diff options
Diffstat (limited to 'src/VBox/Runtime/r3/linux/semeventmulti-linux.cpp')
| -rw-r--r-- | src/VBox/Runtime/r3/linux/semeventmulti-linux.cpp | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/linux/semeventmulti-linux.cpp b/src/VBox/Runtime/r3/linux/semeventmulti-linux.cpp new file mode 100644 index 00000000..9e049069 --- /dev/null +++ b/src/VBox/Runtime/r3/linux/semeventmulti-linux.cpp @@ -0,0 +1,453 @@ +/* $Id: semeventmulti-linux.cpp $ */ +/** @file + * IPRT - Multiple Release Event Semaphore, Linux (2.6.x+). + */ + +/* + * Copyright (C) 2006-2019 Oracle Corporation + * + * This file is part of VirtualBox Open Source Edition (OSE), as + * available from http://www.virtualbox.org. This file is free software; + * you can redistribute it and/or modify it under the terms of the GNU + * General Public License (GPL) as published by the Free Software + * Foundation, in version 2 as it comes in the "COPYING" file of the + * VirtualBox OSE distribution. VirtualBox OSE is distributed in the + * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL) only, as it comes in the "COPYING.CDDL" file of the + * VirtualBox OSE 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. + */ + + +#include <features.h> +#if __GLIBC_PREREQ(2,6) && !defined(IPRT_WITH_FUTEX_BASED_SEMS) + +/* + * glibc 2.6 fixed a serious bug in the mutex implementation. We wrote this + * linux specific event semaphores code in order to work around the bug. As it + * turns out, this code seems to have an unresolved issue (@bugref{2599}), so we'll + * fall back on the pthread based implementation if glibc is known to contain + * the bug fix. + * + * The external reference to epoll_pwait is a hack which prevents that we link + * against glibc < 2.6. + */ +#include "../posix/semeventmulti-posix.cpp" +__asm__ (".global epoll_pwait"); + +#else /* glibc < 2.6 */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <iprt/semaphore.h> +#include "internal/iprt.h" + +#include <iprt/assert.h> +#include <iprt/asm.h> +#include <iprt/err.h> +#include <iprt/lockvalidator.h> +#include <iprt/mem.h> +#include <iprt/time.h> +#include "internal/magics.h" +#include "internal/strict.h" + + +#include <errno.h> +#include <limits.h> +#include <pthread.h> +#include <unistd.h> +#include <sys/time.h> +#include <sys/syscall.h> +#if 0 /* With 2.6.17 futex.h has become C++ unfriendly. */ +# include <linux/futex.h> +#else +# define FUTEX_WAIT 0 +# define FUTEX_WAKE 1 +#endif + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +/** + * Linux multiple wakup event semaphore. + */ +struct RTSEMEVENTMULTIINTERNAL +{ + /** Magic value. */ + uint32_t volatile u32Magic; + /** The futex state variable. + * -1 means signaled. + * 0 means not signaled, no waiters. + * 1 means not signaled and that someone is waiting. + */ + int32_t volatile iState; +#ifdef RTSEMEVENTMULTI_STRICT + /** Signallers. */ + RTLOCKVALRECSHRD Signallers; + /** Indicates that lock validation should be performed. */ + bool volatile fEverHadSignallers; +#endif +}; + + +/** + * Wrapper for the futex syscall. + */ +static long sys_futex(int32_t volatile *uaddr, int op, int val, struct timespec *utime, int32_t *uaddr2, int val3) +{ + errno = 0; + long rc = syscall(__NR_futex, uaddr, op, val, utime, uaddr2, val3); + if (rc < 0) + { + Assert(rc == -1); + rc = -errno; + } + return rc; +} + + +RTDECL(int) RTSemEventMultiCreate(PRTSEMEVENTMULTI phEventMultiSem) +{ + return RTSemEventMultiCreateEx(phEventMultiSem, 0 /*fFlags*/, NIL_RTLOCKVALCLASS, NULL); +} + + +RTDECL(int) RTSemEventMultiCreateEx(PRTSEMEVENTMULTI phEventMultiSem, uint32_t fFlags, RTLOCKVALCLASS hClass, + const char *pszNameFmt, ...) +{ + AssertReturn(!(fFlags & ~RTSEMEVENTMULTI_FLAGS_NO_LOCK_VAL), VERR_INVALID_PARAMETER); + + /* + * Allocate semaphore handle. + */ + struct RTSEMEVENTMULTIINTERNAL *pThis = (struct RTSEMEVENTMULTIINTERNAL *)RTMemAlloc(sizeof(struct RTSEMEVENTMULTIINTERNAL)); + if (pThis) + { + pThis->u32Magic = RTSEMEVENTMULTI_MAGIC; + pThis->iState = 0; +#ifdef RTSEMEVENTMULTI_STRICT + if (!pszNameFmt) + { + static uint32_t volatile s_iSemEventMultiAnon = 0; + RTLockValidatorRecSharedInit(&pThis->Signallers, hClass, RTLOCKVAL_SUB_CLASS_ANY, pThis, + true /*fSignaller*/, !(fFlags & RTSEMEVENTMULTI_FLAGS_NO_LOCK_VAL), + "RTSemEventMulti-%u", ASMAtomicIncU32(&s_iSemEventMultiAnon) - 1); + } + else + { + va_list va; + va_start(va, pszNameFmt); + RTLockValidatorRecSharedInitV(&pThis->Signallers, hClass, RTLOCKVAL_SUB_CLASS_ANY, pThis, + true /*fSignaller*/, !(fFlags & RTSEMEVENTMULTI_FLAGS_NO_LOCK_VAL), + pszNameFmt, va); + va_end(va); + } + pThis->fEverHadSignallers = false; +#else + RT_NOREF(hClass, pszNameFmt); +#endif + + *phEventMultiSem = pThis; + return VINF_SUCCESS; + } + return VERR_NO_MEMORY; +} + + +RTDECL(int) RTSemEventMultiDestroy(RTSEMEVENTMULTI hEventMultiSem) +{ + /* + * Validate input. + */ + struct RTSEMEVENTMULTIINTERNAL *pThis = hEventMultiSem; + if (pThis == NIL_RTSEMEVENTMULTI) + return VINF_SUCCESS; + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, VERR_INVALID_HANDLE); + + /* + * Invalidate the semaphore and wake up anyone waiting on it. + */ + ASMAtomicWriteU32(&pThis->u32Magic, RTSEMEVENTMULTI_MAGIC + 1); + if (ASMAtomicXchgS32(&pThis->iState, -1) == 1) + { + sys_futex(&pThis->iState, FUTEX_WAKE, INT_MAX, NULL, NULL, 0); + usleep(1000); + } + + /* + * Free the semaphore memory and be gone. + */ +#ifdef RTSEMEVENTMULTI_STRICT + RTLockValidatorRecSharedDelete(&pThis->Signallers); +#endif + RTMemFree(pThis); + return VINF_SUCCESS; +} + + +RTDECL(int) RTSemEventMultiSignal(RTSEMEVENTMULTI hEventMultiSem) +{ + /* + * Validate input. + */ + struct RTSEMEVENTMULTIINTERNAL *pThis = hEventMultiSem; + AssertReturn(VALID_PTR(pThis) && pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, + VERR_INVALID_HANDLE); + +#ifdef RTSEMEVENTMULTI_STRICT + if (pThis->fEverHadSignallers) + { + int rc9 = RTLockValidatorRecSharedCheckSignaller(&pThis->Signallers, NIL_RTTHREAD); + if (RT_FAILURE(rc9)) + return rc9; + } +#endif + + + /* + * Signal it. + */ + int32_t iOld = ASMAtomicXchgS32(&pThis->iState, -1); + if (iOld > 0) + { + /* wake up sleeping threads. */ + long cWoken = sys_futex(&pThis->iState, FUTEX_WAKE, INT_MAX, NULL, NULL, 0); + AssertMsg(cWoken >= 0, ("%ld\n", cWoken)); NOREF(cWoken); + } + Assert(iOld == 0 || iOld == -1 || iOld == 1); + return VINF_SUCCESS; +} + + +RTDECL(int) RTSemEventMultiReset(RTSEMEVENTMULTI hEventMultiSem) +{ + /* + * Validate input. + */ + struct RTSEMEVENTMULTIINTERNAL *pThis = hEventMultiSem; + AssertReturn(VALID_PTR(pThis) && pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, + VERR_INVALID_HANDLE); +#ifdef RT_STRICT + int32_t i = pThis->iState; + Assert(i == 0 || i == -1 || i == 1); +#endif + + /* + * Reset it. + */ + ASMAtomicCmpXchgS32(&pThis->iState, 0, -1); + return VINF_SUCCESS; +} + + + +DECLINLINE(int) rtSemEventLnxMultiWait(struct RTSEMEVENTMULTIINTERNAL *pThis, uint32_t fFlags, uint64_t uTimeout, + PCRTLOCKVALSRCPOS pSrcPos) +{ + RT_NOREF(pSrcPos); + + /* + * Validate input. + */ + AssertPtrReturn(pThis, VERR_INVALID_HANDLE); + AssertReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, VERR_INVALID_HANDLE); + AssertReturn(RTSEMWAIT_FLAGS_ARE_VALID(fFlags), VERR_INVALID_PARAMETER); + + /* + * Quickly check whether it's signaled. + */ + int32_t iCur = ASMAtomicUoReadS32(&pThis->iState); + Assert(iCur == 0 || iCur == -1 || iCur == 1); + if (iCur == -1) + return VINF_SUCCESS; + + /* + * Check and convert the timeout value. + */ + struct timespec ts; + struct timespec *pTimeout = NULL; + uint64_t u64Deadline = 0; /* shut up gcc */ + if (!(fFlags & RTSEMWAIT_FLAGS_INDEFINITE)) + { + /* If the timeout is zero, then we're done. */ + if (!uTimeout) + return VERR_TIMEOUT; + + /* Convert it to a deadline + interval timespec. */ + if (fFlags & RTSEMWAIT_FLAGS_MILLISECS) + uTimeout = uTimeout < UINT64_MAX / UINT32_C(1000000) * UINT32_C(1000000) + ? uTimeout * UINT32_C(1000000) + : UINT64_MAX; + if (uTimeout != UINT64_MAX) /* unofficial way of indicating an indefinite wait */ + { + if (fFlags & RTSEMWAIT_FLAGS_RELATIVE) + u64Deadline = RTTimeSystemNanoTS() + uTimeout; + else + { + uint64_t u64Now = RTTimeSystemNanoTS(); + if (uTimeout <= u64Now) + return VERR_TIMEOUT; + u64Deadline = uTimeout; + uTimeout -= u64Now; + } + if ( sizeof(ts.tv_sec) >= sizeof(uint64_t) + || uTimeout <= UINT64_C(1000000000) * UINT32_MAX) + { + ts.tv_nsec = uTimeout % UINT32_C(1000000000); + ts.tv_sec = uTimeout / UINT32_C(1000000000); + pTimeout = &ts; + } + } + } + + /* + * The wait loop. + */ +#ifdef RTSEMEVENTMULTI_STRICT + RTTHREAD hThreadSelf = RTThreadSelfAutoAdopt(); +#else + RTTHREAD hThreadSelf = RTThreadSelf(); +#endif + for (unsigned i = 0;; i++) + { + /* + * Start waiting. We only account for there being or having been + * threads waiting on the semaphore to keep things simple. + */ + iCur = ASMAtomicUoReadS32(&pThis->iState); + Assert(iCur == 0 || iCur == -1 || iCur == 1); + if ( iCur == 1 + || ASMAtomicCmpXchgS32(&pThis->iState, 1, 0)) + { + /* adjust the relative timeout */ + if (pTimeout) + { + int64_t i64Diff = u64Deadline - RTTimeSystemNanoTS(); + if (i64Diff < 1000) + return VERR_TIMEOUT; + ts.tv_sec = (uint64_t)i64Diff / UINT32_C(1000000000); + ts.tv_nsec = (uint64_t)i64Diff % UINT32_C(1000000000); + } +#ifdef RTSEMEVENTMULTI_STRICT + if (pThis->fEverHadSignallers) + { + int rc9 = RTLockValidatorRecSharedCheckBlocking(&pThis->Signallers, hThreadSelf, pSrcPos, false, + uTimeout / UINT32_C(1000000), RTTHREADSTATE_EVENT_MULTI, true); + if (RT_FAILURE(rc9)) + return rc9; + } +#endif + RTThreadBlocking(hThreadSelf, RTTHREADSTATE_EVENT_MULTI, true); + long rc = sys_futex(&pThis->iState, FUTEX_WAIT, 1, pTimeout, NULL, 0); + RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_EVENT_MULTI); + if (RT_UNLIKELY(pThis->u32Magic != RTSEMEVENTMULTI_MAGIC)) + return VERR_SEM_DESTROYED; + if (rc == 0) + return VINF_SUCCESS; + + /* + * Act on the wakup code. + */ + if (rc == -ETIMEDOUT) + { +/** @todo something is broken here. shows up every now and again in the ata + * code. Should try to run the timeout against RTTimeMilliTS to + * check that it's doing the right thing... */ + Assert(pTimeout); + return VERR_TIMEOUT; + } + if (rc == -EWOULDBLOCK) + /* retry, the value changed. */; + else if (rc == -EINTR) + { + if (fFlags & RTSEMWAIT_FLAGS_NORESUME) + return VERR_INTERRUPTED; + } + else + { + /* this shouldn't happen! */ + AssertMsgFailed(("rc=%ld errno=%d\n", rc, errno)); + return RTErrConvertFromErrno(rc); + } + } + else if (iCur == -1) + return VINF_SUCCESS; + } +} + + +#undef RTSemEventMultiWaitEx +RTDECL(int) RTSemEventMultiWaitEx(RTSEMEVENTMULTI hEventMultiSem, uint32_t fFlags, uint64_t uTimeout) +{ +#ifndef RTSEMEVENT_STRICT + return rtSemEventLnxMultiWait(hEventMultiSem, fFlags, uTimeout, NULL); +#else + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API(); + return rtSemEventLnxMultiWait(hEventMultiSem, fFlags, uTimeout, &SrcPos); +#endif +} + + +RTDECL(int) RTSemEventMultiWaitExDebug(RTSEMEVENTMULTI hEventMultiSem, uint32_t fFlags, uint64_t uTimeout, + RTHCUINTPTR uId, RT_SRC_POS_DECL) +{ + RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API(); + return rtSemEventLnxMultiWait(hEventMultiSem, fFlags, uTimeout, &SrcPos); +} + + +RTDECL(void) RTSemEventMultiSetSignaller(RTSEMEVENTMULTI hEventMultiSem, RTTHREAD hThread) +{ +#ifdef RTSEMEVENTMULTI_STRICT + struct RTSEMEVENTMULTIINTERNAL *pThis = hEventMultiSem; + AssertPtrReturnVoid(pThis); + AssertReturnVoid(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC); + + ASMAtomicWriteBool(&pThis->fEverHadSignallers, true); + RTLockValidatorRecSharedResetOwner(&pThis->Signallers, hThread, NULL); +#else + RT_NOREF(hEventMultiSem, hThread); +#endif +} + + +RTDECL(void) RTSemEventMultiAddSignaller(RTSEMEVENTMULTI hEventMultiSem, RTTHREAD hThread) +{ +#ifdef RTSEMEVENTMULTI_STRICT + struct RTSEMEVENTMULTIINTERNAL *pThis = hEventMultiSem; + AssertPtrReturnVoid(pThis); + AssertReturnVoid(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC); + + ASMAtomicWriteBool(&pThis->fEverHadSignallers, true); + RTLockValidatorRecSharedAddOwner(&pThis->Signallers, hThread, NULL); +#else + RT_NOREF(hEventMultiSem, hThread); +#endif +} + + +RTDECL(void) RTSemEventMultiRemoveSignaller(RTSEMEVENTMULTI hEventMultiSem, RTTHREAD hThread) +{ +#ifdef RTSEMEVENTMULTI_STRICT + struct RTSEMEVENTMULTIINTERNAL *pThis = hEventMultiSem; + AssertPtrReturnVoid(pThis); + AssertReturnVoid(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC); + + RTLockValidatorRecSharedRemoveOwner(&pThis->Signallers, hThread); +#else + RT_NOREF(hEventMultiSem, hThread); +#endif +} + +#endif /* glibc < 2.6 || IPRT_WITH_FUTEX_BASED_SEMS */ + |