PDMAllCritSect.cpp@ 38082

Last change on this file since 38082 was 38081, checked in by vboxsync, 14 years ago
PDMCritSectLeave: Release assertion if not owner.
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1	/* $Id: PDMAllCritSect.cpp 38081 2011-07-20 14:21:36Z 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	#ifndef PDMCRITSECT_STRICT
323	return pdmCritSectEnter(pCritSect, rcBusy, NULL);
324	#else
325	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
326	return pdmCritSectEnter(pCritSect, rcBusy, &SrcPos);
327	#endif
328	}
329
330
331	/**
332	* Enters a PDM critical section, with location information for debugging.
333	*
334	* @returns VINF_SUCCESS if entered successfully.
335	* @returns rcBusy when encountering a busy critical section in GC/R0.
336	* @returns VERR_SEM_DESTROYED if the critical section is dead.
337	*
338	* @param pCritSect The PDM critical section to enter.
339	* @param rcBusy The status code to return when we're in GC or R0
340	* and the section is busy. Pass VINF_SUCCESS to
341	* acquired the critical section thru a ring-3
342	* call if necessary.
343	* @param uId Some kind of locking location ID. Typically a
344	* return address up the stack. Optional (0).
345	* @param pszFile The file where the lock is being acquired from.
346	* Optional.
347	* @param iLine The line number in that file. Optional (0).
348	* @param pszFunction The function where the lock is being acquired
349	* from. Optional.
350	*/
351	VMMDECL(int) PDMCritSectEnterDebug(PPDMCRITSECT pCritSect, int rcBusy, RTHCUINTPTR uId, RT_SRC_POS_DECL)
352	{
353	#ifdef PDMCRITSECT_STRICT
354	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
355	return pdmCritSectEnter(pCritSect, rcBusy, &SrcPos);
356	#else
357	return pdmCritSectEnter(pCritSect, rcBusy, NULL);
358	#endif
359	}
360
361
362	/**
363	* Common worker for the debug and normal APIs.
364	*
365	* @retval VINF_SUCCESS on success.
366	* @retval VERR_SEM_BUSY if the critsect was owned.
367	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
368	* @retval VERR_SEM_DESTROYED if RTCritSectDelete was called while waiting.
369	*
370	* @param pCritSect The critical section.
371	*/
372	static int pdmCritSectTryEnter(PPDMCRITSECT pCritSect, PCRTLOCKVALSRCPOS pSrcPos)
373	{
374	/*
375	* If the critical section has already been destroyed, then inform the caller.
376	*/
377	AssertMsgReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC,
378	("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic),
379	VERR_SEM_DESTROYED);
380
381	/*
382	* See if we're lucky.
383	*/
384	/* NOP ... */
385	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
386	return VINF_SUCCESS;
387
388	RTNATIVETHREAD hNativeSelf = pdmCritSectGetNativeSelf(pCritSect);
389	/* ... not owned ... */
390	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, 0, -1))
391	return pdmCritSectEnterFirst(pCritSect, hNativeSelf, pSrcPos);
392
393	/* ... or nested. */
394	if (pCritSect->s.Core.NativeThreadOwner == hNativeSelf)
395	{
396	ASMAtomicIncS32(&pCritSect->s.Core.cLockers);
397	ASMAtomicIncS32(&pCritSect->s.Core.cNestings);
398	Assert(pCritSect->s.Core.cNestings > 1);
399	return VINF_SUCCESS;
400	}
401
402	/* no spinning */
403
404	/*
405	* Return busy.
406	*/
407	#ifdef IN_RING3
408	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionR3);
409	#else
410	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZLock);
411	#endif
412	LogFlow(("PDMCritSectTryEnter: locked\n"));
413	return VERR_SEM_BUSY;
414	}
415
416
417	/**
418	* Try enter a critical section.
419	*
420	* @retval VINF_SUCCESS on success.
421	* @retval VERR_SEM_BUSY if the critsect was owned.
422	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
423	* @retval VERR_SEM_DESTROYED if RTCritSectDelete was called while waiting.
424	*
425	* @param pCritSect The critical section.
426	*/
427	VMMDECL(int) PDMCritSectTryEnter(PPDMCRITSECT pCritSect)
428	{
429	#ifndef PDMCRITSECT_STRICT
430	return pdmCritSectTryEnter(pCritSect, NULL);
431	#else
432	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
433	return pdmCritSectTryEnter(pCritSect, &SrcPos);
434	#endif
435	}
436
437
438	/**
439	* Try enter a critical section, with location information for debugging.
440	*
441	* @retval VINF_SUCCESS on success.
442	* @retval VERR_SEM_BUSY if the critsect was owned.
443	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
444	* @retval VERR_SEM_DESTROYED if RTCritSectDelete was called while waiting.
445	*
446	* @param pCritSect The critical section.
447	* @param uId Some kind of locking location ID. Typically a
448	* return address up the stack. Optional (0).
449	* @param pszFile The file where the lock is being acquired from.
450	* Optional.
451	* @param iLine The line number in that file. Optional (0).
452	* @param pszFunction The function where the lock is being acquired
453	* from. Optional.
454	*/
455	VMMDECL(int) PDMCritSectTryEnterDebug(PPDMCRITSECT pCritSect, RTHCUINTPTR uId, RT_SRC_POS_DECL)
456	{
457	#ifdef PDMCRITSECT_STRICT
458	RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
459	return pdmCritSectTryEnter(pCritSect, &SrcPos);
460	#else
461	return pdmCritSectTryEnter(pCritSect, NULL);
462	#endif
463	}
464
465
466	#ifdef IN_RING3
467	/**
468	* Enters a PDM critical section.
469	*
470	* @returns VINF_SUCCESS if entered successfully.
471	* @returns rcBusy when encountering a busy critical section in GC/R0.
472	* @returns VERR_SEM_DESTROYED if the critical section is dead.
473	*
474	* @param pCritSect The PDM critical section to enter.
475	* @param fCallRing3 Whether this is a VMMRZCallRing3()request.
476	*/
477	VMMR3DECL(int) PDMR3CritSectEnterEx(PPDMCRITSECT pCritSect, bool fCallRing3)
478	{
479	int rc = PDMCritSectEnter(pCritSect, VERR_INTERNAL_ERROR);
480	if ( rc == VINF_SUCCESS
481	&& fCallRing3
482	&& pCritSect->s.Core.pValidatorRec
483	&& pCritSect->s.Core.pValidatorRec->hThread != NIL_RTTHREAD)
484	RTLockValidatorRecExclReleaseOwnerUnchecked(pCritSect->s.Core.pValidatorRec);
485	return rc;
486	}
487	#endif /* IN_RING3 */
488
489
490	/**
491	* Leaves a critical section entered with PDMCritSectEnter().
492	*
493	* @param pCritSect The PDM critical section to leave.
494	*/
495	VMMDECL(void) PDMCritSectLeave(PPDMCRITSECT pCritSect)
496	{
497	AssertMsg(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, ("%p %RX32\n", pCritSect, pCritSect->s.Core.u32Magic));
498	Assert(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC);
499
500	/* Check for NOP sections before asserting ownership. */
501	if (pCritSect->s.Core.fFlags & RTCRITSECT_FLAGS_NOP)
502	return;
503
504	/*
505	* Always check that the caller is the owner (screw performance).
506	*/
507	RTNATIVETHREAD const hNativeSelf = pdmCritSectGetNativeSelf(pCritSect);
508	AssertReleaseMsgReturnVoid(pCritSect->s.Core.NativeThreadOwner == hNativeSelf,
509	("%p %s: %p != %p; cLockers=%d cNestings=%d\n", pCritSect, R3STRING(pCritSect->s.pszName),
510	pCritSect->s.Core.NativeThreadOwner, hNativeSelf,
511	pCritSect->s.Core.cLockers, pCritSect->s.Core.cNestings));
512	Assert(pCritSect->s.Core.cNestings >= 1);
513
514	/*
515	* Nested leave.
516	*/
517	if (pCritSect->s.Core.cNestings > 1)
518	{
519	ASMAtomicDecS32(&pCritSect->s.Core.cNestings);
520	Assert(pCritSect->s.Core.cNestings >= 1);
521	ASMAtomicDecS32(&pCritSect->s.Core.cLockers);
522	Assert(pCritSect->s.Core.cLockers >= 0);
523	return;
524	}
525
526	#ifdef IN_RING0
527	# if 0 /** @todo Make SUPSemEventSignal interrupt safe (handle table++) and enable this for: defined(RT_OS_LINUX) \|\| defined(RT_OS_OS2) */
528	if (1) /* SUPSemEventSignal is safe */
529	# else
530	if (ASMIntAreEnabled())
531	# endif
532	#endif
533	#if defined(IN_RING3) \|\| defined(IN_RING0)
534	{
535	/*
536	* Leave for real.
537	*/
538	/* update members. */
539	# ifdef IN_RING3
540	RTSEMEVENT hEventToSignal = pCritSect->s.EventToSignal;
541	pCritSect->s.EventToSignal = NIL_RTSEMEVENT;
542	# if defined(PDMCRITSECT_STRICT)
543	if (pCritSect->s.Core.pValidatorRec->hThread != NIL_RTTHREAD)
544	RTLockValidatorRecExclReleaseOwnerUnchecked(pCritSect->s.Core.pValidatorRec);
545	# endif
546	Assert(!pCritSect->s.Core.pValidatorRec \|\| pCritSect->s.Core.pValidatorRec->hThread == NIL_RTTHREAD);
547	# endif
548	ASMAtomicAndU32(&pCritSect->s.Core.fFlags, ~PDMCRITSECT_FLAGS_PENDING_UNLOCK);
549	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, NIL_RTNATIVETHREAD);
550	ASMAtomicDecS32(&pCritSect->s.Core.cNestings);
551	Assert(pCritSect->s.Core.cNestings == 0);
552
553	/* stop and decrement lockers. */
554	STAM_PROFILE_ADV_STOP(&pCritSect->s.StatLocked, l);
555	ASMCompilerBarrier();
556	if (ASMAtomicDecS32(&pCritSect->s.Core.cLockers) >= 0)
557	{
558	/* Someone is waiting, wake up one of them. */
559	SUPSEMEVENT hEvent = (SUPSEMEVENT)pCritSect->s.Core.EventSem;
560	PSUPDRVSESSION pSession = pCritSect->s.CTX_SUFF(pVM)->pSession;
561	int rc = SUPSemEventSignal(pSession, hEvent);
562	AssertRC(rc);
563	}
564
565	# ifdef IN_RING3
566	/* Signal exit event. */
567	if (hEventToSignal != NIL_RTSEMEVENT)
568	{
569	LogBird(("Signalling %#x\n", hEventToSignal));
570	int rc = RTSemEventSignal(hEventToSignal);
571	AssertRC(rc);
572	}
573	# endif
574
575	# if defined(DEBUG_bird) && defined(IN_RING0)
576	VMMTrashVolatileXMMRegs();
577	# endif
578	}
579	#endif /* IN_RING3 \|\| IN_RING0 */
580	#ifdef IN_RING0
581	else
582	#endif
583	#if defined(IN_RING0) \|\| defined(IN_RC)
584	{
585	/*
586	* Try leave it.
587	*/
588	if (pCritSect->s.Core.cLockers == 0)
589	{
590	ASMAtomicWriteS32(&pCritSect->s.Core.cNestings, 0);
591	RTNATIVETHREAD hNativeThread = pCritSect->s.Core.NativeThreadOwner;
592	ASMAtomicAndU32(&pCritSect->s.Core.fFlags, ~PDMCRITSECT_FLAGS_PENDING_UNLOCK);
593	STAM_PROFILE_ADV_STOP(&pCritSect->s.StatLocked, l);
594
595	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, NIL_RTNATIVETHREAD);
596	if (ASMAtomicCmpXchgS32(&pCritSect->s.Core.cLockers, -1, 0))
597	return;
598
599	/* darn, someone raced in on us. */
600	ASMAtomicWriteHandle(&pCritSect->s.Core.NativeThreadOwner, hNativeThread);
601	STAM_PROFILE_ADV_START(&pCritSect->s.StatLocked, l);
602	Assert(pCritSect->s.Core.cNestings == 0);
603	ASMAtomicWriteS32(&pCritSect->s.Core.cNestings, 1);
604	}
605	ASMAtomicOrU32(&pCritSect->s.Core.fFlags, PDMCRITSECT_FLAGS_PENDING_UNLOCK);
606
607	/*
608	* Queue the request.
609	*/
610	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
611	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
612	uint32_t i = pVCpu->pdm.s.cQueuedCritSectLeaves++;
613	LogFlow(("PDMCritSectLeave: [%d]=%p => R3\n", i, pCritSect));
614	AssertFatal(i < RT_ELEMENTS(pVCpu->pdm.s.apQueuedCritSectsLeaves));
615	pVCpu->pdm.s.apQueuedCritSectsLeaves[i] = MMHyperCCToR3(pVM, pCritSect);
616	VMCPU_FF_SET(pVCpu, VMCPU_FF_PDM_CRITSECT);
617	VMCPU_FF_SET(pVCpu, VMCPU_FF_TO_R3);
618	STAM_REL_COUNTER_INC(&pVM->pdm.s.StatQueuedCritSectLeaves);
619	STAM_REL_COUNTER_INC(&pCritSect->s.StatContentionRZUnlock);
620	}
621	#endif /* IN_RING0 \|\| IN_RC */
622	}
623
624
625	#if defined(IN_RING3) \|\| defined(IN_RING0)
626	/**
627	* Process the critical sections queued for ring-3 'leave'.
628	*
629	* @param pVCpu The VMCPU handle.
630	*/
631	VMMDECL(void) PDMCritSectFF(PVMCPU pVCpu)
632	{
633	Assert(pVCpu->pdm.s.cQueuedCritSectLeaves > 0);
634
635	const RTUINT c = pVCpu->pdm.s.cQueuedCritSectLeaves;
636	for (RTUINT i = 0; i < c; i++)
637	{
638	# ifdef IN_RING3
639	PPDMCRITSECT pCritSect = pVCpu->pdm.s.apQueuedCritSectsLeaves[i];
640	# else
641	PPDMCRITSECT pCritSect = (PPDMCRITSECT)MMHyperR3ToCC(pVCpu->CTX_SUFF(pVM), pVCpu->pdm.s.apQueuedCritSectsLeaves[i]);
642	# endif
643
644	PDMCritSectLeave(pCritSect);
645	LogFlow(("PDMR3CritSectFF: %p\n", pCritSect));
646	}
647
648	pVCpu->pdm.s.cQueuedCritSectLeaves = 0;
649	VMCPU_FF_CLEAR(pVCpu, VMCPU_FF_PDM_CRITSECT);
650	}
651	#endif /* IN_RING3 \|\| IN_RING0 */
652
653
654	/**
655	* Checks the caller is the owner of the critical section.
656	*
657	* @returns true if owner.
658	* @returns false if not owner.
659	* @param pCritSect The critical section.
660	*/
661	VMMDECL(bool) PDMCritSectIsOwner(PCPDMCRITSECT pCritSect)
662	{
663	#ifdef IN_RING3
664	return RTCritSectIsOwner(&pCritSect->s.Core);
665	#else
666	PVM pVM = pCritSect->s.CTX_SUFF(pVM); AssertPtr(pVM);
667	PVMCPU pVCpu = VMMGetCpu(pVM); AssertPtr(pVCpu);
668	if (pCritSect->s.Core.NativeThreadOwner != pVCpu->hNativeThread)
669	return false;
670	return (pCritSect->s.Core.fFlags & PDMCRITSECT_FLAGS_PENDING_UNLOCK) == 0
671	\|\| pCritSect->s.Core.cNestings > 1;
672	#endif
673	}
674
675
676	/**
677	* Checks the specified VCPU is the owner of the critical section.
678	*
679	* @returns true if owner.
680	* @returns false if not owner.
681	* @param pCritSect The critical section.
682	* @param pVCpu The virtual CPU handle.
683	*/
684	VMMDECL(bool) PDMCritSectIsOwnerEx(PCPDMCRITSECT pCritSect, PVMCPU pVCpu)
685	{
686	#ifdef IN_RING3
687	NOREF(pVCpu);
688	return RTCritSectIsOwner(&pCritSect->s.Core);
689	#else
690	Assert(&pVCpu->CTX_SUFF(pVM)->aCpus[pVCpu->idCpu] == pVCpu);
691	if (pCritSect->s.Core.NativeThreadOwner != pVCpu->hNativeThread)
692	return false;
693	return (pCritSect->s.Core.fFlags & PDMCRITSECT_FLAGS_PENDING_UNLOCK) == 0
694	\|\| pCritSect->s.Core.cNestings > 1;
695	#endif
696	}
697
698
699	/**
700	* Checks if anyone is waiting on the critical section we own.
701	*
702	* @returns true if someone is waiting.
703	* @returns false if no one is waiting.
704	* @param pCritSect The critical section.
705	*/
706	VMMDECL(bool) PDMCritSectHasWaiters(PCPDMCRITSECT pCritSect)
707	{
708	AssertReturn(pCritSect->s.Core.u32Magic == RTCRITSECT_MAGIC, false);
709	Assert(pCritSect->s.Core.NativeThreadOwner == pdmCritSectGetNativeSelf(pCritSect));
710	return pCritSect->s.Core.cLockers >= pCritSect->s.Core.cNestings;
711	}
712
713
714	/**
715	* Checks if a critical section is initialized or not.
716	*
717	* @returns true if initialized.
718	* @returns false if not initialized.
719	* @param pCritSect The critical section.
720	*/
721	VMMDECL(bool) PDMCritSectIsInitialized(PCPDMCRITSECT pCritSect)
722	{
723	return RTCritSectIsInitialized(&pCritSect->s.Core);
724	}
725
726
727	/**
728	* Gets the recursion depth.
729	*
730	* @returns The recursion depth.
731	* @param pCritSect The critical section.
732	*/
733	VMMDECL(uint32_t) PDMCritSectGetRecursion(PCPDMCRITSECT pCritSect)
734	{
735	return RTCritSectGetRecursion(&pCritSect->s.Core);
736	}

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source: vbox/trunk/src/VBox/VMM/VMMAll/PDMAllCritSect.cpp@ 38082

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