src/chrome/browser/printing/print_job.cc

   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
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/printing/print_job.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "base/threading/thread_restrictions.h"
  11 #include "base/threading/worker_pool.h"
  12 #include "base/timer/timer.h"
  13 #include "chrome/browser/chrome_notification_types.h"
  14 #include "chrome/browser/printing/print_job_worker.h"
  15 #include "content/public/browser/notification_service.h"
  16 #include "printing/printed_document.h"
  17 #include "printing/printed_page.h"
  18
  19 using base::TimeDelta;
  20
  21 namespace {
  22
  23 // Helper function to ensure |owner| is valid until at least |callback| returns.
  24 void HoldRefCallback(const scoped_refptr<printing::PrintJobWorkerOwner>& owner,
  25                      const base::Closure& callback) {
  26   callback.Run();
  27 }
  28
  29 }  // namespace
  30
  31 namespace printing {
  32
  33 PrintJob::PrintJob()
  34     : ui_message_loop_(base::MessageLoop::current()),
  35       source_(NULL),
  36       worker_(),
  37       settings_(),
  38       is_job_pending_(false),
  39       is_canceling_(false),
  40       quit_factory_(this) {
  41   DCHECK(ui_message_loop_);
  42   // This is normally a UI message loop, but in unit tests, the message loop is
  43   // of the 'default' type.
  44   DCHECK(base::MessageLoopForUI::IsCurrent() ||
  45          ui_message_loop_->type() == base::MessageLoop::TYPE_DEFAULT);
  46   ui_message_loop_->AddDestructionObserver(this);
  47 }
  48
  49 PrintJob::~PrintJob() {
  50   ui_message_loop_->RemoveDestructionObserver(this);
  51   // The job should be finished (or at least canceled) when it is destroyed.
  52   DCHECK(!is_job_pending_);
  53   DCHECK(!is_canceling_);
  54   if (worker_.get())
  55     DCHECK(worker_->message_loop() == NULL);
  56   DCHECK_EQ(ui_message_loop_, base::MessageLoop::current());
  57 }
  58
  59 void PrintJob::Initialize(PrintJobWorkerOwner* job,
  60                           PrintedPagesSource* source,
  61                           int page_count) {
  62   DCHECK(!source_);
  63   DCHECK(!worker_.get());
  64   DCHECK(!is_job_pending_);
  65   DCHECK(!is_canceling_);
  66   DCHECK(!document_.get());
  67   source_ = source;
  68   worker_.reset(job->DetachWorker(this));
  69   settings_ = job->settings();
  70
  71   PrintedDocument* new_doc =
  72       new PrintedDocument(settings_, source_, job->cookie());
  73   new_doc->set_page_count(page_count);
  74   UpdatePrintedDocument(new_doc);
  75
  76   // Don't forget to register to our own messages.
  77   registrar_.Add(this, chrome::NOTIFICATION_PRINT_JOB_EVENT,
  78                  content::Source<PrintJob>(this));
  79 }
  80
  81 void PrintJob::Observe(int type,
  82                        const content::NotificationSource& source,
  83                        const content::NotificationDetails& details) {
  84   DCHECK_EQ(ui_message_loop_, base::MessageLoop::current());
  85   switch (type) {
  86     case chrome::NOTIFICATION_PRINT_JOB_EVENT: {
  87       OnNotifyPrintJobEvent(*content::Details<JobEventDetails>(details).ptr());
  88       break;
  89     }
  90     default: {
  91       break;
  92     }
  93   }
  94 }
  95
  96 void PrintJob::GetSettingsDone(const PrintSettings& new_settings,
  97                                PrintingContext::Result result) {
  98   NOTREACHED();
  99 }
 100
 101 PrintJobWorker* PrintJob::DetachWorker(PrintJobWorkerOwner* new_owner) {
 102   NOTREACHED();
 103   return NULL;
 104 }
 105
 106 base::MessageLoop* PrintJob::message_loop() {
 107   return ui_message_loop_;
 108 }
 109
 110 const PrintSettings& PrintJob::settings() const {
 111   return settings_;
 112 }
 113
 114 int PrintJob::cookie() const {
 115   if (!document_.get())
 116     // Always use an invalid cookie in this case.
 117     return 0;
 118   return document_->cookie();
 119 }
 120
 121 void PrintJob::WillDestroyCurrentMessageLoop() {
 122   NOTREACHED();
 123 }
 124
 125 void PrintJob::StartPrinting() {
 126   DCHECK_EQ(ui_message_loop_, base::MessageLoop::current());
 127   DCHECK(worker_->message_loop());
 128   DCHECK(!is_job_pending_);
 129   if (!worker_->message_loop() || is_job_pending_)
 130     return;
 131
 132   // Real work is done in PrintJobWorker::StartPrinting().
 133   worker_->message_loop()->PostTask(
 134       FROM_HERE,
 135       base::Bind(&HoldRefCallback, make_scoped_refptr(this),
 136                  base::Bind(&PrintJobWorker::StartPrinting,
 137                             base::Unretained(worker_.get()), document_)));
 138   // Set the flag right now.
 139   is_job_pending_ = true;
 140
 141   // Tell everyone!
 142   scoped_refptr<JobEventDetails> details(
 143       new JobEventDetails(JobEventDetails::NEW_DOC, document_.get(), NULL));
 144   content::NotificationService::current()->Notify(
 145       chrome::NOTIFICATION_PRINT_JOB_EVENT,
 146       content::Source<PrintJob>(this),
 147       content::Details<JobEventDetails>(details.get()));
 148 }
 149
 150 void PrintJob::Stop() {
 151   DCHECK_EQ(ui_message_loop_, base::MessageLoop::current());
 152
 153   if (quit_factory_.HasWeakPtrs()) {
 154     // In case we're running a nested message loop to wait for a job to finish,
 155     // and we finished before the timeout, quit the nested loop right away.
 156     Quit();
 157     quit_factory_.InvalidateWeakPtrs();
 158   }
 159
 160   // Be sure to live long enough.
 161   scoped_refptr<PrintJob> handle(this);
 162
 163   if (worker_->message_loop()) {
 164     ControlledWorkerShutdown();
 165   } else {
 166     // Flush the cached document.
 167     UpdatePrintedDocument(NULL);
 168   }
 169 }
 170
 171 void PrintJob::Cancel() {
 172   if (is_canceling_)
 173     return;
 174   is_canceling_ = true;
 175
 176   // Be sure to live long enough.
 177   scoped_refptr<PrintJob> handle(this);
 178
 179   DCHECK_EQ(ui_message_loop_, base::MessageLoop::current());
 180   base::MessageLoop* worker_loop =
 181       worker_.get() ? worker_->message_loop() : NULL;
 182   if (worker_loop) {
 183     // Call this right now so it renders the context invalid. Do not use
 184     // InvokeLater since it would take too much time.
 185     worker_->Cancel();
 186   }
 187   // Make sure a Cancel() is broadcast.
 188   scoped_refptr<JobEventDetails> details(
 189       new JobEventDetails(JobEventDetails::FAILED, NULL, NULL));
 190   content::NotificationService::current()->Notify(
 191       chrome::NOTIFICATION_PRINT_JOB_EVENT,
 192       content::Source<PrintJob>(this),
 193       content::Details<JobEventDetails>(details.get()));
 194   Stop();
 195   is_canceling_ = false;
 196 }
 197
 198 bool PrintJob::FlushJob(base::TimeDelta timeout) {
 199   // Make sure the object outlive this message loop.
 200   scoped_refptr<PrintJob> handle(this);
 201
 202   base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
 203       base::Bind(&PrintJob::Quit, quit_factory_.GetWeakPtr()), timeout);
 204
 205   base::MessageLoop::ScopedNestableTaskAllower allow(
 206       base::MessageLoop::current());
 207   base::MessageLoop::current()->Run();
 208
 209   return true;
 210 }
 211
 212 void PrintJob::DisconnectSource() {
 213   source_ = NULL;
 214   if (document_.get())
 215     document_->DisconnectSource();
 216 }
 217
 218 bool PrintJob::is_job_pending() const {
 219   return is_job_pending_;
 220 }
 221
 222 PrintedDocument* PrintJob::document() const {
 223   return document_.get();
 224 }
 225
 226 void PrintJob::UpdatePrintedDocument(PrintedDocument* new_document) {
 227   if (document_.get() == new_document)
 228     return;
 229
 230   document_ = new_document;
 231
 232   if (document_.get()) {
 233     settings_ = document_->settings();
 234   }
 235
 236   if (worker_.get() && worker_->message_loop()) {
 237     DCHECK(!is_job_pending_);
 238     // Sync the document with the worker.
 239     worker_->message_loop()->PostTask(
 240         FROM_HERE,
 241         base::Bind(&HoldRefCallback, make_scoped_refptr(this),
 242                    base::Bind(&PrintJobWorker::OnDocumentChanged,
 243                               base::Unretained(worker_.get()), document_)));
 244   }
 245 }
 246
 247 void PrintJob::OnNotifyPrintJobEvent(const JobEventDetails& event_details) {
 248   switch (event_details.type()) {
 249     case JobEventDetails::FAILED: {
 250       settings_.Clear();
 251       // No need to cancel since the worker already canceled itself.
 252       Stop();
 253       break;
 254     }
 255     case JobEventDetails::USER_INIT_DONE:
 256     case JobEventDetails::DEFAULT_INIT_DONE:
 257     case JobEventDetails::USER_INIT_CANCELED: {
 258       DCHECK_EQ(event_details.document(), document_.get());
 259       break;
 260     }
 261     case JobEventDetails::NEW_DOC:
 262     case JobEventDetails::NEW_PAGE:
 263     case JobEventDetails::PAGE_DONE:
 264     case JobEventDetails::JOB_DONE:
 265     case JobEventDetails::ALL_PAGES_REQUESTED: {
 266       // Don't care.
 267       break;
 268     }
 269     case JobEventDetails::DOC_DONE: {
 270       // This will call Stop() and broadcast a JOB_DONE message.
 271       base::MessageLoop::current()->PostTask(
 272           FROM_HERE, base::Bind(&PrintJob::OnDocumentDone, this));
 273       break;
 274     }
 275     default: {
 276       NOTREACHED();
 277       break;
 278     }
 279   }
 280 }
 281
 282 void PrintJob::OnDocumentDone() {
 283   // Be sure to live long enough. The instance could be destroyed by the
 284   // JOB_DONE broadcast.
 285   scoped_refptr<PrintJob> handle(this);
 286
 287   // Stop the worker thread.
 288   Stop();
 289
 290   scoped_refptr<JobEventDetails> details(
 291       new JobEventDetails(JobEventDetails::JOB_DONE, document_.get(), NULL));
 292   content::NotificationService::current()->Notify(
 293       chrome::NOTIFICATION_PRINT_JOB_EVENT,
 294       content::Source<PrintJob>(this),
 295       content::Details<JobEventDetails>(details.get()));
 296 }
 297
 298 void PrintJob::ControlledWorkerShutdown() {
 299   DCHECK_EQ(ui_message_loop_, base::MessageLoop::current());
 300
 301   // The deadlock this code works around is specific to window messaging on
 302   // Windows, so we aren't likely to need it on any other platforms.
 303 #if defined(OS_WIN)
 304   // We could easily get into a deadlock case if worker_->Stop() is used; the
 305   // printer driver created a window as a child of the browser window. By
 306   // canceling the job, the printer driver initiated dialog box is destroyed,
 307   // which sends a blocking message to its parent window. If the browser window
 308   // thread is not processing messages, a deadlock occurs.
 309   //
 310   // This function ensures that the dialog box will be destroyed in a timely
 311   // manner by the mere fact that the thread will terminate. So the potential
 312   // deadlock is eliminated.
 313   worker_->StopSoon();
 314
 315   // Delay shutdown until the worker terminates.  We want this code path
 316   // to wait on the thread to quit before continuing.
 317   if (worker_->IsRunning()) {
 318     base::MessageLoop::current()->PostDelayedTask(
 319         FROM_HERE,
 320         base::Bind(&PrintJob::ControlledWorkerShutdown, this),
 321         base::TimeDelta::FromMilliseconds(100));
 322     return;
 323   }
 324 #endif
 325
 326
 327   // Now make sure the thread object is cleaned up. Do this on a worker
 328   // thread because it may block.
 329   base::WorkerPool::PostTaskAndReply(
 330       FROM_HERE,
 331       base::Bind(&PrintJobWorker::Stop, base::Unretained(worker_.get())),
 332       base::Bind(&PrintJob::HoldUntilStopIsCalled, this),
 333       false);
 334
 335   is_job_pending_ = false;
 336   registrar_.RemoveAll();
 337   UpdatePrintedDocument(NULL);
 338 }
 339
 340 void PrintJob::HoldUntilStopIsCalled() {
 341 }
 342
 343 void PrintJob::Quit() {
 344   base::MessageLoop::current()->Quit();
 345 }
 346
 347 // Takes settings_ ownership and will be deleted in the receiving thread.
 348 JobEventDetails::JobEventDetails(Type type,
 349                                  PrintedDocument* document,
 350                                  PrintedPage* page)
 351     : document_(document),
 352       page_(page),
 353       type_(type) {
 354 }
 355
 356 JobEventDetails::~JobEventDetails() {
 357 }
 358
 359 PrintedDocument* JobEventDetails::document() const { return document_.get(); }
 360
 361 PrintedPage* JobEventDetails::page() const { return page_.get(); }
 362
 363 }  // namespace printing