VirtualBox

source: vbox/trunk/src/VBox/Main/include/MediumLock.h@ 43618

Last change on this file since 43618 was 42526, checked in by vboxsync, 12 years ago

FE/Qt: 6234: Support for VM groups: Initial commit. GUI-3 branch reintegrated to trunk.

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    /branches/VBox-3.0/src/VBox/Main/include/MediumLock.h70973
    /branches/dsen/gui/src/VBox/Main/include/MediumLock.h79076-79078,​79089,​79109-79110,​79112-79113,​79127-79130,​79134,​79141,​79151,​79155,​79157-79159,​79193,​79197
    /branches/dsen/gui2/src/VBox/Main/include/MediumLock.h79224,​79228,​79233,​79235,​79258,​79262-79263,​79273,​79341,​79345,​79354,​79357,​79387-79388,​79559-79569,​79572-79573,​79578,​79581-79582,​79590-79591,​79598-79599,​79602-79603,​79605-79606,​79632,​79635,​79637,​79644
    /branches/dsen/gui3/src/VBox/Main/include/MediumLock.h79645-79692
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1/* $Id: MediumLock.h 42526 2012-08-02 10:31:28Z vboxsync $ */
2
3/** @file
4 *
5 * VirtualBox medium object lock collections
6 */
7
8/*
9 * Copyright (C) 2010 Oracle Corporation
10 *
11 * This file is part of VirtualBox Open Source Edition (OSE), as
12 * available from http://www.virtualbox.org. This file is free software;
13 * you can redistribute it and/or modify it under the terms of the GNU
14 * General Public License (GPL) as published by the Free Software
15 * Foundation, in version 2 as it comes in the "COPYING" file of the
16 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
17 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
18 */
19
20#ifndef ____H_MEDIUMLOCK
21#define ____H_MEDIUMLOCK
22
23/* interface definitions */
24#include "VBox/com/VirtualBox.h"
25#include "VirtualBoxBase.h"
26#include "AutoCaller.h"
27
28#include <iprt/types.h>
29
30#include <list>
31#include <map>
32
33class Medium;
34class MediumAttachment;
35
36/**
37 * Single entry for medium lock lists. Has a medium object reference,
38 * information about what kind of lock should be taken, and if it is
39 * locked right now.
40 */
41class MediumLock
42{
43public:
44 /**
45 * Default medium lock constructor.
46 */
47 MediumLock();
48
49 /**
50 * Default medium lock destructor.
51 */
52 ~MediumLock();
53
54 /**
55 * Create a new medium lock description
56 *
57 * @param aMedium Reference to medium object
58 * @param aLockWrite @c true means a write lock should be taken
59 */
60 MediumLock(const ComObjPtr<Medium> &aMedium, bool aLockWrite);
61
62 /**
63 * Copy constructor. Needed because we contain an AutoCaller
64 * instance which is deliberately not copyable. The copy is not
65 * marked as locked, so be careful.
66 *
67 * @param aMediumLock Reference to source object.
68 */
69 MediumLock(const MediumLock &aMediumLock);
70
71 /**
72 * Update a medium lock description.
73 *
74 * @note May be used in locked state.
75 *
76 * @return COM status code
77 * @param aLockWrite @c true means a write lock should be taken
78 */
79 HRESULT UpdateLock(bool aLockWrite);
80
81 /**
82 * Get medium object reference.
83 */
84 const ComObjPtr<Medium> &GetMedium() const;
85
86 /**
87 * Get medium object lock request type.
88 */
89 bool GetLockRequest() const;
90
91 /**
92 * Acquire a medium lock.
93 *
94 * @return COM status code
95 */
96 HRESULT Lock();
97
98 /**
99 * Release a medium lock.
100 *
101 * @return COM status code
102 */
103 HRESULT Unlock();
104
105private:
106 ComObjPtr<Medium> mMedium;
107 AutoCaller mMediumCaller;
108 bool mLockWrite;
109 bool mIsLocked;
110 /** Flag whether the medium was skipped when taking the locks.
111 * Only existing and accessible media objects need to be locked. */
112 bool mLockSkipped;
113};
114
115
116/**
117 * Medium lock list. Meant for storing the ordered locking information
118 * for a single medium chain.
119 */
120class MediumLockList
121{
122public:
123
124 /* Base list data type. */
125 typedef std::list<MediumLock> Base;
126
127 /**
128 * Default medium lock list constructor.
129 */
130 MediumLockList();
131
132 /**
133 * Default medium lock list destructor.
134 */
135 ~MediumLockList();
136
137 /**
138 * Checks if medium lock declaration list is empty.
139 *
140 * @return true if list is empty.
141 */
142 bool IsEmpty();
143
144 /**
145 * Add a new medium lock declaration to the end of the list.
146 *
147 * @note May be only used in unlocked state.
148 *
149 * @return COM status code
150 * @param aMedium Reference to medium object
151 * @param aLockWrite @c true means a write lock should be taken
152 */
153 HRESULT Append(const ComObjPtr<Medium> &aMedium, bool aLockWrite);
154
155 /**
156 * Add a new medium lock declaration to the beginning of the list.
157 *
158 * @note May be only used in unlocked state.
159 *
160 * @return COM status code
161 * @param aMedium Reference to medium object
162 * @param aLockWrite @c true means a write lock should be taken
163 */
164 HRESULT Prepend(const ComObjPtr<Medium> &aMedium, bool aLockWrite);
165
166 /**
167 * Update a medium lock declaration.
168 *
169 * @note May be used in locked state.
170 *
171 * @return COM status code
172 * @param aMedium Reference to medium object
173 * @param aLockWrite @c true means a write lock should be taken
174 */
175 HRESULT Update(const ComObjPtr<Medium> &aMedium, bool aLockWrite);
176
177 /**
178 * Remove a medium lock declaration and return an updated iterator.
179 *
180 * @note May be used in locked state.
181 *
182 * @return COM status code
183 * @param aIt Iterator for the element to remove
184 */
185 HRESULT RemoveByIterator(Base::iterator &aIt);
186
187 /**
188 * Clear all medium lock declarations.
189 *
190 * @note Implicitly unlocks all locks.
191 *
192 * @return COM status code
193 */
194 HRESULT Clear();
195
196 /**
197 * Get iterator begin() for base list.
198 */
199 Base::iterator GetBegin();
200
201 /**
202 * Get iterator end() for base list.
203 */
204 Base::iterator GetEnd();
205
206 /**
207 * Acquire all medium locks "atomically", i.e. all or nothing.
208 *
209 * @return COM status code
210 */
211 HRESULT Lock();
212
213 /**
214 * Release all medium locks.
215 *
216 * @return COM status code
217 */
218 HRESULT Unlock();
219
220private:
221 Base mMediumLocks;
222 bool mIsLocked;
223};
224
225/**
226 * Medium lock list map. Meant for storing a collection of lock lists.
227 * The usual use case is creating such a map when locking all medium chains
228 * belonging to one VM, however that's not the limit. Be creative.
229 */
230class MediumLockListMap
231{
232public:
233
234 /**
235 * Default medium lock list map constructor.
236 */
237 MediumLockListMap();
238
239 /**
240 * Default medium lock list map destructor.
241 */
242 ~MediumLockListMap();
243
244 /**
245 * Checks if medium lock list map is empty.
246 *
247 * @return true if list is empty.
248 */
249 bool IsEmpty();
250
251 /**
252 * Insert a new medium lock list into the map.
253 *
254 * @note May be only used in unlocked state.
255 *
256 * @return COM status code
257 * @param aMediumAttachment Reference to medium attachment object, the key.
258 * @param aMediumLockList Reference to medium lock list object
259 */
260 HRESULT Insert(const ComObjPtr<MediumAttachment> &aMediumAttachment, MediumLockList *aMediumLockList);
261
262 /**
263 * Replace the medium lock list key by a different one.
264 *
265 * @note May be used in locked state.
266 *
267 * @return COM status code
268 * @param aMediumAttachmentOld Reference to medium attachment object.
269 * @param aMediumAttachmentNew Reference to medium attachment object.
270 */
271 HRESULT ReplaceKey(const ComObjPtr<MediumAttachment> &aMediumAttachmentOld, const ComObjPtr<MediumAttachment> &aMediumAttachmentNew);
272
273 /**
274 * Remove a medium lock list from the map. The list will get deleted.
275 *
276 * @note May be only used in unlocked state.
277 *
278 * @return COM status code
279 * @param aMediumAttachment Reference to medium attachment object, the key.
280 */
281 HRESULT Remove(const ComObjPtr<MediumAttachment> &aMediumAttachment);
282
283 /**
284 * Clear all medium lock declarations in this map.
285 *
286 * @note Implicitly unlocks all locks.
287 *
288 * @return COM status code
289 */
290 HRESULT Clear();
291
292 /**
293 * Get the medium lock list identified by the given key.
294 *
295 * @note May be used in locked state.
296 *
297 * @return COM status code
298 * @param aMediumAttachment Key for medium attachment object.
299 * @param aMediumLockList Out: medium attachment object reference.
300 */
301 HRESULT Get(const ComObjPtr<MediumAttachment> &aMediumAttachment, MediumLockList * &aMediumLockList);
302
303 /**
304 * Acquire all medium locks "atomically", i.e. all or nothing.
305 *
306 * @return COM status code
307 */
308 HRESULT Lock();
309
310 /**
311 * Release all medium locks.
312 *
313 * @return COM status code
314 */
315 HRESULT Unlock();
316
317private:
318 typedef std::map<ComObjPtr<MediumAttachment>, MediumLockList *> Base;
319 Base mMediumLocks;
320 bool mIsLocked;
321};
322
323#endif /* !____H_MEDIUMLOCK */
324/* vi: set tabstop=4 shiftwidth=4 expandtab: */
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