PDMAllCritSect.cpp@ 46422

Last change on this file since 46422 was 45152, checked in by vboxsync, 12 years ago
PDMCritSectRw: Early morphing stage - untested, ring-3 only.
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1	/* $Id: PDMAllCritSect.cpp 45152 2013-03-23 20:36:23Z vboxsync $ */
2	/** @file
3	* PDM - Write-Only Critical Section, All Contexts.
4	*/
5
6	/*
7	* Copyright (C) 2006-2013 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/hm.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	# else
102	NOREF(pSrcPos);
103	# endif
104
105	STAM_PROFILE_ADV_START(&pCritSect->s.StatLocked, l);
106	return VINF_SUCCESS;
107	}
108
109
110	#if defined(IN_RING3) \|\| defined(IN_RING0)
111	/**
112	* Deals with the contended case in ring-3 and ring-0.
113	*
114	* @returns VINF_SUCCESS or VERR_SEM_DESTROYED.
115	* @param pCritSect The critsect.
116	* @param hNativeSelf The native thread handle.
117	*/
118	static int pdmR3R0CritSectEnterContended(PPDMCRITSECT pCritSect, RTNATIVETHREAD hNativeSelf, PCRTLOCKVALSRCPOS pSrcPos)
119	{
120	/*
121	* Start waiting.
122	*/
123	if (ASMAtomicIncS32(&pCritSect->s.Core.cLockers) == 0)
124	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
125	# ifdef IN_RING3
126	STAM_COUNTER_INC(&pCritSect->s.StatContentionR3);
127	# else
128	STAM_COUNTER_INC(&pCritSect->s.StatContentionRZLock);
129	# endif
130
131	/*
132	* The wait loop.
133	*/
134	PSUPDRVSESSION pSession = pCritSect->s.CTX_SUFF(pVM)->pSession;
135	SUPSEMEVENT hEvent = (SUPSEMEVENT)pCritSect->s.Core.EventSem;
136	# ifdef IN_RING3
137	# ifdef PDMCRITSECT_STRICT
138	RTTHREAD hThreadSelf = RTThreadSelfAutoAdopt();
139	int rc2 = RTLockValidatorRecExclCheckOrder(pCritSect->s.Core.pValidatorRec, hThreadSelf, pSrcPos, RT_INDEFINITE_WAIT);
140	if (RT_FAILURE(rc2))
141	return rc2;
142	# else
143	RTTHREAD hThreadSelf = RTThreadSelf();
144	# endif
145	# endif
146	for (;;)
147	{
148	# ifdef PDMCRITSECT_STRICT
149	int rc9 = RTLockValidatorRecExclCheckBlocking(pCritSect->s.Core.pValidatorRec, hThreadSelf, pSrcPos,
150	!(pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NO_NESTING),
151	RT_INDEFINITE_WAIT, RTTHREADSTATE_CRITSECT, true);
152	if (RT_FAILURE(rc9))
153	return rc9;
154	# elif defined(IN_RING3)
155	RTThreadBlocking(hThreadSelf, RTTHREADSTATE_CRITSECT, true);
156	# endif
157	int rc = SUPSemEventWaitNoResume(pSession, hEvent, RT_INDEFINITE_WAIT);
158	# ifdef IN_RING3
159	RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_CRITSECT);
160	# endif
161
162	if (RT_UNLIKELY(pCritSect->s.Core.u32Magic != RTCRITSECT_MAGIC))
163	return VERR_SEM_DESTROYED;
164	if (rc == VINF_SUCCESS)
165	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
166	AssertMsg(rc == VERR_INTERRUPTED, ("rc=%Rrc\n", rc));
167	}
168	/* won't get here */
169	}
170	#endif /* IN_RING3 \|\| IN_RING0 */
171
172
173	/**
174	* Common worker for the debug and normal APIs.
175	*
176	* @returns VINF_SUCCESS if entered successfully.
177	* @returns rcBusy when encountering a busy critical section in GC/R0.
178	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
179	* during the operation.
180	*
181	* @param pCritSect The PDM critical section to enter.
182	* @param rcBusy The status code to return when we're in GC or R0
183	* and the section is busy.
184	*/
185	DECL_FORCE_INLINE(int) pdmCritSectEnter(PPDMCRITSECT pCritSect, int rcBusy, PCRTLOCKVALSRCPOS pSrcPos)
186	{
187	Assert(pCritSect->s.Core.cNestings < 8); /* useful to catch incorrect locking */
188	Assert(pCritSect->s.Core.cNestings >= 0);
189
190	/*
191	* If the critical section has already been destroyed, then inform the caller.
192	*/
193	AssertMsgReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC,
194	("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic),
195	VERR_SEM_DESTROYED);
196
197	/*
198	* See if we're lucky.
199	*/
200	/* NOP ... */
201	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
202	return VINF_SUCCESS;
203
204	RTNATIVETHREAD hNativeSelf = pdmCritSectGetNativeSelf(pCritSect);
205	/* ... not owned ... */
206	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, 0, -1))
207	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
208
209	/* ... or nested. */
210	if (pCritSect->s.Core.NativeThreadOwner == hNativeSelf)
211	{
212	ASMAtomicIncS32(&pCritSect->s.Core.cLockers);
213	ASMAtomicIncS32(&pCritSect->s.Core.cNestings);
214	Assert(pCritSect->s.Core.cNestings > 1);
215	return VINF_SUCCESS;
216	}
217
218	/*
219	* Spin for a bit without incrementing the counter.
220	*/
221	/** @todo Move this to cfgm variables since it doesn't make sense to spin on UNI
222	* cpu systems. */
223	int32_t cSpinsLeft = CTX_SUFF(PDMCRITSECT_SPIN_COUNT_);
224	while (cSpinsLeft-- > 0)
225	{
226	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, 0, -1))
227	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
228	ASMNopPause();
229	/** @todo Should use monitor/mwait on e.g. &cLockers here, possibly with a
230	cli'ed pendingpreemption check up front using sti w/ instruction fusing
231	for avoiding races. Hmm ... This is assuming the other party is actually
232	executing code on another CPU ... which we could keep track of if we
233	wanted. */
234	}
235
236	#ifdef IN_RING3
237	/*
238	* Take the slow path.
239	*/
240	NOREF(rcBusy);
241	return pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
242
243	#else
244	# ifdef IN_RING0
245	/** @todo If preemption is disabled it means we're in VT-x/AMD-V context
246	* and would be better off switching out of that while waiting for
247	* the lock. Several of the locks jumps back to ring-3 just to
248	* get the lock, the ring-3 code will then call the kernel to do
249	* the lock wait and when the call return it will call ring-0
250	* again and resume via in setjmp style. Not very efficient. */
251	# if 0
252	if (ASMIntAreEnabled()) /** @todo this can be handled as well by changing
253	* callers not prepared for longjmp/blocking to
254	* use PDMCritSectTryEnter. */
255	{
256	/*
257	* Leave HM context while waiting if necessary.
258	*/
259	int rc;
260	if (RTThreadPreemptIsEnabled(NIL_RTTHREAD))
261	{
262	STAM_REL_COUNTER_ADD(&pCritSect->s.StatContentionRZLock, 1000000);
263	rc = pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
264	}
265	else
266	{
267	STAM_REL_COUNTER_ADD(&pCritSect->s.StatContentionRZLock, 1000000000);
268	PVM pVM = pCritSect->s.CTX_SUFF(pVM);
269	PVMCPU pVCpu = VMMGetCpu(pVM);
270	HMR0Leave(pVM, pVCpu);
271	RTThreadPreemptRestore(NIL_RTTHREAD, ????);
272
273	rc = pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
274
275	RTThreadPreemptDisable(NIL_RTTHREAD, ????);
276	HMR0Enter(pVM, pVCpu);
277	}
278	return rc;
279	}
280	# else
281	/*
282	* We preemption hasn't been disabled, we can block here in ring-0.
283	*/
284	if ( RTThreadPreemptIsEnabled(NIL_RTTHREAD)
285	&& ASMIntAreEnabled())
286	return pdmR3R0CritSectEnterContended(pCritSect, hNativeSelf, pSrcPos);
287	# endif
288	#endif /* IN_RING0 */
289
290	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZLock);
291
292	/*
293	* Call ring-3 to acquire the critical section?
294	*/
295	if (rcBusy == VINF_SUCCESS)
296	{
297	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
298	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
299	return VMMRZCallRing3(pVM, pVCpu, VMMCALLRING3_PDM_CRIT_SECT_ENTER, MMHyperCCToR3(pVM, pCritSect));
300	}
301
302	/*
303	* Return busy.
304	*/
305	LogFlow(("PDMCritSectEnter: locked => R3 (%Rrc)\n", rcBusy));
306	return rcBusy;
307	#endif /* !IN_RING3 */
308	}
309
310
311	/**
312	* Enters a PDM critical section.
313	*
314	* @returns VINF_SUCCESS if entered successfully.
315	* @returns rcBusy when encountering a busy critical section in RC/R0.
316	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
317	* during the operation.
318	*
319	* @param pCritSect The PDM critical section to enter.
320	* @param rcBusy The status code to return when we're in RC or R0
321	* and the section is busy. Pass VINF_SUCCESS to
322	* acquired the critical section thru a ring-3
323	* call if necessary.
324	*/
325	VMMDECL(int) PDMCritSectEnter(PPDMCRITSECT pCritSect, int rcBusy)
326	{
327	#ifndef PDMCRITSECT_STRICT
328	return pdmCritSectEnter(pCritSect, rcBusy, NULL);
329	#else
330	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
331	return pdmCritSectEnter(pCritSect, rcBusy, &SrcPos);
332	#endif
333	}
334
335
336	/**
337	* Enters a PDM critical section, with location information for debugging.
338	*
339	* @returns VINF_SUCCESS if entered successfully.
340	* @returns rcBusy when encountering a busy critical section in RC/R0.
341	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
342	* during the operation.
343	*
344	* @param pCritSect The PDM critical section to enter.
345	* @param rcBusy The status code to return when we're in RC or R0
346	* and the section is busy. Pass VINF_SUCCESS to
347	* acquired the critical section thru a ring-3
348	* call if necessary.
349	* @param uId Some kind of locking location ID. Typically a
350	* return address up the stack. Optional (0).
351	* @param pszFile The file where the lock is being acquired from.
352	* Optional.
353	* @param iLine The line number in that file. Optional (0).
354	* @param pszFunction The function where the lock is being acquired
355	* from. Optional.
356	*/
357	VMMDECL(int) PDMCritSectEnterDebug(PPDMCRITSECT pCritSect, int rcBusy, RTHCUINTPTR uId, RT_SRC_POS_DECL)
358	{
359	#ifdef PDMCRITSECT_STRICT
360	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
361	return pdmCritSectEnter(pCritSect, rcBusy, &SrcPos);
362	#else
363	NOREF(uId); RT_SRC_POS_NOREF();
364	return pdmCritSectEnter(pCritSect, rcBusy, NULL);
365	#endif
366	}
367
368
369	/**
370	* Common worker for the debug and normal APIs.
371	*
372	* @retval VINF_SUCCESS on success.
373	* @retval VERR_SEM_BUSY if the critsect was owned.
374	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
375	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
376	* during the operation.
377	*
378	* @param pCritSect The critical section.
379	*/
380	static int pdmCritSectTryEnter(PPDMCRITSECT pCritSect, PCRTLOCKVALSRCPOS pSrcPos)
381	{
382	/*
383	* If the critical section has already been destroyed, then inform the caller.
384	*/
385	AssertMsgReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC,
386	("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic),
387	VERR_SEM_DESTROYED);
388
389	/*
390	* See if we're lucky.
391	*/
392	/* NOP ... */
393	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
394	return VINF_SUCCESS;
395
396	RTNATIVETHREAD hNativeSelf = pdmCritSectGetNativeSelf(pCritSect);
397	/* ... not owned ... */
398	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, 0, -1))
399	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
400
401	/* ... or nested. */
402	if (pCritSect->s.Core.NativeThreadOwner == hNativeSelf)
403	{
404	ASMAtomicIncS32(&pCritSect->s.Core.cLockers);
405	ASMAtomicIncS32(&pCritSect->s.Core.cNestings);
406	Assert(pCritSect->s.Core.cNestings > 1);
407	return VINF_SUCCESS;
408	}
409
410	/* no spinning */
411
412	/*
413	* Return busy.
414	*/
415	#ifdef IN_RING3
416	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionR3);
417	#else
418	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZLock);
419	#endif
420	LogFlow(("PDMCritSectTryEnter: locked\n"));
421	return VERR_SEM_BUSY;
422	}
423
424
425	/**
426	* Try enter a critical section.
427	*
428	* @retval VINF_SUCCESS on success.
429	* @retval VERR_SEM_BUSY if the critsect was owned.
430	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
431	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
432	* during the operation.
433	*
434	* @param pCritSect The critical section.
435	*/
436	VMMDECL(int) PDMCritSectTryEnter(PPDMCRITSECT pCritSect)
437	{
438	#ifndef PDMCRITSECT_STRICT
439	return pdmCritSectTryEnter(pCritSect, NULL);
440	#else
441	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
442	return pdmCritSectTryEnter(pCritSect, &SrcPos);
443	#endif
444	}
445
446
447	/**
448	* Try enter a critical section, with location information for debugging.
449	*
450	* @retval VINF_SUCCESS on success.
451	* @retval VERR_SEM_BUSY if the critsect was owned.
452	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
453	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
454	* during the operation.
455	*
456	* @param pCritSect The critical section.
457	* @param uId Some kind of locking location ID. Typically a
458	* return address up the stack. Optional (0).
459	* @param pszFile The file where the lock is being acquired from.
460	* Optional.
461	* @param iLine The line number in that file. Optional (0).
462	* @param pszFunction The function where the lock is being acquired
463	* from. Optional.
464	*/
465	VMMDECL(int) PDMCritSectTryEnterDebug(PPDMCRITSECT pCritSect, RTHCUINTPTR uId, RT_SRC_POS_DECL)
466	{
467	#ifdef PDMCRITSECT_STRICT
468	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
469	return pdmCritSectTryEnter(pCritSect, &SrcPos);
470	#else
471	NOREF(uId); RT_SRC_POS_NOREF();
472	return pdmCritSectTryEnter(pCritSect, NULL);
473	#endif
474	}
475
476
477	#ifdef IN_RING3
478	/**
479	* Enters a PDM critical section.
480	*
481	* @returns VINF_SUCCESS if entered successfully.
482	* @returns rcBusy when encountering a busy critical section in GC/R0.
483	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
484	* during the operation.
485	*
486	* @param pCritSect The PDM critical section to enter.
487	* @param fCallRing3 Whether this is a VMMRZCallRing3()request.
488	*/
489	VMMR3DECL(int) PDMR3CritSectEnterEx(PPDMCRITSECT pCritSect, bool fCallRing3)
490	{
491	int rc = PDMCritSectEnter(pCritSect, VERR_IGNORED);
492	if ( rc == VINF_SUCCESS
493	&& fCallRing3
494	&& pCritSect->s.Core.pValidatorRec
495	&& pCritSect->s.Core.pValidatorRec->hThread != NIL_RTTHREAD)
496	RTLockValidatorRecExclReleaseOwnerUnchecked(pCritSect->s.Core.pValidatorRec);
497	return rc;
498	}
499	#endif /* IN_RING3 */
500
501
502	/**
503	* Leaves a critical section entered with PDMCritSectEnter().
504	*
505	* @returns Indication whether we really exited the critical section.
506	* @retval VINF_SUCCESS if we really exited.
507	* @retval VINF_SEM_NESTED if we only reduced the nesting count.
508	* @retval VERR_NOT_OWNER if you somehow ignore release assertions.
509	*
510	* @param pCritSect The PDM critical section to leave.
511	*/
512	VMMDECL(int) PDMCritSectLeave(PPDMCRITSECT pCritSect)
513	{
514	AssertMsg(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, ("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic));
515	Assert(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC);
516
517	/* Check for NOP sections before asserting ownership. */
518	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
519	return VINF_SUCCESS;
520
521	/*
522	* Always check that the caller is the owner (screw performance).
523	*/
524	RTNATIVETHREAD const hNativeSelf = pdmCritSectGetNativeSelf(pCritSect);
525	AssertReleaseMsgReturn(pCritSect->s.Core.NativeThreadOwner == hNativeSelf,
526	("%p %s: %p != %p; cLockers=%d cNestings=%d\n", pCritSect, R3STRING(pCritSect->s.pszName),
527	pCritSect->s.Core.NativeThreadOwner, hNativeSelf,
528	pCritSect->s.Core.cLockers, pCritSect->s.Core.cNestings),
529	VERR_NOT_OWNER);
530	Assert(pCritSect->s.Core.cNestings >= 1);
531
532	/*
533	* Nested leave.
534	*/
535	if (pCritSect->s.Core.cNestings > 1)
536	{
537	ASMAtomicDecS32(&pCritSect->s.Core.cNestings);
538	Assert(pCritSect->s.Core.cNestings >= 1);
539	ASMAtomicDecS32(&pCritSect->s.Core.cLockers);
540	Assert(pCritSect->s.Core.cLockers >= 0);
541	return VINF_SEM_NESTED;
542	}
543
544	#ifdef IN_RING0
545	# if 0 /** @todo Make SUPSemEventSignal interrupt safe (handle table++) and enable this for: defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2) */
546	if (1) /* SUPSemEventSignal is safe */
547	# else
548	if (ASMIntAreEnabled())
549	# endif
550	#endif
551	#if defined(IN_RING3) \|\| defined(IN_RING0)
552	{
553	/*
554	* Leave for real.
555	*/
556	/* update members. */
557	# ifdef IN_RING3
558	RTSEMEVENT hEventToSignal = pCritSect->s.EventToSignal;
559	pCritSect->s.EventToSignal = NIL_RTSEMEVENT;
560	# if defined(PDMCRITSECT_STRICT)
561	if (pCritSect->s.Core.pValidatorRec->hThread != NIL_RTTHREAD)
562	RTLockValidatorRecExclReleaseOwnerUnchecked(pCritSect->s.Core.pValidatorRec);
563	# endif
564	Assert(!pCritSect->s.Core.pValidatorRec \|\| pCritSect->s.Core.pValidatorRec->hThread == NIL_RTTHREAD);
565	# endif
566	ASMAtomicAndU32(&pCritSect->s.Core.fFlags, ~PDMCRITSECT_FLAGS_PENDING_UNLOCK);
567	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, NIL_RTNATIVETHREAD);
568	ASMAtomicDecS32(&pCritSect->s.Core.cNestings);
569	Assert(pCritSect->s.Core.cNestings == 0);
570
571	/* stop and decrement lockers. */
572	STAM_PROFILE_ADV_STOP(&pCritSect->s.StatLocked, l);
573	ASMCompilerBarrier();
574	if (ASMAtomicDecS32(&pCritSect->s.Core.cLockers) >= 0)
575	{
576	/* Someone is waiting, wake up one of them. */
577	SUPSEMEVENT hEvent = (SUPSEMEVENT)pCritSect->s.Core.EventSem;
578	PSUPDRVSESSION pSession = pCritSect->s.CTX_SUFF(pVM)->pSession;
579	int rc = SUPSemEventSignal(pSession, hEvent);
580	AssertRC(rc);
581	}
582
583	# ifdef IN_RING3
584	/* Signal exit event. */
585	if (hEventToSignal != NIL_RTSEMEVENT)
586	{
587	LogBird(("Signalling %#x\n", hEventToSignal));
588	int rc = RTSemEventSignal(hEventToSignal);
589	AssertRC(rc);
590	}
591	# endif
592
593	# if defined(DEBUG_bird) && defined(IN_RING0)
594	VMMTrashVolatileXMMRegs();
595	# endif
596	}
597	#endif /* IN_RING3 \|\| IN_RING0 */
598	#ifdef IN_RING0
599	else
600	#endif
601	#if defined(IN_RING0) \|\| defined(IN_RC)
602	{
603	/*
604	* Try leave it.
605	*/
606	if (pCritSect->s.Core.cLockers == 0)
607	{
608	ASMAtomicWriteS32(&pCritSect->s.Core.cNestings, 0);
609	RTNATIVETHREAD hNativeThread = pCritSect->s.Core.NativeThreadOwner;
610	ASMAtomicAndU32(&pCritSect->s.Core.fFlags, ~PDMCRITSECT_FLAGS_PENDING_UNLOCK);
611	STAM_PROFILE_ADV_STOP(&pCritSect->s.StatLocked, l);
612
613	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, NIL_RTNATIVETHREAD);
614	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, -1, 0))
615	return VINF_SUCCESS;
616
617	/* darn, someone raced in on us. */
618	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, hNativeThread);
619	STAM_PROFILE_ADV_START(&pCritSect->s.StatLocked, l);
620	Assert(pCritSect->s.Core.cNestings == 0);
621	ASMAtomicWriteS32(&pCritSect->s.Core.cNestings, 1);
622	}
623	ASMAtomicOrU32(&pCritSect->s.Core.fFlags, PDMCRITSECT_FLAGS_PENDING_UNLOCK);
624
625	/*
626	* Queue the request.
627	*/
628	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
629	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
630	uint32_t i = pVCpu->pdm.s.cQueuedCritSectLeaves++;
631	LogFlow(("PDMCritSectLeave: [%d]=%p => R3\n", i, pCritSect));
632	AssertFatal(i < RT_ELEMENTS(pVCpu->pdm.s.apQueuedCritSectLeaves));
633	pVCpu->pdm.s.apQueuedCritSectLeaves[i] = MMHyperCCToR3(pVM, pCritSect);
634	VMCPU_FF_SET(pVCpu, VMCPU_FF_PDM_CRITSECT);
635	VMCPU_FF_SET(pVCpu, VMCPU_FF_TO_R3);
636	STAM_REL_COUNTER_INC(&pVM->pdm.s.StatQueuedCritSectLeaves);
637	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZUnlock);
638	}
639	#endif /* IN_RING0 \|\| IN_RC */
640
641	return VINF_SUCCESS;
642	}
643
644
645	/**
646	* Checks the caller is the owner of the critical section.
647	*
648	* @returns true if owner.
649	* @returns false if not owner.
650	* @param pCritSect The critical section.
651	*/
652	VMMDECL(bool) PDMCritSectIsOwner(PCPDMCRITSECT pCritSect)
653	{
654	#ifdef IN_RING3
655	return RTCritSectIsOwner(&pCritSect->s.Core);
656	#else
657	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
658	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
659	if (pCritSect->s.Core.NativeThreadOwner != pVCpu->hNativeThread)
660	return false;
661	return (pCritSect->s.Core.fFlags & PDMCRITSECT_FLAGS_PENDING_UNLOCK) == 0
662	\|\| pCritSect->s.Core.cNestings > 1;
663	#endif
664	}
665
666
667	/**
668	* Checks the specified VCPU 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	* @param pVCpu Pointer to the VMCPU.
674	*/
675	VMMDECL(bool) PDMCritSectIsOwnerEx(PCPDMCRITSECT pCritSect, PVMCPU pVCpu)
676	{
677	#ifdef IN_RING3
678	NOREF(pVCpu);
679	return RTCritSectIsOwner(&pCritSect->s.Core);
680	#else
681	Assert(&pVCpu->CTX_SUFF(pVM)->aCpus[pVCpu->idCpu] == pVCpu);
682	if (pCritSect->s.Core.NativeThreadOwner != pVCpu->hNativeThread)
683	return false;
684	return (pCritSect->s.Core.fFlags & PDMCRITSECT_FLAGS_PENDING_UNLOCK) == 0
685	\|\| pCritSect->s.Core.cNestings > 1;
686	#endif
687	}
688
689
690	/**
691	* Checks if anyone is waiting on the critical section we own.
692	*
693	* @returns true if someone is waiting.
694	* @returns false if no one is waiting.
695	* @param pCritSect The critical section.
696	*/
697	VMMDECL(bool) PDMCritSectHasWaiters(PCPDMCRITSECT pCritSect)
698	{
699	AssertReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, false);
700	Assert(pCritSect->s.Core.NativeThreadOwner == pdmCritSectGetNativeSelf(pCritSect));
701	return pCritSect->s.Core.cLockers >= pCritSect->s.Core.cNestings;
702	}
703
704
705	/**
706	* Checks if a critical section is initialized or not.
707	*
708	* @returns true if initialized.
709	* @returns false if not initialized.
710	* @param pCritSect The critical section.
711	*/
712	VMMDECL(bool) PDMCritSectIsInitialized(PCPDMCRITSECT pCritSect)
713	{
714	return RTCritSectIsInitialized(&pCritSect->s.Core);
715	}
716
717
718	/**
719	* Gets the recursion depth.
720	*
721	* @returns The recursion depth.
722	* @param pCritSect The critical section.
723	*/
724	VMMDECL(uint32_t) PDMCritSectGetRecursion(PCPDMCRITSECT pCritSect)
725	{
726	return RTCritSectGetRecursion(&pCritSect->s.Core);
727	}
728

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source: vbox/trunk/src/VBox/VMM/VMMAll/PDMAllCritSect.cpp@ 46422

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