtual void WillStartRequest(bool* defer) OVERRIDE { |
63 deferred_ = *defer = !ready_; | 123 deferred_ = *defer = !ready_; |
64 } | 124 } |
65 | 125 |
66 void DidChangePriority(int request_id, net::RequestPriority new_priority) { | 126 void DidChangePriority(int request_id, net::RequestPriority new_priority) { |
67 net::RequestPriority old_priority = request_->priority(); | 127 scheduler_->ReprioritizeRequest(this, new_priority); |
68 request_->set_priority(new_priority); | |
69 if (new_priority > old_priority) { | |
70 Start(); | |
71 } | |
72 } | 128 } |
73 | 129 |
74 ClientId client_id_; | 130 ClientId client_id_; |
75 net::URLRequest* request_; | 131 net::URLRequest* request_; |
76 bool ready_; | 132 bool ready_; |
77 bool deferred_; | 133 bool deferred_; |
78 ResourceScheduler* scheduler_; | 134 ResourceScheduler* scheduler_; |
79 | 135 |
80 DISALLOW_COPY_AND_ASSIGN(ScheduledResourceRequest); | 136 DISALLOW_COPY_AND_ASSIGN(ScheduledResourceRequest); |
81 }; | 137 }; |
82 | 138 |
83 ResourceScheduler::ResourceScheduler() { | 139 ResourceScheduler::ResourceScheduler() { |
84 } | 140 } |
85 | 141 |
86 ResourceScheduler::~ResourceScheduler() { | 142 ResourceScheduler::~ResourceScheduler() { |
87 for (ClientMap::iterator it ALLOW_UNUSED = client_map_.begin(); | 143 for (ClientMap::iterator it ALLOW_UNUSED = client_map_.begin(); |
willchan no longer on Chromium
2013/03/19 20:53:53
Sorry again for nitting on existing code. Why does
James Simonsen
2013/03/19 23:00:46
Done. It used to be more useful.
| |
88 it != client_map_.end(); ++it) { | 144 it != client_map_.end(); ++it) { |
89 DCHECK(it->second->pending_requests.empty()); | 145 DCHECK(it->second->pending_requests.IsEmpty()); |
90 DCHECK(it->second->in_flight_requests.empty()); | 146 DCHECK(it->second->in_flight_requests.empty()); |
91 } | 147 } |
92 DCHECK(unowned_requests_.empty()); | 148 DCHECK(unowned_requests_.empty()); |
93 DCHECK(client_map_.empty()); | 149 DCHECK(client_map_.empty()); |
94 } | 150 } |
95 | 151 |
96 scoped_ptr<ResourceThrottle> ResourceScheduler::ScheduleRequest( | 152 scoped_ptr<ResourceThrottle> ResourceScheduler::ScheduleRequest( |
97 int child_id, | 153 int child_id, |
98 int route_id, | 154 int route_id, |
99 net::URLRequest* url_request) { | 155 net::URLRequest* url_request) { |
100 DCHECK(CalledOnValidThread()); | 156 DCHECK(CalledOnValidThread()); |
101 ClientId client_id = MakeClientId(child_id, route_id); | 157 ClientId client_id = MakeClientId(child_id, route_id); |
102 scoped_ptr<ScheduledResourceRequest> request( | 158 scoped_ptr<ScheduledResourceRequest> request( |
103 new ScheduledResourceRequest(client_id, url_request, this)); | 159 new ScheduledResourceRequest(client_id, url_request, this)); |
104 | 160 |
105 ClientMap::iterator it = client_map_.find(client_id); | 161 ClientMap::iterator it = client_map_.find(client_id); |
106 if (it == client_map_.end()) { | 162 if (it == client_map_.end()) { |
107 // There are several ways this could happen: | 163 // There are several ways this could happen: |
108 // 1. <a ping> requests don't have a route_id. | 164 // 1. <a ping> requests don't have a route_id. |
109 // 2. Most unittests don't send the IPCs needed to register Clients. | 165 // 2. Most unittests don't send the IPCs needed to register Clients. |
110 // 3. The tab is closed while a RequestResource IPC is in flight. | 166 // 3. The tab is closed while a RequestResource IPC is in flight. |
111 unowned_requests_.insert(request.get()); | 167 unowned_requests_.insert(request.get()); |
112 request->Start(); | 168 request->Start(); |
113 return request.PassAs<ResourceThrottle>(); | 169 return request.PassAs<ResourceThrottle>(); |
114 } | 170 } |
115 | 171 |
116 Client* client = it->second; | 172 Client* client = it->second; |
117 | 173 if (ShouldStartRequest(request.get(), client)) { |
118 bool is_synchronous = (url_request->load_flags() & net::LOAD_IGNORE_LIMITS) == | 174 StartRequest(request.get(), client); |
119 net::LOAD_IGNORE_LIMITS; | |
120 bool is_low_priority = | |
121 url_request->priority() < net::LOW && !is_synchronous; | |
122 | |
123 if (is_low_priority && !client->in_flight_requests.empty() && | |
124 !client->has_body) { | |
125 client->pending_requests.push_back(request.get()); | |
126 } else { | 175 } else { |
127 StartRequest(request.get(), client); | 176 client->pending_requests.Insert(request.get(), url_request->priority()); |
128 } | 177 } |
129 return request.PassAs<ResourceThrottle>(); | 178 return request.PassAs<ResourceThrottle>(); |
130 } | 179 } |
131 | 180 |
132 void ResourceScheduler::RemoveRequest(ScheduledResourceRequest* request) { | 181 void ResourceScheduler::RemoveRequest(ScheduledResourceRequest* request) { |
133 DCHECK(CalledOnValidThread()); | 182 DCHECK(CalledOnValidThread()); |
134 if (ContainsKey(unowned_requests_, request)) { | 183 if (ContainsKey(unowned_requests_, request)) { |
135 unowned_requests_.erase(request); | 184 unowned_requests_.erase(request); |
136 return; | 185 return; |
137 } | 186 } |
138 | 187 |
139 ClientMap::iterator client_it = client_map_.find(request->client_id()); | 188 ClientMap::iterator client_it = client_map_.find(request->client_id()); |
140 if (client_it == client_map_.end()) { | 189 if (client_it == client_map_.end()) { |
141 return; | 190 return; |
142 } | 191 } |
143 | 192 |
144 Client* client = client_it->second; | 193 Client* client = client_it->second; |
145 RequestSet::iterator request_it = client->in_flight_requests.find(request); | 194 |
146 if (request_it == client->in_flight_requests.end()) { | 195 if (client->pending_requests.IsQueued(request)) { |
147 bool removed = false; | 196 client->pending_requests.Erase(request); |
148 RequestQueue::iterator queue_it; | |
149 for (queue_it = client->pending_requests.begin(); | |
150 queue_it != client->pending_requests.end(); ++queue_it) { | |
151 if (*queue_it == request) { | |
152 client->pending_requests.erase(queue_it); | |
153 removed = true; | |
154 break; | |
155 } | |
156 } | |
157 DCHECK(removed); | |
158 DCHECK(!ContainsKey(client->in_flight_requests, request)); | 197 DCHECK(!ContainsKey(client->in_flight_requests, request)); |
159 } else { | 198 } else { |
160 size_t erased = client->in_flight_requests.erase(request); | 199 size_t erased = client->in_flight_requests.erase(request); |
161 DCHECK(erased); | 200 DCHECK(erased); |
162 } | |
163 | 201 |
164 if (client->in_flight_requests.empty()) { | 202 // Removing this request may have freed up another to load. |
165 // Since the network is now idle, we may as well load some of the low | 203 LoadAnyStartablePendingRequests(client); |
166 // priority requests. | |
167 LoadPendingRequests(client); | |
168 } | 204 } |
169 } | 205 } |
170 | 206 |
171 void ResourceScheduler::OnClientCreated(int child_id, int route_id) { | 207 void ResourceScheduler::OnClientCreated(int child_id, int route_id) { |
172 DCHECK(CalledOnValidThread()); | 208 DCHECK(CalledOnValidThread()); |
173 ClientId client_id = MakeClientId(child_id, route_id); | 209 ClientId client_id = MakeClientId(child_id, route_id); |
174 DCHECK(!ContainsKey(client_map_, client_id)); | 210 DCHECK(!ContainsKey(client_map_, client_id)); |
175 | 211 |
176 client_map_[client_id] = new Client; | 212 client_map_[client_id] = new Client; |
177 } | 213 } |
(...skipping 39 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
217 ClientMap::iterator it = client_map_.find(client_id); | 253 ClientMap::iterator it = client_map_.find(client_id); |
218 if (it == client_map_.end()) { | 254 if (it == client_map_.end()) { |
219 // The client was likely deleted shortly before we received this IPC. | 255 // The client was likely deleted shortly before we received this IPC. |
220 return; | 256 return; |
221 } | 257 } |
222 | 258 |
223 Client* client = it->second; | 259 Client* client = it->second; |
224 client->has_body = false; | 260 client->has_body = false; |
225 if (!client->has_body) { | 261 if (!client->has_body) { |
226 client->has_body = true; | 262 client->has_body = true; |
227 LoadPendingRequests(client); | 263 LoadAnyStartablePendingRequests(client); |
228 } | 264 } |
229 } | 265 } |
230 | 266 |
231 void ResourceScheduler::StartRequest(ScheduledResourceRequest* request, | 267 void ResourceScheduler::StartRequest(ScheduledResourceRequest* request, |
232 Client* client) { | 268 Client* client) { |
233 client->in_flight_requests.insert(request); | 269 client->in_flight_requests.insert(request); |
234 request->Start(); | 270 request->Start(); |
235 } | 271 } |
236 | 272 |
237 void ResourceScheduler::LoadPendingRequests(Client* client) { | 273 void ResourceScheduler::ReprioritizeRequest(ScheduledResourceRequest* request, |
238 while (!client->pending_requests.empty()) { | 274 net::RequestPriority new_priority) { |
239 ScheduledResourceRequest* request = client->pending_requests.front(); | 275 net::RequestPriority old_priority = request->url_request()->priority(); |
240 client->pending_requests.erase(client->pending_requests.begin()); | 276 DCHECK(new_priority != old_priority); |
willchan no longer on Chromium
2013/03/19 20:53:53
Does DCHECK_NE() not work?
James Simonsen
2013/03/19 23:00:46
Done.
| |
241 StartRequest(request, client); | 277 request->url_request()->set_priority(new_priority); |
278 ClientMap::iterator client_it = client_map_.find(request->client_id()); | |
279 if (client_it == client_map_.end()) { | |
280 // The client was likely deleted shortly before we received this IPC. | |
willchan no longer on Chromium
2013/03/19 20:53:53
I think this RenderViewHost deletion signal seems
James Simonsen
2013/03/19 23:00:46
There can be several renderers on the same channel
willchan no longer on Chromium
2013/03/19 23:08:32
Sorry, forgot about that. But why don't we get a R
| |
281 return; | |
242 } | 282 } |
283 | |
284 Client *client = client_it->second; | |
285 if (!client->pending_requests.IsQueued(request)) { | |
286 DCHECK(ContainsKey(client->in_flight_requests, request)); | |
287 // Request has already started. | |
288 return; | |
289 } | |
290 | |
291 client->pending_requests.Erase(request); | |
292 client->pending_requests.Insert(request, request->url_request()->priority()); | |
293 | |
294 if (new_priority > old_priority) { | |
295 // Check if this request is now able to load at its new priority. | |
296 LoadAnyStartablePendingRequests(client); | |
297 } | |
298 } | |
299 | |
300 void ResourceScheduler::LoadAnyStartablePendingRequests(Client* client) { | |
301 while (!client->pending_requests.IsEmpty()) { | |
302 ScheduledResourceRequest* request = client->pending_requests.FirstMax(); | |
303 if (ShouldStartRequest(request, client)) { | |
304 client->pending_requests.Erase(request); | |
305 StartRequest(request, client); | |
306 } else { | |
307 break; | |
308 } | |
309 } | |
310 } | |
311 | |
312 size_t ResourceScheduler::GetNumLowPriorityRequestsInFlight( | |
313 Client* client) const { | |
314 size_t count = 0; | |
315 for (RequestSet::iterator it = client->in_flight_requests.begin(); | |
316 it != client->in_flight_requests.end(); ++it) { | |
317 if ((*it)->url_request()->priority() < net::LOW) { | |
318 ++count; | |
319 } | |
320 } | |
321 return count; | |
322 } | |
323 | |
324 // ShouldStartRequest is the main scheduling algorithm. It works as follows: | |
325 // | |
326 // 1. High priority requests (>= net::LOW are always issued. | |
willchan no longer on Chromium
2013/03/19 20:53:53
This is very unfortunately named. Can we fix this
James Simonsen
2013/03/19 23:00:46
The whole notion of using priority names is ridicu
| |
327 // 2. Synchronous requests are always high priority. | |
willchan no longer on Chromium
2013/03/19 20:53:53
I'd say instead that synchronous requests are alwa
James Simonsen
2013/03/19 23:00:46
Done.
| |
328 // | |
329 // The remaining, low priority follow these rules: | |
330 // | |
331 // 1. If no high priority requests are in flight, start loading low priority | |
332 // requests. | |
333 // 2. Once the renderer has a <body>, start loading low priority requests. | |
334 // 3. Never exceed 10 low priority requests in flight per client. | |
335 bool ResourceScheduler::ShouldStartRequest(ScheduledResourceRequest* request, | |
336 Client* client) const { | |
337 if (request->url_request()->priority() >= net::LOW || | |
338 !ResourceRequestInfo::ForRequest(request->url_request())->IsAsync()) { | |
339 return true; | |
340 } | |
341 | |
342 size_t num_low_priority_requests_in_flight = | |
343 GetNumLowPriorityRequestsInFlight(client); | |
344 if (num_low_priority_requests_in_flight >= | |
345 kMaxNumLowPriorityRequestsPerClient) { | |
346 return false; | |
347 } | |
348 | |
349 bool have_high_priority_requests_in_flight = | |
350 client->in_flight_requests.size() > num_low_priority_requests_in_flight; | |
351 if (have_high_priority_requests_in_flight && !client->has_body) { | |
352 return false; | |
353 } | |
354 | |
355 return true; | |
243 } | 356 } |
244 | 357 |
245 ResourceScheduler::ClientId ResourceScheduler::MakeClientId( | 358 ResourceScheduler::ClientId ResourceScheduler::MakeClientId( |
246 int child_id, int route_id) { | 359 int child_id, int route_id) { |
247 return (static_cast<ResourceScheduler::ClientId>(child_id) << 32) | route_id; | 360 return (static_cast<ResourceScheduler::ClientId>(child_id) << 32) | route_id; |
248 } | 361 } |
249 | 362 |
250 ResourceScheduler::Client::Client() | |
251 : has_body(false) { | |
252 } | |
253 | |
254 ResourceScheduler::Client::~Client() { | |
255 } | |
256 | |
257 } // namespace content | 363 } // namespace content |
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