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virtualbox/include/iprt/critsect.h
Daniel Baumann df1bda4fe9
Adding upstream version 7.0.20-dfsg.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-22 09:56:04 +02:00

768 lines
29 KiB
C

/** @file
* IPRT - Critical Sections.
*/
/*
* Copyright (C) 2006-2023 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
* in the VirtualBox distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*
* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
*/
#ifndef IPRT_INCLUDED_critsect_h
#define IPRT_INCLUDED_critsect_h
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif
#include <iprt/cdefs.h>
#include <iprt/types.h>
#include <iprt/assert.h>
#if defined(IN_RING3) || defined(IN_RING0)
# include <iprt/thread.h>
#endif
#ifdef RT_LOCK_STRICT_ORDER
# include <iprt/lockvalidator.h>
#endif
RT_C_DECLS_BEGIN
/** @defgroup grp_rt_critsect RTCritSect - Critical Sections
*
* "Critical section" synchronization primitives can be used to
* protect a section of code or data to which access must be exclusive;
* only one thread can hold access to a critical section at one time.
*
* A critical section is a fast recursive write lock; if the critical
* section is not acquired, then entering it is fast (requires no system
* call). IPRT uses the Windows terminology here; on other platform, this
* might be called a "futex" or a "fast mutex". As opposed to IPRT
* "fast mutexes" (see @ref grp_rt_sems_fast_mutex ), critical sections
* are recursive.
*
* Use RTCritSectInit to initialize a critical section; use RTCritSectEnter
* and RTCritSectLeave to acquire and release access.
*
* For an overview of all types of synchronization primitives provided
* by IPRT (event, mutex/fast mutex/read-write mutex semaphores), see
* @ref grp_rt_sems .
*
* @ingroup grp_rt
* @{
*/
/**
* Critical section.
*/
typedef struct RTCRITSECT
{
/** Magic used to validate the section state.
* RTCRITSECT_MAGIC is the value of an initialized & operational section. */
volatile uint32_t u32Magic;
/** Number of lockers.
* -1 if the section is free. */
volatile int32_t cLockers;
/** The owner thread. */
volatile RTNATIVETHREAD NativeThreadOwner;
/** Number of nested enter operations performed.
* Greater or equal to 1 if owned, 0 when free.
*/
volatile int32_t cNestings;
/** Section flags - the RTCRITSECT_FLAGS_* \#defines. */
uint32_t fFlags;
/** The semaphore to block on. */
RTSEMEVENT EventSem;
/** Lock validator record. Only used in strict builds. */
R3R0PTRTYPE(PRTLOCKVALRECEXCL) pValidatorRec;
/** Alignment padding. */
RTHCPTR Alignment;
} RTCRITSECT;
AssertCompileSize(RTCRITSECT, HC_ARCH_BITS == 32 ? 32 : 48);
/** RTCRITSECT::u32Magic value. (Hiromi Uehara) */
#define RTCRITSECT_MAGIC UINT32_C(0x19790326)
/** @name RTCritSectInitEx flags / RTCRITSECT::fFlags
* @{ */
/** If set, nesting(/recursion) is not allowed. */
#define RTCRITSECT_FLAGS_NO_NESTING UINT32_C(0x00000001)
/** Disables lock validation. */
#define RTCRITSECT_FLAGS_NO_LOCK_VAL UINT32_C(0x00000002)
/** Bootstrap hack for use with certain memory allocator locks only! */
#define RTCRITSECT_FLAGS_BOOTSTRAP_HACK UINT32_C(0x00000004)
/** If set, the critical section becomes a dummy that doesn't serialize any
* threads. This flag can only be set at creation time.
*
* The intended use is avoiding lots of conditional code where some component
* might or might not require entering a critical section before access. */
#define RTCRITSECT_FLAGS_NOP UINT32_C(0x00000008)
/** Indicates that this is a ring-0 critical section. */
#define RTCRITSECT_FLAGS_RING0 UINT32_C(0x00000010)
/** @} */
#if defined(IN_RING3) || defined(IN_RING0)
/**
* Initialize a critical section.
*/
RTDECL(int) RTCritSectInit(PRTCRITSECT pCritSect);
/**
* Initialize a critical section.
*
* @returns iprt status code.
* @param pCritSect Pointer to the critical section structure.
* @param fFlags Flags, any combination of the RTCRITSECT_FLAGS
* \#defines.
* @param hClass The class (no reference consumed). If NIL, no lock
* order validation will be performed on this lock.
* @param uSubClass The sub-class. This is used to define lock order
* within a class. RTLOCKVAL_SUB_CLASS_NONE is the
* recommended value here.
* @param pszNameFmt Name format string for the lock validator, optional
* (NULL). Max length is 32 bytes.
* @param ... Format string arguments.
*/
RTDECL(int) RTCritSectInitEx(PRTCRITSECT pCritSect, uint32_t fFlags, RTLOCKVALCLASS hClass, uint32_t uSubClass,
const char *pszNameFmt, ...) RT_IPRT_FORMAT_ATTR_MAYBE_NULL(5, 6);
/**
* Changes the lock validator sub-class of the critical section.
*
* It is recommended to try make sure that nobody is using this critical section
* while changing the value.
*
* @returns The old sub-class. RTLOCKVAL_SUB_CLASS_INVALID is returns if the
* lock validator isn't compiled in or either of the parameters are
* invalid.
* @param pCritSect The critical section.
* @param uSubClass The new sub-class value.
*/
RTDECL(uint32_t) RTCritSectSetSubClass(PRTCRITSECT pCritSect, uint32_t uSubClass);
/**
* Enter a critical section.
*
* @returns VINF_SUCCESS on success.
* @returns VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
* @param pCritSect The critical section.
*/
RTDECL(int) RTCritSectEnter(PRTCRITSECT pCritSect);
/**
* Enter a critical section.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pCritSect The critical section.
* @param uId Where we're entering the section.
* @param SRC_POS The source position where call is being made from.
* Use RT_SRC_POS when possible. Optional.
*/
RTDECL(int) RTCritSectEnterDebug(PRTCRITSECT pCritSect, RTHCUINTPTR uId, RT_SRC_POS_DECL);
/**
* Try enter a critical section.
*
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_BUSY if the critsect was owned.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pCritSect The critical section.
*/
RTDECL(int) RTCritSectTryEnter(PRTCRITSECT pCritSect);
/**
* Try enter a critical section.
*
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_BUSY if the critsect was owned.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pCritSect The critical section.
* @param uId Where we're entering the section.
* @param SRC_POS The source position where call is being made from.
* Use RT_SRC_POS when possible. Optional.
*/
RTDECL(int) RTCritSectTryEnterDebug(PRTCRITSECT pCritSect, RTHCUINTPTR uId, RT_SRC_POS_DECL);
# ifdef IN_RING3 /* Crazy APIs: ring-3 only. */
/**
* Enter multiple critical sections.
*
* This function will enter ALL the specified critical sections before returning.
*
* @returns VINF_SUCCESS on success.
* @returns VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
* @param cCritSects Number of critical sections in the array.
* @param papCritSects Array of critical section pointers.
*
* @remark Please note that this function will not necessarily come out favourable in a
* fight with other threads which are using the normal RTCritSectEnter() function.
* Therefore, avoid having to enter multiple critical sections!
*/
RTDECL(int) RTCritSectEnterMultiple(size_t cCritSects, PRTCRITSECT *papCritSects);
/**
* Enter multiple critical sections.
*
* This function will enter ALL the specified critical sections before returning.
*
* @returns VINF_SUCCESS on success.
* @returns VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param cCritSects Number of critical sections in the array.
* @param papCritSects Array of critical section pointers.
* @param uId Where we're entering the section.
* @param SRC_POS The source position where call is being made from.
* Use RT_SRC_POS when possible. Optional.
*
* @remark See RTCritSectEnterMultiple().
*/
RTDECL(int) RTCritSectEnterMultipleDebug(size_t cCritSects, PRTCRITSECT *papCritSects, RTHCUINTPTR uId, RT_SRC_POS_DECL);
# endif /* IN_RING3 */
/**
* Leave a critical section.
*
* @returns VINF_SUCCESS.
* @param pCritSect The critical section.
*/
RTDECL(int) RTCritSectLeave(PRTCRITSECT pCritSect);
/**
* Leave multiple critical sections.
*
* @returns VINF_SUCCESS.
* @param cCritSects Number of critical sections in the array.
* @param papCritSects Array of critical section pointers.
*/
RTDECL(int) RTCritSectLeaveMultiple(size_t cCritSects, PRTCRITSECT *papCritSects);
/**
* Deletes a critical section.
*
* @returns VINF_SUCCESS.
* @param pCritSect The critical section.
*/
RTDECL(int) RTCritSectDelete(PRTCRITSECT pCritSect);
/**
* Checks the caller is the owner of the critical section.
*
* @returns true if owner.
* @returns false if not owner.
* @param pCritSect The critical section.
*/
DECLINLINE(bool) RTCritSectIsOwner(PCRTCRITSECT pCritSect)
{
return pCritSect->NativeThreadOwner == RTThreadNativeSelf();
}
#endif /* IN_RING3 || IN_RING0 */
/**
* Checks the section is owned by anyone.
*
* @returns true if owned.
* @returns false if not owned.
* @param pCritSect The critical section.
*/
DECLINLINE(bool) RTCritSectIsOwned(PCRTCRITSECT pCritSect)
{
return pCritSect->NativeThreadOwner != NIL_RTNATIVETHREAD;
}
/**
* Gets the thread id of the critical section owner.
*
* @returns Thread id of the owner thread if owned.
* @returns NIL_RTNATIVETHREAD is not owned.
* @param pCritSect The critical section.
*/
DECLINLINE(RTNATIVETHREAD) RTCritSectGetOwner(PCRTCRITSECT pCritSect)
{
return pCritSect->NativeThreadOwner;
}
/**
* Checks if a critical section is initialized or not.
*
* @returns true if initialized.
* @returns false if not initialized.
* @param pCritSect The critical section.
*/
DECLINLINE(bool) RTCritSectIsInitialized(PCRTCRITSECT pCritSect)
{
return pCritSect->u32Magic == RTCRITSECT_MAGIC;
}
/**
* Gets the recursion depth.
*
* @returns The recursion depth.
* @param pCritSect The Critical section
*/
DECLINLINE(uint32_t) RTCritSectGetRecursion(PCRTCRITSECT pCritSect)
{
return (uint32_t)pCritSect->cNestings;
}
/**
* Gets the waiter count
*
* @returns The waiter count
* @param pCritSect The Critical section
*/
DECLINLINE(int32_t) RTCritSectGetWaiters(PCRTCRITSECT pCritSect)
{
return pCritSect->cLockers;
}
/* Lock strict build: Remap the three enter calls to the debug versions. */
#if defined(RT_LOCK_STRICT) && !defined(RTCRITSECT_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
# ifdef IPRT_INCLUDED_asm_h
# define RTCritSectEnter(pCritSect) RTCritSectEnterDebug(pCritSect, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
# define RTCritSectTryEnter(pCritSect) RTCritSectTryEnterDebug(pCritSect, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
# define RTCritSectEnterMultiple(cCritSects, pCritSect) RTCritSectEnterMultipleDebug((cCritSects), (pCritSect), (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
# else
# define RTCritSectEnter(pCritSect) RTCritSectEnterDebug(pCritSect, 0, RT_SRC_POS)
# define RTCritSectTryEnter(pCritSect) RTCritSectTryEnterDebug(pCritSect, 0, RT_SRC_POS)
# define RTCritSectEnterMultiple(cCritSects, pCritSect) RTCritSectEnterMultipleDebug((cCritSects), (pCritSect), 0, RT_SRC_POS)
# endif
#endif
/* Strict lock order: Automatically classify locks by init location. */
#if defined(RT_LOCK_STRICT_ORDER) && defined(IN_RING3) && !defined(RTCRITSECT_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
# define RTCritSectInit(pCritSect) \
RTCritSectInitEx((pCritSect), 0 /*fFlags*/, \
RTLockValidatorClassForSrcPos(RT_SRC_POS, NULL), \
RTLOCKVAL_SUB_CLASS_NONE, NULL)
#endif
/** @} */
/** @defgroup grp_rt_critsectrw RTCritSectRw - Read/Write Critical Sections
* @ingroup grp_rt
* @{
*/
/**
* Union that allows us to atomically update both the state and
* exclusive owner if the hardware supports cmpxchg16b or similar.
*/
typedef union RTCRITSECTRWSTATE
{
struct
{
/** The state variable.
* All accesses are atomic and it bits are defined like this:
* Bits 0..14 - cReads.
* Bit 15 - Unused.
* Bits 16..31 - cWrites.
* Bit 31 - fDirection; 0=Read, 1=Write.
* Bits 32..46 - cWaitingReads
* Bit 47 - Unused.
* Bits 48..62 - cWaitingWrites - doesn't make sense here, not used.
* Bit 63 - Unused.
*/
uint64_t u64State;
/** The write owner. */
RTNATIVETHREAD hNativeWriter;
} s;
RTUINT128U u128;
} RTCRITSECTRWSTATE;
/**
* Read/write critical section.
*/
typedef struct RTCRITSECTRW
{
/** Magic used to validate the section state.
* RTCRITSECTRW_MAGIC is the value of an initialized & operational section. */
volatile uint32_t u32Magic;
/** Indicates whether hEvtRead needs resetting. */
bool volatile fNeedReset;
/** Explicit alignment padding. */
bool volatile afPadding[1];
/** Section flags - the RTCRITSECT_FLAGS_* \#defines. */
uint16_t fFlags;
/** The number of reads made by the current writer. */
uint32_t volatile cWriterReads;
/** The number of recursions made by the current writer. (The initial grabbing
* of the lock counts as the first one.) */
uint32_t volatile cWriteRecursions;
/** The core state. */
RTCRITSECTRWSTATE volatile u;
/** What the writer threads are blocking on. */
RTSEMEVENT hEvtWrite;
/** What the read threads are blocking on when waiting for the writer to
* finish. */
RTSEMEVENTMULTI hEvtRead;
/** The validator record for the writer. */
R3R0PTRTYPE(PRTLOCKVALRECEXCL) pValidatorWrite;
/** The validator record for the readers. */
R3R0PTRTYPE(PRTLOCKVALRECSHRD) pValidatorRead;
} RTCRITSECTRW;
AssertCompileSize(RTCRITSECTRW, HC_ARCH_BITS == 32 ? 48 : 64);
/** RTCRITSECTRW::u32Magic value. (Eric Allan Dolphy, Jr.) */
#define RTCRITSECTRW_MAGIC UINT32_C(0x19280620)
/** RTCRITSECTRW::u32Magic dead value. */
#define RTCRITSECTRW_MAGIC_DEAD UINT32_C(0x19640629)
/** @name RTCRITSECTRW::u64State values.
* @note Using RTCSRW instead of RTCRITSECTRW to save space.
* @{ */
#define RTCSRW_CNT_BITS 15
#define RTCSRW_CNT_MASK UINT64_C(0x00007fff)
#define RTCSRW_CNT_RD_SHIFT 0
#define RTCSRW_CNT_RD_MASK (RTCSRW_CNT_MASK << RTCSRW_CNT_RD_SHIFT)
#define RTCSRW_CNT_WR_SHIFT 16
#define RTCSRW_CNT_WR_MASK (RTCSRW_CNT_MASK << RTCSRW_CNT_WR_SHIFT)
#define RTCSRW_DIR_SHIFT 31
#define RTCSRW_DIR_MASK RT_BIT_64(RTCSRW_DIR_SHIFT)
#define RTCSRW_DIR_READ UINT64_C(0)
#define RTCSRW_DIR_WRITE UINT64_C(1)
#define RTCSRW_WAIT_CNT_RD_SHIFT 32
#define RTCSRW_WAIT_CNT_RD_MASK (RTCSRW_CNT_MASK << RTCSRW_WAIT_CNT_RD_SHIFT)
/* #define RTCSRW_WAIT_CNT_WR_SHIFT 48 */
/* #define RTCSRW_WAIT_CNT_WR_MASK (RTCSRW_CNT_MASK << RTCSRW_WAIT_CNT_WR_SHIFT) */
/** @} */
#if defined(IN_RING3) || defined(IN_RING0)
/**
* Initialize a critical section.
*/
RTDECL(int) RTCritSectRwInit(PRTCRITSECTRW pThis);
/**
* Initialize a critical section.
*
* @returns IPRT status code.
* @param pThis Pointer to the read/write critical section.
* @param fFlags Flags, any combination of the RTCRITSECT_FLAGS
* \#defines.
* @param hClass The class (no reference consumed). If NIL, no lock
* order validation will be performed on this lock.
* @param uSubClass The sub-class. This is used to define lock order
* within a class. RTLOCKVAL_SUB_CLASS_NONE is the
* recommended value here.
* @param pszNameFmt Name format string for the lock validator, optional
* (NULL). Max length is 32 bytes.
* @param ... Format string arguments.
*/
RTDECL(int) RTCritSectRwInitEx(PRTCRITSECTRW pThis, uint32_t fFlags, RTLOCKVALCLASS hClass, uint32_t uSubClass,
const char *pszNameFmt, ...) RT_IPRT_FORMAT_ATTR_MAYBE_NULL(5, 6);
/**
* Changes the lock validator sub-class of the critical section.
*
* It is recommended to try make sure that nobody is using this critical section
* while changing the value.
*
* @returns The old sub-class. RTLOCKVAL_SUB_CLASS_INVALID is returns if the
* lock validator isn't compiled in or either of the parameters are
* invalid.
* @param pThis Pointer to the read/write critical section.
* @param uSubClass The new sub-class value.
*/
RTDECL(uint32_t) RTCritSectRwSetSubClass(PRTCRITSECTRW pThis, uint32_t uSubClass);
/**
* Enter a critical section with shared (read) access.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(int) RTCritSectRwEnterShared(PRTCRITSECTRW pThis);
/**
* Enter a critical section with shared (read) access.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pThis Pointer to the read/write critical section.
* @param uId Where we're entering the section.
* @param SRC_POS The source position where call is being made from.
* Use RT_SRC_POS when possible. Optional.
*/
RTDECL(int) RTCritSectRwEnterSharedDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
/**
* Try enter a critical section with shared (read) access.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_BUSY if the critsect was owned.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(int) RTCritSectRwTryEnterShared(PRTCRITSECTRW pThis);
/**
* Try enter a critical section with shared (read) access.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_BUSY if the critsect was owned.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pThis Pointer to the read/write critical section.
* @param uId Where we're entering the section.
* @param SRC_POS The source position where call is being made from.
* Use RT_SRC_POS when possible. Optional.
*/
RTDECL(int) RTCritSectRwTryEnterSharedDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
/**
* Leave a critical section held with shared access.
*
* @returns IPRT status code.
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(int) RTCritSectRwLeaveShared(PRTCRITSECTRW pThis);
/**
* Enter a critical section with exclusive (write) access.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(int) RTCritSectRwEnterExcl(PRTCRITSECTRW pThis);
/**
* Enter a critical section with exclusive (write) access.
*
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pThis Pointer to the read/write critical section.
* @param uId Where we're entering the section.
* @param SRC_POS The source position where call is being made from.
* Use RT_SRC_POS when possible. Optional.
*/
RTDECL(int) RTCritSectRwEnterExclDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
/**
* Try enter a critical section with exclusive (write) access.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_BUSY if the critsect was owned.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(int) RTCritSectRwTryEnterExcl(PRTCRITSECTRW pThis);
/**
* Try enter a critical section with exclusive (write) access.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS on success.
* @retval VERR_SEM_BUSY if the critsect was owned.
* @retval VERR_SEM_NESTED if nested enter on a no nesting section. (Asserted.)
* @retval VERR_SEM_DESTROYED if the critical section is delete before or
* during the operation.
*
* @param pThis Pointer to the read/write critical section.
* @param uId Where we're entering the section.
* @param SRC_POS The source position where call is being made from.
* Use RT_SRC_POS when possible. Optional.
*/
RTDECL(int) RTCritSectRwTryEnterExclDebug(PRTCRITSECTRW pThis, RTHCUINTPTR uId, RT_SRC_POS_DECL);
/**
* Leave a critical section held exclusively.
*
* @returns IPRT status code; VINF_SUCCESS, VERR_NOT_OWNER, VERR_SEM_DESTROYED,
* or VERR_WRONG_ORDER.
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(int) RTCritSectRwLeaveExcl(PRTCRITSECTRW pThis);
/**
* Deletes a critical section.
*
* @returns VINF_SUCCESS.
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(int) RTCritSectRwDelete(PRTCRITSECTRW pThis);
/**
* Checks the caller is the exclusive (write) owner of the critical section.
*
* @retval true if owner.
* @retval false if not owner.
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(bool) RTCritSectRwIsWriteOwner(PRTCRITSECTRW pThis);
/**
* Checks if the caller is one of the read owners of the critical section.
*
* @note !CAUTION! This API doesn't work reliably if lock validation isn't
* enabled. Meaning, the answer is not trustworhty unless
* RT_LOCK_STRICT or RTCRITSECTRW_STRICT was defined at build time.
* Also, make sure you do not use RTCRITSECTRW_FLAGS_NO_LOCK_VAL when
* creating the semaphore. And finally, if you used a locking class,
* don't disable deadlock detection by setting cMsMinDeadlock to
* RT_INDEFINITE_WAIT.
*
* In short, only use this for assertions.
*
* @returns @c true if reader, @c false if not.
* @param pThis Pointer to the read/write critical section.
* @param fWannaHear What you'd like to hear when lock validation is not
* available. (For avoiding asserting all over the
* place.)
*/
RTDECL(bool) RTCritSectRwIsReadOwner(PRTCRITSECTRW pThis, bool fWannaHear);
/**
* Gets the write recursion count.
*
* @returns The write recursion count (0 if bad critsect).
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(uint32_t) RTCritSectRwGetWriteRecursion(PRTCRITSECTRW pThis);
/**
* Gets the read recursion count of the current writer.
*
* @returns The read recursion count (0 if bad critsect).
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(uint32_t) RTCritSectRwGetWriterReadRecursion(PRTCRITSECTRW pThis);
/**
* Gets the current number of reads.
*
* This includes all read recursions, so it might be higher than the number of
* read owners. It does not include reads done by the current writer.
*
* @returns The read count (0 if bad critsect).
* @param pThis Pointer to the read/write critical section.
*/
RTDECL(uint32_t) RTCritSectRwGetReadCount(PRTCRITSECTRW pThis);
#endif /* IN_RING3 || IN_RING0 */
/**
* Checks if a critical section is initialized or not.
*
* @retval true if initialized.
* @retval false if not initialized.
* @param pThis Pointer to the read/write critical section.
*/
DECLINLINE(bool) RTCritSectRwIsInitialized(PCRTCRITSECTRW pThis)
{
return pThis->u32Magic == RTCRITSECTRW_MAGIC;
}
/* Lock strict build: Remap the three enter calls to the debug versions. */
#if defined(RT_LOCK_STRICT) && !defined(RTCRITSECTRW_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
# ifdef IPRT_INCLUDED_asm_h
# define RTCritSectRwEnterExcl(pThis) RTCritSectRwEnterExclDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
# define RTCritSectRwTryEnterExcl(pThis) RTCritSectRwTryEnterExclDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
# define RTCritSectRwEnterShared(pThis) RTCritSectRwEnterSharedDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
# define RTCritSectRwTryEnterShared(pThis) RTCritSectRwTryEnterSharedDebug(pThis, (uintptr_t)ASMReturnAddress(), RT_SRC_POS)
# else
# define RTCritSectRwEnterExcl(pThis) RTCritSectRwEnterExclDebug(pThis, 0, RT_SRC_POS)
# define RTCritSectRwTryEnterExcl(pThis) RTCritSectRwTryEnterExclDebug(pThis, 0, RT_SRC_POS)
# define RTCritSectRwEnterShared(pThis) RTCritSectRwEnterSharedDebug(pThis, 0, RT_SRC_POS)
# define RTCritSectRwTryEnterShared(pThis) RTCritSectRwTryEnterSharedDebug(pThis, 0, RT_SRC_POS)
# endif
#endif
/* Strict lock order: Automatically classify locks by init location. */
#if defined(RT_LOCK_STRICT_ORDER) && defined(IN_RING3) && !defined(RTCRITSECTRW_WITHOUT_REMAPPING) && !defined(RT_WITH_MANGLING)
# define RTCritSectRwInit(a_pThis) \
RTCritSectRwInitEx((a_pThis), 0 /*fFlags*/, \
RTLockValidatorClassForSrcPos(RT_SRC_POS, NULL), \
RTLOCKVAL_SUB_CLASS_NONE, NULL)
#endif
/** @} */
RT_C_DECLS_END
#endif /* !IPRT_INCLUDED_critsect_h */