1/*
2 *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#ifndef WEBRTC_BASE_LATEBINDINGSYMBOLTABLE_H_
12#define WEBRTC_BASE_LATEBINDINGSYMBOLTABLE_H_
13
14#include <string.h>
15
16#include "webrtc/base/common.h"
17
18namespace rtc {
19
20#if defined(WEBRTC_POSIX)
21typedef void *DllHandle;
22#else
23#error Not implemented for this platform
24#endif
25
26// This is the base class for "symbol table" classes to simplify the dynamic
27// loading of symbols from DLLs. Currently the implementation only supports
28// Linux and OS X, and pure C symbols (or extern "C" symbols that wrap C++
29// functions).  Sub-classes for specific DLLs are generated via the "supermacro"
30// files latebindingsymboltable.h.def and latebindingsymboltable.cc.def. See
31// talk/sound/pulseaudiosymboltable.(h|cc) for an example.
32class LateBindingSymbolTable {
33 public:
34  struct TableInfo {
35    const char *dll_name;
36    int num_symbols;
37    // Array of size num_symbols.
38    const char *const *symbol_names;
39  };
40
41  LateBindingSymbolTable(const TableInfo *info, void **table);
42  ~LateBindingSymbolTable();
43
44  bool IsLoaded() const;
45  // Loads the DLL and the symbol table. Returns true iff the DLL and symbol
46  // table loaded successfully.
47  bool Load();
48  // Like load, but allows overriding the dll path for when the dll path is
49  // dynamic.
50  bool LoadFromPath(const char *dll_path);
51  void Unload();
52
53  // Gets the raw OS handle to the DLL. Be careful what you do with it.
54  DllHandle GetDllHandle() const { return handle_; }
55
56 private:
57  void ClearSymbols();
58
59  const TableInfo *info_;
60  void **table_;
61  DllHandle handle_;
62  bool undefined_symbols_;
63
64  DISALLOW_COPY_AND_ASSIGN(LateBindingSymbolTable);
65};
66
67}  // namespace rtc
68
69#endif  // WEBRTC_BASE_LATEBINDINGSYMBOLTABLE_H_
70