VirtualBoxBase.cpp@ 35242

Last change on this file since 35242 was 34237, checked in by vboxsync, 14 years ago
Main: Be a bit more obvious when logging warnings instead of errors.
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1	/* $Id: VirtualBoxBase.cpp 34237 2010-11-22 13:24:35Z vboxsync $ */
2
3	/** @file
4	*
5	* VirtualBox COM base classes implementation
6	*/
7
8	/*
9	* Copyright (C) 2006-2010 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	#include <iprt/semaphore.h>
21	#include <iprt/asm.h>
22
23	#if !defined (VBOX_WITH_XPCOM)
24	#include <windows.h>
25	#include <dbghelp.h>
26	#else /* !defined (VBOX_WITH_XPCOM) */
27	/// @todo remove when VirtualBoxErrorInfo goes away from here
28	#include <nsIServiceManager.h>
29	#include <nsIExceptionService.h>
30	#endif /* !defined (VBOX_WITH_XPCOM) */
31
32	#include "VirtualBoxBase.h"
33	#include "AutoCaller.h"
34	#include "VirtualBoxErrorInfoImpl.h"
35	#include "Logging.h"
36
37	#include "VBox/com/ErrorInfo.h"
38	#include "VBox/com/MultiResult.h"
39
40	////////////////////////////////////////////////////////////////////////////////
41	//
42	// VirtualBoxBase
43	//
44	////////////////////////////////////////////////////////////////////////////////
45
46	VirtualBoxBase::VirtualBoxBase()
47	: mStateLock(LOCKCLASS_OBJECTSTATE)
48	{
49	mState = NotReady;
50	mStateChangeThread = NIL_RTTHREAD;
51	mCallers = 0;
52	mZeroCallersSem = NIL_RTSEMEVENT;
53	mInitUninitSem = NIL_RTSEMEVENTMULTI;
54	mInitUninitWaiters = 0;
55	mObjectLock = NULL;
56	}
57
58	VirtualBoxBase::~VirtualBoxBase()
59	{
60	if (mObjectLock)
61	delete mObjectLock;
62	Assert(mInitUninitWaiters == 0);
63	Assert(mInitUninitSem == NIL_RTSEMEVENTMULTI);
64	if (mZeroCallersSem != NIL_RTSEMEVENT)
65	RTSemEventDestroy (mZeroCallersSem);
66	mCallers = 0;
67	mStateChangeThread = NIL_RTTHREAD;
68	mState = NotReady;
69	}
70
71	/**
72	* This virtual method returns an RWLockHandle that can be used to
73	* protect instance data. This RWLockHandle is generally referred to
74	* as the "object lock"; its locking class (for lock order validation)
75	* must be returned by another virtual method, getLockingClass(), which
76	* by default returns LOCKCLASS_OTHEROBJECT but is overridden by several
77	* subclasses such as VirtualBox, Host, Machine and others.
78	*
79	* On the first call this method lazily creates the RWLockHandle.
80	*
81	* @return
82	*/
83	/* virtual */
84	RWLockHandle *VirtualBoxBase::lockHandle() const
85	{
86	/* lazy initialization */
87	if (RT_UNLIKELY(!mObjectLock))
88	{
89	AssertCompile (sizeof (RWLockHandle ) == sizeof (void ));
90
91	// getLockingClass() is overridden by many subclasses to return
92	// one of the locking classes listed at the top of AutoLock.h
93	RWLockHandle *objLock = new RWLockHandle(getLockingClass());
94	if (!ASMAtomicCmpXchgPtr(&mObjectLock, objLock, NULL))
95	{
96	delete objLock;
97	objLock = ASMAtomicReadPtrT(&mObjectLock, RWLockHandle *);
98	}
99	return objLock;
100	}
101	return mObjectLock;
102	}
103
104	/**
105	* Increments the number of calls to this object by one.
106	*
107	* After this method succeeds, it is guaranteed that the object will remain
108	* in the Ready (or in the Limited) state at least until #releaseCaller() is
109	* called.
110	*
111	* This method is intended to mark the beginning of sections of code within
112	* methods of COM objects that depend on the readiness (Ready) state. The
113	* Ready state is a primary "ready to serve" state. Usually all code that
114	* works with component's data depends on it. On practice, this means that
115	* almost every public method, setter or getter of the object should add
116	* itself as an object's caller at the very beginning, to protect from an
117	* unexpected uninitialization that may happen on a different thread.
118	*
119	* Besides the Ready state denoting that the object is fully functional,
120	* there is a special Limited state. The Limited state means that the object
121	* is still functional, but its functionality is limited to some degree, so
122	* not all operations are possible. The @a aLimited argument to this method
123	* determines whether the caller represents this limited functionality or
124	* not.
125	*
126	* This method succeeds (and increments the number of callers) only if the
127	* current object's state is Ready. Otherwise, it will return E_ACCESSDENIED
128	* to indicate that the object is not operational. There are two exceptions
129	* from this rule:
130	* <ol>
131	* <li>If the @a aLimited argument is \|true\|, then this method will also
132	* succeed if the object's state is Limited (or Ready, of course).
133	* </li>
134	* <li>If this method is called from the same thread that placed
135	* the object to InInit or InUninit state (i.e. either from within the
136	* AutoInitSpan or AutoUninitSpan scope), it will succeed as well (but
137	* will not increase the number of callers).
138	* </li>
139	* </ol>
140	*
141	* Normally, calling addCaller() never blocks. However, if this method is
142	* called by a thread created from within the AutoInitSpan scope and this
143	* scope is still active (i.e. the object state is InInit), it will block
144	* until the AutoInitSpan destructor signals that it has finished
145	* initialization.
146	*
147	* When this method returns a failure, the caller must not use the object
148	* and should return the failed result code to its own caller.
149	*
150	* @param aState Where to store the current object's state (can be
151	* used in overridden methods to determine the cause of
152	* the failure).
153	* @param aLimited \|true\| to add a limited caller.
154	*
155	* @return S_OK on success or E_ACCESSDENIED on failure.
156	*
157	* @note It is preferable to use the #addLimitedCaller() rather than
158	* calling this method with @a aLimited = \|true\|, for better
159	* self-descriptiveness.
160	*
161	* @sa #addLimitedCaller()
162	* @sa #releaseCaller()
163	*/
164	HRESULT VirtualBoxBase::addCaller(State aState / = NULL */,
165	bool aLimited /* = false */)
166	{
167	AutoWriteLock stateLock(mStateLock COMMA_LOCKVAL_SRC_POS);
168
169	HRESULT rc = E_ACCESSDENIED;
170
171	if (mState == Ready \|\| (aLimited && mState == Limited))
172	{
173	/* if Ready or allows Limited, increase the number of callers */
174	++ mCallers;
175	rc = S_OK;
176	}
177	else
178	if (mState == InInit \|\| mState == InUninit)
179	{
180	if (mStateChangeThread == RTThreadSelf())
181	{
182	/* Called from the same thread that is doing AutoInitSpan or
183	* AutoUninitSpan, just succeed */
184	rc = S_OK;
185	}
186	else if (mState == InInit)
187	{
188	/* addCaller() is called by a "child" thread while the "parent"
189	* thread is still doing AutoInitSpan/AutoReinitSpan, so wait for
190	* the state to become either Ready/Limited or InitFailed (in
191	* case of init failure).
192	*
193	* Note that we increase the number of callers anyway -- to
194	* prevent AutoUninitSpan from early completion if we are
195	* still not scheduled to pick up the posted semaphore when
196	* uninit() is called.
197	*/
198	++ mCallers;
199
200	/* lazy semaphore creation */
201	if (mInitUninitSem == NIL_RTSEMEVENTMULTI)
202	{
203	RTSemEventMultiCreate (&mInitUninitSem);
204	Assert(mInitUninitWaiters == 0);
205	}
206
207	++ mInitUninitWaiters;
208
209	LogFlowThisFunc(("Waiting for AutoInitSpan/AutoReinitSpan to finish...\n"));
210
211	stateLock.leave();
212	RTSemEventMultiWait (mInitUninitSem, RT_INDEFINITE_WAIT);
213	stateLock.enter();
214
215	if (-- mInitUninitWaiters == 0)
216	{
217	/* destroy the semaphore since no more necessary */
218	RTSemEventMultiDestroy (mInitUninitSem);
219	mInitUninitSem = NIL_RTSEMEVENTMULTI;
220	}
221
222	if (mState == Ready \|\| (aLimited && mState == Limited))
223	rc = S_OK;
224	else
225	{
226	Assert(mCallers != 0);
227	-- mCallers;
228	if (mCallers == 0 && mState == InUninit)
229	{
230	/* inform AutoUninitSpan ctor there are no more callers */
231	RTSemEventSignal(mZeroCallersSem);
232	}
233	}
234	}
235	}
236
237	if (aState)
238	*aState = mState;
239
240	if (FAILED(rc))
241	{
242	if (mState == VirtualBoxBase::Limited)
243	rc = setError(rc, "The object functionality is limited");
244	else
245	rc = setError(rc, "The object is not ready");
246	}
247
248	return rc;
249	}
250
251	/**
252	* Decreases the number of calls to this object by one.
253	*
254	* Must be called after every #addCaller() or #addLimitedCaller() when
255	* protecting the object from uninitialization is no more necessary.
256	*/
257	void VirtualBoxBase::releaseCaller()
258	{
259	AutoWriteLock stateLock(mStateLock COMMA_LOCKVAL_SRC_POS);
260
261	if (mState == Ready \|\| mState == Limited)
262	{
263	/* if Ready or Limited, decrease the number of callers */
264	AssertMsgReturn(mCallers != 0, ("mCallers is ZERO!"), (void) 0);
265	--mCallers;
266
267	return;
268	}
269
270	if (mState == InInit \|\| mState == InUninit)
271	{
272	if (mStateChangeThread == RTThreadSelf())
273	{
274	/* Called from the same thread that is doing AutoInitSpan or
275	* AutoUninitSpan: just succeed */
276	return;
277	}
278
279	if (mState == InUninit)
280	{
281	/* the caller is being released after AutoUninitSpan has begun */
282	AssertMsgReturn(mCallers != 0, ("mCallers is ZERO!"), (void) 0);
283	--mCallers;
284
285	if (mCallers == 0)
286	/* inform the AutoUninitSpan ctor there are no more callers /
287	RTSemEventSignal(mZeroCallersSem);
288
289	return;
290	}
291	}
292
293	AssertMsgFailed (("mState = %d!", mState));
294	}
295
296	/**
297	* Sets error info for the current thread. This is an internal function that
298	* gets eventually called by all public variants. If @a aWarning is
299	* @c true, then the highest (31) bit in the @a aResultCode value which
300	* indicates the error severity is reset to zero to make sure the receiver will
301	* recognize that the created error info object represents a warning rather
302	* than an error.
303	*/
304	/* static */
305	HRESULT VirtualBoxBase::setErrorInternal(HRESULT aResultCode,
306	const GUID &aIID,
307	const char *pcszComponent,
308	const Utf8Str &aText,
309	bool aWarning,
310	bool aLogIt)
311	{
312	/* whether multi-error mode is turned on */
313	bool preserve = MultiResult::isMultiEnabled();
314
315	if (aLogIt)
316	LogRel(("%s [COM]: aRC=%Rhrc (%#08x) aIID={%RTuuid} aComponent={%s} aText={%s}, preserve=%RTbool\n",
317	aWarning ? "WARNING" : "ERROR",
318	aResultCode,
319	aResultCode,
320	&aIID,
321	pcszComponent,
322	aText.c_str(),
323	aWarning,
324	preserve));
325
326	/* these are mandatory, others -- not */
327	AssertReturn((!aWarning && FAILED(aResultCode)) \|\|
328	(aWarning && aResultCode != S_OK),
329	E_FAIL);
330	AssertReturn(!aText.isEmpty(), E_FAIL);
331
332	/* reset the error severity bit if it's a warning */
333	if (aWarning)
334	aResultCode &= ~0x80000000;
335
336	HRESULT rc = S_OK;
337
338	do
339	{
340	ComObjPtr<VirtualBoxErrorInfo> info;
341	rc = info.createObject();
342	if (FAILED(rc)) break;
343
344	#if !defined (VBOX_WITH_XPCOM)
345
346	ComPtr<IVirtualBoxErrorInfo> curInfo;
347	if (preserve)
348	{
349	/* get the current error info if any */
350	ComPtr<IErrorInfo> err;
351	rc = ::GetErrorInfo (0, err.asOutParam());
352	if (FAILED(rc)) break;
353	rc = err.queryInterfaceTo(curInfo.asOutParam());
354	if (FAILED(rc))
355	{
356	/* create a IVirtualBoxErrorInfo wrapper for the native
357	* IErrorInfo object */
358	ComObjPtr<VirtualBoxErrorInfo> wrapper;
359	rc = wrapper.createObject();
360	if (SUCCEEDED(rc))
361	{
362	rc = wrapper->init (err);
363	if (SUCCEEDED(rc))
364	curInfo = wrapper;
365	}
366	}
367	}
368	/* On failure, curInfo will stay null */
369	Assert(SUCCEEDED(rc) \|\| curInfo.isNull());
370
371	/* set the current error info and preserve the previous one if any */
372	rc = info->init(aResultCode, aIID, pcszComponent, aText, curInfo);
373	if (FAILED(rc)) break;
374
375	ComPtr<IErrorInfo> err;
376	rc = info.queryInterfaceTo(err.asOutParam());
377	if (SUCCEEDED(rc))
378	rc = ::SetErrorInfo (0, err);
379
380	#else // !defined (VBOX_WITH_XPCOM)
381
382	nsCOMPtr <nsIExceptionService> es;
383	es = do_GetService (NS_EXCEPTIONSERVICE_CONTRACTID, &rc);
384	if (NS_SUCCEEDED(rc))
385	{
386	nsCOMPtr <nsIExceptionManager> em;
387	rc = es->GetCurrentExceptionManager (getter_AddRefs (em));
388	if (FAILED(rc)) break;
389
390	ComPtr<IVirtualBoxErrorInfo> curInfo;
391	if (preserve)
392	{
393	/* get the current error info if any */
394	ComPtr<nsIException> ex;
395	rc = em->GetCurrentException (ex.asOutParam());
396	if (FAILED(rc)) break;
397	rc = ex.queryInterfaceTo(curInfo.asOutParam());
398	if (FAILED(rc))
399	{
400	/* create a IVirtualBoxErrorInfo wrapper for the native
401	* nsIException object */
402	ComObjPtr<VirtualBoxErrorInfo> wrapper;
403	rc = wrapper.createObject();
404	if (SUCCEEDED(rc))
405	{
406	rc = wrapper->init (ex);
407	if (SUCCEEDED(rc))
408	curInfo = wrapper;
409	}
410	}
411	}
412	/* On failure, curInfo will stay null */
413	Assert(SUCCEEDED(rc) \|\| curInfo.isNull());
414
415	/* set the current error info and preserve the previous one if any */
416	rc = info->init(aResultCode, aIID, pcszComponent, Bstr(aText), curInfo);
417	if (FAILED(rc)) break;
418
419	ComPtr<nsIException> ex;
420	rc = info.queryInterfaceTo(ex.asOutParam());
421	if (SUCCEEDED(rc))
422	rc = em->SetCurrentException (ex);
423	}
424	else if (rc == NS_ERROR_UNEXPECTED)
425	{
426	/*
427	* It is possible that setError() is being called by the object
428	* after the XPCOM shutdown sequence has been initiated
429	* (for example, when XPCOM releases all instances it internally
430	* references, which can cause object's FinalConstruct() and then
431	* uninit()). In this case, do_GetService() above will return
432	* NS_ERROR_UNEXPECTED and it doesn't actually make sense to
433	* set the exception (nobody will be able to read it).
434	*/
435	LogWarningFunc(("Will not set an exception because nsIExceptionService is not available "
436	"(NS_ERROR_UNEXPECTED). XPCOM is being shutdown?\n"));
437	rc = NS_OK;
438	}
439
440	#endif // !defined (VBOX_WITH_XPCOM)
441	}
442	while (0);
443
444	AssertComRC (rc);
445
446	return SUCCEEDED(rc) ? aResultCode : rc;
447	}
448
449	/**
450	* Shortcut instance method to calling the static setErrorInternal with the
451	* class interface ID and component name inserted correctly. This uses the
452	* virtual getClassIID() and getComponentName() methods which are automatically
453	* defined by the VIRTUALBOXBASE_ADD_ERRORINFO_SUPPORT macro.
454	* @param aResultCode
455	* @param pcsz
456	* @return
457	*/
458	HRESULT VirtualBoxBase::setError(HRESULT aResultCode, const char *pcsz, ...)
459	{
460	va_list args;
461	va_start(args, pcsz);
462	HRESULT rc = setErrorInternal(aResultCode,
463	this->getClassIID(),
464	this->getComponentName(),
465	Utf8Str(pcsz, args),
466	false /* aWarning */,
467	true /* aLogIt */);
468	va_end(args);
469	return rc;
470	}
471
472	/**
473	* Like setError(), but sets the "warning" bit in the call to setErrorInternal().
474	* @param aResultCode
475	* @param pcsz
476	* @return
477	*/
478	HRESULT VirtualBoxBase::setWarning(HRESULT aResultCode, const char *pcsz, ...)
479	{
480	va_list args;
481	va_start(args, pcsz);
482	HRESULT rc = setErrorInternal(aResultCode,
483	this->getClassIID(),
484	this->getComponentName(),
485	Utf8Str(pcsz, args),
486	true /* aWarning */,
487	true /* aLogIt */);
488	va_end(args);
489	return rc;
490	}
491
492	/**
493	* Like setError(), but disables the "log" flag in the call to setErrorInternal().
494	* @param aResultCode
495	* @param pcsz
496	* @return
497	*/
498	HRESULT VirtualBoxBase::setErrorNoLog(HRESULT aResultCode, const char *pcsz, ...)
499	{
500	va_list args;
501	va_start(args, pcsz);
502	HRESULT rc = setErrorInternal(aResultCode,
503	this->getClassIID(),
504	this->getComponentName(),
505	Utf8Str(pcsz, args),
506	false /* aWarning */,
507	false /* aLogIt */);
508	va_end(args);
509	return rc;
510	}
511
512	////////////////////////////////////////////////////////////////////////////////
513	//
514	// AutoInitSpan methods
515	//
516	////////////////////////////////////////////////////////////////////////////////
517
518	/**
519	* Creates a smart initialization span object that places the object to
520	* InInit state.
521	*
522	* Please see the AutoInitSpan class description for more info.
523	*
524	* @param aObj \|this\| pointer of the managed VirtualBoxBase object whose
525	* init() method is being called.
526	* @param aResult Default initialization result.
527	*/
528	AutoInitSpan::AutoInitSpan(VirtualBoxBase *aObj,
529	Result aResult /* = Failed */)
530	: mObj(aObj),
531	mResult(aResult),
532	mOk(false)
533	{
534	Assert(aObj);
535
536	AutoWriteLock stateLock(mObj->mStateLock COMMA_LOCKVAL_SRC_POS);
537
538	mOk = mObj->mState == VirtualBoxBase::NotReady;
539	AssertReturnVoid (mOk);
540
541	mObj->setState(VirtualBoxBase::InInit);
542	}
543
544	/**
545	* Places the managed VirtualBoxBase object to Ready/Limited state if the
546	* initialization succeeded or partly succeeded, or places it to InitFailed
547	* state and calls the object's uninit() method.
548	*
549	* Please see the AutoInitSpan class description for more info.
550	*/
551	AutoInitSpan::~AutoInitSpan()
552	{
553	/* if the state was other than NotReady, do nothing */
554	if (!mOk)
555	return;
556
557	AutoWriteLock stateLock(mObj->mStateLock COMMA_LOCKVAL_SRC_POS);
558
559	Assert(mObj->mState == VirtualBoxBase::InInit);
560
561	if (mObj->mCallers > 0)
562	{
563	Assert(mObj->mInitUninitWaiters > 0);
564
565	/* We have some pending addCaller() calls on other threads (created
566	* during InInit), signal that InInit is finished and they may go on. */
567	RTSemEventMultiSignal(mObj->mInitUninitSem);
568	}
569
570	if (mResult == Succeeded)
571	{
572	mObj->setState(VirtualBoxBase::Ready);
573	}
574	else
575	if (mResult == Limited)
576	{
577	mObj->setState(VirtualBoxBase::Limited);
578	}
579	else
580	{
581	mObj->setState(VirtualBoxBase::InitFailed);
582	/* leave the lock to prevent nesting when uninit() is called */
583	stateLock.leave();
584	/* call uninit() to let the object uninit itself after failed init() */
585	mObj->uninit();
586	/* Note: the object may no longer exist here (for example, it can call
587	* the destructor in uninit()) */
588	}
589	}
590
591	// AutoReinitSpan methods
592	////////////////////////////////////////////////////////////////////////////////
593
594	/**
595	* Creates a smart re-initialization span object and places the object to
596	* InInit state.
597	*
598	* Please see the AutoInitSpan class description for more info.
599	*
600	* @param aObj \|this\| pointer of the managed VirtualBoxBase object whose
601	* re-initialization method is being called.
602	*/
603	AutoReinitSpan::AutoReinitSpan(VirtualBoxBase *aObj)
604	: mObj(aObj),
605	mSucceeded(false),
606	mOk(false)
607	{
608	Assert(aObj);
609
610	AutoWriteLock stateLock(mObj->mStateLock COMMA_LOCKVAL_SRC_POS);
611
612	mOk = mObj->mState == VirtualBoxBase::Limited;
613	AssertReturnVoid (mOk);
614
615	mObj->setState(VirtualBoxBase::InInit);
616	}
617
618	/**
619	* Places the managed VirtualBoxBase object to Ready state if the
620	* re-initialization succeeded (i.e. #setSucceeded() has been called) or back to
621	* Limited state otherwise.
622	*
623	* Please see the AutoInitSpan class description for more info.
624	*/
625	AutoReinitSpan::~AutoReinitSpan()
626	{
627	/* if the state was other than Limited, do nothing */
628	if (!mOk)
629	return;
630
631	AutoWriteLock stateLock(mObj->mStateLock COMMA_LOCKVAL_SRC_POS);
632
633	Assert(mObj->mState == VirtualBoxBase::InInit);
634
635	if (mObj->mCallers > 0 && mObj->mInitUninitWaiters > 0)
636	{
637	/* We have some pending addCaller() calls on other threads (created
638	* during InInit), signal that InInit is finished and they may go on. */
639	RTSemEventMultiSignal(mObj->mInitUninitSem);
640	}
641
642	if (mSucceeded)
643	{
644	mObj->setState(VirtualBoxBase::Ready);
645	}
646	else
647	{
648	mObj->setState(VirtualBoxBase::Limited);
649	}
650	}
651
652	// AutoUninitSpan methods
653	////////////////////////////////////////////////////////////////////////////////
654
655	/**
656	* Creates a smart uninitialization span object and places this object to
657	* InUninit state.
658	*
659	* Please see the AutoInitSpan class description for more info.
660	*
661	* @note This method blocks the current thread execution until the number of
662	* callers of the managed VirtualBoxBase object drops to zero!
663	*
664	* @param aObj \|this\| pointer of the VirtualBoxBase object whose uninit()
665	* method is being called.
666	*/
667	AutoUninitSpan::AutoUninitSpan(VirtualBoxBase *aObj)
668	: mObj(aObj),
669	mInitFailed(false),
670	mUninitDone(false)
671	{
672	Assert(aObj);
673
674	AutoWriteLock stateLock(mObj->mStateLock COMMA_LOCKVAL_SRC_POS);
675
676	Assert(mObj->mState != VirtualBoxBase::InInit);
677
678	/* Set mUninitDone to \|true\| if this object is already uninitialized
679	* (NotReady) or if another AutoUninitSpan is currently active on some
680	* other thread (InUninit). */
681	mUninitDone = mObj->mState == VirtualBoxBase::NotReady
682	\|\| mObj->mState == VirtualBoxBase::InUninit;
683
684	if (mObj->mState == VirtualBoxBase::InitFailed)
685	{
686	/* we've been called by init() on failure */
687	mInitFailed = true;
688	}
689	else
690	{
691	if (mUninitDone)
692	{
693	/* do nothing if already uninitialized */
694	if (mObj->mState == VirtualBoxBase::NotReady)
695	return;
696
697	/* otherwise, wait until another thread finishes uninitialization.
698	* This is necessary to make sure that when this method returns, the
699	* object is NotReady and therefore can be deleted (for example). */
700
701	/* lazy semaphore creation */
702	if (mObj->mInitUninitSem == NIL_RTSEMEVENTMULTI)
703	{
704	RTSemEventMultiCreate(&mObj->mInitUninitSem);
705	Assert(mObj->mInitUninitWaiters == 0);
706	}
707	++mObj->mInitUninitWaiters;
708
709	LogFlowFunc(("{%p}: Waiting for AutoUninitSpan to finish...\n",
710	mObj));
711
712	stateLock.leave();
713	RTSemEventMultiWait(mObj->mInitUninitSem, RT_INDEFINITE_WAIT);
714	stateLock.enter();
715
716	if (--mObj->mInitUninitWaiters == 0)
717	{
718	/* destroy the semaphore since no more necessary */
719	RTSemEventMultiDestroy(mObj->mInitUninitSem);
720	mObj->mInitUninitSem = NIL_RTSEMEVENTMULTI;
721	}
722
723	return;
724	}
725	}
726
727	/* go to InUninit to prevent from adding new callers */
728	mObj->setState(VirtualBoxBase::InUninit);
729
730	/* wait for already existing callers to drop to zero */
731	if (mObj->mCallers > 0)
732	{
733	/* lazy creation */
734	Assert(mObj->mZeroCallersSem == NIL_RTSEMEVENT);
735	RTSemEventCreate(&mObj->mZeroCallersSem);
736
737	/* wait until remaining callers release the object */
738	LogFlowFunc(("{%p}: Waiting for callers (%d) to drop to zero...\n",
739	mObj, mObj->mCallers));
740
741	stateLock.leave();
742	RTSemEventWait(mObj->mZeroCallersSem, RT_INDEFINITE_WAIT);
743	}
744	}
745
746	/**
747	* Places the managed VirtualBoxBase object to the NotReady state.
748	*/
749	AutoUninitSpan::~AutoUninitSpan()
750	{
751	/* do nothing if already uninitialized */
752	if (mUninitDone)
753	return;
754
755	AutoWriteLock stateLock(mObj->mStateLock COMMA_LOCKVAL_SRC_POS);
756
757	Assert(mObj->mState == VirtualBoxBase::InUninit);
758
759	mObj->setState(VirtualBoxBase::NotReady);
760	}
761
762	////////////////////////////////////////////////////////////////////////////////
763	//
764	// MultiResult methods
765	//
766	////////////////////////////////////////////////////////////////////////////////
767
768	RTTLS MultiResult::sCounter = NIL_RTTLS;
769
770	/static/
771	void MultiResult::incCounter()
772	{
773	if (sCounter == NIL_RTTLS)
774	{
775	sCounter = RTTlsAlloc();
776	AssertReturnVoid(sCounter != NIL_RTTLS);
777	}
778
779	uintptr_t counter = (uintptr_t)RTTlsGet(sCounter);
780	++counter;
781	RTTlsSet(sCounter, (void*)counter);
782	}
783
784	/static/
785	void MultiResult::decCounter()
786	{
787	uintptr_t counter = (uintptr_t)RTTlsGet(sCounter);
788	AssertReturnVoid(counter != 0);
789	--counter;
790	RTTlsSet(sCounter, (void*)counter);
791	}
792
793	/static/
794	bool MultiResult::isMultiEnabled()
795	{
796	return ((uintptr_t)RTTlsGet(MultiResult::sCounter)) > 0;
797	}
798

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source: vbox/trunk/src/VBox/Main/VirtualBoxBase.cpp@ 35242

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