PDMCritSect.cpp@ 39402

Last change on this file since 39402 was 39402, checked in by vboxsync, 13 years ago
VMM: don't use generic IPE status codes, use specific ones. Part 1.
Property svn:eol-style set to `native` Property svn:keywords set to `Id`
File size: 23.0 KB

Line
1	/* $Id: PDMCritSect.cpp 39402 2011-11-23 16:25:04Z vboxsync $ */
2	/** @file
3	* PDM - Critical Sections, Ring-3.
4	*/
5
6	/*
7	* Copyright (C) 2006-2009 Oracle Corporation
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 (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18
19	/*******************************************************************************
20	* Header Files *
21	*******************************************************************************/
22	#define LOG_GROUP LOG_GROUP_PDM//_CRITSECT
23	#include "PDMInternal.h"
24	#include <VBox/vmm/pdmcritsect.h>
25	#include <VBox/vmm/mm.h>
26	#include <VBox/vmm/vm.h>
27	#include <VBox/vmm/uvm.h>
28
29	#include <VBox/err.h>
30	#include <VBox/log.h>
31	#include <VBox/sup.h>
32	#include <iprt/asm.h>
33	#include <iprt/assert.h>
34	#include <iprt/lockvalidator.h>
35	#include <iprt/string.h>
36	#include <iprt/thread.h>
37
38
39	/*******************************************************************************
40	* Internal Functions *
41	*******************************************************************************/
42	static int pdmR3CritSectDeleteOne(PVM pVM, PUVM pUVM, PPDMCRITSECTINT pCritSect, PPDMCRITSECTINT pPrev, bool fFinal);
43
44
45
46	/**
47	* Register statistics related to the critical sections.
48	*
49	* @returns VBox status code.
50	* @param pVM The VM handle.
51	*/
52	int pdmR3CritSectInitStats(PVM pVM)
53	{
54	STAM_REG(pVM, &pVM->pdm.s.StatQueuedCritSectLeaves, STAMTYPE_COUNTER, "/PDM/QueuedCritSectLeaves", STAMUNIT_OCCURENCES,
55	"Number of times a critical section leave request needed to be queued for ring-3 execution.");
56	return VINF_SUCCESS;
57	}
58
59
60	/**
61	* Relocates all the critical sections.
62	*
63	* @param pVM The VM handle.
64	*/
65	void pdmR3CritSectRelocate(PVM pVM)
66	{
67	PUVM pUVM = pVM->pUVM;
68	RTCritSectEnter(&pUVM->pdm.s.ListCritSect);
69
70	for (PPDMCRITSECTINT pCur = pUVM->pdm.s.pCritSects;
71	pCur;
72	pCur = pCur->pNext)
73	pCur->pVMRC = pVM->pVMRC;
74
75	RTCritSectLeave(&pUVM->pdm.s.ListCritSect);
76	}
77
78
79	/**
80	* Deletes all remaining critical sections.
81	*
82	* This is called at the very end of the termination process. It is also called
83	* at the end of vmR3CreateU failure cleanup, which may cause it to be called
84	* twice depending on where vmR3CreateU actually failed. We have to do the
85	* latter call because other components expect the critical sections to be
86	* automatically deleted.
87	*
88	* @returns VBox status.
89	* First error code, rest is lost.
90	* @param pVMU The user mode VM handle.
91	* @remark Don't confuse this with PDMR3CritSectDelete.
92	*/
93	VMMDECL(int) PDMR3CritSectTerm(PVM pVM)
94	{
95	PUVM pUVM = pVM->pUVM;
96	int rc = VINF_SUCCESS;
97	RTCritSectEnter(&pUVM->pdm.s.ListCritSect);
98
99	while (pUVM->pdm.s.pCritSects)
100	{
101	int rc2 = pdmR3CritSectDeleteOne(pVM, pUVM, pUVM->pdm.s.pCritSects, NULL, true /* final */);
102	AssertRC(rc2);
103	if (RT_FAILURE(rc2) && RT_SUCCESS(rc))
104	rc = rc2;
105	}
106
107	RTCritSectLeave(&pUVM->pdm.s.ListCritSect);
108	return rc;
109	}
110
111
112	/**
113	* Initializes a critical section and inserts it into the list.
114	*
115	* @returns VBox status code.
116	* @param pVM The Vm handle.
117	* @param pCritSect The critical section.
118	* @param pvKey The owner key.
119	* @param RT_SRC_POS_DECL The source position.
120	* @param pszName The name of the critical section (for statistics).
121	* @param pszNameFmt Format string for naming the critical section. For
122	* statistics and lock validation.
123	* @param va Arguments for the format string.
124	*/
125	static int pdmR3CritSectInitOne(PVM pVM, PPDMCRITSECTINT pCritSect, void *pvKey, RT_SRC_POS_DECL,
126	const char *pszNameFmt, va_list va)
127	{
128	VM_ASSERT_EMT(pVM);
129
130	/*
131	* Allocate the semaphore.
132	*/
133	AssertCompile(sizeof(SUPSEMEVENT) == sizeof(pCritSect->Core.EventSem));
134	int rc = SUPSemEventCreate(pVM->pSession, (PSUPSEMEVENT)&pCritSect->Core.EventSem);
135	if (RT_SUCCESS(rc))
136	{
137	/* Only format the name once. */
138	char pszName = RTStrAPrintf2V(pszNameFmt, va); /* @todo plug the "leak"... */
139	if (pszName)
140	{
141	#ifndef PDMCRITSECT_STRICT
142	pCritSect->Core.pValidatorRec = NULL;
143	#else
144	rc = RTLockValidatorRecExclCreate(&pCritSect->Core.pValidatorRec,
145	# ifdef RT_LOCK_STRICT_ORDER
146	RTLockValidatorClassForSrcPos(RT_SRC_POS_ARGS, "%s", pszName),
147	# else
148	NIL_RTLOCKVALCLASS,
149	# endif
150	RTLOCKVAL_SUB_CLASS_NONE,
151	pCritSect, true, "%s", pszName);
152	#endif
153	if (RT_SUCCESS(rc))
154	{
155	/*
156	* Initialize the structure (first bit is c&p from RTCritSectInitEx).
157	*/
158	pCritSect->Core.u32Magic = RTCRITSECT_MAGIC;
159	pCritSect->Core.fFlags = 0;
160	pCritSect->Core.cNestings = 0;
161	pCritSect->Core.cLockers = -1;
162	pCritSect->Core.NativeThreadOwner = NIL_RTNATIVETHREAD;
163	pCritSect->pVMR3 = pVM;
164	pCritSect->pVMR0 = pVM->pVMR0;
165	pCritSect->pVMRC = pVM->pVMRC;
166	pCritSect->pvKey = pvKey;
167	pCritSect->fAutomaticDefaultCritsect = false;
168	pCritSect->fUsedByTimerOrSimilar = false;
169	pCritSect->EventToSignal = NIL_RTSEMEVENT;
170	pCritSect->pNext = pVM->pUVM->pdm.s.pCritSects;
171	pCritSect->pszName = pszName;
172	pVM->pUVM->pdm.s.pCritSects = pCritSect;
173	STAMR3RegisterF(pVM, &pCritSect->StatContentionRZLock, STAMTYPE_COUNTER, STAMVISIBILITY_ALWAYS, STAMUNIT_OCCURENCES, NULL, "/PDM/CritSects/%s/ContentionRZLock", pCritSect->pszName);
174	STAMR3RegisterF(pVM, &pCritSect->StatContentionRZUnlock,STAMTYPE_COUNTER, STAMVISIBILITY_ALWAYS, STAMUNIT_OCCURENCES, NULL, "/PDM/CritSects/%s/ContentionRZUnlock", pCritSect->pszName);
175	STAMR3RegisterF(pVM, &pCritSect->StatContentionR3, STAMTYPE_COUNTER, STAMVISIBILITY_ALWAYS, STAMUNIT_OCCURENCES, NULL, "/PDM/CritSects/%s/ContentionR3", pCritSect->pszName);
176	#ifdef VBOX_WITH_STATISTICS
177	STAMR3RegisterF(pVM, &pCritSect->StatLocked, STAMTYPE_PROFILE_ADV, STAMVISIBILITY_ALWAYS, STAMUNIT_TICKS_PER_OCCURENCE, NULL, "/PDM/CritSects/%s/Locked", pCritSect->pszName);
178	#endif
179	return VINF_SUCCESS;
180	}
181
182	RTStrFree(pszName);
183	}
184	else
185	rc = VERR_NO_STR_MEMORY;
186	SUPSemEventClose(pVM->pSession, (SUPSEMEVENT)pCritSect->Core.EventSem);
187	}
188	return rc;
189	}
190
191
192	/**
193	* Initializes a PDM critical section for internal use.
194	*
195	* The PDM critical sections are derived from the IPRT critical sections, but
196	* works in GC as well.
197	*
198	* @returns VBox status code.
199	* @param pVM The VM handle.
200	* @param pDevIns Device instance.
201	* @param pCritSect Pointer to the critical section.
202	* @param RT_SRC_POS_DECL Use RT_SRC_POS.
203	* @param pszNameFmt Format string for naming the critical section. For
204	* statistics and lock validation.
205	* @param ... Arguments for the format string.
206	* @thread EMT(0)
207	*/
208	VMMR3DECL(int) PDMR3CritSectInit(PVM pVM, PPDMCRITSECT pCritSect, RT_SRC_POS_DECL, const char *pszNameFmt, ...)
209	{
210	#if HC_ARCH_BITS == 64 && GC_ARCH_BITS == 32
211	AssertCompile(sizeof(pCritSect->padding) >= sizeof(pCritSect->s));
212	#endif
213	Assert(RT_ALIGN_P(pCritSect, sizeof(uintptr_t)) == pCritSect);
214	va_list va;
215	va_start(va, pszNameFmt);
216	int rc = pdmR3CritSectInitOne(pVM, &pCritSect->s, pCritSect, RT_SRC_POS_ARGS, pszNameFmt, va);
217	va_end(va);
218	return rc;
219	}
220
221
222	/**
223	* Initializes a PDM critical section for a device.
224	*
225	* The PDM critical sections are derived from the IPRT critical sections, but
226	* works in GC as well.
227	*
228	* @returns VBox status code.
229	* @param pVM The VM handle.
230	* @param pDevIns Device instance.
231	* @param pCritSect Pointer to the critical section.
232	* @param pszNameFmt Format string for naming the critical section. For
233	* statistics and lock validation.
234	* @param va Arguments for the format string.
235	*/
236	int pdmR3CritSectInitDevice(PVM pVM, PPDMDEVINS pDevIns, PPDMCRITSECT pCritSect, RT_SRC_POS_DECL,
237	const char *pszNameFmt, va_list va)
238	{
239	return pdmR3CritSectInitOne(pVM, &pCritSect->s, pDevIns, RT_SRC_POS_ARGS, pszNameFmt, va);
240	}
241
242
243	/**
244	* Initializes the automatic default PDM critical section for a device.
245	*
246	* @returns VBox status code.
247	* @param pVM The VM handle.
248	* @param pDevIns Device instance.
249	* @param pCritSect Pointer to the critical section.
250	*/
251	int pdmR3CritSectInitDeviceAuto(PVM pVM, PPDMDEVINS pDevIns, PPDMCRITSECT pCritSect, RT_SRC_POS_DECL,
252	const char *pszNameFmt, ...)
253	{
254	va_list va;
255	va_start(va, pszNameFmt);
256	int rc = pdmR3CritSectInitOne(pVM, &pCritSect->s, pDevIns, RT_SRC_POS_ARGS, pszNameFmt, va);
257	if (RT_SUCCESS(rc))
258	pCritSect->s.fAutomaticDefaultCritsect = true;
259	va_end(va);
260	return rc;
261	}
262
263
264	/**
265	* Initializes a PDM critical section for a driver.
266	*
267	* @returns VBox status code.
268	* @param pVM The VM handle.
269	* @param pDrvIns Driver instance.
270	* @param pCritSect Pointer to the critical section.
271	* @param pszNameFmt Format string for naming the critical section. For
272	* statistics and lock validation.
273	* @param ... Arguments for the format string.
274	*/
275	int pdmR3CritSectInitDriver(PVM pVM, PPDMDRVINS pDrvIns, PPDMCRITSECT pCritSect, RT_SRC_POS_DECL,
276	const char *pszNameFmt, ...)
277	{
278	va_list va;
279	va_start(va, pszNameFmt);
280	int rc = pdmR3CritSectInitOne(pVM, &pCritSect->s, pDrvIns, RT_SRC_POS_ARGS, pszNameFmt, va);
281	va_end(va);
282	return rc;
283	}
284
285
286	/**
287	* Deletes one critical section.
288	*
289	* @returns Return code from RTCritSectDelete.
290	*
291	* @param pVM The VM handle.
292	* @param pCritSect The critical section.
293	* @param pPrev The previous critical section in the list.
294	* @param fFinal Set if this is the final call and statistics shouldn't be deregistered.
295	*
296	* @remarks Caller must have entered the ListCritSect.
297	*/
298	static int pdmR3CritSectDeleteOne(PVM pVM, PUVM pUVM, PPDMCRITSECTINT pCritSect, PPDMCRITSECTINT pPrev, bool fFinal)
299	{
300	/*
301	* Assert free waiters and so on (c&p from RTCritSectDelete).
302	*/
303	Assert(pCritSect->Core.u32Magic == RTCRITSECT_MAGIC);
304	Assert(pCritSect->Core.cNestings == 0);
305	Assert(pCritSect->Core.cLockers == -1);
306	Assert(pCritSect->Core.NativeThreadOwner == NIL_RTNATIVETHREAD);
307	Assert(RTCritSectIsOwner(&pUVM->pdm.s.ListCritSect));
308
309	/*
310	* Unlink it.
311	*/
312	if (pPrev)
313	pPrev->pNext = pCritSect->pNext;
314	else
315	pUVM->pdm.s.pCritSects = pCritSect->pNext;
316
317	/*
318	* Delete it (parts taken from RTCritSectDelete).
319	* In case someone is waiting we'll signal the semaphore cLockers + 1 times.
320	*/
321	ASMAtomicWriteU32(&pCritSect->Core.u32Magic, 0);
322	SUPSEMEVENT hEvent = (SUPSEMEVENT)pCritSect->Core.EventSem;
323	pCritSect->Core.EventSem = NIL_RTSEMEVENT;
324	while (pCritSect->Core.cLockers-- >= 0)
325	SUPSemEventSignal(pVM->pSession, hEvent);
326	ASMAtomicWriteS32(&pCritSect->Core.cLockers, -1);
327	int rc = SUPSemEventClose(pVM->pSession, hEvent);
328	AssertRC(rc);
329	RTLockValidatorRecExclDestroy(&pCritSect->Core.pValidatorRec);
330	pCritSect->pNext = NULL;
331	pCritSect->pvKey = NULL;
332	pCritSect->pVMR3 = NULL;
333	pCritSect->pVMR0 = NIL_RTR0PTR;
334	pCritSect->pVMRC = NIL_RTRCPTR;
335	RTStrFree((char *)pCritSect->pszName);
336	pCritSect->pszName = NULL;
337	if (!fFinal)
338	{
339	STAMR3Deregister(pVM, &pCritSect->StatContentionRZLock);
340	STAMR3Deregister(pVM, &pCritSect->StatContentionRZUnlock);
341	STAMR3Deregister(pVM, &pCritSect->StatContentionR3);
342	#ifdef VBOX_WITH_STATISTICS
343	STAMR3Deregister(pVM, &pCritSect->StatLocked);
344	#endif
345	}
346	return rc;
347	}
348
349
350	/**
351	* Deletes all critical sections with a give initializer key.
352	*
353	* @returns VBox status code.
354	* The entire list is processed on failure, so we'll only
355	* return the first error code. This shouldn't be a problem
356	* since errors really shouldn't happen here.
357	* @param pVM The VM handle.
358	* @param pvKey The initializer key.
359	*/
360	static int pdmR3CritSectDeleteByKey(PVM pVM, void *pvKey)
361	{
362	/*
363	* Iterate the list and match key.
364	*/
365	PUVM pUVM = pVM->pUVM;
366	int rc = VINF_SUCCESS;
367	PPDMCRITSECTINT pPrev = NULL;
368	RTCritSectEnter(&pUVM->pdm.s.ListCritSect);
369	PPDMCRITSECTINT pCur = pUVM->pdm.s.pCritSects;
370	while (pCur)
371	{
372	if (pCur->pvKey == pvKey)
373	{
374	int rc2 = pdmR3CritSectDeleteOne(pVM, pUVM, pCur, pPrev, false /* not final */);
375	AssertRC(rc2);
376	if (RT_FAILURE(rc2) && RT_SUCCESS(rc))
377	rc = rc2;
378	}
379
380	/* next */
381	pPrev = pCur;
382	pCur = pCur->pNext;
383	}
384	RTCritSectLeave(&pUVM->pdm.s.ListCritSect);
385	return rc;
386	}
387
388
389	/**
390	* Deletes all undeleted critical sections initialized by a given device.
391	*
392	* @returns VBox status code.
393	* @param pVM The VM handle.
394	* @param pDevIns The device handle.
395	*/
396	int pdmR3CritSectDeleteDevice(PVM pVM, PPDMDEVINS pDevIns)
397	{
398	return pdmR3CritSectDeleteByKey(pVM, pDevIns);
399	}
400
401
402	/**
403	* Deletes all undeleted critical sections initialized by a given driver.
404	*
405	* @returns VBox status code.
406	* @param pVM The VM handle.
407	* @param pDrvIns The driver handle.
408	*/
409	int pdmR3CritSectDeleteDriver(PVM pVM, PPDMDRVINS pDrvIns)
410	{
411	return pdmR3CritSectDeleteByKey(pVM, pDrvIns);
412	}
413
414
415	/**
416	* Deletes the critical section.
417	*
418	* @returns VBox status code.
419	* @param pCritSect The PDM critical section to destroy.
420	*/
421	VMMR3DECL(int) PDMR3CritSectDelete(PPDMCRITSECT pCritSect)
422	{
423	if (!RTCritSectIsInitialized(&pCritSect->s.Core))
424	return VINF_SUCCESS;
425
426	/*
427	* Find and unlink it.
428	*/
429	PVM pVM = pCritSect->s.pVMR3;
430	PUVM pUVM = pVM->pUVM;
431	AssertReleaseReturn(pVM, VERR_PDM_CRITSECT_IPE);
432	PPDMCRITSECTINT pPrev = NULL;
433	RTCritSectEnter(&pUVM->pdm.s.ListCritSect);
434	PPDMCRITSECTINT pCur = pUVM->pdm.s.pCritSects;
435	while (pCur)
436	{
437	if (pCur == &pCritSect->s)
438	{
439	int rc = pdmR3CritSectDeleteOne(pVM, pUVM, pCur, pPrev, false /* not final */);
440	RTCritSectLeave(&pUVM->pdm.s.ListCritSect);
441	return rc;
442	}
443
444	/* next */
445	pPrev = pCur;
446	pCur = pCur->pNext;
447	}
448	RTCritSectLeave(&pUVM->pdm.s.ListCritSect);
449	AssertReleaseMsgFailed(("pCritSect=%p wasn't found!\n", pCritSect));
450	return VERR_PDM_CRITSECT_NOT_FOUND;
451	}
452
453
454	/**
455	* Gets the name of the critical section.
456	*
457	*
458	* @returns Pointer to the critical section name (read only) on success,
459	* NULL on failure (invalid critical section).
460	* @param pCritSect The critical section.
461	*/
462	VMMR3DECL(const char *) PDMR3CritSectName(PCPDMCRITSECT pCritSect)
463	{
464	AssertPtrReturn(pCritSect, NULL);
465	AssertReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, NULL);
466	return pCritSect->s.pszName;
467	}
468
469
470	/**
471	* Yield the critical section if someone is waiting on it.
472	*
473	* When yielding, we'll leave the critical section and try to make sure the
474	* other waiting threads get a chance of entering before we reclaim it.
475	*
476	* @retval true if yielded.
477	* @retval false if not yielded.
478	* @param pCritSect The critical section.
479	*/
480	VMMR3DECL(bool) PDMR3CritSectYield(PPDMCRITSECT pCritSect)
481	{
482	AssertPtrReturn(pCritSect, false);
483	AssertReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, false);
484	Assert(pCritSect->s.Core.NativeThreadOwner == RTThreadNativeSelf());
485	Assert(!(pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP));
486
487	/* No recursion allowed here. */
488	int32_t const cNestings = pCritSect->s.Core.cNestings;
489	AssertReturn(cNestings == 1, false);
490
491	int32_t const cLockers = ASMAtomicReadS32(&pCritSect->s.Core.cLockers);
492	if (cLockers < cNestings)
493	return false;
494
495	#ifdef PDMCRITSECT_STRICT
496	RTLOCKVALSRCPOS const SrcPos = pCritSect->s.Core.pValidatorRec->SrcPos;
497	#endif
498	PDMCritSectLeave(pCritSect);
499
500	/*
501	* If we're lucky, then one of the waiters has entered the lock already.
502	* We spin a little bit in hope for this to happen so we can avoid the
503	* yield detour.
504	*/
505	if (ASMAtomicUoReadS32(&pCritSect->s.Core.cNestings) == 0)
506	{
507	int cLoops = 20;
508	while ( cLoops > 0
509	&& ASMAtomicUoReadS32(&pCritSect->s.Core.cNestings) == 0
510	&& ASMAtomicUoReadS32(&pCritSect->s.Core.cLockers) >= 0)
511	{
512	ASMNopPause();
513	cLoops--;
514	}
515	if (cLoops == 0)
516	RTThreadYield();
517	}
518
519	#ifdef PDMCRITSECT_STRICT
520	int rc = PDMCritSectEnterDebug(pCritSect, VERR_IGNORED,
521	SrcPos.uId, SrcPos.pszFile, SrcPos.uLine, SrcPos.pszFunction);
522	#else
523	int rc = PDMCritSectEnter(pCritSect, VERR_IGNORED);
524	#endif
525	AssertLogRelRC(rc);
526	return true;
527	}
528
529
530	/**
531	* Schedule a event semaphore for signalling upon critsect exit.
532	*
533	* @returns VINF_SUCCESS on success.
534	* @returns VERR_TOO_MANY_SEMAPHORES if an event was already scheduled.
535	* @returns VERR_NOT_OWNER if we're not the critsect owner.
536	* @returns VERR_SEM_DESTROYED if RTCritSectDelete was called while waiting.
537	*
538	* @param pCritSect The critical section.
539	* @param EventToSignal The semaphore that should be signalled.
540	*/
541	VMMR3DECL(int) PDMR3CritSectScheduleExitEvent(PPDMCRITSECT pCritSect, RTSEMEVENT EventToSignal)
542	{
543	AssertPtr(pCritSect);
544	Assert(!(pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP));
545	Assert(EventToSignal != NIL_RTSEMEVENT);
546	if (RT_UNLIKELY(!RTCritSectIsOwner(&pCritSect->s.Core)))
547	return VERR_NOT_OWNER;
548	if (RT_LIKELY( pCritSect->s.EventToSignal == NIL_RTSEMEVENT
549	\|\| pCritSect->s.EventToSignal == EventToSignal))
550	{
551	pCritSect->s.EventToSignal = EventToSignal;
552	return VINF_SUCCESS;
553	}
554	return VERR_TOO_MANY_SEMAPHORES;
555	}
556
557
558	/**
559	* Counts the critical sections owned by the calling thread, optionally
560	* returning a comma separated list naming them.
561	*
562	* This is for diagnostic purposes only.
563	*
564	* @returns Lock count.
565	*
566	* @param pVM The VM handle.
567	* @param pszNames Where to return the critical section names.
568	* @param cbNames The size of the buffer.
569	*/
570	VMMR3DECL(uint32_t) PDMR3CritSectCountOwned(PVM pVM, char *pszNames, size_t cbNames)
571	{
572	/*
573	* Init the name buffer.
574	*/
575	size_t cchLeft = cbNames;
576	if (cchLeft)
577	{
578	cchLeft--;
579	pszNames[0] = pszNames[cchLeft] = '\0';
580	}
581
582	/*
583	* Iterate the critical sections.
584	*/
585	/* This is unsafe, but wtf. */
586	RTNATIVETHREAD const hNativeThread = RTThreadNativeSelf();
587	uint32_t cCritSects = 0;
588	for (PPDMCRITSECTINT pCur = pVM->pUVM->pdm.s.pCritSects;
589	pCur;
590	pCur = pCur->pNext)
591	{
592	/* Same as RTCritSectIsOwner(). */
593	if (pCur->Core.NativeThreadOwner == hNativeThread)
594	{
595	cCritSects++;
596
597	/*
598	* Copy the name if there is space. Fun stuff.
599	*/
600	if (cchLeft)
601	{
602	/* try add comma. */
603	if (cCritSects != 1)
604	{
605	*pszNames++ = ',';
606	if (--cchLeft)
607	{
608	*pszNames++ = ' ';
609	cchLeft--;
610	}
611	}
612
613	/* try copy the name. */
614	if (cchLeft)
615	{
616	size_t const cchName = strlen(pCur->pszName);
617	if (cchName < cchLeft)
618	{
619	memcpy(pszNames, pCur->pszName, cchName);
620	pszNames += cchName;
621	cchLeft -= cchName;
622	}
623	else
624	{
625	if (cchLeft > 2)
626	{
627	memcpy(pszNames, pCur->pszName, cchLeft - 2);
628	pszNames += cchLeft - 2;
629	cchLeft = 2;
630	}
631	while (cchLeft-- > 0)
632	*pszNames++ = '+';
633	}
634	}
635	*pszNames = '\0';
636	}
637	}
638	}
639
640	return cCritSects;
641	}
642
643
644	/**
645	* Leave all critical sections the calling thread owns.
646	*
647	* This is only used when entering guru meditation in order to prevent other
648	* EMTs and I/O threads from deadlocking.
649	*
650	* @param pVM The VM handle.
651	*/
652	VMMR3DECL(void) PDMR3CritSectLeaveAll(PVM pVM)
653	{
654	RTNATIVETHREAD const hNativeSelf = RTThreadNativeSelf();
655	PUVM pUVM = pVM->pUVM;
656
657	RTCritSectEnter(&pUVM->pdm.s.ListCritSect);
658	for (PPDMCRITSECTINT pCur = pUVM->pdm.s.pCritSects;
659	pCur;
660	pCur = pCur->pNext)
661	{
662	while ( pCur->Core.NativeThreadOwner == hNativeSelf
663	&& pCur->Core.cNestings > 0)
664	PDMCritSectLeave((PPDMCRITSECT)pCur);
665	}
666	RTCritSectLeave(&pUVM->pdm.s.ListCritSect);
667	}
668
669
670	/**
671	* Gets the address of the NOP critical section.
672	*
673	* The NOP critical section will not perform any thread serialization but let
674	* all enter immediately and concurrently.
675	*
676	* @returns The address of the NOP critical section.
677	* @param pVM The VM handle.
678	*/
679	VMMR3DECL(PPDMCRITSECT) PDMR3CritSectGetNop(PVM pVM)
680	{
681	VM_ASSERT_VALID_EXT_RETURN(pVM, NULL);
682	return &pVM->pdm.s.NopCritSect;
683	}
684
685
686	/**
687	* Gets the ring-0 address of the NOP critical section.
688	*
689	* @returns The ring-0 address of the NOP critical section.
690	* @param pVM The VM handle.
691	*/
692	VMMR3DECL(R0PTRTYPE(PPDMCRITSECT)) PDMR3CritSectGetNopR0(PVM pVM)
693	{
694	VM_ASSERT_VALID_EXT_RETURN(pVM, NIL_RTR0PTR);
695	return MMHyperR3ToR0(pVM, &pVM->pdm.s.NopCritSect);
696	}
697
698
699	/**
700	* Gets the raw-mode context address of the NOP critical section.
701	*
702	* @returns The raw-mode context address of the NOP critical section.
703	* @param pVM The VM handle.
704	*/
705	VMMR3DECL(RCPTRTYPE(PPDMCRITSECT)) PDMR3CritSectGetNopRC(PVM pVM)
706	{
707	VM_ASSERT_VALID_EXT_RETURN(pVM, NIL_RTRCPTR);
708	return MMHyperR3ToRC(pVM, &pVM->pdm.s.NopCritSect);
709	}
710

Note: See TracBrowser for help on using the repository browser.

source: vbox/trunk/src/VBox/VMM/VMMR3/PDMCritSect.cpp@ 39402

Download in other formats: