src/osx/core/evtloop_cf.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/osx/core/evtloop_cf.cpp
   3 // Purpose:     wxEventLoop implementation common to both Carbon and Cocoa
   4 // Author:      Vadim Zeitlin
   5 // Created:     2009-10-18
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2009 Vadim Zeitlin <vadim@wxwidgets.org>
   8 // Licence:     wxWindows licence
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 // ============================================================================
  12 // declarations
  13 // ============================================================================
  14
  15 // ----------------------------------------------------------------------------
  16 // headers
  17 // ----------------------------------------------------------------------------
  18
  19 // for compilers that support precompilation, includes "wx.h".
  20 #include "wx/wxprec.h"
  21
  22 #ifdef __BORLANDC__
  23     #pragma hdrstop
  24 #endif
  25
  26 #include "wx/evtloop.h"
  27
  28 #if wxUSE_EVENTLOOP_SOURCE
  29
  30 #ifndef WX_PRECOMP
  31     #include "wx/log.h"
  32     #include "wx/app.h"
  33 #endif
  34
  35 #include "wx/evtloopsrc.h"
  36
  37 #include "wx/scopedptr.h"
  38
  39 #include "wx/osx/private.h"
  40 #include "wx/osx/core/cfref.h"
  41 #include "wx/thread.h"
  42
  43 #if wxUSE_GUI
  44     #include "wx/nonownedwnd.h"
  45 #endif
  46
  47 // ============================================================================
  48 // wxCFEventLoopSource and wxCFEventLoop implementation
  49 // ============================================================================
  50
  51 #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
  52 namespace
  53 {
  54
  55 void EnableDescriptorCallBacks(CFFileDescriptorRef cffd, int flags)
  56 {
  57     if ( flags & wxEVENT_SOURCE_INPUT )
  58         CFFileDescriptorEnableCallBacks(cffd, kCFFileDescriptorReadCallBack);
  59     if ( flags & wxEVENT_SOURCE_OUTPUT )
  60         CFFileDescriptorEnableCallBacks(cffd, kCFFileDescriptorWriteCallBack);
  61 }
  62
  63 void
  64 wx_cffiledescriptor_callback(CFFileDescriptorRef cffd,
  65                              CFOptionFlags flags,
  66                              void *ctxData)
  67 {
  68     wxLogTrace(wxTRACE_EVT_SOURCE,
  69                "CFFileDescriptor callback, flags=%d", flags);
  70
  71     wxCFEventLoopSource * const
  72         source = static_cast<wxCFEventLoopSource *>(ctxData);
  73
  74     wxEventLoopSourceHandler * const
  75         handler = source->GetHandler();
  76     if ( flags & kCFFileDescriptorReadCallBack )
  77         handler->OnReadWaiting();
  78     if ( flags & kCFFileDescriptorWriteCallBack )
  79         handler->OnWriteWaiting();
  80
  81     // we need to re-enable callbacks to be called again
  82     EnableDescriptorCallBacks(cffd, source->GetFlags());
  83 }
  84
  85 } // anonymous namespace
  86
  87 wxEventLoopSource *
  88 wxCFEventLoop::AddSourceForFD(int fd,
  89                               wxEventLoopSourceHandler *handler,
  90                               int flags)
  91 {
  92     wxCHECK_MSG( fd != -1, NULL, "can't monitor invalid fd" );
  93
  94     wxScopedPtr<wxCFEventLoopSource>
  95         source(new wxCFEventLoopSource(handler, flags));
  96
  97     CFFileDescriptorContext ctx = { 0, source.get(), NULL, NULL, NULL };
  98     wxCFRef<CFFileDescriptorRef>
  99         cffd(CFFileDescriptorCreate
 100              (
 101                   kCFAllocatorDefault,
 102                   fd,
 103                   true,   // close on invalidate
 104                   wx_cffiledescriptor_callback,
 105                   &ctx
 106              ));
 107     if ( !cffd )
 108         return NULL;
 109
 110     source->SetFileDescriptor(cffd.release());
 111
 112     wxCFRef<CFRunLoopSourceRef>
 113         cfsrc(CFFileDescriptorCreateRunLoopSource(kCFAllocatorDefault, cffd, 0));
 114     if ( !cfsrc )
 115         return NULL;
 116
 117     CFRunLoopRef cfloop = CFGetCurrentRunLoop();
 118     CFRunLoopAddSource(cfloop, cfsrc, kCFRunLoopDefaultMode);
 119
 120     return source.release();
 121 }
 122
 123 void wxCFEventLoopSource::SetFileDescriptor(CFFileDescriptorRef cffd)
 124 {
 125     wxASSERT_MSG( !m_cffd, "shouldn't be called more than once" );
 126
 127     m_cffd = cffd;
 128 }
 129
 130 wxCFEventLoopSource::~wxCFEventLoopSource()
 131 {
 132     if ( m_cffd )
 133         CFRelease(m_cffd);
 134 }
 135
 136 #else // OS X < 10.5
 137
 138 wxEventLoopSource *
 139 wxCFEventLoop::AddSourceForFD(int WXUNUSED(fd),
 140                               wxEventLoopSourceHandler * WXUNUSED(handler),
 141                               int WXUNUSED(flags))
 142 {
 143     return NULL;
 144 }
 145
 146 #endif // MAC_OS_X_VERSION_MAX_ALLOWED
 147
 148 #endif // wxUSE_EVENTLOOP_SOURCE
 149
 150 extern "C" void wxObserverCallBack(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info)
 151 {
 152     wxCFEventLoop * eventloop = static_cast<wxCFEventLoop *>(info);
 153     if ( eventloop )
 154         eventloop->ObserverCallBack(observer, activity);
 155 }
 156
 157 void wxCFEventLoop::ObserverCallBack(CFRunLoopObserverRef WXUNUSED(observer), int activity)
 158 {
 159     if ( activity & kCFRunLoopBeforeTimers )
 160     {
 161         // process pending wx events first as they correspond to low-level events
 162         // which happened before, i.e. typically pending events were queued by a
 163         // previous call to Dispatch() and if we didn't process them now the next
 164         // call to it might enqueue them again (as happens with e.g. socket events
 165         // which would be generated as long as there is input available on socket
 166         // and this input is only removed from it when pending event handlers are
 167         // executed)
 168
 169         if ( wxTheApp )
 170             wxTheApp->ProcessPendingEvents();
 171     }
 172
 173     if ( activity & kCFRunLoopBeforeWaiting )
 174     {
 175         if ( ProcessIdle() )
 176         {
 177             WakeUp();
 178         }
 179         else
 180         {
 181 #if wxUSE_THREADS
 182             wxMutexGuiLeaveOrEnter();
 183 #endif
 184         }
 185     }
 186 }
 187
 188 wxCFEventLoop::wxCFEventLoop()
 189 {
 190     m_shouldExit = false;
 191
 192     m_runLoop = CFGetCurrentRunLoop();
 193
 194     CFRunLoopObserverContext ctxt;
 195     bzero( &ctxt, sizeof(ctxt) );
 196     ctxt.info = this;
 197     m_runLoopObserver = CFRunLoopObserverCreate( kCFAllocatorDefault, kCFRunLoopBeforeTimers | kCFRunLoopBeforeWaiting , true /* repeats */, 0,
 198                                             wxObserverCallBack, &ctxt );
 199     CFRunLoopAddObserver(m_runLoop, m_runLoopObserver, kCFRunLoopCommonModes);
 200     CFRelease(m_runLoopObserver);
 201 }
 202
 203 wxCFEventLoop::~wxCFEventLoop()
 204 {
 205     CFRunLoopRemoveObserver(m_runLoop, m_runLoopObserver, kCFRunLoopCommonModes);
 206 }
 207
 208
 209 CFRunLoopRef wxCFEventLoop::CFGetCurrentRunLoop() const
 210 {
 211     return CFRunLoopGetCurrent();
 212 }
 213
 214 void wxCFEventLoop::WakeUp()
 215 {
 216     CFRunLoopWakeUp(m_runLoop);
 217 }
 218
 219 #if wxUSE_BASE
 220
 221 void wxMacWakeUp()
 222 {
 223     wxEventLoopBase * const loop = wxEventLoopBase::GetActive();
 224
 225     if ( loop )
 226         loop->WakeUp();
 227 }
 228
 229 #endif
 230
 231 bool wxCFEventLoop::YieldFor(long eventsToProcess)
 232 {
 233 #if wxUSE_THREADS
 234     // Yielding from a non-gui thread needs to bail out, otherwise we end up
 235     // possibly sending events in the thread too.
 236     if ( !wxThread::IsMain() )
 237     {
 238         return true;
 239     }
 240 #endif // wxUSE_THREADS
 241
 242     m_isInsideYield = true;
 243     m_eventsToProcessInsideYield = eventsToProcess;
 244
 245 #if wxUSE_LOG
 246     // disable log flushing from here because a call to wxYield() shouldn't
 247     // normally result in message boxes popping up &c
 248     wxLog::Suspend();
 249 #endif // wxUSE_LOG
 250
 251     // process all pending events:
 252     while ( DoProcessEvents() == 1 )
 253         ;
 254
 255     // it's necessary to call ProcessIdle() to update the frames sizes which
 256     // might have been changed (it also will update other things set from
 257     // OnUpdateUI() which is a nice (and desired) side effect)
 258     while ( ProcessIdle() ) {}
 259
 260     // if there are pending events, we must process them.
 261     if (wxTheApp)
 262         wxTheApp->ProcessPendingEvents();
 263
 264 #if wxUSE_LOG
 265     wxLog::Resume();
 266 #endif // wxUSE_LOG
 267     m_isInsideYield = false;
 268
 269     return true;
 270 }
 271
 272 // implement/override base class pure virtual
 273 bool wxCFEventLoop::Pending() const
 274 {
 275     return true;
 276 }
 277
 278 int wxCFEventLoop::DoProcessEvents()
 279 {
 280     return DispatchTimeout( 0 );
 281 }
 282
 283 bool wxCFEventLoop::Dispatch()
 284 {
 285     return DoProcessEvents() != 0;
 286 }
 287
 288 int wxCFEventLoop::DispatchTimeout(unsigned long timeout)
 289 {
 290     if ( !wxTheApp )
 291         return 0;
 292
 293     int status = DoDispatchTimeout(timeout);
 294
 295     switch( status )
 296     {
 297         case 0:
 298             break;
 299         case -1:
 300             if ( m_shouldExit )
 301                 return 0;
 302
 303             break;
 304         case 1:
 305             break;
 306     }
 307
 308     return status;
 309 }
 310
 311 int wxCFEventLoop::DoDispatchTimeout(unsigned long timeout)
 312 {
 313     SInt32 status = CFRunLoopRunInMode(kCFRunLoopDefaultMode, timeout / 1000.0 , true);
 314     switch( status )
 315     {
 316         case kCFRunLoopRunFinished:
 317             wxFAIL_MSG( "incorrect run loop state" );
 318             break;
 319         case kCFRunLoopRunStopped:
 320             return 0;
 321             break;
 322         case kCFRunLoopRunTimedOut:
 323             return -1;
 324             break;
 325         case kCFRunLoopRunHandledSource:
 326         default:
 327             break;
 328     }
 329     return 1;
 330 }
 331
 332 void wxCFEventLoop::DoRun()
 333 {
 334     for ( ;; )
 335     {
 336         // generate and process idle events for as long as we don't
 337         // have anything else to do
 338         DoProcessEvents();
 339
 340         // if the "should exit" flag is set, the loop should terminate
 341         // but not before processing any remaining messages so while
 342         // Pending() returns true, do process them
 343         if ( m_shouldExit )
 344         {
 345             while ( DoProcessEvents() == 1 )
 346                 ;
 347
 348             break;
 349         }
 350     }
 351 }
 352
 353 void wxCFEventLoop::DoStop()
 354 {
 355     CFRunLoopStop(CFGetCurrentRunLoop());
 356 }
 357
 358 // enters a loop calling OnNextIteration(), Pending() and Dispatch() and
 359 // terminating when Exit() is called
 360 int wxCFEventLoop::Run()
 361 {
 362     // event loops are not recursive, you need to create another loop!
 363     wxCHECK_MSG( !IsRunning(), -1, wxT("can't reenter a message loop") );
 364
 365     // ProcessIdle() and ProcessEvents() below may throw so the code here should
 366     // be exception-safe, hence we must use local objects for all actions we
 367     // should undo
 368     wxEventLoopActivator activate(this);
 369
 370     // we must ensure that OnExit() is called even if an exception is thrown
 371     // from inside ProcessEvents() but we must call it from Exit() in normal
 372     // situations because it is supposed to be called synchronously,
 373     // wxModalEventLoop depends on this (so we can't just use ON_BLOCK_EXIT or
 374     // something similar here)
 375 #if wxUSE_EXCEPTIONS
 376     for ( ;; )
 377     {
 378         try
 379         {
 380 #endif // wxUSE_EXCEPTIONS
 381
 382             DoRun();
 383
 384 #if wxUSE_EXCEPTIONS
 385             // exit the outer loop as well
 386             break;
 387         }
 388         catch ( ... )
 389         {
 390             try
 391             {
 392                 if ( !wxTheApp || !wxTheApp->OnExceptionInMainLoop() )
 393                 {
 394                     OnExit();
 395                     break;
 396                 }
 397                 //else: continue running the event loop
 398             }
 399             catch ( ... )
 400             {
 401                 // OnException() throwed, possibly rethrowing the same
 402                 // exception again: very good, but we still need OnExit() to
 403                 // be called
 404                 OnExit();
 405                 throw;
 406             }
 407         }
 408     }
 409 #endif // wxUSE_EXCEPTIONS
 410
 411     return m_exitcode;
 412 }
 413
 414 // sets the "should exit" flag and wakes up the loop so that it terminates
 415 // soon
 416 void wxCFEventLoop::Exit(int rc)
 417 {
 418     m_exitcode = rc;
 419     m_shouldExit = true;
 420     DoStop();
 421 }
 422
 423 // TODO Move to thread_osx.cpp
 424
 425 #if wxUSE_THREADS
 426
 427 // ----------------------------------------------------------------------------
 428 // GUI Serialization copied from MSW implementation
 429 // ----------------------------------------------------------------------------
 430
 431 // if it's false, some secondary thread is holding the GUI lock
 432 static bool gs_bGuiOwnedByMainThread = true;
 433
 434 // critical section which controls access to all GUI functions: any secondary
 435 // thread (i.e. except the main one) must enter this crit section before doing
 436 // any GUI calls
 437 static wxCriticalSection *gs_critsectGui = NULL;
 438
 439 // critical section which protects gs_nWaitingForGui variable
 440 static wxCriticalSection *gs_critsectWaitingForGui = NULL;
 441
 442 // number of threads waiting for GUI in wxMutexGuiEnter()
 443 static size_t gs_nWaitingForGui = 0;
 444
 445 void wxOSXThreadModuleOnInit()
 446 {
 447     gs_critsectWaitingForGui = new wxCriticalSection();
 448     gs_critsectGui = new wxCriticalSection();
 449     gs_critsectGui->Enter();
 450 }
 451
 452
 453 void wxOSXThreadModuleOnExit()
 454 {
 455     if ( gs_critsectGui )
 456     {
 457         if ( !wxGuiOwnedByMainThread() )
 458         {
 459             gs_critsectGui->Enter();
 460             gs_bGuiOwnedByMainThread = true;
 461         }
 462
 463         gs_critsectGui->Leave();
 464         wxDELETE(gs_critsectGui);
 465     }
 466
 467     wxDELETE(gs_critsectWaitingForGui);
 468 }
 469
 470
 471 // wake up the main thread
 472 void WXDLLIMPEXP_BASE wxWakeUpMainThread()
 473 {
 474     wxMacWakeUp();
 475 }
 476
 477 void wxMutexGuiEnterImpl()
 478 {
 479     // this would dead lock everything...
 480     wxASSERT_MSG( !wxThread::IsMain(),
 481                  wxT("main thread doesn't want to block in wxMutexGuiEnter()!") );
 482
 483     // the order in which we enter the critical sections here is crucial!!
 484
 485     // set the flag telling to the main thread that we want to do some GUI
 486     {
 487         wxCriticalSectionLocker enter(*gs_critsectWaitingForGui);
 488
 489         gs_nWaitingForGui++;
 490     }
 491
 492     wxWakeUpMainThread();
 493
 494     // now we may block here because the main thread will soon let us in
 495     // (during the next iteration of OnIdle())
 496     gs_critsectGui->Enter();
 497 }
 498
 499 void wxMutexGuiLeaveImpl()
 500 {
 501     wxCriticalSectionLocker enter(*gs_critsectWaitingForGui);
 502
 503     if ( wxThread::IsMain() )
 504     {
 505         gs_bGuiOwnedByMainThread = false;
 506     }
 507     else
 508     {
 509         // decrement the number of threads waiting for GUI access now
 510         wxASSERT_MSG( gs_nWaitingForGui > 0,
 511                      wxT("calling wxMutexGuiLeave() without entering it first?") );
 512
 513         gs_nWaitingForGui--;
 514
 515         wxWakeUpMainThread();
 516     }
 517
 518     gs_critsectGui->Leave();
 519 }
 520
 521 void WXDLLIMPEXP_BASE wxMutexGuiLeaveOrEnter()
 522 {
 523     wxASSERT_MSG( wxThread::IsMain(),
 524                  wxT("only main thread may call wxMutexGuiLeaveOrEnter()!") );
 525
 526     if ( !gs_critsectWaitingForGui )
 527         return;
 528
 529     wxCriticalSectionLocker enter(*gs_critsectWaitingForGui);
 530
 531     if ( gs_nWaitingForGui == 0 )
 532     {
 533         // no threads are waiting for GUI - so we may acquire the lock without
 534         // any danger (but only if we don't already have it)
 535         if ( !wxGuiOwnedByMainThread() )
 536         {
 537             gs_critsectGui->Enter();
 538
 539             gs_bGuiOwnedByMainThread = true;
 540         }
 541         //else: already have it, nothing to do
 542     }
 543     else
 544     {
 545         // some threads are waiting, release the GUI lock if we have it
 546         if ( wxGuiOwnedByMainThread() )
 547             wxMutexGuiLeave();
 548         //else: some other worker thread is doing GUI
 549     }
 550 }
 551
 552 bool WXDLLIMPEXP_BASE wxGuiOwnedByMainThread()
 553 {
 554     return gs_bGuiOwnedByMainThread;
 555 }
 556
 557 #endif