VirtualBoxBase.cpp@ 3668

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1	/** @file
2	*
3	* VirtualBox COM base classes implementation
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 innotek GmbH
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License as published by the Free Software Foundation,
13	* in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
14	* distribution. VirtualBox OSE is distributed in the hope that it will
15	* be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* If you received this file as part of a commercial VirtualBox
18	* distribution, then only the terms of your commercial VirtualBox
19	* license agreement apply instead of the previous paragraph.
20	*/
21
22	#if !defined (VBOX_WITH_XPCOM)
23	#if defined (RT_OS_WINDOWS)
24	#include <windows.h>
25	#include <dbghelp.h>
26	#endif
27	#else // !defined (VBOX_WITH_XPCOM)
28	#include <nsIServiceManager.h>
29	#include <nsIExceptionService.h>
30	#endif // !defined (VBOX_WITH_XPCOM)
31
32	#include "VirtualBoxBase.h"
33	#include "VirtualBoxErrorInfoImpl.h"
34	#include "Logging.h"
35
36	#include <iprt/semaphore.h>
37
38	// VirtualBoxBaseNEXT_base methods
39	////////////////////////////////////////////////////////////////////////////////
40
41	VirtualBoxBaseNEXT_base::VirtualBoxBaseNEXT_base()
42	{
43	mState = NotReady;
44	mStateChangeThread = NIL_RTTHREAD;
45	mCallers = 0;
46	mZeroCallersSem = NIL_RTSEMEVENT;
47	mInitDoneSem = NIL_RTSEMEVENTMULTI;
48	mInitDoneSemUsers = 0;
49	RTCritSectInit (&mStateLock);
50	mObjectLock = NULL;
51	}
52
53	VirtualBoxBaseNEXT_base::~VirtualBoxBaseNEXT_base()
54	{
55	if (mObjectLock)
56	delete mObjectLock;
57	RTCritSectDelete (&mStateLock);
58	Assert (mInitDoneSemUsers == 0);
59	Assert (mInitDoneSem == NIL_RTSEMEVENTMULTI);
60	if (mZeroCallersSem != NIL_RTSEMEVENT)
61	RTSemEventDestroy (mZeroCallersSem);
62	mCallers = 0;
63	mStateChangeThread = NIL_RTTHREAD;
64	mState = NotReady;
65	}
66
67	// AutoLock::Lockable interface
68	AutoLock::Handle *VirtualBoxBaseNEXT_base::lockHandle() const
69	{
70	/* lasy initialization */
71	if (!mObjectLock)
72	mObjectLock = new AutoLock::Handle;
73	return mObjectLock;
74	}
75
76	/**
77	* Increments the number of calls to this object by one.
78	*
79	* After this method succeeds, it is guaranted that the object will remain in
80	* the Ready (or in the Limited) state at least until #releaseCaller() is
81	* called.
82	*
83	* This method is intended to mark the beginning of sections of code within
84	* methods of COM objects that depend on the readiness (Ready) state. The
85	* Ready state is a primary "ready to serve" state. Usually all code that
86	* works with component's data depends on it. On practice, this means that
87	* almost every public method, setter or getter of the object should add
88	* itself as an object's caller at the very beginning, to protect from an
89	* unexpected uninitialization that may happen on a different thread.
90	*
91	* Besides the Ready state denoting that the object is fully functional,
92	* there is a special Limited state. The Limited state means that the object
93	* is still functional, but its functionality is limited to some degree, so
94	* not all operations are possible. The @a aLimited argument to this method
95	* determines whether the caller represents this limited functionality or not.
96	*
97	* This method succeeeds (and increments the number of callers) only if the
98	* current object's state is Ready. Otherwise, it will return E_UNEXPECTED to
99	* indicate that the object is not operational. There are two exceptions from
100	* this rule:
101	* <ol>
102	* <li>If the @a aLimited argument is \|true\|, then this method will also
103	* succeeed if the object's state is Limited (or Ready, of course).</li>
104	* <li>If this method is called from the same thread that placed the object
105	* to InInit or InUninit state (i.e. either from within the AutoInitSpan
106	* or AutoUninitSpan scope), it will succeed as well (but will not
107	* increase the number of callers).</li>
108	* </ol>
109	*
110	* Normally, calling addCaller() never blocks. However, if this method is
111	* called by a thread created from within the AutoInitSpan scope and this
112	* scope is still active (i.e. the object state is InInit), it will block
113	* until the AutoInitSpan destructor signals that it has finished
114	* initialization.
115	*
116	* When this method returns a failure, the caller must not use the object
117	* and can return the failed result code to his caller.
118	*
119	* @param aState where to store the current object's state
120	* (can be used in overriden methods to determine the
121	* cause of the failure)
122	* @param aLimited \|true\| to add a limited caller.
123	* @return S_OK on success or E_UNEXPECTED on failure
124	*
125	* @note It is preferrable to use the #addLimitedCaller() rather than calling
126	* this method with @a aLimited = \|true\|, for better
127	* self-descriptiveness.
128	*
129	* @sa #addLimitedCaller()
130	* @sa #releaseCaller()
131	*/
132	HRESULT VirtualBoxBaseNEXT_base::addCaller (State aState / = NULL */,
133	bool aLimited /* = false */)
134	{
135	AutoLock stateLock (mStateLock);
136
137	HRESULT rc = E_UNEXPECTED;
138
139	if (mState == Ready \|\| (aLimited && mState == Limited))
140	{
141	/* if Ready or allows Limited, increase the number of callers */
142	++ mCallers;
143	rc = S_OK;
144	}
145	else
146	if ((mState == InInit \|\| mState == InUninit))
147	{
148	if (mStateChangeThread == RTThreadSelf())
149	{
150	/*
151	* Called from the same thread that is doing AutoInitSpan or
152	* AutoUninitSpan, just succeed
153	*/
154	rc = S_OK;
155	}
156	else if (mState == InInit)
157	{
158	/* addCaller() is called by a "child" thread while the "parent"
159	* thread is still doing AutoInitSpan/AutoReadySpan. Wait for the
160	* state to become either Ready/Limited or InitFailed/InInit/NotReady
161	* (in case of init failure). Note that we increase the number of
162	* callers anyway to prevent AutoUninitSpan from early completion.
163	*/
164	++ mCallers;
165
166	/* lazy creation */
167	if (mInitDoneSem == NIL_RTSEMEVENTMULTI)
168	RTSemEventMultiCreate (&mInitDoneSem);
169	++ mInitDoneSemUsers;
170
171	LogFlowThisFunc (("Waiting for AutoInitSpan/AutoReadySpan to finish...\n"));
172
173	stateLock.leave();
174	RTSemEventMultiWait (mInitDoneSem, RT_INDEFINITE_WAIT);
175	stateLock.enter();
176
177	if (-- mInitDoneSemUsers == 0)
178	{
179	/* destroy the semaphore since no more necessary */
180	RTSemEventMultiDestroy (mInitDoneSem);
181	mInitDoneSem = NIL_RTSEMEVENTMULTI;
182	}
183
184	if (mState == Ready)
185	rc = S_OK;
186	else
187	{
188	AssertMsg (mCallers != 0, ("mCallers is ZERO!"));
189	-- mCallers;
190	if (mCallers == 0 && mState == InUninit)
191	{
192	/* inform AutoUninitSpan ctor there are no more callers */
193	RTSemEventSignal (mZeroCallersSem);
194	}
195	}
196	}
197	}
198
199	if (aState)
200	*aState = mState;
201
202	return rc;
203	}
204
205	/**
206	* Decrements the number of calls to this object by one.
207	* Must be called after every #addCaller() or #addLimitedCaller() when the
208	* object is no more necessary.
209	*/
210	void VirtualBoxBaseNEXT_base::releaseCaller()
211	{
212	AutoLock stateLock (mStateLock);
213
214	if (mState == Ready \|\| mState == Limited)
215	{
216	/* if Ready or Limited, decrease the number of callers */
217	AssertMsgReturn (mCallers != 0, ("mCallers is ZERO!"), (void) 0);
218	-- mCallers;
219
220	return;
221	}
222
223	if ((mState == InInit \|\| mState == InUninit))
224	{
225	if (mStateChangeThread == RTThreadSelf())
226	{
227	/*
228	* Called from the same thread that is doing AutoInitSpan or
229	* AutoUninitSpan, just succeed
230	*/
231	return;
232	}
233
234	if (mState == InUninit)
235	{
236	/* the caller is being released after AutoUninitSpan has begun */
237	AssertMsgReturn (mCallers != 0, ("mCallers is ZERO!"), (void) 0);
238	-- mCallers;
239
240	if (mCallers == 0)
241	{
242	/* inform the AutoUninitSpan ctor there are no more callers */
243	RTSemEventSignal (mZeroCallersSem);
244	}
245
246	return;
247	}
248	}
249
250	AssertMsgFailed (("mState = %d!", mState));
251	}
252
253	// VirtualBoxBaseNEXT_base::AutoInitSpan methods
254	////////////////////////////////////////////////////////////////////////////////
255
256	/**
257	* Creates a smart initialization span object and places the object to
258	* InInit state.
259	*
260	* @param aObj \|this\| pointer of the managed VirtualBoxBase object whose
261	* init() method is being called
262	* @param aStatus initial initialization status for this span
263	*/
264	VirtualBoxBaseNEXT_base::AutoInitSpan::
265	AutoInitSpan (VirtualBoxBaseNEXT_base aObj, Status aStatus / = Failed */)
266	: mObj (aObj), mStatus (aStatus), mOk (false)
267	{
268	Assert (aObj);
269
270	AutoLock stateLock (mObj->mStateLock);
271
272	Assert (mObj->mState != InInit && mObj->mState != InUninit &&
273	mObj->mState != InitFailed);
274
275	mOk = mObj->mState == NotReady;
276	if (!mOk)
277	return;
278
279	mObj->setState (InInit);
280	}
281
282	/**
283	* Places the managed VirtualBoxBase object to Ready/Limited state if the
284	* initialization succeeded or partly succeeded, or places it to InitFailed
285	* state and calls the object's uninit() method otherwise.
286	*/
287	VirtualBoxBaseNEXT_base::AutoInitSpan::~AutoInitSpan()
288	{
289	/* if the state was other than NotReady, do nothing */
290	if (!mOk)
291	return;
292
293	AutoLock stateLock (mObj->mStateLock);
294
295	Assert (mObj->mState == InInit);
296
297	if (mObj->mCallers > 0)
298	{
299	Assert (mObj->mInitDoneSemUsers > 0);
300
301	/* We have some pending addCaller() calls on other threads (created
302	* during InInit), signal that InInit is finished. */
303	RTSemEventMultiSignal (mObj->mInitDoneSem);
304	}
305
306	if (mStatus == Succeeded)
307	{
308	mObj->setState (Ready);
309	}
310	else
311	if (mStatus == Limited)
312	{
313	mObj->setState (VirtualBoxBaseNEXT_base::Limited);
314	}
315	else
316	{
317	mObj->setState (InitFailed);
318	/* leave the lock to prevent nesting when uninit() is called */
319	stateLock.leave();
320	/* call uninit() to let the object uninit itself after failed init() */
321	mObj->uninit();
322	/* Note: the object may no longer exist here (for example, it can call
323	* the destructor in uninit()) */
324	}
325	}
326
327	// VirtualBoxBaseNEXT_base::AutoReadySpan methods
328	////////////////////////////////////////////////////////////////////////////////
329
330	/**
331	* Creates a smart re-initialization span object and places the object to
332	* InInit state.
333	*
334	* @param aObj \|this\| pointer of the managed VirtualBoxBase object whose
335	* re-initialization method is being called
336	*/
337	VirtualBoxBaseNEXT_base::AutoReadySpan::
338	AutoReadySpan (VirtualBoxBaseNEXT_base *aObj)
339	: mObj (aObj), mSucceeded (false), mOk (false)
340	{
341	Assert (aObj);
342
343	AutoLock stateLock (mObj->mStateLock);
344
345	Assert (mObj->mState != InInit && mObj->mState != InUninit &&
346	mObj->mState != InitFailed);
347
348	mOk = mObj->mState == Limited;
349	if (!mOk)
350	return;
351
352	mObj->setState (InInit);
353	}
354
355	/**
356	* Places the managed VirtualBoxBase object to Ready state if the
357	* re-initialization succeeded (i.e. #setSucceeded() has been called) or
358	* back to Limited state otherwise.
359	*/
360	VirtualBoxBaseNEXT_base::AutoReadySpan::~AutoReadySpan()
361	{
362	/* if the state was other than Limited, do nothing */
363	if (!mOk)
364	return;
365
366	AutoLock stateLock (mObj->mStateLock);
367
368	Assert (mObj->mState == InInit);
369
370	if (mObj->mCallers > 0 && mObj->mInitDoneSemUsers > 0)
371	{
372	/* We have some pending addCaller() calls on other threads,
373	* signal that InInit is finished. */
374	RTSemEventMultiSignal (mObj->mInitDoneSem);
375	}
376
377	if (mSucceeded)
378	{
379	mObj->setState (Ready);
380	}
381	else
382	{
383	mObj->setState (Limited);
384	}
385	}
386
387	// VirtualBoxBaseNEXT_base::AutoUninitSpan methods
388	////////////////////////////////////////////////////////////////////////////////
389
390	/**
391	* Creates a smart uninitialization span object and places this object to
392	* InUninit state.
393	*
394	* @note This method blocks the current thread execution until the number of
395	* callers of the managed VirtualBoxBase object drops to zero!
396	*
397	* @param aObj \|this\| pointer of the VirtualBoxBase object whose uninit()
398	* method is being called
399	*/
400	VirtualBoxBaseNEXT_base::AutoUninitSpan::AutoUninitSpan (VirtualBoxBaseNEXT_base *aObj)
401	: mObj (aObj), mInitFailed (false), mUninitDone (false)
402	{
403	Assert (aObj);
404
405	AutoLock stateLock (mObj->mStateLock);
406
407	Assert (mObj->mState != InInit);
408
409	/*
410	* Set mUninitDone to \|true\| if this object is already uninitialized
411	* (NotReady) or if another AutoUninitSpan is currently active on some
412	* other thread (InUninit).
413	*/
414	mUninitDone = mObj->mState == NotReady \|\|
415	mObj->mState == InUninit;
416
417	if (mObj->mState == InitFailed)
418	{
419	/* we've been called by init() on failure */
420	mInitFailed = true;
421	}
422	else
423	{
424	/* do nothing if already uninitialized */
425	if (mUninitDone)
426	return;
427	}
428
429	/* go to InUninit to prevent from adding new callers */
430	mObj->setState (InUninit);
431
432	if (mObj->mCallers > 0)
433	{
434	/* lazy creation */
435	Assert (mObj->mZeroCallersSem == NIL_RTSEMEVENT);
436	RTSemEventCreate (&mObj->mZeroCallersSem);
437
438	/* wait until remaining callers release the object */
439	LogFlowThisFunc (("Waiting for callers (%d) to drop to zero...\n",
440	mObj->mCallers));
441
442	stateLock.leave();
443	RTSemEventWait (mObj->mZeroCallersSem, RT_INDEFINITE_WAIT);
444	}
445	}
446
447	/**
448	* Places the managed VirtualBoxBase object to the NotReady state.
449	*/
450	VirtualBoxBaseNEXT_base::AutoUninitSpan::~AutoUninitSpan()
451	{
452	/* do nothing if already uninitialized */
453	if (mUninitDone)
454	return;
455
456	AutoLock stateLock (mObj->mStateLock);
457
458	Assert (mObj->mState == InUninit);
459
460	mObj->setState (NotReady);
461	}
462
463	// VirtualBoxBase methods
464	////////////////////////////////////////////////////////////////////////////////
465
466	/**
467	* Translates the given text string according to the currently installed
468	* translation table and current context. The current context is determined
469	* by the context parameter. Additionally, a comment to the source text
470	* string text can be given. This comment (which is NULL by default)
471	* is helpful in sutuations where it is necessary to distinguish between
472	* two or more semantically different roles of the same source text in the
473	* same context.
474	*
475	* @param context the context of the the translation (can be NULL
476	* to indicate the global context)
477	* @param sourceText the string to translate
478	* @param comment the comment to the string (NULL means no comment)
479	*
480	* @return
481	* the translated version of the source string in UTF-8 encoding,
482	* or the source string itself if the translation is not found
483	* in the given context.
484	*/
485	// static
486	const char VirtualBoxBase::translate (const char context, const char *sourceText,
487	const char *comment)
488	{
489	// Log(("VirtualBoxBase::translate:\n"
490	// " context={%s}\n"
491	// " sourceT={%s}\n"
492	// " comment={%s}\n",
493	// context, sourceText, comment));
494
495	/// @todo (dmik) incorporate Qt translation file parsing and lookup
496
497	return sourceText;
498	}
499
500	/// @todo (dmik)
501	// Using StackWalk() is not necessary here once we have ASMReturnAddress().
502	// Delete later.
503
504	#if defined(DEBUG) && 0
505
506	//static
507	void VirtualBoxBase::AutoLock::CritSectEnter (RTCRITSECT *aLock)
508	{
509	AssertReturn (aLock, (void) 0);
510
511	#if (defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2)) && defined(__GNUC__)
512
513	RTCritSectEnterDebug (aLock,
514	"AutoLock::lock()/enter() return address >>>", 0,
515	(RTUINTPTR) __builtin_return_address (1));
516
517	#elif defined(RT_OS_WINDOWS)
518
519	STACKFRAME sf;
520	memset (&sf, 0, sizeof(sf));
521	{
522	__asm eip:
523	__asm mov eax, eip
524	__asm lea ebx, sf
525	__asm mov [ebx]sf.AddrPC.Offset, eax
526	__asm mov [ebx]sf.AddrStack.Offset, esp
527	__asm mov [ebx]sf.AddrFrame.Offset, ebp
528	}
529	sf.AddrPC.Mode = AddrModeFlat;
530	sf.AddrStack.Mode = AddrModeFlat;
531	sf.AddrFrame.Mode = AddrModeFlat;
532
533	HANDLE process = GetCurrentProcess();
534	HANDLE thread = GetCurrentThread();
535
536	// get our stack frame
537	BOOL ok = StackWalk (IMAGE_FILE_MACHINE_I386, process, thread,
538	&sf, NULL, NULL,
539	SymFunctionTableAccess,
540	SymGetModuleBase,
541	NULL);
542	// sanity check of the returned stack frame
543	ok = ok & (sf.AddrFrame.Offset != 0);
544	if (ok)
545	{
546	// get the stack frame of our caller which is either
547	// lock() or enter()
548	ok = StackWalk (IMAGE_FILE_MACHINE_I386, process, thread,
549	&sf, NULL, NULL,
550	SymFunctionTableAccess,
551	SymGetModuleBase,
552	NULL);
553	// sanity check of the returned stack frame
554	ok = ok & (sf.AddrFrame.Offset != 0);
555	}
556
557	if (ok)
558	{
559	// the return address here should be the code where lock() or enter()
560	// has been called from (to be more precise, where it will return)
561	RTCritSectEnterDebug (aLock,
562	"AutoLock::lock()/enter() return address >>>", 0,
563	(RTUINTPTR) sf.AddrReturn.Offset);
564	}
565	else
566	{
567	RTCritSectEnter (aLock);
568	}
569
570	#else
571
572	RTCritSectEnter (aLock);
573
574	#endif // defined(RT_OS_LINUX)...
575	}
576
577	#endif // defined(DEBUG)
578
579	// VirtualBoxSupportTranslationBase methods
580	////////////////////////////////////////////////////////////////////////////////
581
582	/**
583	* Modifies the given argument so that it will contain only a class name
584	* (null-terminated). The argument must point to a <b>non-constant</b>
585	* string containing a valid value, as it is generated by the
586	* __PRETTY_FUNCTION__ built-in macro of the GCC compiler, or by the
587	* __FUNCTION__ macro of any other compiler.
588	*
589	* The function assumes that the macro is used within the member of the
590	* class derived from the VirtualBoxSupportTranslation<> template.
591	*
592	* @param prettyFunctionName string to modify
593	* @return
594	* true on success and false otherwise
595	*/
596	bool VirtualBoxSupportTranslationBase::cutClassNameFrom__PRETTY_FUNCTION__ (char *fn)
597	{
598	Assert (fn);
599	if (!fn)
600	return false;
601
602	#if defined (__GNUC__)
603
604	// the format is like:
605	// VirtualBoxSupportTranslation<C>::VirtualBoxSupportTranslation() [with C = VirtualBox]
606
607	#define START " = "
608	#define END "]"
609
610	#elif defined (_MSC_VER)
611
612	// the format is like:
613	// VirtualBoxSupportTranslation<class VirtualBox>::__ctor
614
615	#define START "<class "
616	#define END ">::"
617
618	#endif
619
620	char *start = strstr (fn, START);
621	Assert (start);
622	if (start)
623	{
624	start += sizeof (START) - 1;
625	char *end = strstr (start, END);
626	Assert (end && (end > start));
627	if (end && (end > start))
628	{
629	size_t len = end - start;
630	memmove (fn, start, len);
631	fn [len] = 0;
632	return true;
633	}
634	}
635
636	#undef END
637	#undef START
638
639	return false;
640	}
641
642	// VirtualBoxSupportErrorInfoImplBase methods
643	////////////////////////////////////////////////////////////////////////////////
644
645	/**
646	* Sets error info for the current thread. This is an internal function that
647	* gets eventually called by all public variants. If @a aPreserve is
648	* @c true, then the current error info object set on the thread before this
649	* method is called will be preserved in the IVirtualBoxErrorInfo::next
650	* attribute of the new error info object that will be then set as the
651	* current error info object.
652	*/
653	// static
654	HRESULT VirtualBoxSupportErrorInfoImplBase::setErrorInternal (
655	HRESULT aResultCode, const GUID &aIID,
656	const Bstr &aComponent, const Bstr &aText,
657	bool aPreserve)
658	{
659	LogRel (("ERROR [COM]: aRC=%#08x aIID={%Vuuid} aComponent={%ls} aText={%ls} "
660	"aPreserve=%RTbool\n",
661	aResultCode, &aIID, aComponent.raw(), aText.raw(), aPreserve));
662
663	/* these are mandatory, others -- not */
664	AssertReturn (FAILED (aResultCode), E_FAIL);
665	AssertReturn (!aText.isEmpty(), E_FAIL);
666
667	HRESULT rc = S_OK;
668
669	do
670	{
671	ComObjPtr <VirtualBoxErrorInfo> info;
672	rc = info.createObject();
673	CheckComRCBreakRC (rc);
674
675	#if !defined (VBOX_WITH_XPCOM)
676	#if defined (RT_OS_WINDOWS)
677
678	ComPtr <IVirtualBoxErrorInfo> curInfo;
679	if (aPreserve)
680	{
681	/* get the current error info if any */
682	ComPtr <IErrorInfo> err;
683	rc = ::GetErrorInfo (0, err.asOutParam());
684	CheckComRCBreakRC (rc);
685	rc = err.queryInterfaceTo (curInfo.asOutParam());
686	if (FAILED (rc))
687	{
688	/* create a IVirtualBoxErrorInfo wrapper for the native
689	* IErrorInfo object */
690	ComObjPtr <VirtualBoxErrorInfo> wrapper;
691	rc = wrapper.createObject();
692	if (SUCCEEDED (rc))
693	{
694	rc = wrapper->init (err);
695	if (SUCCEEDED (rc))
696	curInfo = wrapper;
697	}
698	}
699	}
700	/* On failure, curInfo will stay null */
701	Assert (SUCCEEDED (rc) \|\| curInfo.isNull());
702
703	/* set the current error info and preserve the previous one if any */
704	rc = info->init (aResultCode, aIID, aComponent, aText, curInfo);
705	CheckComRCBreakRC (rc);
706
707	ComPtr <IErrorInfo> err;
708	rc = info.queryInterfaceTo (err.asOutParam());
709	if (SUCCEEDED (rc))
710	rc = ::SetErrorInfo (0, err);
711
712	#endif
713	#else // !defined (VBOX_WITH_XPCOM)
714
715	nsCOMPtr <nsIExceptionService> es;
716	es = do_GetService (NS_EXCEPTIONSERVICE_CONTRACTID, &rc);
717	if (NS_SUCCEEDED (rc))
718	{
719	nsCOMPtr <nsIExceptionManager> em;
720	rc = es->GetCurrentExceptionManager (getter_AddRefs (em));
721	CheckComRCBreakRC (rc);
722
723	ComPtr <IVirtualBoxErrorInfo> curInfo;
724	if (aPreserve)
725	{
726	/* get the current error info if any */
727	ComPtr <nsIException> ex;
728	rc = em->GetCurrentException (ex.asOutParam());
729	CheckComRCBreakRC (rc);
730	rc = ex.queryInterfaceTo (curInfo.asOutParam());
731	if (FAILED (rc))
732	{
733	/* create a IVirtualBoxErrorInfo wrapper for the native
734	* nsIException object */
735	ComObjPtr <VirtualBoxErrorInfo> wrapper;
736	rc = wrapper.createObject();
737	if (SUCCEEDED (rc))
738	{
739	rc = wrapper->init (ex);
740	if (SUCCEEDED (rc))
741	curInfo = wrapper;
742	}
743	}
744	}
745	/* On failure, curInfo will stay null */
746	Assert (SUCCEEDED (rc) \|\| curInfo.isNull());
747
748	/* set the current error info and preserve the previous one if any */
749	rc = info->init (aResultCode, aIID, aComponent, aText, curInfo);
750	CheckComRCBreakRC (rc);
751
752	ComPtr <nsIException> ex;
753	rc = info.queryInterfaceTo (ex.asOutParam());
754	if (SUCCEEDED (rc))
755	rc = em->SetCurrentException (ex);
756	}
757	else if (rc == NS_ERROR_UNEXPECTED)
758	{
759	/*
760	* It is possible that setError() is being called by the object
761	* after the XPCOM shutdown sequence has been initiated
762	* (for example, when XPCOM releases all instances it internally
763	* references, which can cause object's FinalConstruct() and then
764	* uninit()). In this case, do_GetService() above will return
765	* NS_ERROR_UNEXPECTED and it doesn't actually make sense to
766	* set the exception (nobody will be able to read it).
767	*/
768	LogWarningFunc (("Will not set an exception because "
769	"nsIExceptionService is not available "
770	"(NS_ERROR_UNEXPECTED). "
771	"XPCOM is being shutdown?\n"));
772	rc = NS_OK;
773	}
774
775	#endif // !defined (VBOX_WITH_XPCOM)
776	}
777	while (0);
778
779	AssertComRC (rc);
780
781	return SUCCEEDED (rc) ? aResultCode : rc;
782	}
783
784	// VirtualBoxBaseWithChildren methods
785	////////////////////////////////////////////////////////////////////////////////
786
787	/**
788	* Uninitializes all dependent children registered with #addDependentChild().
789	*
790	* @note
791	* This method will call uninit() methods of children. If these methods
792	* access the parent object, uninitDependentChildren() must be called
793	* either at the beginning of the parent uninitialization sequence (when
794	* it is still operational) or after setReady(false) is called to
795	* indicate the parent is out of action.
796	*/
797	void VirtualBoxBaseWithChildren::uninitDependentChildren()
798	{
799	/// @todo (r=dmik) see todo in VirtualBoxBase.h, in
800	// template <class C> void removeDependentChild (C *child)
801
802	LogFlowThisFuncEnter();
803
804	AutoLock alock (this);
805	AutoLock mapLock (mMapLock);
806
807	LogFlowThisFunc (("count=%d...\n", mDependentChildren.size()));
808
809	if (mDependentChildren.size())
810	{
811	/* We keep the lock until we have enumerated all children.
812	* Those ones that will try to call #removeDependentChild() from
813	* a different thread will have to wait */
814
815	Assert (mUninitDoneSem == NIL_RTSEMEVENT);
816	int vrc = RTSemEventCreate (&mUninitDoneSem);
817	AssertRC (vrc);
818
819	Assert (mChildrenLeft == 0);
820	mChildrenLeft = mDependentChildren.size();
821
822	for (DependentChildren::iterator it = mDependentChildren.begin();
823	it != mDependentChildren.end(); ++ it)
824	{
825	VirtualBoxBase child = (it).second;
826	Assert (child);
827	if (child)
828	child->uninit();
829	}
830
831	mDependentChildren.clear();
832	}
833
834	/* Wait until all children started uninitializing on their own
835	* (and therefore are waiting for some parent's method or for
836	* #removeDependentChild() to return) are finished uninitialization */
837
838	if (mUninitDoneSem != NIL_RTSEMEVENT)
839	{
840	/* let stuck children run */
841	mapLock.leave();
842	alock.leave();
843
844	LogFlowThisFunc (("Waiting for uninitialization of all children...\n"));
845
846	RTSemEventWait (mUninitDoneSem, RT_INDEFINITE_WAIT);
847
848	alock.enter();
849	mapLock.enter();
850
851	RTSemEventDestroy (mUninitDoneSem);
852	mUninitDoneSem = NIL_RTSEMEVENT;
853	Assert (mChildrenLeft == 0);
854	}
855
856	LogFlowThisFuncLeave();
857	}
858
859	/**
860	* Returns a pointer to the dependent child corresponding to the given
861	* interface pointer (used as a key in the map) or NULL if the interface
862	* pointer doesn't correspond to any child registered using
863	* #addDependentChild().
864	*
865	* @param unk
866	* Pointer to map to the dependent child object (it is ComPtr <IUnknown>
867	* rather than IUnknown , to guarantee IUnknown identity)
868	* @return
869	* Pointer to the dependent child object
870	*/
871	VirtualBoxBase *VirtualBoxBaseWithChildren::getDependentChild (
872	const ComPtr <IUnknown> &unk)
873	{
874	AssertReturn (!!unk, NULL);
875
876	AutoLock alock (mMapLock);
877	if (mUninitDoneSem != NIL_RTSEMEVENT)
878	return NULL;
879
880	DependentChildren::const_iterator it = mDependentChildren.find (unk);
881	if (it == mDependentChildren.end())
882	return NULL;
883	return (*it).second;
884	}
885
886	/** Helper for addDependentChild() template method */
887	void VirtualBoxBaseWithChildren::addDependentChild (
888	const ComPtr <IUnknown> &unk, VirtualBoxBase *child)
889	{
890	AssertReturn (!!unk && child, (void) 0);
891
892	AutoLock alock (mMapLock);
893
894	if (mUninitDoneSem != NIL_RTSEMEVENT)
895	{
896	// for this very unlikely case, we have to increase the number of
897	// children left, for symmetry with #removeDependentChild()
898	++ mChildrenLeft;
899	return;
900	}
901
902	std::pair <DependentChildren::iterator, bool> result =
903	mDependentChildren.insert (DependentChildren::value_type (unk, child));
904	AssertMsg (result.second, ("Failed to insert a child to the map\n"));
905	}
906
907	/** Helper for removeDependentChild() template method */
908	void VirtualBoxBaseWithChildren::removeDependentChild (const ComPtr <IUnknown> &unk)
909	{
910	/// @todo (r=dmik) see todo in VirtualBoxBase.h, in
911	// template <class C> void removeDependentChild (C *child)
912
913	AssertReturn (!!unk, (void) 0);
914
915	AutoLock alock (mMapLock);
916
917	if (mUninitDoneSem != NIL_RTSEMEVENT)
918	{
919	// uninitDependentChildren() is in action, just increase the number
920	// of children left and signal a semaphore when it reaches zero
921	Assert (mChildrenLeft != 0);
922	-- mChildrenLeft;
923	if (mChildrenLeft == 0)
924	{
925	int vrc = RTSemEventSignal (mUninitDoneSem);
926	AssertRC (vrc);
927	}
928	return;
929	}
930
931	DependentChildren::size_type result = mDependentChildren.erase (unk);
932	AssertMsg (result == 1, ("Failed to remove a child from the map\n"));
933	NOREF (result);
934	}
935

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source: vbox/trunk/src/VBox/Main/VirtualBoxBase.cpp@ 3668

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