1/* 2 * libjingle 3 * Copyright 2004--2010, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#ifndef TALK_BASE_LATEBINDINGSYMBOLTABLE_H_ 29#define TALK_BASE_LATEBINDINGSYMBOLTABLE_H_ 30 31#include <string.h> 32 33#include "talk/base/common.h" 34 35namespace talk_base { 36 37#ifdef POSIX 38typedef void *DllHandle; 39#else 40#error Not implemented for this platform 41#endif 42 43// This is the base class for "symbol table" classes to simplify the dynamic 44// loading of symbols from DLLs. Currently the implementation only supports 45// Linux and OS X, and pure C symbols (or extern "C" symbols that wrap C++ 46// functions). Sub-classes for specific DLLs are generated via the "supermacro" 47// files latebindingsymboltable.h.def and latebindingsymboltable.cc.def. See 48// talk/sound/pulseaudiosymboltable.(h|cc) for an example. 49class LateBindingSymbolTable { 50 public: 51 struct TableInfo { 52 const char *dll_name; 53 int num_symbols; 54 // Array of size num_symbols. 55 const char *const *symbol_names; 56 }; 57 58 LateBindingSymbolTable(const TableInfo *info, void **table); 59 ~LateBindingSymbolTable(); 60 61 bool IsLoaded() const; 62 // Loads the DLL and the symbol table. Returns true iff the DLL and symbol 63 // table loaded successfully. 64 bool Load(); 65 // Like load, but allows overriding the dll path for when the dll path is 66 // dynamic. 67 bool LoadFromPath(const char *dll_path); 68 void Unload(); 69 70 private: 71 void ClearSymbols(); 72 73 const TableInfo *info_; 74 void **table_; 75 DllHandle handle_; 76 bool undefined_symbols_; 77 78 DISALLOW_COPY_AND_ASSIGN(LateBindingSymbolTable); 79}; 80 81} // namespace talk_base 82 83#endif // TALK_BASE_LATEBINDINGSYMBOLTABLE_H_ 84