src/common/dynload.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:         dynload.cpp
   3 // Purpose:      Dynamic loading framework
   4 // Author:       Ron Lee, David Falkinder, Vadim Zeitlin and a cast of 1000's
   5 //               (derived in part from dynlib.cpp (c) 1998 Guilhem Lavaux)
   6 // Modified by:
   7 // Created:      03/12/01
   8 // RCS-ID:       $Id$
   9 // Copyright:    (c) 2001 Ron Lee <ron@debian.org>
  10 // Licence:      wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  14 #pragma implementation "dynload.h"
  15 #endif
  16
  17 // ----------------------------------------------------------------------------
  18 // headers
  19 // ----------------------------------------------------------------------------
  20
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #if wxUSE_DYNAMIC_LOADER
  28
  29 #ifdef __WINDOWS__
  30     #include "wx/msw/private.h"
  31 #endif
  32
  33 #ifndef WX_PRECOMP
  34     #include "wx/log.h"
  35     #include "wx/intl.h"
  36     #include "wx/hash.h"
  37     #include "wx/utils.h"
  38 #endif
  39
  40 #include "wx/strconv.h"
  41
  42 #include "wx/dynload.h"
  43 #include "wx/module.h"
  44
  45
  46 // ---------------------------------------------------------------------------
  47 // wxPluginLibrary
  48 // ---------------------------------------------------------------------------
  49
  50
  51 wxDLImports*  wxPluginLibrary::ms_classes = NULL;
  52
  53 class wxPluginLibraryModule : public wxModule
  54 {
  55 public:
  56     wxPluginLibraryModule() { }
  57
  58     // TODO: create ms_classes on demand, why always preallocate it?
  59     virtual bool OnInit()
  60     {
  61         wxPluginLibrary::ms_classes = new wxDLImports(wxKEY_STRING);
  62         wxPluginManager::CreateManifest();
  63         return TRUE;
  64     }
  65
  66     virtual void OnExit()
  67     {
  68         delete wxPluginLibrary::ms_classes;
  69         wxPluginLibrary::ms_classes = NULL;
  70         wxPluginManager::ClearManifest();
  71     }
  72
  73 private:
  74     DECLARE_DYNAMIC_CLASS(wxPluginLibraryModule )
  75 };
  76
  77 IMPLEMENT_DYNAMIC_CLASS(wxPluginLibraryModule, wxModule)
  78
  79
  80 wxPluginLibrary::wxPluginLibrary(const wxString &libname, int flags)
  81         : m_linkcount(1)
  82         , m_objcount(0)
  83 {
  84     m_before = wxClassInfo::sm_first;
  85     Load( libname, flags );
  86     m_after = wxClassInfo::sm_first;
  87
  88     if( m_handle != 0 )
  89     {
  90         UpdateClassInfo();
  91         RegisterModules();
  92     }
  93     else
  94     {
  95         // Flag us for deletion
  96         --m_linkcount;
  97     }
  98 }
  99
 100 wxPluginLibrary::~wxPluginLibrary()
 101 {
 102     if( m_handle != 0 )
 103     {
 104         UnregisterModules();
 105         RestoreClassInfo();
 106     }
 107 }
 108
 109 wxPluginLibrary *wxPluginLibrary::RefLib()
 110 {
 111     wxCHECK_MSG( m_linkcount > 0, NULL,
 112                  _T("Library had been already deleted!") );
 113
 114     ++m_linkcount;
 115     return this;
 116 }
 117
 118 bool wxPluginLibrary::UnrefLib()
 119 {
 120     wxASSERT_MSG( m_objcount == 0,
 121                   _T("Library unloaded before all objects were destroyed") );
 122
 123     if ( --m_linkcount == 0 )
 124     {
 125         delete this;
 126         return TRUE;
 127     }
 128
 129     return FALSE;
 130 }
 131
 132 // ------------------------
 133 // Private methods
 134 // ------------------------
 135
 136 void wxPluginLibrary::UpdateClassInfo()
 137 {
 138     wxClassInfo     *info;
 139     wxHashTable     *t = wxClassInfo::sm_classTable;
 140
 141         // FIXME: Below is simply a cut and paste specialisation of
 142         //        wxClassInfo::InitializeClasses.  Once this stabilises,
 143         //        the two should probably be merged.
 144         //
 145         //        Actually it's becoming questionable whether we should merge
 146         //        this info with the main ClassInfo tables since we can nearly
 147         //        handle this completely internally now and it does expose
 148         //        certain (minimal % user_stupidy) risks.
 149
 150     for(info = m_after; info != m_before; info = info->m_next)
 151     {
 152         if( info->m_className )
 153         {
 154             if( t->Get(info->m_className) == 0 )
 155                 t->Put(info->m_className, (wxObject *)info);
 156
 157             // Hash all the class names into a local table too so
 158             // we can quickly find the entry they correspond to.
 159             (*ms_classes)[info->m_className] = this;
 160         }
 161     }
 162 }
 163
 164 void wxPluginLibrary::RestoreClassInfo()
 165 {
 166     wxClassInfo *info;
 167
 168     for(info = m_after; info != m_before; info = info->m_next)
 169     {
 170         wxClassInfo::sm_classTable->Delete(info->m_className);
 171         ms_classes->erase(ms_classes->find(info->m_className));
 172     }
 173
 174     if( wxClassInfo::sm_first == m_after )
 175         wxClassInfo::sm_first = m_before;
 176     else
 177     {
 178         info = wxClassInfo::sm_first;
 179         while( info->m_next && info->m_next != m_after ) info = info->m_next;
 180
 181         wxASSERT_MSG( info, _T("ClassInfo from wxPluginLibrary not found on purge"));
 182
 183         info->m_next = m_before;
 184     }
 185 }
 186
 187 void wxPluginLibrary::RegisterModules()
 188 {
 189     // Plugin libraries might have wxModules, Register and initialise them if
 190     // they do.
 191     //
 192     // Note that these classes are NOT included in the reference counting since
 193     // it's implicit that they will be unloaded if and when the last handle to
 194     // the library is.  We do have to keep a copy of the module's pointer
 195     // though, as there is currently no way to Unregister it without it.
 196
 197     wxASSERT_MSG( m_linkcount == 1,
 198                   _T("RegisterModules should only be called for the first load") );
 199
 200     for ( wxClassInfo *info = m_after; info != m_before; info = info->m_next)
 201     {
 202         if( info->IsKindOf(CLASSINFO(wxModule)) )
 203         {
 204             wxModule *m = wxDynamicCast(info->CreateObject(), wxModule);
 205
 206             wxASSERT_MSG( m, _T("wxDynamicCast of wxModule failed") );
 207
 208             m_wxmodules.push_back(m);
 209             wxModule::RegisterModule(m);
 210         }
 211     }
 212
 213     // FIXME: Likewise this is (well was) very similar to InitializeModules()
 214
 215     for ( wxModuleList::iterator it = m_wxmodules.begin();
 216           it != m_wxmodules.end();
 217           ++it)
 218     {
 219         if( !(*it)->Init() )
 220         {
 221             wxLogDebug(_T("wxModule::Init() failed for wxPluginLibrary"));
 222
 223             // XXX: Watch this, a different hash implementation might break it,
 224             //      a good hash implementation would let us fix it though.
 225
 226             // The name of the game is to remove any uninitialised modules and
 227             // let the dtor Exit the rest on shutdown, (which we'll initiate
 228             // shortly).
 229
 230             wxModuleList::iterator oldNode = m_wxmodules.end();
 231             do {
 232                 ++it;
 233                 if( oldNode != m_wxmodules.end() )
 234                     m_wxmodules.erase(oldNode);
 235                 wxModule::UnregisterModule( *it );
 236                 oldNode = it;
 237             } while( it != m_wxmodules.end() );
 238
 239             --m_linkcount;     // Flag us for deletion
 240             break;
 241         }
 242     }
 243 }
 244
 245 void wxPluginLibrary::UnregisterModules()
 246 {
 247     wxModuleList::iterator it;
 248
 249     for ( it = m_wxmodules.begin(); it != m_wxmodules.end(); ++it )
 250         (*it)->Exit();
 251
 252     for ( it = m_wxmodules.begin(); it != m_wxmodules.end(); ++it )
 253         wxModule::UnregisterModule( *it );
 254
 255     WX_CLEAR_LIST(wxModuleList, m_wxmodules);
 256 }
 257
 258
 259 // ---------------------------------------------------------------------------
 260 // wxPluginManager
 261 // ---------------------------------------------------------------------------
 262
 263 wxDLManifest*   wxPluginManager::ms_manifest = NULL;
 264
 265 // ------------------------
 266 // Static accessors
 267 // ------------------------
 268
 269 wxPluginLibrary *
 270 wxPluginManager::LoadLibrary(const wxString &libname, int flags)
 271 {
 272     wxString realname(libname);
 273
 274     if( !(flags & wxDL_VERBATIM) )
 275         realname += wxDynamicLibrary::GetDllExt();
 276
 277     wxPluginLibrary *entry;
 278
 279     if ( flags & wxDL_NOSHARE )
 280     {
 281         entry = NULL;
 282     }
 283     else
 284     {
 285         entry = FindByName(realname);
 286     }
 287
 288     if ( entry )
 289     {
 290         wxLogTrace(_T("dll"),
 291                    _T("LoadLibrary(%s): already loaded."), realname.c_str());
 292
 293         entry->RefLib();
 294     }
 295     else
 296     {
 297         entry = new wxPluginLibrary( libname, flags );
 298
 299         if ( entry->IsLoaded() )
 300         {
 301             (*ms_manifest)[realname] = entry;
 302
 303             wxLogTrace(_T("dll"),
 304                        _T("LoadLibrary(%s): loaded ok."), realname.c_str());
 305
 306         }
 307         else
 308         {
 309             wxLogTrace(_T("dll"),
 310                        _T("LoadLibrary(%s): failed to load."), realname.c_str());
 311
 312             // we have created entry just above
 313             if ( !entry->UnrefLib() )
 314             {
 315                 // ... so UnrefLib() is supposed to delete it
 316                 wxFAIL_MSG( _T("Currently linked library is not loaded?") );
 317             }
 318
 319             entry = NULL;
 320         }
 321     }
 322
 323     return entry;
 324 }
 325
 326 bool wxPluginManager::UnloadLibrary(const wxString& libname)
 327 {
 328     wxString realname = libname;
 329
 330     wxPluginLibrary *entry = FindByName(realname);
 331
 332     if ( !entry )
 333     {
 334         realname += wxDynamicLibrary::GetDllExt();
 335
 336         entry = FindByName(realname);
 337     }
 338
 339     if ( !entry )
 340     {
 341         wxLogDebug(_T("Attempt to unload library '%s' which is not loaded."),
 342                    libname.c_str());
 343
 344         return FALSE;
 345     }
 346
 347     wxLogTrace(_T("dll"), _T("UnloadLibrary(%s)"), realname.c_str());
 348
 349     if ( !entry->UnrefLib() )
 350     {
 351         // not really unloaded yet
 352         return FALSE;
 353     }
 354
 355     ms_manifest->erase(ms_manifest->find(realname));
 356
 357     return TRUE;
 358 }
 359
 360 // ------------------------
 361 // Class implementation
 362 // ------------------------
 363
 364 bool wxPluginManager::Load(const wxString &libname, int flags)
 365 {
 366     m_entry = wxPluginManager::LoadLibrary(libname, flags);
 367
 368     return IsLoaded();
 369 }
 370
 371 void wxPluginManager::Unload()
 372 {
 373     wxCHECK_RET( m_entry, _T("unloading an invalid wxPluginManager?") );
 374
 375     for ( wxDLManifest::iterator i = ms_manifest->begin();
 376           i != ms_manifest->end();
 377           ++i )
 378     {
 379         if ( i->second == m_entry )
 380         {
 381             ms_manifest->erase(i);
 382             break;
 383         }
 384     }
 385
 386     m_entry->UnrefLib();
 387
 388     m_entry = NULL;
 389 }
 390
 391
 392
 393 #if WXWIN_COMPATIBILITY_2_2
 394
 395 wxPluginLibrary *wxPluginManager::GetObjectFromHandle(wxDllType handle)
 396 {
 397     for ( wxDLManifest::iterator i = ms_manifest->begin();
 398           i != ms_manifest->end();
 399           ++i )
 400     {
 401         wxPluginLibrary * const lib = i->second;
 402
 403         if ( lib->GetLibHandle() == handle )
 404             return lib;
 405     }
 406
 407     return NULL;
 408 }
 409
 410 // ---------------------------------------------------------------------------
 411 // wxDllLoader   (all these methods are static)
 412 // ---------------------------------------------------------------------------
 413
 414
 415 wxDllType wxDllLoader::LoadLibrary(const wxString &name, bool *success)
 416 {
 417     wxPluginLibrary *p = wxPluginManager::LoadLibrary
 418                          (
 419                             name,
 420                             wxDL_DEFAULT | wxDL_VERBATIM | wxDL_NOSHARE
 421                          );
 422
 423     if ( success )
 424         *success = p != NULL;
 425
 426     return p ? p->GetLibHandle() : 0;
 427 }
 428
 429 void wxDllLoader::UnloadLibrary(wxDllType handle)
 430 {
 431     wxPluginLibrary *p = wxPluginManager::GetObjectFromHandle(handle);
 432
 433     wxCHECK_RET( p, _T("Unloading a library not loaded with wxDllLoader?") );
 434
 435     p->UnrefLib();
 436 }
 437
 438 void *
 439 wxDllLoader::GetSymbol(wxDllType dllHandle, const wxString &name, bool *success)
 440 {
 441     wxPluginLibrary *p = wxPluginManager::GetObjectFromHandle(dllHandle);
 442
 443     if ( !p )
 444     {
 445         wxFAIL_MSG( _T("Using a library not loaded with wxDllLoader?") );
 446
 447         if ( success )
 448             *success = FALSE;
 449
 450         return NULL;
 451     }
 452
 453     return p->GetSymbol(name, success);
 454 }
 455
 456
 457 // ---------------------------------------------------------------------------
 458 // Global variables
 459 // ---------------------------------------------------------------------------
 460
 461 wxLibraries wxTheLibraries;
 462
 463 // ============================================================================
 464 // implementation
 465 // ============================================================================
 466
 467 // construct the full name from the base shared object name: adds a .dll
 468 // suffix under Windows or .so under Unix
 469 static wxString ConstructLibraryName(const wxString& basename)
 470 {
 471     wxString fullname;
 472     fullname << basename << wxDllLoader::GetDllExt();
 473
 474     return fullname;
 475 }
 476
 477 // ---------------------------------------------------------------------------
 478 // wxLibrary (one instance per dynamic library)
 479 // ---------------------------------------------------------------------------
 480
 481 wxLibrary::wxLibrary(wxDllType handle)
 482 {
 483     typedef wxClassInfo *(*t_get_first)(void);
 484     t_get_first get_first;
 485
 486     m_handle = handle;
 487
 488     // Some system may use a local heap for library.
 489     get_first = (t_get_first)GetSymbol(_T("wxGetClassFirst"));
 490     // It is a wxWindows DLL.
 491     if (get_first)
 492         PrepareClasses(get_first());
 493 }
 494
 495 wxLibrary::~wxLibrary()
 496 {
 497     if ( m_handle )
 498     {
 499         wxDllLoader::UnloadLibrary(m_handle);
 500     }
 501 }
 502
 503 wxObject *wxLibrary::CreateObject(const wxString& name)
 504 {
 505     wxClassInfo *info = (wxClassInfo *)classTable.Get(name);
 506
 507     if (!info)
 508         return NULL;
 509
 510     return info->CreateObject();
 511 }
 512
 513 void wxLibrary::PrepareClasses(wxClassInfo *first)
 514 {
 515     // Index all class infos by their class name
 516     wxClassInfo *info = first;
 517     while (info)
 518     {
 519         if (info->m_className)
 520             classTable.Put(info->m_className, (wxObject *)info);
 521         info = info->m_next;
 522     }
 523
 524 #if !wxUSE_EXTENDED_RTTI
 525     // Set base pointers for each wxClassInfo
 526     info = first;
 527     while (info)
 528     {
 529         if (info->GetBaseClassName1())
 530             info->m_baseInfo1 = (wxClassInfo *)classTable.Get(info->GetBaseClassName1());
 531         if (info->GetBaseClassName2())
 532             info->m_baseInfo2 = (wxClassInfo *)classTable.Get(info->GetBaseClassName2());
 533         info = info->m_next;
 534     }
 535 #endif
 536 }
 537
 538 void *wxLibrary::GetSymbol(const wxString& symbname)
 539 {
 540    return wxDllLoader::GetSymbol(m_handle, symbname);
 541 }
 542
 543
 544 // ---------------------------------------------------------------------------
 545 // wxLibraries (only one instance should normally exist)
 546 // ---------------------------------------------------------------------------
 547
 548 wxLibraries::wxLibraries():m_loaded(wxKEY_STRING)
 549 {
 550 }
 551
 552 wxLibraries::~wxLibraries()
 553 {
 554     wxNode *node = m_loaded.First();
 555
 556     while (node) {
 557         wxLibrary *lib = (wxLibrary *)node->Data();
 558         delete lib;
 559
 560         node = node->Next();
 561     }
 562 }
 563
 564 wxLibrary *wxLibraries::LoadLibrary(const wxString& name)
 565 {
 566     wxLibrary   *lib;
 567     wxClassInfo *old_sm_first;
 568     wxNode      *node = m_loaded.Find(name.GetData());
 569
 570     if (node != NULL)
 571         return ((wxLibrary *)node->Data());
 572
 573     // If DLL shares data, this is necessary.
 574     old_sm_first = wxClassInfo::sm_first;
 575     wxClassInfo::sm_first = NULL;
 576
 577     wxString libname = ConstructLibraryName(name);
 578
 579     bool success = FALSE;
 580     wxDllType handle = wxDllLoader::LoadLibrary(libname, &success);
 581     if(success)
 582     {
 583        lib = new wxLibrary(handle);
 584        wxClassInfo::sm_first = old_sm_first;
 585
 586        m_loaded.Append(name.GetData(), lib);
 587     }
 588     else
 589        lib = NULL;
 590     return lib;
 591 }
 592
 593 wxObject *wxLibraries::CreateObject(const wxString& path)
 594 {
 595     wxNode *node = m_loaded.First();
 596     wxObject *obj;
 597
 598     while (node) {
 599         obj = ((wxLibrary *)node->Data())->CreateObject(path);
 600         if (obj)
 601             return obj;
 602
 603         node = node->Next();
 604     }
 605     return NULL;
 606 }
 607
 608 #endif  // WXWIN_COMPATIBILITY_2_2
 609
 610
 611 #endif  // wxUSE_DYNAMIC_LOADER
 612