PDMAllCritSect.cpp@ 37582

Last change on this file since 37582 was 37582, checked in by vboxsync, 14 years ago
PDMCritSect: Fixed PDMCritSectIsOwner[Ex] returning true in ring-0/rawmode when it should not.
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1	/* $Id: PDMAllCritSect.cpp 37582 2011-06-22 09:24:45Z vboxsync $ */
2	/** @file
3	* PDM - Critical Sections, All Contexts.
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 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/vmm.h>
27	#include <VBox/vmm/vm.h>
28	#include <VBox/err.h>
29	#include <VBox/vmm/hwaccm.h>
30
31	#include <VBox/log.h>
32	#include <iprt/asm.h>
33	#include <iprt/asm-amd64-x86.h>
34	#include <iprt/assert.h>
35	#ifdef IN_RING3
36	# include <iprt/lockvalidator.h>
37	# include <iprt/semaphore.h>
38	#endif
39	#if defined(IN_RING3) \|\| defined(IN_RING0)
40	# include <iprt/thread.h>
41	#endif
42
43
44	/*******************************************************************************
45	* Defined Constants And Macros *
46	*******************************************************************************/
47	/** The number loops to spin for in ring-3. */
48	#define PDMCRITSECT_SPIN_COUNT_R3 20
49	/** The number loops to spin for in ring-0. */
50	#define PDMCRITSECT_SPIN_COUNT_R0 256
51	/** The number loops to spin for in the raw-mode context. */
52	#define PDMCRITSECT_SPIN_COUNT_RC 256
53
54
55	/* Undefine the automatic VBOX_STRICT API mappings. */
56	#undef PDMCritSectEnter
57	#undef PDMCritSectTryEnter
58
59
60	/**
61	* Gets the ring-3 native thread handle of the calling thread.
62	*
63	* @returns native thread handle (ring-3).
64	* @param pCritSect The critical section. This is used in R0 and RC.
65	*/
66	DECL_FORCE_INLINE(RTNATIVETHREAD) pdmCritSectGetNativeSelf(PCPDMCRITSECT pCritSect)
67	{
68	#ifdef IN_RING3
69	NOREF(pCritSect);
70	RTNATIVETHREAD hNativeSelf = RTThreadNativeSelf();
71	#else
72	AssertMsgReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, ("%RX32\n", pCritSect->s.Core.u32Magic),
73	NIL_RTNATIVETHREAD);
74	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
75	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
76	RTNATIVETHREAD hNativeSelf = pVCpu->hNativeThread; Assert(hNativeSelf != NIL_RTNATIVETHREAD);
77	#endif
78	return hNativeSelf;
79	}
80
81
82	/**
83	* Tail code called when we've won the battle for the lock.
84	*
85	* @returns VINF_SUCCESS.
86	*
87	* @param pCritSect The critical section.
88	* @param hNativeSelf The native handle of this thread.
89	*/
90	DECL_FORCE_INLINE(int) pdmCritSectEnterFirst(PPDMCRITSECT pCritSect, RTNATIVETHREAD hNativeSelf, PCRTLOCKVALSRCPOS pSrcPos)
91	{
92	AssertMsg(pCritSect->s.Core.NativeThreadOwner == NIL_RTNATIVETHREAD, ("NativeThreadOwner=%p\n", pCritSect->s.Core.NativeThreadOwner));
93	Assert(!(pCritSect->s.Core.fFlags & PDMCRITSECT_FLAGS_PENDING_UNLOCK));
94
95	ASMAtomicWriteS32(&pCritSect->s.Core.cNestings, 1);
96	Assert(pCritSect->s.Core.cNestings == 1);
97	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, hNativeSelf);
98
99	# ifdef PDMCRITSECT_STRICT
100	RTLockValidatorRecExclSetOwner(pCritSect->s.Core.pValidatorRec, NIL_RTTHREAD, pSrcPos, true);
101	# endif
102
103	STAM_PROFILE_ADV_START(&pCritSect->s.StatLocked, l);
104	return VINF_SUCCESS;
105	}
106
107
108	#if defined(IN_RING3) \|\| defined(IN_RING0)
109	/**
110	* Deals with the contended case in ring-3 and ring-0.
111	*
112	* @returns VINF_SUCCESS or VERR_SEM_DESTROYED.
113	* @param pCritSect The critsect.
114	* @param hNativeSelf The native thread handle.
115	*/
116	static int pdmR3R0CritSectEnterContended(PPDMCRITSECT pCritSect, RTNATIVETHREAD hNativeSelf, PCRTLOCKVALSRCPOS pSrcPos)
117	{
118	/*
119	* Start waiting.
120	*/
121	if (ASMAtomicIncS32(&pCritSect->s.Core.cLockers) == 0)
122	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
123	# ifdef IN_RING3
124	STAM_COUNTER_INC(&pCritSect->s.StatContentionR3);
125	# else
126	STAM_COUNTER_INC(&pCritSect->s.StatContentionRZLock);
127	# endif
128
129	/*
130	* The wait loop.
131	*/
132	PSUPDRVSESSION pSession = pCritSect->s.CTX_SUFF(pVM)->pSession;
133	SUPSEMEVENT hEvent = (SUPSEMEVENT)pCritSect->s.Core.EventSem;
134	# ifdef IN_RING3
135	# ifdef PDMCRITSECT_STRICT
136	RTTHREAD hThreadSelf = RTThreadSelfAutoAdopt();
137	int rc2 = RTLockValidatorRecExclCheckOrder(pCritSect->s.Core.pValidatorRec, hThreadSelf, pSrcPos, RT_INDEFINITE_WAIT);
138	if (RT_FAILURE(rc2))
139	return rc2;
140	# else
141	RTTHREAD hThreadSelf = RTThreadSelf();
142	# endif
143	# endif
144	for (;;)
145	{
146	# ifdef PDMCRITSECT_STRICT
147	int rc9 = RTLockValidatorRecExclCheckBlocking(pCritSect->s.Core.pValidatorRec, hThreadSelf, pSrcPos,
148	!(pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NO_NESTING),
149	RT_INDEFINITE_WAIT, RTTHREADSTATE_CRITSECT, true);
150	if (RT_FAILURE(rc9))
151	return rc9;
152	# elif defined(IN_RING3)
153	RTThreadBlocking(hThreadSelf, RTTHREADSTATE_CRITSECT, true);
154	# endif
155	int rc = SUPSemEventWaitNoResume(pSession, hEvent, RT_INDEFINITE_WAIT);
156	# ifdef IN_RING3
157	RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_CRITSECT);
158	# endif
159
160	if (RT_UNLIKELY(pCritSect->s.Core.u32Magic != RTCRITSECT_MAGIC))
161	return VERR_SEM_DESTROYED;
162	if (rc == VINF_SUCCESS)
163	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
164	AssertMsg(rc == VERR_INTERRUPTED, ("rc=%Rrc\n", rc));
165	}
166	/* won't get here */
167	}
168	#endif /* IN_RING3 \|\| IN_RING0 */
169
170
171	/**
172	* Common worker for the debug and normal APIs.
173	*
174	* @returns VINF_SUCCESS if entered successfully.
175	* @returns rcBusy when encountering a busy critical section in GC/R0.
176	* @returns VERR_SEM_DESTROYED if the critical section is dead.
177	*
178	* @param pCritSect The PDM critical section to enter.
179	* @param rcBusy The status code to return when we're in GC or R0
180	* and the section is busy.
181	*/
182	DECL_FORCE_INLINE(int) pdmCritSectEnter(PPDMCRITSECT pCritSect, int rcBusy, PCRTLOCKVALSRCPOS pSrcPos)
183	{
184	Assert(pCritSect->s.Core.cNestings < 8); /* useful to catch incorrect locking */
185	Assert(pCritSect->s.Core.cNestings >= 0);
186
187	/*
188	* If the critical section has already been destroyed, then inform the caller.
189	*/
190	AssertMsgReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC,
191	("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic),
192	VERR_SEM_DESTROYED);
193
194	/*
195	* See if we're lucky.
196	*/
197	/* NOP ... */
198	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
199	return VINF_SUCCESS;
200
201	RTNATIVETHREAD hNativeSelf = pdmCritSectGetNativeSelf(pCritSect);
202	/* ... not owned ... */
203	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, 0, -1))
204	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
205
206	/* ... or nested. */
207	if (pCritSect->s.Core.NativeThreadOwner == hNativeSelf)
208	{
209	ASMAtomicIncS32(&pCritSect->s.Core.cLockers);
210	ASMAtomicIncS32(&pCritSect->s.Core.cNestings);
211	Assert(pCritSect->s.Core.cNestings > 1);
212	return VINF_SUCCESS;
213	}
214
215	/*
216	* Spin for a bit without incrementing the counter.
217	*/
218	/** @todo Move this to cfgm variables since it doesn't make sense to spin on UNI
219	* cpu systems. */
220	int32_t cSpinsLeft = CTX_SUFF(PDMCRITSECT_SPIN_COUNT_);
221	while (cSpinsLeft-- > 0)
222	{
223	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, 0, -1))
224	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
225	ASMNopPause();
226	/** @todo Should use monitor/mwait on e.g. &cLockers here, possibly with a
227	cli'ed pendingpreemption check up front using sti w/ instruction fusing
228	for avoiding races. Hmm ... This is assuming the other party is actually
229	executing code on another CPU ... which we could keep track of if we
230	wanted. */
231	}
232
233	#ifdef IN_RING3
234	/*
235	* Take the slow path.
236	*/
237	return pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
238
239	#else
240	# ifdef IN_RING0
241	/** @todo If preemption is disabled it means we're in VT-x/AMD-V context
242	* and would be better off switching out of that while waiting for
243	* the lock. Several of the locks jumps back to ring-3 just to
244	* get the lock, the ring-3 code will then call the kernel to do
245	* the lock wait and when the call return it will call ring-0
246	* again and resume via in setjmp style. Not very efficient. */
247	# if 0
248	if (ASMIntAreEnabled()) /** @todo this can be handled as well by changing
249	* callers not prepared for longjmp/blocking to
250	* use PDMCritSectTryEnter. */
251	{
252	/*
253	* Leave HWACCM context while waiting if necessary.
254	*/
255	int rc;
256	if (RTThreadPreemptIsEnabled(NIL_RTTHREAD))
257	{
258	STAM_REL_COUNTER_ADD(&pCritSect->s.StatContentionRZLock, 1000000);
259	rc = pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
260	}
261	else
262	{
263	STAM_REL_COUNTER_ADD(&pCritSect->s.StatContentionRZLock, 1000000000);
264	PVM pVM = pCritSect->s.CTX_SUFF(pVM);
265	PVMCPU pVCpu = VMMGetCpu(pVM);
266	HWACCMR0Leave(pVM, pVCpu);
267	RTThreadPreemptRestore(NIL_RTTHREAD, ????);
268
269	rc = pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
270
271	RTThreadPreemptDisable(NIL_RTTHREAD, ????);
272	HWACCMR0Enter(pVM, pVCpu);
273	}
274	return rc;
275	}
276	# else
277	/*
278	* We preemption hasn't been disabled, we can block here in ring-0.
279	*/
280	if ( RTThreadPreemptIsEnabled(NIL_RTTHREAD)
281	&& ASMIntAreEnabled())
282	return pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
283	# endif
284	#endif /* IN_RING0 */
285
286	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZLock);
287
288	/*
289	* Call ring-3 to acquire the critical section?
290	*/
291	if (rcBusy == VINF_SUCCESS)
292	{
293	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
294	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
295	return VMMRZCallRing3(pVM, pVCpu, VMMCALLRING3_PDM_CRIT_SECT_ENTER, MMHyperCCToR3(pVM, pCritSect));
296	}
297
298	/*
299	* Return busy.
300	*/
301	LogFlow(("PDMCritSectEnter: locked => R3 (%Rrc)\n", rcBusy));
302	return rcBusy;
303	#endif /* !IN_RING3 */
304	}
305
306
307	/**
308	* Enters a PDM critical section.
309	*
310	* @returns VINF_SUCCESS if entered successfully.
311	* @returns rcBusy when encountering a busy critical section in GC/R0.
312	* @returns VERR_SEM_DESTROYED if the critical section is dead.
313	*
314	* @param pCritSect The PDM critical section to enter.
315	* @param rcBusy The status code to return when we're in GC or R0
316	* and the section is busy. Pass VINF_SUCCESS to
317	* acquired the critical section thru a ring-3
318	* call if necessary.
319	*/
320	VMMDECL(int) PDMCritSectEnter(PPDMCRITSECT pCritSect, int rcBusy)
321	{
322	int rc;
323	#ifndef IN_RING3
324	if (rcBusy == VINF_SUCCESS)
325	{
326	# ifndef PDMCRITSECT_STRICT
327	rc = pdmCritSectEnter(pCritSect, VERR_SEM_BUSY, NULL);
328	# else
329	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
330	rc = pdmCritSectEnter(pCritSect, VERR_SEM_BUSY, &SrcPos);
331	# endif
332	if (rc == VERR_SEM_BUSY)
333	{
334
335	}
336	}
337	else
338	#endif /* !IN_RING3 */
339	{
340	#ifndef PDMCRITSECT_STRICT
341	rc = pdmCritSectEnter(pCritSect, rcBusy, NULL);
342	#else
343	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
344	rc = pdmCritSectEnter(pCritSect, rcBusy, &SrcPos);
345	#endif
346	}
347	return rc;
348	}
349
350
351	/**
352	* Enters a PDM critical section, with location information for debugging.
353	*
354	* @returns VINF_SUCCESS if entered successfully.
355	* @returns rcBusy when encountering a busy critical section in GC/R0.
356	* @returns VERR_SEM_DESTROYED if the critical section is dead.
357	*
358	* @param pCritSect The PDM critical section to enter.
359	* @param rcBusy The status code to return when we're in GC or R0
360	* and the section is busy. Pass VINF_SUCCESS to
361	* acquired the critical section thru a ring-3
362	* call if necessary.
363	* @param uId Some kind of locking location ID. Typically a
364	* return address up the stack. Optional (0).
365	* @param pszFile The file where the lock is being acquired from.
366	* Optional.
367	* @param iLine The line number in that file. Optional (0).
368	* @param pszFunction The function where the lock is being acquired
369	* from. Optional.
370	*/
371	VMMDECL(int) PDMCritSectEnterDebug(PPDMCRITSECT pCritSect, int rcBusy, RTHCUINTPTR uId, RT_SRC_POS_DECL)
372	{
373	#ifdef PDMCRITSECT_STRICT
374	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
375	return pdmCritSectEnter(pCritSect, rcBusy, &SrcPos);
376	#else
377	return pdmCritSectEnter(pCritSect, rcBusy, NULL);
378	#endif
379	}
380
381
382	/**
383	* Common worker for the debug and normal APIs.
384	*
385	* @retval VINF_SUCCESS on success.
386	* @retval VERR_SEM_BUSY if the critsect was owned.
387	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
388	* @retval VERR_SEM_DESTROYED if RTCritSectDelete was called while waiting.
389	*
390	* @param pCritSect The critical section.
391	*/
392	static int pdmCritSectTryEnter(PPDMCRITSECT pCritSect, PCRTLOCKVALSRCPOS pSrcPos)
393	{
394	/*
395	* If the critical section has already been destroyed, then inform the caller.
396	*/
397	AssertMsgReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC,
398	("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic),
399	VERR_SEM_DESTROYED);
400
401	/*
402	* See if we're lucky.
403	*/
404	/* NOP ... */
405	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
406	return VINF_SUCCESS;
407
408	RTNATIVETHREAD hNativeSelf = pdmCritSectGetNativeSelf(pCritSect);
409	/* ... not owned ... */
410	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, 0, -1))
411	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
412
413	/* ... or nested. */
414	if (pCritSect->s.Core.NativeThreadOwner == hNativeSelf)
415	{
416	ASMAtomicIncS32(&pCritSect->s.Core.cLockers);
417	ASMAtomicIncS32(&pCritSect->s.Core.cNestings);
418	Assert(pCritSect->s.Core.cNestings > 1);
419	return VINF_SUCCESS;
420	}
421
422	/* no spinning */
423
424	/*
425	* Return busy.
426	*/
427	#ifdef IN_RING3
428	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionR3);
429	#else
430	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZLock);
431	#endif
432	LogFlow(("PDMCritSectTryEnter: locked\n"));
433	return VERR_SEM_BUSY;
434	}
435
436
437	/**
438	* Try enter a critical section.
439	*
440	* @retval VINF_SUCCESS on success.
441	* @retval VERR_SEM_BUSY if the critsect was owned.
442	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
443	* @retval VERR_SEM_DESTROYED if RTCritSectDelete was called while waiting.
444	*
445	* @param pCritSect The critical section.
446	*/
447	VMMDECL(int) PDMCritSectTryEnter(PPDMCRITSECT pCritSect)
448	{
449	#ifndef PDMCRITSECT_STRICT
450	return pdmCritSectTryEnter(pCritSect, NULL);
451	#else
452	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
453	return pdmCritSectTryEnter(pCritSect, &SrcPos);
454	#endif
455	}
456
457
458	/**
459	* Try enter a critical section, with location information for debugging.
460	*
461	* @retval VINF_SUCCESS on success.
462	* @retval VERR_SEM_BUSY if the critsect was owned.
463	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
464	* @retval VERR_SEM_DESTROYED if RTCritSectDelete was called while waiting.
465	*
466	* @param pCritSect The critical section.
467	* @param uId Some kind of locking location ID. Typically a
468	* return address up the stack. Optional (0).
469	* @param pszFile The file where the lock is being acquired from.
470	* Optional.
471	* @param iLine The line number in that file. Optional (0).
472	* @param pszFunction The function where the lock is being acquired
473	* from. Optional.
474	*/
475	VMMDECL(int) PDMCritSectTryEnterDebug(PPDMCRITSECT pCritSect, RTHCUINTPTR uId, RT_SRC_POS_DECL)
476	{
477	#ifdef PDMCRITSECT_STRICT
478	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
479	return pdmCritSectTryEnter(pCritSect, &SrcPos);
480	#else
481	return pdmCritSectTryEnter(pCritSect, NULL);
482	#endif
483	}
484
485
486	#ifdef IN_RING3
487	/**
488	* Enters a PDM critical section.
489	*
490	* @returns VINF_SUCCESS if entered successfully.
491	* @returns rcBusy when encountering a busy critical section in GC/R0.
492	* @returns VERR_SEM_DESTROYED if the critical section is dead.
493	*
494	* @param pCritSect The PDM critical section to enter.
495	* @param fCallRing3 Whether this is a VMMRZCallRing3()request.
496	*/
497	VMMR3DECL(int) PDMR3CritSectEnterEx(PPDMCRITSECT pCritSect, bool fCallRing3)
498	{
499	int rc = PDMCritSectEnter(pCritSect, VERR_INTERNAL_ERROR);
500	if ( rc == VINF_SUCCESS
501	&& fCallRing3
502	&& pCritSect->s.Core.pValidatorRec
503	&& pCritSect->s.Core.pValidatorRec->hThread != NIL_RTTHREAD)
504	RTLockValidatorRecExclReleaseOwnerUnchecked(pCritSect->s.Core.pValidatorRec);
505	return rc;
506	}
507	#endif /* IN_RING3 */
508
509
510	/**
511	* Leaves a critical section entered with PDMCritSectEnter().
512	*
513	* @param pCritSect The PDM critical section to leave.
514	*/
515	VMMDECL(void) PDMCritSectLeave(PPDMCRITSECT pCritSect)
516	{
517	AssertMsg(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, ("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic));
518	Assert(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC);
519
520	/* Check for NOP sections before asserting ownership. */
521	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
522	return;
523
524	Assert(pCritSect->s.Core.NativeThreadOwner == pdmCritSectGetNativeSelf(pCritSect));
525	Assert(pCritSect->s.Core.cNestings >= 1);
526
527	/*
528	* Nested leave.
529	*/
530	if (pCritSect->s.Core.cNestings > 1)
531	{
532	ASMAtomicDecS32(&pCritSect->s.Core.cNestings);
533	Assert(pCritSect->s.Core.cNestings >= 1);
534	ASMAtomicDecS32(&pCritSect->s.Core.cLockers);
535	Assert(pCritSect->s.Core.cLockers >= 0);
536	return;
537	}
538
539	#ifdef IN_RING0
540	# if 0 /** @todo Make SUPSemEventSignal interrupt safe (handle table++) and enable this for: defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2) */
541	if (1) /* SUPSemEventSignal is safe */
542	# else
543	if (ASMIntAreEnabled())
544	# endif
545	#endif
546	#if defined(IN_RING3) \|\| defined(IN_RING0)
547	{
548	/*
549	* Leave for real.
550	*/
551	/* update members. */
552	# ifdef IN_RING3
553	RTSEMEVENT hEventToSignal = pCritSect->s.EventToSignal;
554	pCritSect->s.EventToSignal = NIL_RTSEMEVENT;
555	# if defined(PDMCRITSECT_STRICT)
556	if (pCritSect->s.Core.pValidatorRec->hThread != NIL_RTTHREAD)
557	RTLockValidatorRecExclReleaseOwnerUnchecked(pCritSect->s.Core.pValidatorRec);
558	# endif
559	Assert(!pCritSect->s.Core.pValidatorRec \|\| pCritSect->s.Core.pValidatorRec->hThread == NIL_RTTHREAD);
560	# endif
561	ASMAtomicAndU32(&pCritSect->s.Core.fFlags, ~PDMCRITSECT_FLAGS_PENDING_UNLOCK);
562	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, NIL_RTNATIVETHREAD);
563	ASMAtomicDecS32(&pCritSect->s.Core.cNestings);
564	Assert(pCritSect->s.Core.cNestings == 0);
565
566	/* stop and decrement lockers. */
567	STAM_PROFILE_ADV_STOP(&pCritSect->s.StatLocked, l);
568	ASMCompilerBarrier();
569	if (ASMAtomicDecS32(&pCritSect->s.Core.cLockers) >= 0)
570	{
571	/* Someone is waiting, wake up one of them. */
572	SUPSEMEVENT hEvent = (SUPSEMEVENT)pCritSect->s.Core.EventSem;
573	PSUPDRVSESSION pSession = pCritSect->s.CTX_SUFF(pVM)->pSession;
574	int rc = SUPSemEventSignal(pSession, hEvent);
575	AssertRC(rc);
576	}
577
578	# ifdef IN_RING3
579	/* Signal exit event. */
580	if (hEventToSignal != NIL_RTSEMEVENT)
581	{
582	LogBird(("Signalling %#x\n", hEventToSignal));
583	int rc = RTSemEventSignal(hEventToSignal);
584	AssertRC(rc);
585	}
586	# endif
587
588	# if defined(DEBUG_bird) && defined(IN_RING0)
589	VMMTrashVolatileXMMRegs();
590	# endif
591	}
592	#endif /* IN_RING3 \|\| IN_RING0 */
593	#ifdef IN_RING0
594	else
595	#endif
596	#if defined(IN_RING0) \|\| defined(IN_RC)
597	{
598	/*
599	* Try leave it.
600	*/
601	if (pCritSect->s.Core.cLockers == 0)
602	{
603	ASMAtomicWriteS32(&pCritSect->s.Core.cNestings, 0);
604	RTNATIVETHREAD hNativeThread = pCritSect->s.Core.NativeThreadOwner;
605	ASMAtomicAndU32(&pCritSect->s.Core.fFlags, ~PDMCRITSECT_FLAGS_PENDING_UNLOCK);
606	STAM_PROFILE_ADV_STOP(&pCritSect->s.StatLocked, l);
607
608	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, NIL_RTNATIVETHREAD);
609	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, -1, 0))
610	return;
611
612	/* darn, someone raced in on us. */
613	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, hNativeThread);
614	STAM_PROFILE_ADV_START(&pCritSect->s.StatLocked, l);
615	Assert(pCritSect->s.Core.cNestings == 0);
616	ASMAtomicWriteS32(&pCritSect->s.Core.cNestings, 1);
617	}
618	ASMAtomicOrU32(&pCritSect->s.Core.fFlags, PDMCRITSECT_FLAGS_PENDING_UNLOCK);
619
620	/*
621	* Queue the request.
622	*/
623	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
624	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
625	uint32_t i = pVCpu->pdm.s.cQueuedCritSectLeaves++;
626	LogFlow(("PDMCritSectLeave: [%d]=%p => R3\n", i, pCritSect));
627	AssertFatal(i < RT_ELEMENTS(pVCpu->pdm.s.apQueuedCritSectsLeaves));
628	pVCpu->pdm.s.apQueuedCritSectsLeaves[i] = MMHyperCCToR3(pVM, pCritSect);
629	VMCPU_FF_SET(pVCpu, VMCPU_FF_PDM_CRITSECT);
630	VMCPU_FF_SET(pVCpu, VMCPU_FF_TO_R3);
631	STAM_REL_COUNTER_INC(&pVM->pdm.s.StatQueuedCritSectLeaves);
632	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZUnlock);
633	}
634	#endif /* IN_RING0 \|\| IN_RC */
635	}
636
637
638	#if defined(IN_RING3) \|\| defined(IN_RING0)
639	/**
640	* Process the critical sections queued for ring-3 'leave'.
641	*
642	* @param pVCpu The VMCPU handle.
643	*/
644	VMMDECL(void) PDMCritSectFF(PVMCPU pVCpu)
645	{
646	Assert(pVCpu->pdm.s.cQueuedCritSectLeaves > 0);
647
648	const RTUINT c = pVCpu->pdm.s.cQueuedCritSectLeaves;
649	for (RTUINT i = 0; i < c; i++)
650	{
651	# ifdef IN_RING3
652	PPDMCRITSECT pCritSect = pVCpu->pdm.s.apQueuedCritSectsLeaves[i];
653	# else
654	PPDMCRITSECT pCritSect = (PPDMCRITSECT)MMHyperR3ToCC(pVCpu->CTX_SUFF(pVM), pVCpu->pdm.s.apQueuedCritSectsLeaves[i]);
655	# endif
656
657	PDMCritSectLeave(pCritSect);
658	LogFlow(("PDMR3CritSectFF: %p\n", pCritSect));
659	}
660
661	pVCpu->pdm.s.cQueuedCritSectLeaves = 0;
662	VMCPU_FF_CLEAR(pVCpu, VMCPU_FF_PDM_CRITSECT);
663	}
664	#endif /* IN_RING3 \|\| IN_RING0 */
665
666
667	/**
668	* Checks the caller is the owner of the critical section.
669	*
670	* @returns true if owner.
671	* @returns false if not owner.
672	* @param pCritSect The critical section.
673	*/
674	VMMDECL(bool) PDMCritSectIsOwner(PCPDMCRITSECT pCritSect)
675	{
676	#ifdef IN_RING3
677	return RTCritSectIsOwner(&pCritSect->s.Core);
678	#else
679	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
680	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
681	if (pCritSect->s.Core.NativeThreadOwner != pVCpu->hNativeThread)
682	return false;
683	return (pCritSect->s.Core.fFlags & PDMCRITSECT_FLAGS_PENDING_UNLOCK) == 0
684	\|\| pCritSect->s.Core.cNestings > 1;
685	#endif
686	}
687
688
689	/**
690	* Checks the specified VCPU is the owner of the critical section.
691	*
692	* @returns true if owner.
693	* @returns false if not owner.
694	* @param pCritSect The critical section.
695	* @param pVCpu The virtual CPU handle.
696	*/
697	VMMDECL(bool) PDMCritSectIsOwnerEx(PCPDMCRITSECT pCritSect, PVMCPU pVCpu)
698	{
699	#ifdef IN_RING3
700	NOREF(pVCpu);
701	return RTCritSectIsOwner(&pCritSect->s.Core);
702	#else
703	Assert(&pVCpu->CTX_SUFF(pVM)->aCpus[pVCpu->idCpu] == pVCpu);
704	if (pCritSect->s.Core.NativeThreadOwner != pVCpu->hNativeThread)
705	return false;
706	return (pCritSect->s.Core.fFlags & PDMCRITSECT_FLAGS_PENDING_UNLOCK) == 0
707	\|\| pCritSect->s.Core.cNestings > 1;
708	#endif
709	}
710
711
712	/**
713	* Checks if anyone is waiting on the critical section we own.
714	*
715	* @returns true if someone is waiting.
716	* @returns false if no one is waiting.
717	* @param pCritSect The critical section.
718	*/
719	VMMDECL(bool) PDMCritSectHasWaiters(PCPDMCRITSECT pCritSect)
720	{
721	AssertReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, false);
722	Assert(pCritSect->s.Core.NativeThreadOwner == pdmCritSectGetNativeSelf(pCritSect));
723	return pCritSect->s.Core.cLockers >= pCritSect->s.Core.cNestings;
724	}
725
726
727	/**
728	* Checks if a critical section is initialized or not.
729	*
730	* @returns true if initialized.
731	* @returns false if not initialized.
732	* @param pCritSect The critical section.
733	*/
734	VMMDECL(bool) PDMCritSectIsInitialized(PCPDMCRITSECT pCritSect)
735	{
736	return RTCritSectIsInitialized(&pCritSect->s.Core);
737	}
738
739
740	/**
741	* Gets the recursion depth.
742	*
743	* @returns The recursion depth.
744	* @param pCritSect The critical section.
745	*/
746	VMMDECL(uint32_t) PDMCritSectGetRecursion(PCPDMCRITSECT pCritSect)
747	{
748	return RTCritSectGetRecursion(&pCritSect->s.Core);
749	}

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source: vbox/trunk/src/VBox/VMM/VMMAll/PDMAllCritSect.cpp@ 37582

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