src/threadmanager.cpp

   1 // Author: Max Howell (C) Copyright 2004
   2 // (c) 2005 Jeff Mitchell <kde-dev@emailgoeshere.com>
   3 // See COPYING file that comes with this distribution
   4 //
   5
   6 // the asserts we use in this module prevent crashes, so best to abort the application if they fail
   7 #define QT_FATAL_ASSERT
   8 #define DEBUG_PREFIX "ThreadManager"
   9
  10 #include "threadmanager.h"
  11
  12 #include "amarokconfig.h"
  13 #include "collectiondb.h"
  14 #include "debug.h"
  15 #include "statusbar.h"
  16
  17 #include <KCursor>
  18
  19 #include <QApplication>
  20 #include <QByteArray>
  21 #include <QEvent>
  22
  23 using Amarok::StatusBar;
  24
  25
  26 class ThreadManager::JobCompletedEvent: public QEvent
  27 {
  28 public:
  29     static const int JobCompletedEventType = 1321;
  30     JobCompletedEvent( Job *j ): QEvent( Type( JobCompletedEventType ) ), job( j ) { }
  31     Job *job;
  32 };
  33
  34 ThreadManager::ThreadManager()
  35 {
  36     startTimer( 5 * 60 * 1000 ); // prunes the thread pool every 5 minutes
  37 }
  38
  39 ThreadManager::~ThreadManager()
  40 {
  41     DEBUG_BLOCK
  42
  43     for( ThreadList::Iterator it = m_threads.begin(), end = m_threads.end(); it != end; ++it )
  44     {
  45 #ifdef HAVE_INOTIFY
  46         // we don't delete the thread's job as amarok is gone
  47         // and the Job dtor may expect amarok to be there etc.
  48         if ( (*it)->job() && (*it)->job()->name() == QByteArray( "INotify" ) )
  49         {
  50             debug() << "Forcibly terminating INotify thread...\n";
  51             (*it)->terminate();
  52             continue;
  53         }
  54 #endif
  55
  56         if( (*it)->job() && (*it)->job()->name() )
  57             debug() << "Waiting on thread " << (*it)->job()->name() << "...\n";
  58         else
  59             debug() << "Waiting on thread...\n";
  60         (*it)->wait();
  61     }
  62 }
  63
  64 uint
  65 ThreadManager::jobCount( const QByteArray &name )
  66 {
  67     uint count = 0;
  68
  69     for( JobList::Iterator it = m_jobs.begin(), end = m_jobs.end(); it != end; ++it )
  70         if ( name == (*it)->name() )
  71             count++;
  72
  73     return count;
  74 }
  75
  76 int
  77 ThreadManager::queueJob( Job *job )
  78 {
  79     SHOULD_BE_GUI
  80
  81     if (!job)
  82         return -1;
  83
  84     // this list contains all pending and running jobs
  85     m_jobs += job;
  86
  87     const uint count = jobCount( job->name() );
  88
  89     if ( count == 1 )
  90         gimmeThread()->runJob( job );
  91
  92     return count;
  93 }
  94
  95 int
  96 ThreadManager::queueJobs( const JobList &jobs )
  97 {
  98     SHOULD_BE_GUI
  99
 100     if ( jobs.isEmpty() )
 101         return -1;
 102
 103     m_jobs += jobs;
 104
 105     const QByteArray name = jobs.front()->name();
 106     const int count = jobCount( name );
 107
 108     if ( count == jobs.count() )
 109         gimmeThread()->runJob( jobs.front() );
 110
 111     return count;
 112 }
 113
 114 void
 115 ThreadManager::onlyOneJob( Job *job )
 116 {
 117     SHOULD_BE_GUI
 118
 119     const QByteArray name = job->name();
 120
 121     // first cause all current jobs with this name to be aborted
 122     abortAllJobsNamed( name );
 123
 124     // now queue this job.
 125     // if there is a running Job of its type this one will be
 126     // started when that one returns to the GUI thread.
 127     m_jobs += job;
 128
 129     // if there weren't any jobs of this type running, we must
 130     // start this job.
 131     if ( jobCount( name ) == 1 )
 132         gimmeThread()->runJob( job );
 133 }
 134
 135 int
 136 ThreadManager::abortAllJobsNamed( const QByteArray &name )
 137 {
 138     SHOULD_BE_GUI
 139
 140     int count = 0;
 141
 142     for( JobList::Iterator it = m_jobs.begin(), end = m_jobs.end(); it != end; ++it )
 143         if ( name == (*it)->name() ) {
 144             count++;
 145             (*it)->abort();
 146         }
 147
 148     return count;
 149 }
 150
 151 ThreadManager::Thread*
 152 ThreadManager::gimmeThread()
 153 {
 154     for( ThreadList::ConstIterator it = m_threads.begin(), end = m_threads.end(); it != end; ++it )
 155         if ( !(*it)->isRunning() && (*it)->job() == 0 )
 156             return *it;
 157
 158     Thread *thread = new Thread;
 159     m_threads += thread;
 160     return thread;
 161 }
 162
 163 bool
 164 ThreadManager::event( QEvent *e )
 165 {
 166     switch( e->type() )
 167     {
 168     case JobCompletedEvent::JobCompletedEventType: {
 169         Job *job = static_cast<JobCompletedEvent*>( e )->job;
 170         DebugStream d = debug() << "Job ";
 171         const QByteArray name = job->name();
 172         Thread *thread = job->m_thread;
 173
 174         QApplication::postEvent(
 175                 ThreadManager::instance(),
 176                 new QEvent( QEvent::Type( ThreadManager::RestoreOverrideCursorEventType ) ) );
 177
 178         if ( !job->isAborted() ) {
 179             d << "completed";
 180             job->completeJob();
 181         }
 182         else d << "aborted";
 183
 184         m_jobs.remove( job );
 185         delete job;
 186
 187         d << ": " << name;
 188         d << ". Jobs pending: " << jobCount( name );
 189         d << endl;
 190
 191         for( JobList::ConstIterator it = m_jobs.begin(), end = m_jobs.end(); it != end; ++it )
 192             if ( name == (*it)->name() ) {
 193                 thread->runJob( (*it) );
 194                 return true;
 195             }
 196
 197         // this thread is done
 198         thread->m_job = 0;
 199
 200         break;
 201     }
 202
 203     case QEvent::Timer:
 204         debug() << "Threads in pool: " << m_threads.count();
 205
 206 //         for( ThreadList::Iterator it = m_threads.begin(), end = m_threads.end(); it != end; ++it )
 207 //             if ( (*it)->readyForTrash() ) {
 208 //                 m_threads.remove( it );
 209 //                 delete *it;
 210 //                 break; // only delete 1 thread every 5 minutes
 211 //             }
 212         break;
 213
 214     case OverrideCursorEventType:
 215         // we have to do this for the PlaylistLoader case, as Qt uses the same
 216         // function for drag and drop operations.
 217         QApplication::setOverrideCursor( Qt::BusyCursor );
 218         break;
 219
 220     case RestoreOverrideCursorEventType:
 221         // we have to do this for the PlaylistLoader case, as Qt uses the same
 222         // function for drag and drop operations.
 223         QApplication::restoreOverrideCursor();
 224         break;
 225
 226     default:
 227         return false;
 228     }
 229
 230     return true;
 231 }
 232
 233
 234 /// @class ThreadManager::Thread
 235
 236 ThreadManager::Thread::Thread()
 237     : QThread()
 238 {}
 239
 240 ThreadManager::Thread::~Thread()
 241 {
 242     Q_ASSERT( isFinished() );
 243 }
 244
 245 void
 246 ThreadManager::Thread::runJob( Job *job )
 247 {
 248     job->m_thread = this;
 249
 250     if ( job->isAborted() )
 251         QApplication::postEvent( ThreadManager::instance(), new JobCompletedEvent( job ) );
 252
 253     else {
 254         m_job = job;
 255         if( isRunning() )
 256             wait();
 257         start( Thread::IdlePriority );
 258
 259         QApplication::postEvent(
 260                 ThreadManager::instance(),
 261                 new QEvent( QEvent::Type( ThreadManager::OverrideCursorEventType ) ) );
 262     }
 263 }
 264
 265 void
 266 ThreadManager::Thread::run()
 267 {
 268     // BE THREAD-SAFE!
 269
 270     DEBUG_BLOCK
 271
 272     //keep this first, before anything that uses the database, or SQLite may error out
 273     if ( AmarokConfig::databaseEngine().toInt() == DbConnection::sqlite )
 274         CollectionDB::instance()->releasePreviousConnection( this );
 275
 276     if( m_job )
 277     {
 278         m_job->m_aborted |= !m_job->doJob();
 279         QApplication::postEvent( ThreadManager::instance(), new JobCompletedEvent( m_job ) );
 280     }
 281
 282     // almost always the thread doesn't finish until after the
 283     // above event is already finished processing
 284
 285 }
 286
 287
 288 /// @class ProgressEvent
 289 /// @short Used by ThreadManager::Job internally
 290
 291 class ProgressEvent : public QEvent {
 292 public:
 293     static const int ProgressEventType = 30303;
 294     ProgressEvent( int progress )
 295             : QEvent( Type( ProgressEventType ) )
 296             , progress( progress ) {}
 297
 298     const int progress;
 299 };
 300
 301
 302
 303 /// @class ThreadManager::Job
 304
 305 ThreadManager::Job::Job( const char *name )
 306         : QEvent( Type( ThreadManager::JobEventType ) )
 307         , m_name( name )
 308         , m_thread( 0 )
 309         , m_percentDone( 0 )
 310         , m_progressDone( 0 )
 311         , m_totalSteps( 1 ) // no divide by zero
 312 {}
 313
 314 ThreadManager::Job::~Job()
 315 {
 316     /*if( m_thread->running() && m_thread->job() == this )
 317         warning() << "Deleting a job before its thread has finished with it!\n";*/
 318 }
 319
 320 void
 321 ThreadManager::Job::setProgressTotalSteps( uint steps )
 322 {
 323     if ( steps == 0 ) {
 324         warning() << "You can't set steps to 0!\n";
 325         steps = 1;
 326     }
 327
 328     m_totalSteps = steps;
 329
 330     QApplication::postEvent( this, new ProgressEvent( -1 ) );
 331 }
 332
 333 void
 334 ThreadManager::Job::setProgress( uint steps )
 335 {
 336     m_progressDone = steps;
 337
 338     uint newPercent = uint( (100 * steps) / m_totalSteps);
 339
 340     if ( newPercent != m_percentDone ) {
 341         m_percentDone = newPercent;
 342         QApplication::postEvent( this, new ProgressEvent( newPercent ) );
 343     }
 344 }
 345
 346 void
 347 ThreadManager::Job::setStatus( const QString &status )
 348 {
 349     m_status = status;
 350
 351     QApplication::postEvent( this, new ProgressEvent( -2 ) );
 352 }
 353
 354 void
 355 ThreadManager::Job::incrementProgress()
 356 {
 357     setProgress( m_progressDone + 1 );
 358 }
 359
 360 void
 361 ThreadManager::Job::customEvent( QEvent *e )
 362 {
 363     int progress = static_cast<ProgressEvent*>(e)->progress;
 364
 365     switch( progress )
 366     {
 367     case -2:
 368         StatusBar::instance()->setProgressStatus( this, m_status );
 369         break;
 370
 371     case -1:
 372         StatusBar::instance()->newProgressOperation( this )
 373                 .setDescription( m_description )
 374                 .setAbortSlot( this, SLOT(abort()) )
 375                 .setMaximum( 100 );
 376         break;
 377
 378     default:
 379         StatusBar::instance()->setProgress( this, progress );
 380     }
 381 }
 382
 383
 384
 385 ThreadManager::DependentJob::DependentJob( QObject *dependent, const char *name )
 386     : Job( name )
 387     , m_dependent( dependent )
 388 {
 389     Q_ASSERT( dependent != this );
 390     connect( dependent, SIGNAL(destroyed()), SLOT(abort()) );
 391
 392     QApplication::postEvent( dependent, new QEvent( Type( JobStartedEventType ) ) );
 393 }
 394
 395 void
 396 ThreadManager::DependentJob::completeJob()
 397 {
 398     //synchronous, so we don't get deleted twice
 399     QApplication::sendEvent( m_dependent, this );
 400 }
 401
 402 #include "threadmanager.moc"
 403 #undef QT_FATAL_ASSERT //enable-final