VirtualBoxBase.cpp@ 5688

Last change on this file since 5688 was 5251, checked in by vboxsync, 17 years ago
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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
18	#if !defined (VBOX_WITH_XPCOM)
19	#if defined (RT_OS_WINDOWS)
20	#include <windows.h>
21	#include <dbghelp.h>
22	#endif
23	#else // !defined (VBOX_WITH_XPCOM)
24	#include <nsIServiceManager.h>
25	#include <nsIExceptionService.h>
26	#endif // !defined (VBOX_WITH_XPCOM)
27
28	#include "VirtualBoxBase.h"
29	#include "VirtualBoxErrorInfoImpl.h"
30	#include "Logging.h"
31
32	#include <iprt/semaphore.h>
33
34	// VirtualBoxBaseNEXT_base methods
35	////////////////////////////////////////////////////////////////////////////////
36
37	VirtualBoxBaseNEXT_base::VirtualBoxBaseNEXT_base()
38	{
39	mState = NotReady;
40	mStateChangeThread = NIL_RTTHREAD;
41	mCallers = 0;
42	mZeroCallersSem = NIL_RTSEMEVENT;
43	mInitDoneSem = NIL_RTSEMEVENTMULTI;
44	mInitDoneSemUsers = 0;
45	RTCritSectInit (&mStateLock);
46	mObjectLock = NULL;
47	}
48
49	VirtualBoxBaseNEXT_base::~VirtualBoxBaseNEXT_base()
50	{
51	if (mObjectLock)
52	delete mObjectLock;
53	RTCritSectDelete (&mStateLock);
54	Assert (mInitDoneSemUsers == 0);
55	Assert (mInitDoneSem == NIL_RTSEMEVENTMULTI);
56	if (mZeroCallersSem != NIL_RTSEMEVENT)
57	RTSemEventDestroy (mZeroCallersSem);
58	mCallers = 0;
59	mStateChangeThread = NIL_RTTHREAD;
60	mState = NotReady;
61	}
62
63	// AutoLock::Lockable interface
64	AutoLock::Handle *VirtualBoxBaseNEXT_base::lockHandle() const
65	{
66	/* lasy initialization */
67	if (!mObjectLock)
68	mObjectLock = new AutoLock::Handle;
69	return mObjectLock;
70	}
71
72	/**
73	* Increments the number of calls to this object by one.
74	*
75	* After this method succeeds, it is guaranted that the object will remain in
76	* the Ready (or in the Limited) state at least until #releaseCaller() is
77	* called.
78	*
79	* This method is intended to mark the beginning of sections of code within
80	* methods of COM objects that depend on the readiness (Ready) state. The
81	* Ready state is a primary "ready to serve" state. Usually all code that
82	* works with component's data depends on it. On practice, this means that
83	* almost every public method, setter or getter of the object should add
84	* itself as an object's caller at the very beginning, to protect from an
85	* unexpected uninitialization that may happen on a different thread.
86	*
87	* Besides the Ready state denoting that the object is fully functional,
88	* there is a special Limited state. The Limited state means that the object
89	* is still functional, but its functionality is limited to some degree, so
90	* not all operations are possible. The @a aLimited argument to this method
91	* determines whether the caller represents this limited functionality or not.
92	*
93	* This method succeeeds (and increments the number of callers) only if the
94	* current object's state is Ready. Otherwise, it will return E_UNEXPECTED to
95	* indicate that the object is not operational. There are two exceptions from
96	* this rule:
97	* <ol>
98	* <li>If the @a aLimited argument is \|true\|, then this method will also
99	* succeeed if the object's state is Limited (or Ready, of course).</li>
100	* <li>If this method is called from the same thread that placed the object
101	* to InInit or InUninit state (i.e. either from within the AutoInitSpan
102	* or AutoUninitSpan scope), it will succeed as well (but will not
103	* increase the number of callers).</li>
104	* </ol>
105	*
106	* Normally, calling addCaller() never blocks. However, if this method is
107	* called by a thread created from within the AutoInitSpan scope and this
108	* scope is still active (i.e. the object state is InInit), it will block
109	* until the AutoInitSpan destructor signals that it has finished
110	* initialization.
111	*
112	* When this method returns a failure, the caller must not use the object
113	* and can return the failed result code to his caller.
114	*
115	* @param aState where to store the current object's state
116	* (can be used in overriden methods to determine the
117	* cause of the failure)
118	* @param aLimited \|true\| to add a limited caller.
119	* @return S_OK on success or E_UNEXPECTED on failure
120	*
121	* @note It is preferrable to use the #addLimitedCaller() rather than calling
122	* this method with @a aLimited = \|true\|, for better
123	* self-descriptiveness.
124	*
125	* @sa #addLimitedCaller()
126	* @sa #releaseCaller()
127	*/
128	HRESULT VirtualBoxBaseNEXT_base::addCaller (State aState / = NULL */,
129	bool aLimited /* = false */)
130	{
131	AutoLock stateLock (mStateLock);
132
133	HRESULT rc = E_UNEXPECTED;
134
135	if (mState == Ready \|\| (aLimited && mState == Limited))
136	{
137	/* if Ready or allows Limited, increase the number of callers */
138	++ mCallers;
139	rc = S_OK;
140	}
141	else
142	if ((mState == InInit \|\| mState == InUninit))
143	{
144	if (mStateChangeThread == RTThreadSelf())
145	{
146	/*
147	* Called from the same thread that is doing AutoInitSpan or
148	* AutoUninitSpan, just succeed
149	*/
150	rc = S_OK;
151	}
152	else if (mState == InInit)
153	{
154	/* addCaller() is called by a "child" thread while the "parent"
155	* thread is still doing AutoInitSpan/AutoReadySpan. Wait for the
156	* state to become either Ready/Limited or InitFailed/InInit/NotReady
157	* (in case of init failure). Note that we increase the number of
158	* callers anyway to prevent AutoUninitSpan from early completion.
159	*/
160	++ mCallers;
161
162	/* lazy creation */
163	if (mInitDoneSem == NIL_RTSEMEVENTMULTI)
164	RTSemEventMultiCreate (&mInitDoneSem);
165	++ mInitDoneSemUsers;
166
167	LogFlowThisFunc (("Waiting for AutoInitSpan/AutoReadySpan to finish...\n"));
168
169	stateLock.leave();
170	RTSemEventMultiWait (mInitDoneSem, RT_INDEFINITE_WAIT);
171	stateLock.enter();
172
173	if (-- mInitDoneSemUsers == 0)
174	{
175	/* destroy the semaphore since no more necessary */
176	RTSemEventMultiDestroy (mInitDoneSem);
177	mInitDoneSem = NIL_RTSEMEVENTMULTI;
178	}
179
180	if (mState == Ready)
181	rc = S_OK;
182	else
183	{
184	AssertMsg (mCallers != 0, ("mCallers is ZERO!"));
185	-- mCallers;
186	if (mCallers == 0 && mState == InUninit)
187	{
188	/* inform AutoUninitSpan ctor there are no more callers */
189	RTSemEventSignal (mZeroCallersSem);
190	}
191	}
192	}
193	}
194
195	if (aState)
196	*aState = mState;
197
198	return rc;
199	}
200
201	/**
202	* Decrements the number of calls to this object by one.
203	* Must be called after every #addCaller() or #addLimitedCaller() when the
204	* object is no more necessary.
205	*/
206	void VirtualBoxBaseNEXT_base::releaseCaller()
207	{
208	AutoLock stateLock (mStateLock);
209
210	if (mState == Ready \|\| mState == Limited)
211	{
212	/* if Ready or Limited, decrease the number of callers */
213	AssertMsgReturn (mCallers != 0, ("mCallers is ZERO!"), (void) 0);
214	-- mCallers;
215
216	return;
217	}
218
219	if ((mState == InInit \|\| mState == InUninit))
220	{
221	if (mStateChangeThread == RTThreadSelf())
222	{
223	/*
224	* Called from the same thread that is doing AutoInitSpan or
225	* AutoUninitSpan, just succeed
226	*/
227	return;
228	}
229
230	if (mState == InUninit)
231	{
232	/* the caller is being released after AutoUninitSpan has begun */
233	AssertMsgReturn (mCallers != 0, ("mCallers is ZERO!"), (void) 0);
234	-- mCallers;
235
236	if (mCallers == 0)
237	{
238	/* inform the AutoUninitSpan ctor there are no more callers */
239	RTSemEventSignal (mZeroCallersSem);
240	}
241
242	return;
243	}
244	}
245
246	AssertMsgFailed (("mState = %d!", mState));
247	}
248
249	// VirtualBoxBaseNEXT_base::AutoInitSpan methods
250	////////////////////////////////////////////////////////////////////////////////
251
252	/**
253	* Creates a smart initialization span object and places the object to
254	* InInit state.
255	*
256	* @param aObj \|this\| pointer of the managed VirtualBoxBase object whose
257	* init() method is being called
258	* @param aStatus initial initialization status for this span
259	*/
260	VirtualBoxBaseNEXT_base::AutoInitSpan::
261	AutoInitSpan (VirtualBoxBaseNEXT_base aObj, Status aStatus / = Failed */)
262	: mObj (aObj), mStatus (aStatus), mOk (false)
263	{
264	Assert (aObj);
265
266	AutoLock stateLock (mObj->mStateLock);
267
268	Assert (mObj->mState != InInit && mObj->mState != InUninit &&
269	mObj->mState != InitFailed);
270
271	mOk = mObj->mState == NotReady;
272	if (!mOk)
273	return;
274
275	mObj->setState (InInit);
276	}
277
278	/**
279	* Places the managed VirtualBoxBase object to Ready/Limited state if the
280	* initialization succeeded or partly succeeded, or places it to InitFailed
281	* state and calls the object's uninit() method otherwise.
282	*/
283	VirtualBoxBaseNEXT_base::AutoInitSpan::~AutoInitSpan()
284	{
285	/* if the state was other than NotReady, do nothing */
286	if (!mOk)
287	return;
288
289	AutoLock stateLock (mObj->mStateLock);
290
291	Assert (mObj->mState == InInit);
292
293	if (mObj->mCallers > 0)
294	{
295	Assert (mObj->mInitDoneSemUsers > 0);
296
297	/* We have some pending addCaller() calls on other threads (created
298	* during InInit), signal that InInit is finished. */
299	RTSemEventMultiSignal (mObj->mInitDoneSem);
300	}
301
302	if (mStatus == Succeeded)
303	{
304	mObj->setState (Ready);
305	}
306	else
307	if (mStatus == Limited)
308	{
309	mObj->setState (VirtualBoxBaseNEXT_base::Limited);
310	}
311	else
312	{
313	mObj->setState (InitFailed);
314	/* leave the lock to prevent nesting when uninit() is called */
315	stateLock.leave();
316	/* call uninit() to let the object uninit itself after failed init() */
317	mObj->uninit();
318	/* Note: the object may no longer exist here (for example, it can call
319	* the destructor in uninit()) */
320	}
321	}
322
323	// VirtualBoxBaseNEXT_base::AutoReadySpan methods
324	////////////////////////////////////////////////////////////////////////////////
325
326	/**
327	* Creates a smart re-initialization span object and places the object to
328	* InInit state.
329	*
330	* @param aObj \|this\| pointer of the managed VirtualBoxBase object whose
331	* re-initialization method is being called
332	*/
333	VirtualBoxBaseNEXT_base::AutoReadySpan::
334	AutoReadySpan (VirtualBoxBaseNEXT_base *aObj)
335	: mObj (aObj), mSucceeded (false), mOk (false)
336	{
337	Assert (aObj);
338
339	AutoLock stateLock (mObj->mStateLock);
340
341	Assert (mObj->mState != InInit && mObj->mState != InUninit &&
342	mObj->mState != InitFailed);
343
344	mOk = mObj->mState == Limited;
345	if (!mOk)
346	return;
347
348	mObj->setState (InInit);
349	}
350
351	/**
352	* Places the managed VirtualBoxBase object to Ready state if the
353	* re-initialization succeeded (i.e. #setSucceeded() has been called) or
354	* back to Limited state otherwise.
355	*/
356	VirtualBoxBaseNEXT_base::AutoReadySpan::~AutoReadySpan()
357	{
358	/* if the state was other than Limited, do nothing */
359	if (!mOk)
360	return;
361
362	AutoLock stateLock (mObj->mStateLock);
363
364	Assert (mObj->mState == InInit);
365
366	if (mObj->mCallers > 0 && mObj->mInitDoneSemUsers > 0)
367	{
368	/* We have some pending addCaller() calls on other threads,
369	* signal that InInit is finished. */
370	RTSemEventMultiSignal (mObj->mInitDoneSem);
371	}
372
373	if (mSucceeded)
374	{
375	mObj->setState (Ready);
376	}
377	else
378	{
379	mObj->setState (Limited);
380	}
381	}
382
383	// VirtualBoxBaseNEXT_base::AutoUninitSpan methods
384	////////////////////////////////////////////////////////////////////////////////
385
386	/**
387	* Creates a smart uninitialization span object and places this object to
388	* InUninit state.
389	*
390	* @note This method blocks the current thread execution until the number of
391	* callers of the managed VirtualBoxBase object drops to zero!
392	*
393	* @param aObj \|this\| pointer of the VirtualBoxBase object whose uninit()
394	* method is being called
395	*/
396	VirtualBoxBaseNEXT_base::AutoUninitSpan::AutoUninitSpan (VirtualBoxBaseNEXT_base *aObj)
397	: mObj (aObj), mInitFailed (false), mUninitDone (false)
398	{
399	Assert (aObj);
400
401	AutoLock stateLock (mObj->mStateLock);
402
403	Assert (mObj->mState != InInit);
404
405	/*
406	* Set mUninitDone to \|true\| if this object is already uninitialized
407	* (NotReady) or if another AutoUninitSpan is currently active on some
408	* other thread (InUninit).
409	*/
410	mUninitDone = mObj->mState == NotReady \|\|
411	mObj->mState == InUninit;
412
413	if (mObj->mState == InitFailed)
414	{
415	/* we've been called by init() on failure */
416	mInitFailed = true;
417	}
418	else
419	{
420	/* do nothing if already uninitialized */
421	if (mUninitDone)
422	return;
423	}
424
425	/* go to InUninit to prevent from adding new callers */
426	mObj->setState (InUninit);
427
428	if (mObj->mCallers > 0)
429	{
430	/* lazy creation */
431	Assert (mObj->mZeroCallersSem == NIL_RTSEMEVENT);
432	RTSemEventCreate (&mObj->mZeroCallersSem);
433
434	/* wait until remaining callers release the object */
435	LogFlowThisFunc (("Waiting for callers (%d) to drop to zero...\n",
436	mObj->mCallers));
437
438	stateLock.leave();
439	RTSemEventWait (mObj->mZeroCallersSem, RT_INDEFINITE_WAIT);
440	}
441	}
442
443	/**
444	* Places the managed VirtualBoxBase object to the NotReady state.
445	*/
446	VirtualBoxBaseNEXT_base::AutoUninitSpan::~AutoUninitSpan()
447	{
448	/* do nothing if already uninitialized */
449	if (mUninitDone)
450	return;
451
452	AutoLock stateLock (mObj->mStateLock);
453
454	Assert (mObj->mState == InUninit);
455
456	mObj->setState (NotReady);
457	}
458
459	// VirtualBoxBase methods
460	////////////////////////////////////////////////////////////////////////////////
461
462	/**
463	* Translates the given text string according to the currently installed
464	* translation table and current context. The current context is determined
465	* by the context parameter. Additionally, a comment to the source text
466	* string text can be given. This comment (which is NULL by default)
467	* is helpful in sutuations where it is necessary to distinguish between
468	* two or more semantically different roles of the same source text in the
469	* same context.
470	*
471	* @param context the context of the the translation (can be NULL
472	* to indicate the global context)
473	* @param sourceText the string to translate
474	* @param comment the comment to the string (NULL means no comment)
475	*
476	* @return
477	* the translated version of the source string in UTF-8 encoding,
478	* or the source string itself if the translation is not found
479	* in the given context.
480	*/
481	// static
482	const char VirtualBoxBase::translate (const char context, const char *sourceText,
483	const char *comment)
484	{
485	// Log(("VirtualBoxBase::translate:\n"
486	// " context={%s}\n"
487	// " sourceT={%s}\n"
488	// " comment={%s}\n",
489	// context, sourceText, comment));
490
491	/// @todo (dmik) incorporate Qt translation file parsing and lookup
492
493	return sourceText;
494	}
495
496	/// @todo (dmik)
497	// Using StackWalk() is not necessary here once we have ASMReturnAddress().
498	// Delete later.
499
500	#if defined(DEBUG) && 0
501
502	//static
503	void VirtualBoxBase::AutoLock::CritSectEnter (RTCRITSECT *aLock)
504	{
505	AssertReturn (aLock, (void) 0);
506
507	#if (defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2)) && defined(__GNUC__)
508
509	RTCritSectEnterDebug (aLock,
510	"AutoLock::lock()/enter() return address >>>", 0,
511	(RTUINTPTR) __builtin_return_address (1));
512
513	#elif defined(RT_OS_WINDOWS)
514
515	STACKFRAME sf;
516	memset (&sf, 0, sizeof(sf));
517	{
518	__asm eip:
519	__asm mov eax, eip
520	__asm lea ebx, sf
521	__asm mov [ebx]sf.AddrPC.Offset, eax
522	__asm mov [ebx]sf.AddrStack.Offset, esp
523	__asm mov [ebx]sf.AddrFrame.Offset, ebp
524	}
525	sf.AddrPC.Mode = AddrModeFlat;
526	sf.AddrStack.Mode = AddrModeFlat;
527	sf.AddrFrame.Mode = AddrModeFlat;
528
529	HANDLE process = GetCurrentProcess();
530	HANDLE thread = GetCurrentThread();
531
532	// get our stack frame
533	BOOL ok = StackWalk (IMAGE_FILE_MACHINE_I386, process, thread,
534	&sf, NULL, NULL,
535	SymFunctionTableAccess,
536	SymGetModuleBase,
537	NULL);
538	// sanity check of the returned stack frame
539	ok = ok & (sf.AddrFrame.Offset != 0);
540	if (ok)
541	{
542	// get the stack frame of our caller which is either
543	// lock() or enter()
544	ok = StackWalk (IMAGE_FILE_MACHINE_I386, process, thread,
545	&sf, NULL, NULL,
546	SymFunctionTableAccess,
547	SymGetModuleBase,
548	NULL);
549	// sanity check of the returned stack frame
550	ok = ok & (sf.AddrFrame.Offset != 0);
551	}
552
553	if (ok)
554	{
555	// the return address here should be the code where lock() or enter()
556	// has been called from (to be more precise, where it will return)
557	RTCritSectEnterDebug (aLock,
558	"AutoLock::lock()/enter() return address >>>", 0,
559	(RTUINTPTR) sf.AddrReturn.Offset);
560	}
561	else
562	{
563	RTCritSectEnter (aLock);
564	}
565
566	#else
567
568	RTCritSectEnter (aLock);
569
570	#endif // defined(RT_OS_LINUX)...
571	}
572
573	#endif // defined(DEBUG)
574
575	// VirtualBoxSupportTranslationBase methods
576	////////////////////////////////////////////////////////////////////////////////
577
578	/**
579	* Modifies the given argument so that it will contain only a class name
580	* (null-terminated). The argument must point to a <b>non-constant</b>
581	* string containing a valid value, as it is generated by the
582	* __PRETTY_FUNCTION__ built-in macro of the GCC compiler, or by the
583	* __FUNCTION__ macro of any other compiler.
584	*
585	* The function assumes that the macro is used within the member of the
586	* class derived from the VirtualBoxSupportTranslation<> template.
587	*
588	* @param prettyFunctionName string to modify
589	* @return
590	* true on success and false otherwise
591	*/
592	bool VirtualBoxSupportTranslationBase::cutClassNameFrom__PRETTY_FUNCTION__ (char *fn)
593	{
594	Assert (fn);
595	if (!fn)
596	return false;
597
598	#if defined (__GNUC__)
599
600	// the format is like:
601	// VirtualBoxSupportTranslation<C>::VirtualBoxSupportTranslation() [with C = VirtualBox]
602
603	#define START " = "
604	#define END "]"
605
606	#elif defined (_MSC_VER)
607
608	// the format is like:
609	// VirtualBoxSupportTranslation<class VirtualBox>::__ctor
610
611	#define START "<class "
612	#define END ">::"
613
614	#endif
615
616	char *start = strstr (fn, START);
617	Assert (start);
618	if (start)
619	{
620	start += sizeof (START) - 1;
621	char *end = strstr (start, END);
622	Assert (end && (end > start));
623	if (end && (end > start))
624	{
625	size_t len = end - start;
626	memmove (fn, start, len);
627	fn [len] = 0;
628	return true;
629	}
630	}
631
632	#undef END
633	#undef START
634
635	return false;
636	}
637
638	// VirtualBoxSupportErrorInfoImplBase methods
639	////////////////////////////////////////////////////////////////////////////////
640
641	/**
642	* Sets error info for the current thread. This is an internal function that
643	* gets eventually called by all public variants. If @a aPreserve is
644	* @c true, then the current error info object set on the thread before this
645	* method is called will be preserved in the IVirtualBoxErrorInfo::next
646	* attribute of the new error info object that will be then set as the
647	* current error info object.
648	*/
649	// static
650	HRESULT VirtualBoxSupportErrorInfoImplBase::setErrorInternal (
651	HRESULT aResultCode, const GUID &aIID,
652	const Bstr &aComponent, const Bstr &aText,
653	bool aPreserve)
654	{
655	LogRel (("ERROR [COM]: aRC=%#08x aIID={%Vuuid} aComponent={%ls} aText={%ls} "
656	"aPreserve=%RTbool\n",
657	aResultCode, &aIID, aComponent.raw(), aText.raw(), aPreserve));
658
659	/* these are mandatory, others -- not */
660	AssertReturn (FAILED (aResultCode), E_FAIL);
661	AssertReturn (!aText.isEmpty(), E_FAIL);
662
663	HRESULT rc = S_OK;
664
665	do
666	{
667	ComObjPtr <VirtualBoxErrorInfo> info;
668	rc = info.createObject();
669	CheckComRCBreakRC (rc);
670
671	#if !defined (VBOX_WITH_XPCOM)
672	#if defined (RT_OS_WINDOWS)
673
674	ComPtr <IVirtualBoxErrorInfo> curInfo;
675	if (aPreserve)
676	{
677	/* get the current error info if any */
678	ComPtr <IErrorInfo> err;
679	rc = ::GetErrorInfo (0, err.asOutParam());
680	CheckComRCBreakRC (rc);
681	rc = err.queryInterfaceTo (curInfo.asOutParam());
682	if (FAILED (rc))
683	{
684	/* create a IVirtualBoxErrorInfo wrapper for the native
685	* IErrorInfo object */
686	ComObjPtr <VirtualBoxErrorInfo> wrapper;
687	rc = wrapper.createObject();
688	if (SUCCEEDED (rc))
689	{
690	rc = wrapper->init (err);
691	if (SUCCEEDED (rc))
692	curInfo = wrapper;
693	}
694	}
695	}
696	/* On failure, curInfo will stay null */
697	Assert (SUCCEEDED (rc) \|\| curInfo.isNull());
698
699	/* set the current error info and preserve the previous one if any */
700	rc = info->init (aResultCode, aIID, aComponent, aText, curInfo);
701	CheckComRCBreakRC (rc);
702
703	ComPtr <IErrorInfo> err;
704	rc = info.queryInterfaceTo (err.asOutParam());
705	if (SUCCEEDED (rc))
706	rc = ::SetErrorInfo (0, err);
707
708	#endif
709	#else // !defined (VBOX_WITH_XPCOM)
710
711	nsCOMPtr <nsIExceptionService> es;
712	es = do_GetService (NS_EXCEPTIONSERVICE_CONTRACTID, &rc);
713	if (NS_SUCCEEDED (rc))
714	{
715	nsCOMPtr <nsIExceptionManager> em;
716	rc = es->GetCurrentExceptionManager (getter_AddRefs (em));
717	CheckComRCBreakRC (rc);
718
719	ComPtr <IVirtualBoxErrorInfo> curInfo;
720	if (aPreserve)
721	{
722	/* get the current error info if any */
723	ComPtr <nsIException> ex;
724	rc = em->GetCurrentException (ex.asOutParam());
725	CheckComRCBreakRC (rc);
726	rc = ex.queryInterfaceTo (curInfo.asOutParam());
727	if (FAILED (rc))
728	{
729	/* create a IVirtualBoxErrorInfo wrapper for the native
730	* nsIException object */
731	ComObjPtr <VirtualBoxErrorInfo> wrapper;
732	rc = wrapper.createObject();
733	if (SUCCEEDED (rc))
734	{
735	rc = wrapper->init (ex);
736	if (SUCCEEDED (rc))
737	curInfo = wrapper;
738	}
739	}
740	}
741	/* On failure, curInfo will stay null */
742	Assert (SUCCEEDED (rc) \|\| curInfo.isNull());
743
744	/* set the current error info and preserve the previous one if any */
745	rc = info->init (aResultCode, aIID, aComponent, aText, curInfo);
746	CheckComRCBreakRC (rc);
747
748	ComPtr <nsIException> ex;
749	rc = info.queryInterfaceTo (ex.asOutParam());
750	if (SUCCEEDED (rc))
751	rc = em->SetCurrentException (ex);
752	}
753	else if (rc == NS_ERROR_UNEXPECTED)
754	{
755	/*
756	* It is possible that setError() is being called by the object
757	* after the XPCOM shutdown sequence has been initiated
758	* (for example, when XPCOM releases all instances it internally
759	* references, which can cause object's FinalConstruct() and then
760	* uninit()). In this case, do_GetService() above will return
761	* NS_ERROR_UNEXPECTED and it doesn't actually make sense to
762	* set the exception (nobody will be able to read it).
763	*/
764	LogWarningFunc (("Will not set an exception because "
765	"nsIExceptionService is not available "
766	"(NS_ERROR_UNEXPECTED). "
767	"XPCOM is being shutdown?\n"));
768	rc = NS_OK;
769	}
770
771	#endif // !defined (VBOX_WITH_XPCOM)
772	}
773	while (0);
774
775	AssertComRC (rc);
776
777	return SUCCEEDED (rc) ? aResultCode : rc;
778	}
779
780	// VirtualBoxBaseWithChildren methods
781	////////////////////////////////////////////////////////////////////////////////
782
783	/**
784	* Uninitializes all dependent children registered with #addDependentChild().
785	*
786	* @note
787	* This method will call uninit() methods of children. If these methods
788	* access the parent object, uninitDependentChildren() must be called
789	* either at the beginning of the parent uninitialization sequence (when
790	* it is still operational) or after setReady(false) is called to
791	* indicate the parent is out of action.
792	*/
793	void VirtualBoxBaseWithChildren::uninitDependentChildren()
794	{
795	/// @todo (r=dmik) see todo in VirtualBoxBase.h, in
796	// template <class C> void removeDependentChild (C *child)
797
798	LogFlowThisFuncEnter();
799
800	AutoLock alock (this);
801	AutoLock mapLock (mMapLock);
802
803	LogFlowThisFunc (("count=%d...\n", mDependentChildren.size()));
804
805	if (mDependentChildren.size())
806	{
807	/* We keep the lock until we have enumerated all children.
808	* Those ones that will try to call #removeDependentChild() from
809	* a different thread will have to wait */
810
811	Assert (mUninitDoneSem == NIL_RTSEMEVENT);
812	int vrc = RTSemEventCreate (&mUninitDoneSem);
813	AssertRC (vrc);
814
815	Assert (mChildrenLeft == 0);
816	mChildrenLeft = (unsigned)mDependentChildren.size();
817
818	for (DependentChildren::iterator it = mDependentChildren.begin();
819	it != mDependentChildren.end(); ++ it)
820	{
821	VirtualBoxBase child = (it).second;
822	Assert (child);
823	if (child)
824	child->uninit();
825	}
826
827	mDependentChildren.clear();
828	}
829
830	/* Wait until all children started uninitializing on their own
831	* (and therefore are waiting for some parent's method or for
832	* #removeDependentChild() to return) are finished uninitialization */
833
834	if (mUninitDoneSem != NIL_RTSEMEVENT)
835	{
836	/* let stuck children run */
837	mapLock.leave();
838	alock.leave();
839
840	LogFlowThisFunc (("Waiting for uninitialization of all children...\n"));
841
842	RTSemEventWait (mUninitDoneSem, RT_INDEFINITE_WAIT);
843
844	alock.enter();
845	mapLock.enter();
846
847	RTSemEventDestroy (mUninitDoneSem);
848	mUninitDoneSem = NIL_RTSEMEVENT;
849	Assert (mChildrenLeft == 0);
850	}
851
852	LogFlowThisFuncLeave();
853	}
854
855	/**
856	* Returns a pointer to the dependent child corresponding to the given
857	* interface pointer (used as a key in the map) or NULL if the interface
858	* pointer doesn't correspond to any child registered using
859	* #addDependentChild().
860	*
861	* @param unk
862	* Pointer to map to the dependent child object (it is ComPtr <IUnknown>
863	* rather than IUnknown , to guarantee IUnknown identity)
864	* @return
865	* Pointer to the dependent child object
866	*/
867	VirtualBoxBase *VirtualBoxBaseWithChildren::getDependentChild (
868	const ComPtr <IUnknown> &unk)
869	{
870	AssertReturn (!!unk, NULL);
871
872	AutoLock alock (mMapLock);
873	if (mUninitDoneSem != NIL_RTSEMEVENT)
874	return NULL;
875
876	DependentChildren::const_iterator it = mDependentChildren.find (unk);
877	if (it == mDependentChildren.end())
878	return NULL;
879	return (*it).second;
880	}
881
882	/** Helper for addDependentChild() template method */
883	void VirtualBoxBaseWithChildren::addDependentChild (
884	const ComPtr <IUnknown> &unk, VirtualBoxBase *child)
885	{
886	AssertReturn (!!unk && child, (void) 0);
887
888	AutoLock alock (mMapLock);
889
890	if (mUninitDoneSem != NIL_RTSEMEVENT)
891	{
892	// for this very unlikely case, we have to increase the number of
893	// children left, for symmetry with #removeDependentChild()
894	++ mChildrenLeft;
895	return;
896	}
897
898	std::pair <DependentChildren::iterator, bool> result =
899	mDependentChildren.insert (DependentChildren::value_type (unk, child));
900	AssertMsg (result.second, ("Failed to insert a child to the map\n"));
901	}
902
903	/** Helper for removeDependentChild() template method */
904	void VirtualBoxBaseWithChildren::removeDependentChild (const ComPtr <IUnknown> &unk)
905	{
906	/// @todo (r=dmik) see todo in VirtualBoxBase.h, in
907	// template <class C> void removeDependentChild (C *child)
908
909	AssertReturn (!!unk, (void) 0);
910
911	AutoLock alock (mMapLock);
912
913	if (mUninitDoneSem != NIL_RTSEMEVENT)
914	{
915	// uninitDependentChildren() is in action, just increase the number
916	// of children left and signal a semaphore when it reaches zero
917	Assert (mChildrenLeft != 0);
918	-- mChildrenLeft;
919	if (mChildrenLeft == 0)
920	{
921	int vrc = RTSemEventSignal (mUninitDoneSem);
922	AssertRC (vrc);
923	}
924	return;
925	}
926
927	DependentChildren::size_type result = mDependentChildren.erase (unk);
928	AssertMsg (result == 1, ("Failed to remove a child from the map\n"));
929	NOREF (result);
930	}
931

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source: vbox/trunk/src/VBox/Main/VirtualBoxBase.cpp@ 5688

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