1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
// Copyright 2010 Google Inc. All Rights Reserved.
#ifndef TALK_BASE_WIN32TOOLHELP_H_
#define TALK_BASE_WIN32TOOLHELP_H_
#ifndef WIN32
#error WIN32 Only
#endif
#include "talk/base/win32.h"
// Should be included first, but that causes redefinitions.
#include <tlhelp32.h>
#include "talk/base/constructormagic.h"
namespace talk_base {
// The toolhelp api used to enumerate processes and their modules
// on Windows is very repetetive and clunky to use. This little
// template wraps it to make it a little more programmer friendly.
//
// Traits: Traits type that adapts the enumerator to the corresponding
// win32 toolhelp api. Each traits class need to:
// - define the type of the enumerated data as a public symbol Type
//
// - implement bool First(HANDLE, T*) normally calls a
// Xxxx32First method in the toolhelp API. Ex Process32First(...)
//
// - implement bool Next(HANDLE, T*) normally calls a
// Xxxx32Next method in the toolhelp API. Ex Process32Next(...)
//
// - implement bool CloseHandle(HANDLE)
//
template<typename Traits>
class ToolhelpEnumeratorBase {
public:
ToolhelpEnumeratorBase(HANDLE snapshot)
: snapshot_(snapshot), broken_(false), first_(true) {
// Clear out the Traits::Type structure instance.
Zero(¤t_);
}
virtual ~ToolhelpEnumeratorBase() {
Close();
}
// Moves forward to the next object using the First and Next
// pointers. If either First or Next ever indicates an failure
// all subsequent calls to this method will fail; the enumerator
// object is considered broken.
bool Next() {
if (!Valid()) {
return false;
}
// Move the iteration forward.
current_.dwSize = sizeof(typename Traits::Type);
bool incr_ok = false;
if (first_) {
incr_ok = Traits::First(snapshot_, ¤t_);
first_ = false;
} else {
incr_ok = Traits::Next(snapshot_, ¤t_);
}
if (!incr_ok) {
Zero(¤t_);
broken_ = true;
}
return incr_ok;
}
const typename Traits::Type& current() const {
return current_;
}
void Close() {
if (snapshot_ != INVALID_HANDLE_VALUE) {
Traits::CloseHandle(snapshot_);
snapshot_ = INVALID_HANDLE_VALUE;
}
}
private:
// Checks the state of the snapshot handle.
bool Valid() {
return snapshot_ != INVALID_HANDLE_VALUE && !broken_;
}
static void Zero(typename Traits::Type* buff) {
ZeroMemory(buff, sizeof(typename Traits::Type));
}
HANDLE snapshot_;
typename Traits::Type current_;
bool broken_;
bool first_;
};
class ToolhelpTraits {
public:
static HANDLE CreateSnapshot(uint32 flags, uint32 process_id) {
return CreateToolhelp32Snapshot(flags, process_id);
}
static bool CloseHandle(HANDLE handle) {
return ::CloseHandle(handle) == TRUE;
}
};
class ToolhelpProcessTraits : public ToolhelpTraits {
public:
typedef PROCESSENTRY32 Type;
static bool First(HANDLE handle, Type* t) {
return ::Process32First(handle, t) == TRUE;
}
static bool Next(HANDLE handle, Type* t) {
return ::Process32Next(handle, t) == TRUE;
}
};
class ProcessEnumerator : public ToolhelpEnumeratorBase<ToolhelpProcessTraits> {
public:
ProcessEnumerator()
: ToolhelpEnumeratorBase(
ToolhelpProcessTraits::CreateSnapshot(TH32CS_SNAPPROCESS, 0)) {
}
private:
DISALLOW_EVIL_CONSTRUCTORS(ProcessEnumerator);
};
class ToolhelpModuleTraits : public ToolhelpTraits {
public:
typedef MODULEENTRY32 Type;
static bool First(HANDLE handle, Type* t) {
return ::Module32First(handle, t) == TRUE;
}
static bool Next(HANDLE handle, Type* t) {
return ::Module32Next(handle, t) == TRUE;
}
};
class ModuleEnumerator : public ToolhelpEnumeratorBase<ToolhelpModuleTraits> {
public:
explicit ModuleEnumerator(uint32 process_id)
: ToolhelpEnumeratorBase(
ToolhelpModuleTraits::CreateSnapshot(TH32CS_SNAPMODULE,
process_id)) {
}
private:
DISALLOW_EVIL_CONSTRUCTORS(ModuleEnumerator);
};
} // namespace talk_base
#endif // TALK_BASE_WIN32TOOLHELP_H_
|
