diff options
Diffstat (limited to 'src/VBox/Runtime/r3/posix/semrw-posix.cpp')
| -rw-r--r-- | src/VBox/Runtime/r3/posix/semrw-posix.cpp | 741 |
1 files changed, 741 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/posix/semrw-posix.cpp b/src/VBox/Runtime/r3/posix/semrw-posix.cpp new file mode 100644 index 00000000..ab657566 --- /dev/null +++ b/src/VBox/Runtime/r3/posix/semrw-posix.cpp @@ -0,0 +1,741 @@ +/* $Id: semrw-posix.cpp $ */ +/** @file + * IPRT - Read-Write Semaphore, POSIX. + */ + +/* + * 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 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <iprt/semaphore.h> +#include "internal/iprt.h" + +#include <iprt/asm.h> +#include <iprt/assert.h> +#include <iprt/err.h> +#include <iprt/lockvalidator.h> +#include <iprt/mem.h> +#include <iprt/thread.h> + +#include <errno.h> +#include <pthread.h> +#include <unistd.h> +#include <sys/time.h> + +#include "internal/magics.h" +#include "internal/strict.h" + + +/********************************************************************************************************************************* +* Defined Constants And Macros * +*********************************************************************************************************************************/ +/** @todo move this to r3/posix/something.h. */ +#ifdef RT_OS_SOLARIS +# define ATOMIC_GET_PTHREAD_T(ppvVar, pThread) ASMAtomicReadSize(ppvVar, pThread) +# define ATOMIC_SET_PTHREAD_T(ppvVar, pThread) ASMAtomicWriteSize(ppvVar, pThread) +#else +AssertCompileSize(pthread_t, sizeof(void *)); +# define ATOMIC_GET_PTHREAD_T(ppvVar, pThread) do { *(pThread) = (pthread_t)ASMAtomicReadPtr((void * volatile *)ppvVar); } while (0) +# define ATOMIC_SET_PTHREAD_T(ppvVar, pThread) ASMAtomicWritePtr((void * volatile *)ppvVar, (void *)pThread) +#endif + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +/** Posix internal representation of a read-write semaphore. */ +struct RTSEMRWINTERNAL +{ + /** The usual magic. (RTSEMRW_MAGIC) */ + uint32_t u32Magic; + /** The number of readers. + * (For preventing screwing up the lock on linux). */ + uint32_t volatile cReaders; + /** Number of write recursions. */ + uint32_t cWrites; + /** Number of read recursions by the writer. */ + uint32_t cWriterReads; + /** The write owner of the lock. */ + volatile pthread_t Writer; + /** pthread rwlock. */ + pthread_rwlock_t RWLock; +#ifdef RTSEMRW_STRICT + /** The validator record for the writer. */ + RTLOCKVALRECEXCL ValidatorWrite; + /** The validator record for the readers. */ + RTLOCKVALRECSHRD ValidatorRead; +#endif +}; + + + +#undef RTSemRWCreate +RTDECL(int) RTSemRWCreate(PRTSEMRW phRWSem) +{ + return RTSemRWCreateEx(phRWSem, 0 /*fFlags*/, NIL_RTLOCKVALCLASS, RTLOCKVAL_SUB_CLASS_NONE, "RTSemRW"); +} + + +RTDECL(int) RTSemRWCreateEx(PRTSEMRW phRWSem, uint32_t fFlags, + RTLOCKVALCLASS hClass, uint32_t uSubClass, const char *pszNameFmt, ...) +{ + AssertReturn(!(fFlags & ~RTSEMRW_FLAGS_NO_LOCK_VAL), VERR_INVALID_PARAMETER); + + /* + * Allocate handle. + */ + int rc; + struct RTSEMRWINTERNAL *pThis = (struct RTSEMRWINTERNAL *)RTMemAlloc(sizeof(struct RTSEMRWINTERNAL)); + if (pThis) + { + /* + * Create the rwlock. + */ + rc = pthread_rwlock_init(&pThis->RWLock, NULL); + if (!rc) + { + pThis->u32Magic = RTSEMRW_MAGIC; + pThis->cReaders = 0; + pThis->cWrites = 0; + pThis->cWriterReads = 0; + pThis->Writer = (pthread_t)-1; +#ifdef RTSEMRW_STRICT + bool const fLVEnabled = !(fFlags & RTSEMRW_FLAGS_NO_LOCK_VAL); + if (!pszNameFmt) + { + static uint32_t volatile s_iSemRWAnon = 0; + uint32_t i = ASMAtomicIncU32(&s_iSemRWAnon) - 1; + RTLockValidatorRecExclInit(&pThis->ValidatorWrite, hClass, uSubClass, pThis, + fLVEnabled, "RTSemRW-%u", i); + RTLockValidatorRecSharedInit(&pThis->ValidatorRead, hClass, uSubClass, pThis, + false /*fSignaller*/, fLVEnabled, "RTSemRW-%u", i); + } + else + { + va_list va; + va_start(va, pszNameFmt); + RTLockValidatorRecExclInitV(&pThis->ValidatorWrite, hClass, uSubClass, pThis, + fLVEnabled, pszNameFmt, va); + va_end(va); + va_start(va, pszNameFmt); + RTLockValidatorRecSharedInitV(&pThis->ValidatorRead, hClass, uSubClass, pThis, + false /*fSignaller*/, fLVEnabled, pszNameFmt, va); + va_end(va); + } + RTLockValidatorRecMakeSiblings(&pThis->ValidatorWrite.Core, &pThis->ValidatorRead.Core); +#else + RT_NOREF_PV(hClass); RT_NOREF_PV(uSubClass); RT_NOREF_PV(pszNameFmt); +#endif + *phRWSem = pThis; + return VINF_SUCCESS; + } + + rc = RTErrConvertFromErrno(rc); + RTMemFree(pThis); + } + else + rc = VERR_NO_MEMORY; + + return rc; +} + + +RTDECL(int) RTSemRWDestroy(RTSEMRW hRWSem) +{ + /* + * Validate input, nil handle is fine. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + if (pThis == NIL_RTSEMRW) + return VINF_SUCCESS; + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + VERR_INVALID_HANDLE); + Assert(pThis->Writer == (pthread_t)-1); + Assert(!pThis->cReaders); + Assert(!pThis->cWrites); + Assert(!pThis->cWriterReads); + + /* + * Try destroy it. + */ + AssertReturn(ASMAtomicCmpXchgU32(&pThis->u32Magic, ~RTSEMRW_MAGIC, RTSEMRW_MAGIC), VERR_INVALID_HANDLE); + int rc = pthread_rwlock_destroy(&pThis->RWLock); + if (!rc) + { +#ifdef RTSEMRW_STRICT + RTLockValidatorRecSharedDelete(&pThis->ValidatorRead); + RTLockValidatorRecExclDelete(&pThis->ValidatorWrite); +#endif + RTMemFree(pThis); + rc = VINF_SUCCESS; + } + else + { + ASMAtomicWriteU32(&pThis->u32Magic, RTSEMRW_MAGIC); + AssertMsgFailed(("Failed to destroy read-write sem %p, rc=%d.\n", hRWSem, rc)); + rc = RTErrConvertFromErrno(rc); + } + + return rc; +} + + +RTDECL(uint32_t) RTSemRWSetSubClass(RTSEMRW hRWSem, uint32_t uSubClass) +{ +#ifdef RTSEMRW_STRICT + /* + * Validate handle. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, RTLOCKVAL_SUB_CLASS_INVALID); + AssertReturn(pThis->u32Magic == RTSEMRW_MAGIC, RTLOCKVAL_SUB_CLASS_INVALID); + + RTLockValidatorRecSharedSetSubClass(&pThis->ValidatorRead, uSubClass); + return RTLockValidatorRecExclSetSubClass(&pThis->ValidatorWrite, uSubClass); +#else + RT_NOREF_PV(hRWSem); RT_NOREF_PV(uSubClass); + return RTLOCKVAL_SUB_CLASS_INVALID; +#endif +} + + +DECL_FORCE_INLINE(int) rtSemRWRequestRead(RTSEMRW hRWSem, RTMSINTERVAL cMillies, PCRTLOCKVALSRCPOS pSrcPos) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + VERR_INVALID_HANDLE); + + /* + * Check if it's the writer (implement write+read recursion). + */ + pthread_t Self = pthread_self(); + pthread_t Writer; + ATOMIC_GET_PTHREAD_T(&pThis->Writer, &Writer); + if (Writer == Self) + { +#ifdef RTSEMRW_STRICT + int rc9 = RTLockValidatorRecExclRecursionMixed(&pThis->ValidatorWrite, &pThis->ValidatorRead.Core, pSrcPos); + if (RT_FAILURE(rc9)) + return rc9; +#endif + Assert(pThis->cWriterReads < INT32_MAX); + pThis->cWriterReads++; + return VINF_SUCCESS; + } + + /* + * Try lock it. + */ + RTTHREAD hThreadSelf = NIL_RTTHREAD; + if (cMillies > 0) + { +#ifdef RTSEMRW_STRICT + hThreadSelf = RTThreadSelfAutoAdopt(); + int rc9 = RTLockValidatorRecSharedCheckOrderAndBlocking(&pThis->ValidatorRead, hThreadSelf, pSrcPos, true, + cMillies, RTTHREADSTATE_RW_READ, true); + if (RT_FAILURE(rc9)) + return rc9; +#else + hThreadSelf = RTThreadSelf(); + RTThreadBlocking(hThreadSelf, RTTHREADSTATE_RW_READ, true); + RT_NOREF_PV(pSrcPos); +#endif + } + + if (cMillies == RT_INDEFINITE_WAIT) + { + /* take rwlock */ + int rc = pthread_rwlock_rdlock(&pThis->RWLock); + RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_RW_READ); + if (rc) + { + AssertMsgFailed(("Failed read lock read-write sem %p, rc=%d.\n", hRWSem, rc)); + return RTErrConvertFromErrno(rc); + } + } + else + { +#ifdef RT_OS_DARWIN + AssertMsgFailed(("Not implemented on Darwin yet because of incomplete pthreads API.")); + return VERR_NOT_IMPLEMENTED; + +#else /* !RT_OS_DARWIN */ + /* + * Get current time and calc end of wait time. + */ + struct timespec ts = {0,0}; + clock_gettime(CLOCK_REALTIME, &ts); + if (cMillies != 0) + { + ts.tv_nsec += (cMillies % 1000) * 1000000; + ts.tv_sec += cMillies / 1000; + if (ts.tv_nsec >= 1000000000) + { + ts.tv_nsec -= 1000000000; + ts.tv_sec++; + } + } + + /* take rwlock */ + int rc = pthread_rwlock_timedrdlock(&pThis->RWLock, &ts); + RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_RW_READ); + if (rc) + { + AssertMsg(rc == ETIMEDOUT, ("Failed read lock read-write sem %p, rc=%d.\n", hRWSem, rc)); + return RTErrConvertFromErrno(rc); + } +#endif /* !RT_OS_DARWIN */ + } + + ASMAtomicIncU32(&pThis->cReaders); +#ifdef RTSEMRW_STRICT + RTLockValidatorRecSharedAddOwner(&pThis->ValidatorRead, hThreadSelf, pSrcPos); +#endif + return VINF_SUCCESS; +} + + +#undef RTSemRWRequestRead +RTDECL(int) RTSemRWRequestRead(RTSEMRW hRWSem, RTMSINTERVAL cMillies) +{ +#ifndef RTSEMRW_STRICT + return rtSemRWRequestRead(hRWSem, cMillies, NULL); +#else + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API(); + return rtSemRWRequestRead(hRWSem, cMillies, &SrcPos); +#endif +} + + +RTDECL(int) RTSemRWRequestReadDebug(RTSEMRW hRWSem, RTMSINTERVAL cMillies, RTHCUINTPTR uId, RT_SRC_POS_DECL) +{ + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API(); + return rtSemRWRequestRead(hRWSem, cMillies, &SrcPos); +} + + +#undef RTSemRWRequestReadNoResume +RTDECL(int) RTSemRWRequestReadNoResume(RTSEMRW hRWSem, RTMSINTERVAL cMillies) +{ + /* EINTR isn't returned by the wait functions we're using. */ +#ifndef RTSEMRW_STRICT + return rtSemRWRequestRead(hRWSem, cMillies, NULL); +#else + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API(); + return rtSemRWRequestRead(hRWSem, cMillies, &SrcPos); +#endif +} + + +RTDECL(int) RTSemRWRequestReadNoResumeDebug(RTSEMRW hRWSem, RTMSINTERVAL cMillies, RTHCUINTPTR uId, RT_SRC_POS_DECL) +{ + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API(); + return rtSemRWRequestRead(hRWSem, cMillies, &SrcPos); +} + + +RTDECL(int) RTSemRWReleaseRead(RTSEMRW hRWSem) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + VERR_INVALID_HANDLE); + + /* + * Check if it's the writer. + */ + pthread_t Self = pthread_self(); + pthread_t Writer; + ATOMIC_GET_PTHREAD_T(&pThis->Writer, &Writer); + if (Writer == Self) + { + AssertMsgReturn(pThis->cWriterReads > 0, ("pThis=%p\n", pThis), VERR_NOT_OWNER); +#ifdef RTSEMRW_STRICT + int rc9 = RTLockValidatorRecExclUnwindMixed(&pThis->ValidatorWrite, &pThis->ValidatorRead.Core); + if (RT_FAILURE(rc9)) + return rc9; +#endif + pThis->cWriterReads--; + return VINF_SUCCESS; + } + + /* + * Try unlock it. + */ +#ifdef RTSEMRW_STRICT + int rc9 = RTLockValidatorRecSharedCheckAndRelease(&pThis->ValidatorRead, RTThreadSelf()); + if (RT_FAILURE(rc9)) + return rc9; +#endif +#ifdef RT_OS_LINUX /* glibc (at least 2.8) may screw up when unlocking a lock we don't own. */ + if (ASMAtomicReadU32(&pThis->cReaders) == 0) + { + AssertMsgFailed(("Not owner of %p\n", pThis)); + return VERR_NOT_OWNER; + } +#endif + ASMAtomicDecU32(&pThis->cReaders); + int rc = pthread_rwlock_unlock(&pThis->RWLock); + if (rc) + { + ASMAtomicIncU32(&pThis->cReaders); + AssertMsgFailed(("Failed read unlock read-write sem %p, rc=%d.\n", hRWSem, rc)); + return RTErrConvertFromErrno(rc); + } + return VINF_SUCCESS; +} + + +DECL_FORCE_INLINE(int) rtSemRWRequestWrite(RTSEMRW hRWSem, RTMSINTERVAL cMillies, PCRTLOCKVALSRCPOS pSrcPos) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + VERR_INVALID_HANDLE); + + /* + * Recursion? + */ + pthread_t Self = pthread_self(); + pthread_t Writer; + ATOMIC_GET_PTHREAD_T(&pThis->Writer, &Writer); + if (Writer == Self) + { +#ifdef RTSEMRW_STRICT + int rc9 = RTLockValidatorRecExclRecursion(&pThis->ValidatorWrite, pSrcPos); + if (RT_FAILURE(rc9)) + return rc9; +#endif + Assert(pThis->cWrites < INT32_MAX); + pThis->cWrites++; + return VINF_SUCCESS; + } + + /* + * Try lock it. + */ + RTTHREAD hThreadSelf = NIL_RTTHREAD; + if (cMillies) + { +#ifdef RTSEMRW_STRICT + hThreadSelf = RTThreadSelfAutoAdopt(); + int rc9 = RTLockValidatorRecExclCheckOrderAndBlocking(&pThis->ValidatorWrite, hThreadSelf, pSrcPos, true, + cMillies, RTTHREADSTATE_RW_WRITE, true); + if (RT_FAILURE(rc9)) + return rc9; +#else + hThreadSelf = RTThreadSelf(); + RTThreadBlocking(hThreadSelf, RTTHREADSTATE_RW_WRITE, true); + RT_NOREF_PV(pSrcPos); +#endif + } + + if (cMillies == RT_INDEFINITE_WAIT) + { + /* take rwlock */ + int rc = pthread_rwlock_wrlock(&pThis->RWLock); + RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_RW_WRITE); + if (rc) + { + AssertMsgFailed(("Failed write lock read-write sem %p, rc=%d.\n", hRWSem, rc)); + return RTErrConvertFromErrno(rc); + } + } + else + { +#ifdef RT_OS_DARWIN + AssertMsgFailed(("Not implemented on Darwin yet because of incomplete pthreads API.")); + return VERR_NOT_IMPLEMENTED; +#else /* !RT_OS_DARWIN */ + /* + * Get current time and calc end of wait time. + */ + struct timespec ts = {0,0}; + clock_gettime(CLOCK_REALTIME, &ts); + if (cMillies != 0) + { + ts.tv_nsec += (cMillies % 1000) * 1000000; + ts.tv_sec += cMillies / 1000; + if (ts.tv_nsec >= 1000000000) + { + ts.tv_nsec -= 1000000000; + ts.tv_sec++; + } + } + + /* take rwlock */ + int rc = pthread_rwlock_timedwrlock(&pThis->RWLock, &ts); + RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_RW_WRITE); + if (rc) + { + AssertMsg(rc == ETIMEDOUT, ("Failed read lock read-write sem %p, rc=%d.\n", hRWSem, rc)); + return RTErrConvertFromErrno(rc); + } +#endif /* !RT_OS_DARWIN */ + } + + ATOMIC_SET_PTHREAD_T(&pThis->Writer, Self); + pThis->cWrites = 1; + Assert(!pThis->cReaders); +#ifdef RTSEMRW_STRICT + RTLockValidatorRecExclSetOwner(&pThis->ValidatorWrite, hThreadSelf, pSrcPos, true); +#endif + return VINF_SUCCESS; +} + + +#undef RTSemRWRequestWrite +RTDECL(int) RTSemRWRequestWrite(RTSEMRW hRWSem, RTMSINTERVAL cMillies) +{ +#ifndef RTSEMRW_STRICT + return rtSemRWRequestWrite(hRWSem, cMillies, NULL); +#else + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API(); + return rtSemRWRequestWrite(hRWSem, cMillies, &SrcPos); +#endif +} + + +RTDECL(int) RTSemRWRequestWriteDebug(RTSEMRW hRWSem, RTMSINTERVAL cMillies, RTHCUINTPTR uId, RT_SRC_POS_DECL) +{ + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API(); + return rtSemRWRequestWrite(hRWSem, cMillies, &SrcPos); +} + + +#undef RTSemRWRequestWriteNoResume +RTDECL(int) RTSemRWRequestWriteNoResume(RTSEMRW hRWSem, RTMSINTERVAL cMillies) +{ + /* EINTR isn't returned by the wait functions we're using. */ +#ifndef RTSEMRW_STRICT + return rtSemRWRequestWrite(hRWSem, cMillies, NULL); +#else + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API(); + return rtSemRWRequestWrite(hRWSem, cMillies, &SrcPos); +#endif +} + + +RTDECL(int) RTSemRWRequestWriteNoResumeDebug(RTSEMRW hRWSem, RTMSINTERVAL cMillies, RTHCUINTPTR uId, RT_SRC_POS_DECL) +{ + /* EINTR isn't returned by the wait functions we're using. */ + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API(); + return rtSemRWRequestWrite(hRWSem, cMillies, &SrcPos); +} + + +RTDECL(int) RTSemRWReleaseWrite(RTSEMRW hRWSem) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + VERR_INVALID_HANDLE); + + /* + * Verify ownership and implement recursion. + */ + pthread_t Self = pthread_self(); + pthread_t Writer; + ATOMIC_GET_PTHREAD_T(&pThis->Writer, &Writer); + AssertMsgReturn(Writer == Self, ("pThis=%p\n", pThis), VERR_NOT_OWNER); + AssertReturn(pThis->cWriterReads == 0 || pThis->cWrites > 1, VERR_WRONG_ORDER); + + if (pThis->cWrites > 1) + { +#ifdef RTSEMRW_STRICT + int rc9 = RTLockValidatorRecExclUnwind(&pThis->ValidatorWrite); + if (RT_FAILURE(rc9)) + return rc9; +#endif + pThis->cWrites--; + return VINF_SUCCESS; + } + + /* + * Try unlock it. + */ +#ifdef RTSEMRW_STRICT + int rc9 = RTLockValidatorRecExclReleaseOwner(&pThis->ValidatorWrite, true); + if (RT_FAILURE(rc9)) + return rc9; +#endif + + pThis->cWrites--; + ATOMIC_SET_PTHREAD_T(&pThis->Writer, (pthread_t)-1); + int rc = pthread_rwlock_unlock(&pThis->RWLock); + if (rc) + { + AssertMsgFailed(("Failed write unlock read-write sem %p, rc=%d.\n", hRWSem, rc)); + return RTErrConvertFromErrno(rc); + } + + return VINF_SUCCESS; +} + + +RTDECL(bool) RTSemRWIsWriteOwner(RTSEMRW hRWSem) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, false); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + false); + + /* + * Check ownership. + */ + pthread_t Self = pthread_self(); + pthread_t Writer; + ATOMIC_GET_PTHREAD_T(&pThis->Writer, &Writer); + return Writer == Self; +} + + +RTDECL(bool) RTSemRWIsReadOwner(RTSEMRW hRWSem, bool fWannaHear) +{ + /* + * Validate handle. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, false); + AssertReturn(pThis->u32Magic == RTSEMRW_MAGIC, false); + + /* + * Check write ownership. The writer is also a valid reader. + */ + pthread_t Self = pthread_self(); + pthread_t Writer; + ATOMIC_GET_PTHREAD_T(&pThis->Writer, &Writer); + if (Writer == Self) + return true; + if (Writer != (pthread_t)-1) + return false; + + /* + * If there are no readers, we cannot be one of them, can we? + */ + if (ASMAtomicReadU32(&pThis->cReaders) == 0) + return false; + +#ifdef RTSEMRW_STRICT + /* + * Ask the lock validator. + */ + NOREF(fWannaHear); + return RTLockValidatorRecSharedIsOwner(&pThis->ValidatorRead, NIL_RTTHREAD); +#else + /* + * Just tell the caller what he want to hear. + */ + return fWannaHear; +#endif +} +RT_EXPORT_SYMBOL(RTSemRWIsReadOwner); + + +RTDECL(uint32_t) RTSemRWGetWriteRecursion(RTSEMRW hRWSem) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, 0); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + 0); + + /* + * Return the requested data. + */ + return pThis->cWrites; +} + + +RTDECL(uint32_t) RTSemRWGetWriterReadRecursion(RTSEMRW hRWSem) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, 0); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + 0); + + /* + * Return the requested data. + */ + return pThis->cWriterReads; +} + + +RTDECL(uint32_t) RTSemRWGetReadCount(RTSEMRW hRWSem) +{ + /* + * Validate input. + */ + struct RTSEMRWINTERNAL *pThis = hRWSem; + AssertPtrReturn(pThis, 0); + AssertMsgReturn(pThis->u32Magic == RTSEMRW_MAGIC, + ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), + 0); + + /* + * Return the requested data. + */ + return pThis->cReaders; +} + |