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;
  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         UpdateClasses();
  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         RestoreClasses();
 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 || --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::UpdateClasses()
 137 {
 138     for (wxClassInfo *info = m_after; info != m_before; info = info->m_next)
 139     {
 140         if( info->m_className )
 141         {
 142             // Hash all the class names into a local table too so
 143             // we can quickly find the entry they correspond to.
 144             (*ms_classes)[info->m_className] = this;
 145         }
 146     }
 147 }
 148
 149 void wxPluginLibrary::RestoreClasses()
 150 {
 151     // Check if there is a need to restore classes.
 152     if (!ms_classes)
 153         return;
 154
 155     for(wxClassInfo *info = m_after; info != m_before; info = info->m_next)
 156     {
 157         ms_classes->erase(ms_classes->find(info->m_className));
 158     }
 159 }
 160
 161 void wxPluginLibrary::RegisterModules()
 162 {
 163     // Plugin libraries might have wxModules, Register and initialise them if
 164     // they do.
 165     //
 166     // Note that these classes are NOT included in the reference counting since
 167     // it's implicit that they will be unloaded if and when the last handle to
 168     // the library is.  We do have to keep a copy of the module's pointer
 169     // though, as there is currently no way to Unregister it without it.
 170
 171     wxASSERT_MSG( m_linkcount == 1,
 172                   _T("RegisterModules should only be called for the first load") );
 173
 174     for ( wxClassInfo *info = m_after; info != m_before; info = info->m_next)
 175     {
 176         if( info->IsKindOf(CLASSINFO(wxModule)) )
 177         {
 178             wxModule *m = wxDynamicCast(info->CreateObject(), wxModule);
 179
 180             wxASSERT_MSG( m, _T("wxDynamicCast of wxModule failed") );
 181
 182             m_wxmodules.push_back(m);
 183             wxModule::RegisterModule(m);
 184         }
 185     }
 186
 187     // FIXME: Likewise this is (well was) very similar to InitializeModules()
 188
 189     for ( wxModuleList::iterator it = m_wxmodules.begin();
 190           it != m_wxmodules.end();
 191           ++it)
 192     {
 193         if( !(*it)->Init() )
 194         {
 195             wxLogDebug(_T("wxModule::Init() failed for wxPluginLibrary"));
 196
 197             // XXX: Watch this, a different hash implementation might break it,
 198             //      a good hash implementation would let us fix it though.
 199
 200             // The name of the game is to remove any uninitialised modules and
 201             // let the dtor Exit the rest on shutdown, (which we'll initiate
 202             // shortly).
 203
 204             wxModuleList::iterator oldNode = m_wxmodules.end();
 205             do {
 206                 ++it;
 207                 if( oldNode != m_wxmodules.end() )
 208                     m_wxmodules.erase(oldNode);
 209                 wxModule::UnregisterModule( *it );
 210                 oldNode = it;
 211             } while( it != m_wxmodules.end() );
 212
 213             --m_linkcount;     // Flag us for deletion
 214             break;
 215         }
 216     }
 217 }
 218
 219 void wxPluginLibrary::UnregisterModules()
 220 {
 221     wxModuleList::iterator it;
 222
 223     for ( it = m_wxmodules.begin(); it != m_wxmodules.end(); ++it )
 224         (*it)->Exit();
 225
 226     for ( it = m_wxmodules.begin(); it != m_wxmodules.end(); ++it )
 227         wxModule::UnregisterModule( *it );
 228
 229     // NB: content of the list was deleted by UnregisterModule calls above:
 230     m_wxmodules.clear();
 231 }
 232
 233
 234 // ---------------------------------------------------------------------------
 235 // wxPluginManager
 236 // ---------------------------------------------------------------------------
 237
 238 wxDLManifest*   wxPluginManager::ms_manifest = NULL;
 239
 240 // ------------------------
 241 // Static accessors
 242 // ------------------------
 243
 244 wxPluginLibrary *
 245 wxPluginManager::LoadLibrary(const wxString &libname, int flags)
 246 {
 247     wxString realname(libname);
 248
 249     if( !(flags & wxDL_VERBATIM) )
 250         realname += wxDynamicLibrary::GetDllExt();
 251
 252     wxPluginLibrary *entry;
 253
 254     if ( flags & wxDL_NOSHARE )
 255     {
 256         entry = NULL;
 257     }
 258     else
 259     {
 260         entry = FindByName(realname);
 261     }
 262
 263     if ( entry )
 264     {
 265         wxLogTrace(_T("dll"),
 266                    _T("LoadLibrary(%s): already loaded."), realname.c_str());
 267
 268         entry->RefLib();
 269     }
 270     else
 271     {
 272         entry = new wxPluginLibrary( libname, flags );
 273
 274         if ( entry->IsLoaded() )
 275         {
 276             (*ms_manifest)[realname] = entry;
 277
 278             wxLogTrace(_T("dll"),
 279                        _T("LoadLibrary(%s): loaded ok."), realname.c_str());
 280
 281         }
 282         else
 283         {
 284             wxLogTrace(_T("dll"),
 285                        _T("LoadLibrary(%s): failed to load."), realname.c_str());
 286
 287             // we have created entry just above
 288             if ( !entry->UnrefLib() )
 289             {
 290                 // ... so UnrefLib() is supposed to delete it
 291                 wxFAIL_MSG( _T("Currently linked library is not loaded?") );
 292             }
 293
 294             entry = NULL;
 295         }
 296     }
 297
 298     return entry;
 299 }
 300
 301 bool wxPluginManager::UnloadLibrary(const wxString& libname)
 302 {
 303     wxString realname = libname;
 304
 305     wxPluginLibrary *entry = FindByName(realname);
 306
 307     if ( !entry )
 308     {
 309         realname += wxDynamicLibrary::GetDllExt();
 310
 311         entry = FindByName(realname);
 312     }
 313
 314     if ( !entry )
 315     {
 316         wxLogDebug(_T("Attempt to unload library '%s' which is not loaded."),
 317                    libname.c_str());
 318
 319         return FALSE;
 320     }
 321
 322     wxLogTrace(_T("dll"), _T("UnloadLibrary(%s)"), realname.c_str());
 323
 324     if ( !entry->UnrefLib() )
 325     {
 326         // not really unloaded yet
 327         return FALSE;
 328     }
 329
 330     ms_manifest->erase(ms_manifest->find(realname));
 331
 332     return TRUE;
 333 }
 334
 335 // ------------------------
 336 // Class implementation
 337 // ------------------------
 338
 339 bool wxPluginManager::Load(const wxString &libname, int flags)
 340 {
 341     m_entry = wxPluginManager::LoadLibrary(libname, flags);
 342
 343     return IsLoaded();
 344 }
 345
 346 void wxPluginManager::Unload()
 347 {
 348     wxCHECK_RET( m_entry, _T("unloading an invalid wxPluginManager?") );
 349
 350     for ( wxDLManifest::iterator i = ms_manifest->begin();
 351           i != ms_manifest->end();
 352           ++i )
 353     {
 354         if ( i->second == m_entry )
 355         {
 356             ms_manifest->erase(i);
 357             break;
 358         }
 359     }
 360
 361     m_entry->UnrefLib();
 362
 363     m_entry = NULL;
 364 }
 365
 366
 367
 368 #if WXWIN_COMPATIBILITY_2_2
 369
 370 wxPluginLibrary *wxPluginManager::GetObjectFromHandle(wxDllType handle)
 371 {
 372     for ( wxDLManifest::iterator i = ms_manifest->begin();
 373           i != ms_manifest->end();
 374           ++i )
 375     {
 376         wxPluginLibrary * const lib = i->second;
 377
 378         if ( lib->GetLibHandle() == handle )
 379             return lib;
 380     }
 381
 382     return NULL;
 383 }
 384
 385 // ---------------------------------------------------------------------------
 386 // wxDllLoader   (all these methods are static)
 387 // ---------------------------------------------------------------------------
 388
 389
 390 wxDllType wxDllLoader::LoadLibrary(const wxString &name, bool *success)
 391 {
 392     wxPluginLibrary *p = wxPluginManager::LoadLibrary
 393                          (
 394                             name,
 395                             wxDL_DEFAULT | wxDL_VERBATIM | wxDL_NOSHARE
 396                          );
 397
 398     if ( success )
 399         *success = p != NULL;
 400
 401     return p ? p->GetLibHandle() : 0;
 402 }
 403
 404 void wxDllLoader::UnloadLibrary(wxDllType handle)
 405 {
 406     wxPluginLibrary *p = wxPluginManager::GetObjectFromHandle(handle);
 407
 408     wxCHECK_RET( p, _T("Unloading a library not loaded with wxDllLoader?") );
 409
 410     p->UnrefLib();
 411 }
 412
 413 void *
 414 wxDllLoader::GetSymbol(wxDllType dllHandle, const wxString &name, bool *success)
 415 {
 416     wxPluginLibrary *p = wxPluginManager::GetObjectFromHandle(dllHandle);
 417
 418     if ( !p )
 419     {
 420         wxFAIL_MSG( _T("Using a library not loaded with wxDllLoader?") );
 421
 422         if ( success )
 423             *success = FALSE;
 424
 425         return NULL;
 426     }
 427
 428     return p->GetSymbol(name, success);
 429 }
 430
 431
 432 // ---------------------------------------------------------------------------
 433 // Global variables
 434 // ---------------------------------------------------------------------------
 435
 436 wxLibraries wxTheLibraries;
 437
 438 // ============================================================================
 439 // implementation
 440 // ============================================================================
 441
 442 // construct the full name from the base shared object name: adds a .dll
 443 // suffix under Windows or .so under Unix
 444 static wxString ConstructLibraryName(const wxString& basename)
 445 {
 446     wxString fullname;
 447     fullname << basename << wxDllLoader::GetDllExt();
 448
 449     return fullname;
 450 }
 451
 452 // ---------------------------------------------------------------------------
 453 // wxLibrary (one instance per dynamic library)
 454 // ---------------------------------------------------------------------------
 455
 456 wxLibrary::wxLibrary(wxDllType handle)
 457 {
 458     typedef wxClassInfo *(*t_get_first)(void);
 459     t_get_first get_first;
 460
 461     m_handle = handle;
 462
 463     // Some system may use a local heap for library.
 464     get_first = (t_get_first)GetSymbol(_T("wxGetClassFirst"));
 465     // It is a wxWidgets DLL.
 466     if (get_first)
 467         PrepareClasses(get_first());
 468 }
 469
 470 wxLibrary::~wxLibrary()
 471 {
 472     if ( m_handle )
 473     {
 474         wxDllLoader::UnloadLibrary(m_handle);
 475     }
 476 }
 477
 478 wxObject *wxLibrary::CreateObject(const wxString& name)
 479 {
 480     wxClassInfo *info = (wxClassInfo *)classTable.Get(name);
 481
 482     if (!info)
 483         return NULL;
 484
 485     return info->CreateObject();
 486 }
 487
 488 void wxLibrary::PrepareClasses(wxClassInfo *first)
 489 {
 490     // Index all class infos by their class name
 491     wxClassInfo *info = first;
 492     while (info)
 493     {
 494         if (info->m_className)
 495             classTable.Put(info->m_className, (wxObject *)info);
 496         info = info->m_next;
 497     }
 498
 499 #if !wxUSE_EXTENDED_RTTI
 500     // Set base pointers for each wxClassInfo
 501     info = first;
 502     while (info)
 503     {
 504         if (info->GetBaseClassName1())
 505             info->m_baseInfo1 = (wxClassInfo *)classTable.Get(info->GetBaseClassName1());
 506         if (info->GetBaseClassName2())
 507             info->m_baseInfo2 = (wxClassInfo *)classTable.Get(info->GetBaseClassName2());
 508         info = info->m_next;
 509     }
 510 #endif
 511 }
 512
 513 void *wxLibrary::GetSymbol(const wxString& symbname)
 514 {
 515    return wxDllLoader::GetSymbol(m_handle, symbname);
 516 }
 517
 518
 519 // ---------------------------------------------------------------------------
 520 // wxLibraries (only one instance should normally exist)
 521 // ---------------------------------------------------------------------------
 522
 523 wxLibraries::wxLibraries():m_loaded(wxKEY_STRING)
 524 {
 525 }
 526
 527 wxLibraries::~wxLibraries()
 528 {
 529     wxNode *node = m_loaded.First();
 530
 531     while (node) {
 532         wxLibrary *lib = (wxLibrary *)node->Data();
 533         delete lib;
 534
 535         node = node->Next();
 536     }
 537 }
 538
 539 wxLibrary *wxLibraries::LoadLibrary(const wxString& name)
 540 {
 541     wxLibrary   *lib;
 542     wxClassInfo *old_sm_first;
 543     wxNode      *node = m_loaded.Find(name.GetData());
 544
 545     if (node != NULL)
 546         return ((wxLibrary *)node->Data());
 547
 548     // If DLL shares data, this is necessary.
 549     old_sm_first = wxClassInfo::sm_first;
 550     wxClassInfo::sm_first = NULL;
 551
 552     wxString libname = ConstructLibraryName(name);
 553
 554     bool success = FALSE;
 555     wxDllType handle = wxDllLoader::LoadLibrary(libname, &success);
 556     if(success)
 557     {
 558        lib = new wxLibrary(handle);
 559        wxClassInfo::sm_first = old_sm_first;
 560
 561        m_loaded.Append(name.GetData(), lib);
 562     }
 563     else
 564        lib = NULL;
 565     return lib;
 566 }
 567
 568 wxObject *wxLibraries::CreateObject(const wxString& path)
 569 {
 570     wxNode *node = m_loaded.First();
 571     wxObject *obj;
 572
 573     while (node) {
 574         obj = ((wxLibrary *)node->Data())->CreateObject(path);
 575         if (obj)
 576             return obj;
 577
 578         node = node->Next();
 579     }
 580     return NULL;
 581 }
 582
 583 #endif  // WXWIN_COMPATIBILITY_2_2
 584
 585
 586 #endif  // wxUSE_DYNAMIC_LOADER
 587