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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*
* Copyright (C) 2010-2011 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef JAVA_REF_HXX
#define JAVA_REF_HXX
#include "Global.hxx"
#include <jni.h>
#include <assert.h>
namespace Java {
/**
* Hold a local reference on a JNI object.
*/
template<typename T>
class LocalRef {
JNIEnv *const env;
const T value;
public:
/**
* The local reference is obtained by the caller.
*/
LocalRef(JNIEnv *_env, T _value):env(_env), value(_value) {
assert(env != nullptr);
assert(value != nullptr);
}
~LocalRef() {
env->DeleteLocalRef(value);
}
LocalRef(const LocalRef &other) = delete;
LocalRef &operator=(const LocalRef &other) = delete;
T Get() const {
return value;
}
operator T() const {
return value;
}
};
/**
* Hold a global reference on a JNI object.
*/
template<typename T>
class GlobalRef {
T value;
public:
/**
* Constructs an uninitialized object. The method set() must be
* called before it is destructed.
*/
GlobalRef() = default;
GlobalRef(JNIEnv *env, T _value):value(_value) {
assert(env != nullptr);
assert(value != nullptr);
value = (T)env->NewGlobalRef(value);
}
~GlobalRef() {
GetEnv()->DeleteGlobalRef(value);
}
GlobalRef(const GlobalRef &other) = delete;
GlobalRef &operator=(const GlobalRef &other) = delete;
/**
* Sets the object, ignoring the previous value. This is only
* allowed once after the default constructor was used.
*/
void Set(JNIEnv *env, T _value) {
assert(_value != nullptr);
value = (T)env->NewGlobalRef(_value);
}
T Get() const {
return value;
}
operator T() const {
return value;
}
};
/**
* Container for a global reference to a JNI object that gets
* initialised and deinitialised explicitly. Since there is no
* implicit initialisation in the default constructor, this is a
* trivial C++ class. It should only be used for global variables
* that are implicitly initialised with zeroes.
*/
template<typename T>
class TrivialRef {
T value;
public:
constexpr TrivialRef() {};
TrivialRef(const TrivialRef &other) = delete;
TrivialRef &operator=(const TrivialRef &other) = delete;
bool IsDefined() const {
return value != nullptr;
}
/**
* Obtain a global reference on the specified object and store it.
* This object must not be set already.
*/
void Set(JNIEnv *env, T _value) {
assert(value == nullptr);
assert(_value != nullptr);
value = (T)env->NewGlobalRef(_value);
}
/**
* Release the global reference and clear this object.
*/
void Clear(JNIEnv *env) {
assert(value != nullptr);
env->DeleteGlobalRef(value);
value = nullptr;
}
/**
* Release the global reference and clear this object. It is
* allowed to call this method without ever calling Set().
*/
void ClearOptional(JNIEnv *env) {
if (value != nullptr)
Clear(env);
}
T Get() const {
return value;
}
operator T() const {
return value;
}
};
}
#endif
|
