henrike@webrtc.org | 47be73b | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2010 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 | #ifndef WEBRTC_BASE_WIN32TOOLHELP_H_ |
| 11 | #define WEBRTC_BASE_WIN32TOOLHELP_H_ |
| 12 | |
| 13 | #if !defined(WEBRTC_WIN) |
| 14 | #error WEBRTC_WIN Only |
| 15 | #endif |
| 16 | |
| 17 | #include "webrtc/base/win32.h" |
| 18 | |
| 19 | // Should be included first, but that causes redefinitions. |
| 20 | #include <tlhelp32.h> |
| 21 | |
| 22 | #include "webrtc/base/constructormagic.h" |
| 23 | |
| 24 | namespace rtc { |
| 25 | |
| 26 | // The toolhelp api used to enumerate processes and their modules |
| 27 | // on Windows is very repetetive and clunky to use. This little |
| 28 | // template wraps it to make it a little more programmer friendly. |
| 29 | // |
| 30 | // Traits: Traits type that adapts the enumerator to the corresponding |
| 31 | // win32 toolhelp api. Each traits class need to: |
| 32 | // - define the type of the enumerated data as a public symbol Type |
| 33 | // |
| 34 | // - implement bool First(HANDLE, T*) normally calls a |
| 35 | // Xxxx32First method in the toolhelp API. Ex Process32First(...) |
| 36 | // |
| 37 | // - implement bool Next(HANDLE, T*) normally calls a |
| 38 | // Xxxx32Next method in the toolhelp API. Ex Process32Next(...) |
| 39 | // |
| 40 | // - implement bool CloseHandle(HANDLE) |
| 41 | // |
| 42 | template<typename Traits> |
| 43 | class ToolhelpEnumeratorBase { |
| 44 | public: |
| 45 | ToolhelpEnumeratorBase(HANDLE snapshot) |
| 46 | : snapshot_(snapshot), broken_(false), first_(true) { |
| 47 | |
| 48 | // Clear out the Traits::Type structure instance. |
| 49 | Zero(¤t_); |
| 50 | } |
| 51 | |
| 52 | virtual ~ToolhelpEnumeratorBase() { |
| 53 | Close(); |
| 54 | } |
| 55 | |
| 56 | // Moves forward to the next object using the First and Next |
| 57 | // pointers. If either First or Next ever indicates an failure |
| 58 | // all subsequent calls to this method will fail; the enumerator |
| 59 | // object is considered broken. |
| 60 | bool Next() { |
| 61 | if (!Valid()) { |
| 62 | return false; |
| 63 | } |
| 64 | |
| 65 | // Move the iteration forward. |
| 66 | current_.dwSize = sizeof(typename Traits::Type); |
| 67 | bool incr_ok = false; |
| 68 | if (first_) { |
| 69 | incr_ok = Traits::First(snapshot_, ¤t_); |
| 70 | first_ = false; |
| 71 | } else { |
| 72 | incr_ok = Traits::Next(snapshot_, ¤t_); |
| 73 | } |
| 74 | |
| 75 | if (!incr_ok) { |
| 76 | Zero(¤t_); |
| 77 | broken_ = true; |
| 78 | } |
| 79 | |
| 80 | return incr_ok; |
| 81 | } |
| 82 | |
| 83 | const typename Traits::Type& current() const { |
| 84 | return current_; |
| 85 | } |
| 86 | |
| 87 | void Close() { |
| 88 | if (snapshot_ != INVALID_HANDLE_VALUE) { |
| 89 | Traits::CloseHandle(snapshot_); |
| 90 | snapshot_ = INVALID_HANDLE_VALUE; |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | private: |
| 95 | // Checks the state of the snapshot handle. |
| 96 | bool Valid() { |
| 97 | return snapshot_ != INVALID_HANDLE_VALUE && !broken_; |
| 98 | } |
| 99 | |
| 100 | static void Zero(typename Traits::Type* buff) { |
| 101 | ZeroMemory(buff, sizeof(typename Traits::Type)); |
| 102 | } |
| 103 | |
| 104 | HANDLE snapshot_; |
| 105 | typename Traits::Type current_; |
| 106 | bool broken_; |
| 107 | bool first_; |
| 108 | }; |
| 109 | |
| 110 | class ToolhelpTraits { |
| 111 | public: |
| 112 | static HANDLE CreateSnapshot(uint32 flags, uint32 process_id) { |
| 113 | return CreateToolhelp32Snapshot(flags, process_id); |
| 114 | } |
| 115 | |
| 116 | static bool CloseHandle(HANDLE handle) { |
| 117 | return ::CloseHandle(handle) == TRUE; |
| 118 | } |
| 119 | }; |
| 120 | |
| 121 | class ToolhelpProcessTraits : public ToolhelpTraits { |
| 122 | public: |
| 123 | typedef PROCESSENTRY32 Type; |
| 124 | |
| 125 | static bool First(HANDLE handle, Type* t) { |
| 126 | return ::Process32First(handle, t) == TRUE; |
| 127 | } |
| 128 | |
| 129 | static bool Next(HANDLE handle, Type* t) { |
| 130 | return ::Process32Next(handle, t) == TRUE; |
| 131 | } |
| 132 | }; |
| 133 | |
| 134 | class ProcessEnumerator : public ToolhelpEnumeratorBase<ToolhelpProcessTraits> { |
| 135 | public: |
| 136 | ProcessEnumerator() |
| 137 | : ToolhelpEnumeratorBase( |
| 138 | ToolhelpProcessTraits::CreateSnapshot(TH32CS_SNAPPROCESS, 0)) { |
| 139 | } |
| 140 | |
| 141 | private: |
| 142 | DISALLOW_EVIL_CONSTRUCTORS(ProcessEnumerator); |
| 143 | }; |
| 144 | |
| 145 | class ToolhelpModuleTraits : public ToolhelpTraits { |
| 146 | public: |
| 147 | typedef MODULEENTRY32 Type; |
| 148 | |
| 149 | static bool First(HANDLE handle, Type* t) { |
| 150 | return ::Module32First(handle, t) == TRUE; |
| 151 | } |
| 152 | |
| 153 | static bool Next(HANDLE handle, Type* t) { |
| 154 | return ::Module32Next(handle, t) == TRUE; |
| 155 | } |
| 156 | }; |
| 157 | |
| 158 | class ModuleEnumerator : public ToolhelpEnumeratorBase<ToolhelpModuleTraits> { |
| 159 | public: |
| 160 | explicit ModuleEnumerator(uint32 process_id) |
| 161 | : ToolhelpEnumeratorBase( |
| 162 | ToolhelpModuleTraits::CreateSnapshot(TH32CS_SNAPMODULE, |
| 163 | process_id)) { |
| 164 | } |
| 165 | |
| 166 | private: |
| 167 | DISALLOW_EVIL_CONSTRUCTORS(ModuleEnumerator); |
| 168 | }; |
| 169 | |
| 170 | } // namespace rtc |
| 171 | |
| 172 | #endif // WEBRTC_BASE_WIN32TOOLHELP_H_ |