critsect.h@ 48418

Last change on this file since 48418 was 45151, checked in by vboxsync, 12 years ago
iprt/critsect.h: Cleanups (R/W mostly).
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1	/** @file
2	* IPRT - Critical Sections.
3	*/
4
5	/*
6	* Copyright (C) 2006-2013 Oracle Corporation
7	*
8	* This file is part of VirtualBox Open Source Edition (OSE), as
9	* available from http://www.virtualbox.org. This file is free software;
10	* you can redistribute it and/or modify it under the terms of the GNU
11	* General Public License (GPL) as published by the Free Software
12	* Foundation, in version 2 as it comes in the "COPYING" file of the
13	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
14	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
15	*
16	* The contents of this file may alternatively be used under the terms
17	* of the Common Development and Distribution License Version 1.0
18	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
19	* VirtualBox OSE distribution, in which case the provisions of the
20	* CDDL are applicable instead of those of the GPL.
21	*
22	* You may elect to license modified versions of this file under the
23	* terms and conditions of either the GPL or the CDDL or both.
24	*/
25
26	#ifndef ___iprt_critsect_h
27	#define ___iprt_critsect_h
28
29	#include <iprt/cdefs.h>
30	#include <iprt/types.h>
31	#include <iprt/assert.h>
32	#ifdef IN_RING3
33	# include <iprt/thread.h>
34	#endif
35	#ifdef RT_LOCK_STRICT_ORDER
36	# include <iprt/lockvalidator.h>
37	#endif
38
39	RT_C_DECLS_BEGIN
40
41	/** @defgroup grp_rt_critsect RTCritSect - Critical Sections
42	*
43	* "Critical section" synchronization primitives can be used to
44	* protect a section of code or data to which access must be exclusive;
45	* only one thread can hold access to a critical section at one time.
46	*
47	* A critical section is a fast recursive write lock; if the critical
48	* section is not acquired, then entering it is fast (requires no system
49	* call). IPRT uses the Windows terminology here; on other platform, this
50	* might be called a "futex" or a "fast mutex". As opposed to IPRT
51	* "fast mutexes" (see @ref grp_rt_sems_fast_mutex ), critical sections
52	* are recursive.
53	*
54	* Use RTCritSectInit to initialize a critical section; use RTCritSectEnter
55	* and RTCritSectLeave to acquire and release access.
56	*
57	* For an overview of all types of synchronization primitives provided
58	* by IPRT (event, mutex/fast mutex/read-write mutex semaphores), see
59	* @ref grp_rt_sems .
60	*
61	* @ingroup grp_rt
62	* @{
63	*/
64
65	/**
66	* Critical section.
67	*/
68	typedef struct RTCRITSECT
69	{
70	/** Magic used to validate the section state.
71	* RTCRITSECT_MAGIC is the value of an initialized & operational section. */
72	volatile uint32_t u32Magic;
73	/** Number of lockers.
74	* -1 if the section is free. */
75	volatile int32_t cLockers;
76	/** The owner thread. */
77	volatile RTNATIVETHREAD NativeThreadOwner;
78	/** Number of nested enter operations performed.
79	* Greater or equal to 1 if owned, 0 when free.
80	*/
81	volatile int32_t cNestings;
82	/** Section flags - the RTCRITSECT_FLAGS_* \#defines. */
83	uint32_t fFlags;
84	/** The semaphore to block on. */
85	RTSEMEVENT EventSem;
86	/** Lock validator record. Only used in strict builds. */
87	R3R0PTRTYPE(PRTLOCKVALRECEXCL) pValidatorRec;
88	/** Alignmnet padding. */
89	RTHCPTR Alignment;
90	} RTCRITSECT;
91	AssertCompileSize(RTCRITSECT, HC_ARCH_BITS == 32 ? 32 : 48);
92
93	/** RTCRITSECT::u32Magic value. (Hiromi Uehara) */
94	#define RTCRITSECT_MAGIC UINT32_C(0x19790326)
95
96	/** @name RTCritSectInitEx flags / RTCRITSECT::fFlags
97	* @{ */
98	/** If set, nesting(/recursion) is not allowed. */
99	#define RTCRITSECT_FLAGS_NO_NESTING UINT32_C(0x00000001)
100	/** Disables lock validation. */
101	#define RTCRITSECT_FLAGS_NO_LOCK_VAL UINT32_C(0x00000002)
102	/** Bootstrap hack for use with certain memory allocator locks only! */
103	#define RTCRITSECT_FLAGS_BOOTSTRAP_HACK UINT32_C(0x00000004)
104	/** If set, the critical section becomes a dummy that doesn't serialize any
105	* threads. This flag can only be set at creation time.
106	*
107	* The intended use is avoiding lots of conditional code where some component
108	* might or might not require entering a critical section before access. */
109	#define RTCRITSECT_FLAGS_NOP UINT32_C(0x00000008)
110	/** @} */
111
112
113	#ifdef IN_RING3
114
115	/**
116	* Initialize a critical section.
117	*/
118	RTDECL(int) RTCritSectInit(PRTCRITSECT pCritSect);
119
120	/**
121	* Initialize a critical section.
122	*
123	* @returns iprt status code.
124	* @param pCritSect Pointer to the critical section structure.
125	* @param fFlags Flags, any combination of the RTCRITSECT_FLAGS
126	* \#defines.
127	* @param hClass The class (no reference consumed). If NIL, no lock
128	* order validation will be performed on this lock.
129	* @param uSubClass The sub-class. This is used to define lock order
130	* within a class. RTLOCKVAL_SUB_CLASS_NONE is the
131	* recommended value here.
132	* @param pszNameFmt Name format string for the lock validator, optional
133	* (NULL). Max length is 32 bytes.
134	* @param ... Format string arguments.
135	*/
136	RTDECL(int) RTCritSectInitEx(PRTCRITSECT pCritSect, uint32_t fFlags,
137	RTLOCKVALCLASS hClass, uint32_t uSubClass, const char *pszNameFmt, ...);
138
139	/**
140	* Changes the lock validator sub-class of the critical section.
141	*
142	* It is recommended to try make sure that nobody is using this critical section
143	* while changing the value.
144	*
145	* @returns The old sub-class. RTLOCKVAL_SUB_CLASS_INVALID is returns if the
146	* lock validator isn't compiled in or either of the parameters are
147	* invalid.
148	* @param pCritSect The critical section.
149	* @param uSubClass The new sub-class value.
150	*/
151	RTDECL(uint32_t) RTCritSectSetSubClass(PRTCRITSECT pCritSect, uint32_t uSubClass);
152
153	/**
154	* Enter a critical section.
155	*
156	* @returns VINF_SUCCESS on success.
157	* @returns VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
158	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
159	* during the operation.
160	* @param pCritSect The critical section.
161	*/
162	RTDECL(int) RTCritSectEnter(PRTCRITSECT pCritSect);
163
164	/**
165	* Enter a critical section.
166	*
167	* @returns IPRT status code.
168	* @retval VINF_SUCCESS on success.
169	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
170	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
171	* during the operation.
172	*
173	* @param pCritSect The critical section.
174	* @param uId Where we're entering the section.
175	* @param pszFile The source position - file.
176	* @param iLine The source position - line.
177	* @param pszFunction The source position - function.
178	*/
179	RTDECL(int) RTCritSectEnterDebug(PRTCRITSECT pCritSect, RTHCUINTPTR uId, RT_SRC_POS_DECL);
180
181	/**
182	* Try enter a critical section.
183	*
184	* @retval VINF_SUCCESS on success.
185	* @retval VERR_SEM_BUSY if the critsect was owned.
186	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
187	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
188	* during the operation.
189	*
190	* @param pCritSect The critical section.
191	*/
192	RTDECL(int) RTCritSectTryEnter(PRTCRITSECT pCritSect);
193
194	/**
195	* Try enter a critical section.
196	*
197	* @retval VINF_SUCCESS on success.
198	* @retval VERR_SEM_BUSY if the critsect was owned.
199	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
200	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
201	* during the operation.
202	*
203	* @param pCritSect The critical section.
204	* @param uId Where we're entering the section.
205	* @param pszFile The source position - file.
206	* @param iLine The source position - line.
207	* @param pszFunction The source position - function.
208	*/
209	RTDECL(int) RTCritSectTryEnterDebug(PRTCRITSECT pCritSect, RTHCUINTPTR uId, RT_SRC_POS_DECL);
210
211	/**
212	* Enter multiple critical sections.
213	*
214	* This function will enter ALL the specified critical sections before returning.
215	*
216	* @returns VINF_SUCCESS on success.
217	* @returns VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
218	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
219	* during the operation.
220	* @param cCritSects Number of critical sections in the array.
221	* @param papCritSects Array of critical section pointers.
222	*
223	* @remark Please note that this function will not necessarily come out favourable in a
224	* fight with other threads which are using the normal RTCritSectEnter() function.
225	* Therefore, avoid having to enter multiple critical sections!
226	*/
227	RTDECL(int) RTCritSectEnterMultiple(size_t cCritSects, PRTCRITSECT *papCritSects);
228
229	/**
230	* Enter multiple critical sections.
231	*
232	* This function will enter ALL the specified critical sections before returning.
233	*
234	* @returns VINF_SUCCESS on success.
235	* @returns VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
236	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
237	* during the operation.
238	*
239	* @param cCritSects Number of critical sections in the array.
240	* @param papCritSects Array of critical section pointers.
241	* @param uId Where we're entering the section.
242	* @param pszFile The source position - file.
243	* @param iLine The source position - line.
244	* @param pszFunction The source position - function.
245	*
246	* @remark See RTCritSectEnterMultiple().
247	*/
248	RTDECL(int) RTCritSectEnterMultipleDebug(size_t cCritSects, PRTCRITSECT *papCritSects, RTUINTPTR uId, RT_SRC_POS_DECL);
249
250	/**
251	* Leave a critical section.
252	*
253	* @returns VINF_SUCCESS.
254	* @param pCritSect The critical section.
255	*/
256	RTDECL(int) RTCritSectLeave(PRTCRITSECT pCritSect);
257
258	/**
259	* Leave multiple critical sections.
260	*
261	* @returns VINF_SUCCESS.
262	* @param cCritSects Number of critical sections in the array.
263	* @param papCritSects Array of critical section pointers.
264	*/
265	RTDECL(int) RTCritSectLeaveMultiple(size_t cCritSects, PRTCRITSECT *papCritSects);
266
267	/**
268	* Deletes a critical section.
269	*
270	* @returns VINF_SUCCESS.
271	* @param pCritSect The critical section.
272	*/
273	RTDECL(int) RTCritSectDelete(PRTCRITSECT pCritSect);
274
275	/**
276	* Checks the caller is the owner of the critical section.
277	*
278	* @returns true if owner.
279	* @returns false if not owner.
280	* @param pCritSect The critical section.
281	*/
282	DECLINLINE(bool) RTCritSectIsOwner(PCRTCRITSECT pCritSect)
283	{
284	return pCritSect->NativeThreadOwner == RTThreadNativeSelf();
285	}
286
287	#endif /* IN_RING3 */
288
289	/**
290	* Checks the section is owned by anyone.
291	*
292	* @returns true if owned.
293	* @returns false if not owned.
294	* @param pCritSect The critical section.
295	*/
296	DECLINLINE(bool) RTCritSectIsOwned(PCRTCRITSECT pCritSect)
297	{
298	return pCritSect->NativeThreadOwner != NIL_RTNATIVETHREAD;
299	}
300
301	/**
302	* Gets the thread id of the critical section owner.
303	*
304	* @returns Thread id of the owner thread if owned.
305	* @returns NIL_RTNATIVETHREAD is not owned.
306	* @param pCritSect The critical section.
307	*/
308	DECLINLINE(RTNATIVETHREAD) RTCritSectGetOwner(PCRTCRITSECT pCritSect)
309	{
310	return pCritSect->NativeThreadOwner;
311	}
312
313	/**
314	* Checks if a critical section is initialized or not.
315	*
316	* @returns true if initialized.
317	* @returns false if not initialized.
318	* @param pCritSect The critical section.
319	*/
320	DECLINLINE(bool) RTCritSectIsInitialized(PCRTCRITSECT pCritSect)
321	{
322	return pCritSect->u32Magic == RTCRITSECT_MAGIC;
323	}
324
325	/**
326	* Gets the recursion depth.
327	*
328	* @returns The recursion depth.
329	* @param pCritSect The Critical section
330	*/
331	DECLINLINE(uint32_t) RTCritSectGetRecursion(PCRTCRITSECT pCritSect)
332	{
333	return pCritSect->cNestings;
334	}
335
336	/**
337	* Gets the waiter count
338	*
339	* @returns The waiter count
340	* @param pCritSect The Critical section
341	*/
342	DECLINLINE(int32_t) RTCritSectGetWaiters(PCRTCRITSECT pCritSect)
343	{
344	return pCritSect->cLockers;
345	}
346
347	/* Lock strict build: Remap the three enter calls to the debug versions. */
348	#if defined(RT_LOCK_STRICT) && !defined(RTCRITSECT_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
349	# ifdef ___iprt_asm_h
350	# define RTCritSectEnter(pCritSect) RTCritSectEnterDebug(pCritSect, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
351	# define RTCritSectTryEnter(pCritSect) RTCritSectTryEnterDebug(pCritSect, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
352	# define RTCritSectEnterMultiple(cCritSects, pCritSect) RTCritSectEnterMultipleDebug((cCritSects), (pCritSect), (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
353	# else
354	# define RTCritSectEnter(pCritSect) RTCritSectEnterDebug(pCritSect, 0, RT_SRC_POS)
355	# define RTCritSectTryEnter(pCritSect) RTCritSectTryEnterDebug(pCritSect, 0, RT_SRC_POS)
356	# define RTCritSectEnterMultiple(cCritSects, pCritSect) RTCritSectEnterMultipleDebug((cCritSects), (pCritSect), 0, RT_SRC_POS)
357	# endif
358	#endif
359
360	/* Strict lock order: Automatically classify locks by init location. */
361	#if defined(RT_LOCK_STRICT_ORDER) && defined(IN_RING3) && !defined(RTCRITSECT_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
362	# define RTCritSectInit(pCritSect) \
363	RTCritSectInitEx((pCritSect), 0 /fFlags/, \
364	RTLockValidatorClassForSrcPos(RT_SRC_POS, NULL), \
365	RTLOCKVAL_SUB_CLASS_NONE, NULL)
366	#endif
367
368	/** @} */
369
370
371
372	/** @defgroup grp_rt_critsectrw RTCritSectRw - Read/Write Critical Sections
373	* @ingroup grp_rt
374	* @{
375	*/
376
377	/**
378	* Read/write critical section.
379	*/
380	typedef struct RTCRITSECTRW
381	{
382	/** Magic used to validate the section state.
383	* RTCRITSECTRW_MAGIC is the value of an initialized & operational section. */
384	volatile uint32_t u32Magic;
385
386	/** Indicates whether hEvtRead needs resetting. */
387	bool volatile fNeedReset;
388	/** Explicit alignment padding. */
389	bool volatile afPadding[1];
390	/** Section flags - the RTCRITSECT_FLAGS_* \#defines. */
391	uint16_t fFlags;
392
393	/** The state variable.
394	* All accesses are atomic and it bits are defined like this:
395	* Bits 0..14 - cReads.
396	* Bit 15 - Unused.
397	* Bits 16..31 - cWrites. - doesn't make sense here
398	* Bit 31 - fDirection; 0=Read, 1=Write.
399	* Bits 32..46 - cWaitingReads
400	* Bit 47 - Unused.
401	* Bits 48..62 - cWaitingWrites
402	* Bit 63 - Unused.
403	*/
404	uint64_t volatile u64State;
405	/** The write owner. */
406	RTNATIVETHREAD volatile hNativeWriter;
407	/** The number of reads made by the current writer. */
408	uint32_t volatile cWriterReads;
409	/** The number of recursions made by the current writer. (The initial grabbing
410	* of the lock counts as the first one.) */
411	uint32_t volatile cWriteRecursions;
412
413	/** What the writer threads are blocking on. */
414	RTSEMEVENT hEvtWrite;
415	/** What the read threads are blocking on when waiting for the writer to
416	* finish. */
417	RTSEMEVENTMULTI hEvtRead;
418
419	/** The validator record for the writer. */
420	R3R0PTRTYPE(PRTLOCKVALRECEXCL) pValidatorWrite;
421	/** The validator record for the readers. */
422	R3R0PTRTYPE(PRTLOCKVALRECSHRD) pValidatorRead;
423	#if HC_ARCH_BITS == 32
424	/** Size padding. */
425	RTHCPTR HCPtrPadding;
426	#endif
427	} RTCRITSECTRW;
428	AssertCompileSize(RTCRITSECTRW, HC_ARCH_BITS == 32 ? 48 : 64);
429
430	/** RTCRITSECTRW::u32Magic value. (Eric Allan Dolphy, Jr.) */
431	#define RTCRITSECTRW_MAGIC UINT32_C(0x19280620)
432	/** RTCRITSECTRW::u32Magic dead value. */
433	#define RTCRITSECTRW_MAGIC_DEAD UINT32_C(0x19640629)
434
435	/** @name RTCRITSECTRW::u64State values.
436	* @note Using RTCSRW instead of RTCRITSECTRW to save space.
437	* @{ */
438	#define RTCSRW_CNT_BITS 15
439	#define RTCSRW_CNT_MASK UINT64_C(0x00007fff)
440
441	#define RTCSRW_CNT_RD_SHIFT 0
442	#define RTCSRW_CNT_RD_MASK (RTCSRW_CNT_MASK << RTCSRW_CNT_RD_SHIFT)
443	#define RTCSRW_CNT_WR_SHIFT 16
444	#define RTCSRW_CNT_WR_MASK (RTCSRW_CNT_MASK << RTCSRW_CNT_WR_SHIFT)
445
446	#define RTCSRW_DIR_SHIFT 31
447	#define RTCSRW_DIR_MASK RT_BIT_64(RTCSRW_DIR_SHIFT)
448	#define RTCSRW_DIR_READ UINT64_C(0)
449	#define RTCSRW_DIR_WRITE UINT64_C(1)
450
451	#define RTCSRW_WAIT_CNT_RD_SHIFT 32
452	#define RTCSRW_WAIT_CNT_RD_MASK (RTCSRW_CNT_MASK << RTCSRW_WAIT_CNT_RD_SHIFT)
453	/* #define RTCSRW_WAIT_CNT_WR_SHIFT 48 */
454	/* #define RTCSRW_WAIT_CNT_WR_MASK (RTCSRW_CNT_MASK << RTCSRW_WAIT_CNT_WR_SHIFT) */
455	/** @} */
456
457	#ifdef IN_RING3
458
459	/**
460	* Initialize a critical section.
461	*/
462	RTDECL(int) RTCritSectRwInit(PRTCRITSECTRW pThis);
463
464	/**
465	* Initialize a critical section.
466	*
467	* @returns IPRT status code.
468	* @param pThis Pointer to the read/write critical section.
469	* @param fFlags Flags, any combination of the RTCRITSECT_FLAGS
470	* \#defines.
471	* @param hClass The class (no reference consumed). If NIL, no lock
472	* order validation will be performed on this lock.
473	* @param uSubClass The sub-class. This is used to define lock order
474	* within a class. RTLOCKVAL_SUB_CLASS_NONE is the
475	* recommended value here.
476	* @param pszNameFmt Name format string for the lock validator, optional
477	* (NULL). Max length is 32 bytes.
478	* @param ... Format string arguments.
479	*/
480	RTDECL(int) RTCritSectRwInitEx(PRTCRITSECTRW pThis, uint32_t fFlags,
481	RTLOCKVALCLASS hClass, uint32_t uSubClass, const char *pszNameFmt, ...);
482
483	/**
484	* Changes the lock validator sub-class of the critical section.
485	*
486	* It is recommended to try make sure that nobody is using this critical section
487	* while changing the value.
488	*
489	* @returns The old sub-class. RTLOCKVAL_SUB_CLASS_INVALID is returns if the
490	* lock validator isn't compiled in or either of the parameters are
491	* invalid.
492	* @param pThis Pointer to the read/write critical section.
493	* @param uSubClass The new sub-class value.
494	*/
495	RTDECL(uint32_t) RTCritSectRwSetSubClass(PRTCRITSECTRW pThis, uint32_t uSubClass);
496
497
498	/**
499	* Enter a critical section with shared (read) access.
500	*
501	* @returns IPRT status code.
502	* @retval VINF_SUCCESS on success.
503	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
504	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
505	* during the operation.
506	* @param pThis Pointer to the read/write critical section.
507	*/
508	RTDECL(int) RTCritSectRwEnterShared(PRTCRITSECTRW pThis);
509
510	/**
511	* Enter a critical section with shared (read) access.
512	*
513	* @returns IPRT status code.
514	* @retval VINF_SUCCESS on success.
515	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
516	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
517	* during the operation.
518	*
519	* @param pThis Pointer to the read/write critical section.
520	* @param uId Where we're entering the section.
521	* @param pszFile The source position - file.
522	* @param iLine The source position - line.
523	* @param pszFunction The source position - function.
524	*/
525	RTDECL(int) RTCritSectRwEnterSharedDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
526
527	/**
528	* Try enter a critical section with shared (read) access.
529	*
530	* @returns IPRT status code.
531	* @retval VINF_SUCCESS on success.
532	* @retval VERR_SEM_BUSY if the critsect was owned.
533	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
534	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
535	* during the operation.
536	*
537	* @param pThis Pointer to the read/write critical section.
538	*/
539	RTDECL(int) RTCritSectRwTryEnterShared(PRTCRITSECTRW pThis);
540
541	/**
542	* Try enter a critical section with shared (read) access.
543	*
544	* @returns IPRT status code.
545	* @retval VINF_SUCCESS on success.
546	* @retval VERR_SEM_BUSY if the critsect was owned.
547	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
548	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
549	* during the operation.
550	*
551	* @param pThis Pointer to the read/write critical section.
552	* @param uId Where we're entering the section.
553	* @param pszFile The source position - file.
554	* @param iLine The source position - line.
555	* @param pszFunction The source position - function.
556	*/
557	RTDECL(int) RTCritSectRwTryEnterSharedDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
558
559	/**
560	* Leave a critical section held with shared access.
561	*
562	* @returns IPRT status code.
563	* @param pThis Pointer to the read/write critical section.
564	*/
565	RTDECL(int) RTCritSectRwLeaveShared(PRTCRITSECTRW pThis);
566
567
568	/**
569	* Enter a critical section with exclusive (write) access.
570	*
571	* @returns IPRT status code.
572	* @retval VINF_SUCCESS on success.
573	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
574	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
575	* during the operation.
576	* @param pThis Pointer to the read/write critical section.
577	*/
578	RTDECL(int) RTCritSectRwEnterExcl(PRTCRITSECTRW pThis);
579
580	/**
581	* Enter a critical section with exclusive (write) access.
582	*
583	* @retval VINF_SUCCESS on success.
584	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
585	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
586	* during the operation.
587	*
588	* @param pThis Pointer to the read/write critical section.
589	* @param uId Where we're entering the section.
590	* @param pszFile The source position - file.
591	* @param iLine The source position - line.
592	* @param pszFunction The source position - function.
593	*/
594	RTDECL(int) RTCritSectRwEnterExclDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
595
596	/**
597	* Try enter a critical section with exclusive (write) access.
598	*
599	* @returns IPRT status code.
600	* @retval VINF_SUCCESS on success.
601	* @retval VERR_SEM_BUSY if the critsect was owned.
602	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
603	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
604	* during the operation.
605	*
606	* @param pThis Pointer to the read/write critical section.
607	*/
608	RTDECL(int) RTCritSectRwTryEnterExcl(PRTCRITSECTRW pThis);
609
610	/**
611	* Try enter a critical section with exclusive (write) access.
612	*
613	* @returns IPRT status code.
614	* @retval VINF_SUCCESS on success.
615	* @retval VERR_SEM_BUSY if the critsect was owned.
616	* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
617	* @retval VERR_SEM_DESTROYED if the critical section is delete before or
618	* during the operation.
619	*
620	* @param pThis Pointer to the read/write critical section.
621	* @param uId Where we're entering the section.
622	* @param pszFile The source position - file.
623	* @param iLine The source position - line.
624	* @param pszFunction The source position - function.
625	*/
626	RTDECL(int) RTCritSectRwTryEnterExclDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
627
628	/**
629	* Leave a critical section held exclusively.
630	*
631	* @returns IPRT status code; VINF_SUCCESS, VERR_NOT_OWNER, VERR_SEM_DESTROYED,
632	* or VERR_WRONG_ORDER.
633	* @param pThis Pointer to the read/write critical section.
634	*/
635	RTDECL(int) RTCritSectRwLeaveExcl(PRTCRITSECTRW pThis);
636
637
638	/**
639	* Deletes a critical section.
640	*
641	* @returns VINF_SUCCESS.
642	* @param pThis Pointer to the read/write critical section.
643	*/
644	RTDECL(int) RTCritSectRwDelete(PRTCRITSECTRW pThis);
645
646	/**
647	* Checks the caller is the exclusive (write) owner of the critical section.
648	*
649	* @retval @c true if owner.
650	* @retval @c false if not owner.
651	* @param pThis Pointer to the read/write critical section.
652	*/
653	RTDECL(bool) RTCritSectRwIsWriteOwner(PRTCRITSECTRW pThis);
654
655	/**
656	* Checks if the caller is one of the read owners of the critical section.
657	*
658	* @note !CAUTION! This API doesn't work reliably if lock validation isn't
659	* enabled. Meaning, the answer is not trustworhty unless
660	* RT_LOCK_STRICT or RTCRITSECTRW_STRICT was defined at build time.
661	* Also, make sure you do not use RTCRITSECTRW_FLAGS_NO_LOCK_VAL when
662	* creating the semaphore. And finally, if you used a locking class,
663	* don't disable deadlock detection by setting cMsMinDeadlock to
664	* RT_INDEFINITE_WAIT.
665	*
666	* In short, only use this for assertions.
667	*
668	* @returns @c true if reader, @c false if not.
669	* @param pThis Pointer to the read/write critical section.
670	* @param fWannaHear What you'd like to hear when lock validation is not
671	* available. (For avoiding asserting all over the
672	* place.)
673	*/
674	RTDECL(bool) RTCritSectRwIsReadOwner(PRTCRITSECTRW pThis, bool fWannaHear);
675
676	/**
677	* Gets the write recursion count.
678	*
679	* @returns The write recursion count (0 if bad critsect).
680	* @param pThis Pointer to the read/write critical section.
681	*/
682	RTDECL(uint32_t) RTCritSectRwGetWriteRecursion(PRTCRITSECTRW pThis);
683
684	/**
685	* Gets the read recursion count of the current writer.
686	*
687	* @returns The read recursion count (0 if bad critsect).
688	* @param pThis Pointer to the read/write critical section.
689	*/
690	RTDECL(uint32_t) RTCritSectRwGetWriterReadRecursion(PRTCRITSECTRW pThis);
691
692	/**
693	* Gets the current number of reads.
694	*
695	* This includes all read recursions, so it might be higher than the number of
696	* read owners. It does not include reads done by the current writer.
697	*
698	* @returns The read count (0 if bad critsect).
699	* @param pThis Pointer to the read/write critical section.
700	*/
701	RTDECL(uint32_t) RTCritSectRwGetReadCount(PRTCRITSECTRW pThis);
702
703	#endif /* IN_RING3 */
704
705	/**
706	* Checks if a critical section is initialized or not.
707	*
708	* @retval @c true if initialized.
709	* @retval @c false if not initialized.
710	* @param pThis Pointer to the read/write critical section.
711	*/
712	DECLINLINE(bool) RTCritSectRwIsInitialized(PCRTCRITSECTRW pThis)
713	{
714	return pThis->u32Magic == RTCRITSECTRW_MAGIC;
715	}
716
717	/* Lock strict build: Remap the three enter calls to the debug versions. */
718	#if defined(RT_LOCK_STRICT) && !defined(RTCRITSECTRW_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
719	# ifdef ___iprt_asm_h
720	# define RTCritSectRwEnterExcl(pThis) RTCritSectRwEnterExclDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
721	# define RTCritSectRwTryEnterExcl(pThis) RTCritSectRwTryEnterExclDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
722	# define RTCritSectRwEnterShared(pThis) RTCritSectRwEnterSharedDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
723	# define RTCritSectRwTryEnterShared(pThis) RTCritSectRwTryEnterSharedDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
724	# else
725	# define RTCritSectRwEnterExcl(pThis) RTCritSectRwEnterExclDebug(pThis, 0, RT_SRC_POS)
726	# define RTCritSectRwTryEnterExcl(pThis) RTCritSectRwTryEnterExclDebug(pThis, 0, RT_SRC_POS)
727	# define RTCritSectRwEnterShared(pThis) RTCritSectRwEnterSharedDebug(pThis, 0, RT_SRC_POS)
728	# define RTCritSectRwTryEnterShared(pThis) RTCritSectRwTryEnterSharedDebug(pThis, 0, RT_SRC_POS)
729	# endif
730	#endif
731
732	/* Strict lock order: Automatically classify locks by init location. */
733	#if defined(RT_LOCK_STRICT_ORDER) && defined(IN_RING3) && !defined(RTCRITSECTRW_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
734	# define RTCritSectRwInit(a_pThis) \
735	RTCritSectRwInitEx((a_pThis), 0 /fFlags/, \
736	RTLockValidatorClassForSrcPos(RT_SRC_POS, NULL), \
737	RTLOCKVAL_SUB_CLASS_NONE, NULL)
738	#endif
739
740	/** @} */
741
742	RT_C_DECLS_END
743
744	#endif
745

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source: vbox/trunk/include/iprt/critsect.h@ 48418

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