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1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : /*
3 : * This file is part of the LibreOffice project.
4 : *
5 : * This Source Code Form is subject to the terms of the Mozilla Public
6 : * License, v. 2.0. If a copy of the MPL was not distributed with this
7 : * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8 : *
9 : * This file incorporates work covered by the following license notice:
10 : *
11 : * Licensed to the Apache Software Foundation (ASF) under one or more
12 : * contributor license agreements. See the NOTICE file distributed
13 : * with this work for additional information regarding copyright
14 : * ownership. The ASF licenses this file to you under the Apache
15 : * License, Version 2.0 (the "License"); you may not use this file
16 : * except in compliance with the License. You may obtain a copy of
17 : * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 : */
19 :
20 : #ifndef INCLUDED_JVMACCESS_VIRTUALMACHINE_HXX
21 : #define INCLUDED_JVMACCESS_VIRTUALMACHINE_HXX
22 :
23 : #include "jvmaccessdllapi.h"
24 : #include "rtl/ref.hxx"
25 : #include "salhelper/simplereferenceobject.hxx"
26 :
27 : #ifdef SOLAR_JAVA
28 : #include "jni.h"
29 : #else
30 : struct JNIEnv_;
31 : typedef JNIEnv_ JNIEnv;
32 : struct JavaVM_;
33 : typedef JavaVM_ JavaVM;
34 : typedef int jint;
35 : typedef void * jobject;
36 : #endif
37 :
38 : namespace jvmaccess {
39 :
40 : /** An encapsulating wrapper around a Java virtual machine.
41 : */
42 : class JVMACCESS_DLLPUBLIC VirtualMachine: public salhelper::SimpleReferenceObject
43 : {
44 : public:
45 : /** A helper to attach a thread to a Java virtual machine.
46 :
47 : @descr
48 : Upon construction of a guard the current thread is attached to the
49 : virtual machine, and upon destruction of the guard the thread is
50 : detached again. For any one thread, multiple instances of this class
51 : may be used in a stack-like fashion (care is taken to only really
52 : detach the thread from the virtual machine upon destruction of the guard
53 : at the bottom of the stack).
54 : */
55 : class JVMACCESS_DLLPUBLIC AttachGuard
56 : {
57 : public:
58 : /** An exception indicating failure to create an AttachGuard.
59 : */
60 : class JVMACCESS_DLLPUBLIC CreationException
61 : {
62 : public:
63 : CreationException();
64 :
65 : CreationException(CreationException const &);
66 :
67 : virtual ~CreationException();
68 :
69 : CreationException & operator =(CreationException const &);
70 : };
71 :
72 : /** Attach the current thread to a virtual machine.
73 :
74 : @param rMachine
75 : The virtual machine to attach to. Must not be a null reference.
76 :
77 : @exception CreationException
78 : Thrown in case attaching fails (due to a JNI problem).
79 : */
80 : explicit AttachGuard(rtl::Reference< VirtualMachine > const & rMachine);
81 :
82 : /** Detach the current thread from the virtual machine again.
83 : */
84 : ~AttachGuard();
85 :
86 : /** Get a JNI environment pointer for the current thread.
87 :
88 : @return
89 : A valid JNI environment pointer. Will never be null.
90 : */
91 0 : inline JNIEnv * getEnvironment() const { return m_pEnvironment; }
92 :
93 : private:
94 : AttachGuard(AttachGuard &); // not implemented
95 : void operator =(AttachGuard); // not implemented
96 :
97 : rtl::Reference< VirtualMachine > m_xMachine;
98 : JNIEnv * m_pEnvironment;
99 : bool m_bDetach;
100 : };
101 :
102 : /** Create a wrapper around a Java virtual machine.
103 :
104 : @param pVm
105 : A JNI pointer to virtual machine. Must not be null.
106 :
107 : @param nVersion
108 : The JNI version of the virtual machine pointed to by pVm. Must be at
109 : least JNI_VERSION_1_2. This parameter should be of type jint, not int,
110 : but at least on some platforms the definition of jint changed from
111 : JDK 1.3 (long) to JDK 1.4 (int), so that the mangled C++ name of the
112 : constructor would depend on the JDK version used at compile time.
113 :
114 : @param bDestroy
115 : Whether to destroy the virtual machine when destructing the wrapper
116 : (i.e., whether the wrapper owns the virtual machine pointed to by pVm).
117 :
118 : @param pMainThreadEnv
119 : A valid JNI environment pointer for the current thread; must not be
120 : null. The current thread must be "initially attached" to the virtual
121 : machine while this constructor is being called (i.e., it must be the
122 : thread that has called JNI_CreateJavaVM in case the virtual machine has
123 : been started via the JNI Invocation API, and it must not already have
124 : called DetachCurrentThread; or it must be executing native code called
125 : from a "primordial" virtual machine). This environment pointer was
126 : formerly used to obtain a reference to the thread's current context
127 : class loader (java.lang.Thread.getCurrentClassLoader; if later a native
128 : thread was attached to the virtual machine, that thread's context class
129 : loader would be null, so the AttachGuard first of all set it to the
130 : saved value; this feature has been removed again for performance reasons
131 : and because the default context class loader is often not useful, so
132 : that code relying on a context class loader has to set one explicitly,
133 : anyway). This parameter is currently unused (but may be used again in
134 : the future).
135 : */
136 : VirtualMachine(JavaVM * pVm, int nVersion, bool bDestroy,
137 : JNIEnv * pMainThreadEnv);
138 :
139 : private:
140 : VirtualMachine(VirtualMachine &); // not implemented
141 : void operator =(VirtualMachine); // not implemented
142 :
143 : virtual ~VirtualMachine();
144 :
145 : JNIEnv * attachThread(bool * pAttached) const;
146 :
147 : void detachThread() const;
148 :
149 : JavaVM * m_pVm;
150 : jint m_nVersion;
151 : bool m_bDestroy;
152 :
153 : friend class AttachGuard; // to access attachThread, detachThread
154 : };
155 :
156 : }
157 :
158 : #endif // INCLUDED_JVMACCESS_VIRTUALMACHINE_HXX
159 :
160 : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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