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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:01:46 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:01:46 +0000
commitf8fe689a81f906d1b91bb3220acde2a4ecb14c5b (patch)
tree26484e9d7e2c67806c2d1760196ff01aaa858e8c /src/VBox/Runtime/r3/linux/semevent-linux.cpp
parentInitial commit. (diff)
downloadvirtualbox-upstream.tar.xz
virtualbox-upstream.zip
Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/VBox/Runtime/r3/linux/semevent-linux.cpp')
-rw-r--r--src/VBox/Runtime/r3/linux/semevent-linux.cpp417
1 files changed, 417 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/linux/semevent-linux.cpp b/src/VBox/Runtime/r3/linux/semevent-linux.cpp
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+++ b/src/VBox/Runtime/r3/linux/semevent-linux.cpp
@@ -0,0 +1,417 @@
+/* $Id: semevent-linux.cpp $ */
+/** @file
+ * IPRT - 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. We
+ * will 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/semevent-posix.cpp"
+__asm__ (".global epoll_pwait");
+
+#else /* glibc < 2.6 */
+
+
+/*********************************************************************************************************************************
+* 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/time.h>
+#include "internal/magics.h"
+#include "internal/mem.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 (single wakup) event semaphore.
+ */
+struct RTSEMEVENTINTERNAL
+{
+ /** Magic value. */
+ intptr_t volatile iMagic;
+ /** The futex state variable.
+ * 0 means not signalled.
+ 1 means signalled. */
+ uint32_t volatile fSignalled;
+ /** The number of waiting threads */
+ int32_t volatile cWaiters;
+#ifdef RTSEMEVENT_STRICT
+ /** Signallers. */
+ RTLOCKVALRECSHRD Signallers;
+ /** Indicates that lock validation should be performed. */
+ bool volatile fEverHadSignallers;
+#endif
+ /** The creation flags. */
+ uint32_t fFlags;
+};
+
+
+/**
+ * Wrapper for the futex syscall.
+ */
+static long sys_futex(uint32_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) RTSemEventCreate(PRTSEMEVENT phEventSem)
+{
+ return RTSemEventCreateEx(phEventSem, 0 /*fFlags*/, NIL_RTLOCKVALCLASS, NULL);
+}
+
+
+RTDECL(int) RTSemEventCreateEx(PRTSEMEVENT phEventSem, uint32_t fFlags, RTLOCKVALCLASS hClass, const char *pszNameFmt, ...)
+{
+ AssertReturn(!(fFlags & ~(RTSEMEVENT_FLAGS_NO_LOCK_VAL | RTSEMEVENT_FLAGS_BOOTSTRAP_HACK)), VERR_INVALID_PARAMETER);
+ Assert(!(fFlags & RTSEMEVENT_FLAGS_BOOTSTRAP_HACK) || (fFlags & RTSEMEVENT_FLAGS_NO_LOCK_VAL));
+
+ /*
+ * Allocate semaphore handle.
+ */
+ struct RTSEMEVENTINTERNAL *pThis;
+ if (!(fFlags & RTSEMEVENT_FLAGS_BOOTSTRAP_HACK))
+ pThis = (struct RTSEMEVENTINTERNAL *)RTMemAlloc(sizeof(struct RTSEMEVENTINTERNAL));
+ else
+ pThis = (struct RTSEMEVENTINTERNAL *)rtMemBaseAlloc(sizeof(struct RTSEMEVENTINTERNAL));
+ if (pThis)
+ {
+ pThis->iMagic = RTSEMEVENT_MAGIC;
+ pThis->cWaiters = 0;
+ pThis->fSignalled = 0;
+ pThis->fFlags = fFlags;
+#ifdef RTSEMEVENT_STRICT
+ if (!pszNameFmt)
+ {
+ static uint32_t volatile s_iSemEventAnon = 0;
+ RTLockValidatorRecSharedInit(&pThis->Signallers, hClass, RTLOCKVAL_SUB_CLASS_ANY, pThis,
+ true /*fSignaller*/, !(fFlags & RTSEMEVENT_FLAGS_NO_LOCK_VAL),
+ "RTSemEvent-%u", ASMAtomicIncU32(&s_iSemEventAnon) - 1);
+ }
+ else
+ {
+ va_list va;
+ va_start(va, pszNameFmt);
+ RTLockValidatorRecSharedInitV(&pThis->Signallers, hClass, RTLOCKVAL_SUB_CLASS_ANY, pThis,
+ true /*fSignaller*/, !(fFlags & RTSEMEVENT_FLAGS_NO_LOCK_VAL),
+ pszNameFmt, va);
+ va_end(va);
+ }
+ pThis->fEverHadSignallers = false;
+#else
+ RT_NOREF(hClass, pszNameFmt);
+#endif
+
+ *phEventSem = pThis;
+ return VINF_SUCCESS;
+ }
+ return VERR_NO_MEMORY;
+}
+
+
+RTDECL(int) RTSemEventDestroy(RTSEMEVENT hEventSem)
+{
+ /*
+ * Validate input.
+ */
+ struct RTSEMEVENTINTERNAL *pThis = hEventSem;
+ if (pThis == NIL_RTSEMEVENT)
+ return VINF_SUCCESS;
+ AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
+ AssertReturn(pThis->iMagic == RTSEMEVENT_MAGIC, VERR_INVALID_HANDLE);
+
+ /*
+ * Invalidate the semaphore and wake up anyone waiting on it.
+ */
+ ASMAtomicXchgSize(&pThis->iMagic, RTSEMEVENT_MAGIC | UINT32_C(0x80000000));
+ if (ASMAtomicXchgS32(&pThis->cWaiters, INT32_MIN / 2) > 0)
+ {
+ sys_futex(&pThis->fSignalled, FUTEX_WAKE, INT_MAX, NULL, NULL, 0);
+ usleep(1000);
+ }
+
+ /*
+ * Free the semaphore memory and be gone.
+ */
+#ifdef RTSEMEVENT_STRICT
+ RTLockValidatorRecSharedDelete(&pThis->Signallers);
+#endif
+ if (!(pThis->fFlags & RTSEMEVENT_FLAGS_BOOTSTRAP_HACK))
+ RTMemFree(pThis);
+ else
+ rtMemBaseFree(pThis);
+ return VINF_SUCCESS;
+}
+
+
+RTDECL(int) RTSemEventSignal(RTSEMEVENT hEventSem)
+{
+ /*
+ * Validate input.
+ */
+ struct RTSEMEVENTINTERNAL *pThis = hEventSem;
+ AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
+ AssertReturn(pThis->iMagic == RTSEMEVENT_MAGIC, VERR_INVALID_HANDLE);
+
+#ifdef RTSEMEVENT_STRICT
+ if (pThis->fEverHadSignallers)
+ {
+ int rc9 = RTLockValidatorRecSharedCheckSignaller(&pThis->Signallers, NIL_RTTHREAD);
+ if (RT_FAILURE(rc9))
+ return rc9;
+ }
+#endif
+
+ ASMAtomicWriteU32(&pThis->fSignalled, 1);
+ if (ASMAtomicReadS32(&pThis->cWaiters) < 1)
+ return VINF_SUCCESS;
+
+ /* somebody is waiting, try wake up one of them. */
+ long cWoken = sys_futex(&pThis->fSignalled, FUTEX_WAKE, 1, NULL, NULL, 0);
+ if (RT_LIKELY(cWoken >= 0))
+ return VINF_SUCCESS;
+
+ if (RT_UNLIKELY(pThis->iMagic != RTSEMEVENT_MAGIC))
+ return VERR_SEM_DESTROYED;
+
+ return VERR_INVALID_PARAMETER;
+}
+
+
+static int rtSemEventWait(RTSEMEVENT hEventSem, RTMSINTERVAL cMillies, bool fAutoResume)
+{
+#ifdef RTSEMEVENT_STRICT
+ PCRTLOCKVALSRCPOS pSrcPos = NULL;
+#endif
+
+ /*
+ * Validate input.
+ */
+ struct RTSEMEVENTINTERNAL *pThis = hEventSem;
+ AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
+ AssertReturn(pThis->iMagic == RTSEMEVENT_MAGIC, VERR_INVALID_HANDLE);
+
+ /*
+ * Quickly check whether it's signaled.
+ */
+ /** @todo this isn't fair if someone is already waiting on it. They should
+ * have the first go at it!
+ * (ASMAtomicReadS32(&pThis->cWaiters) == 0 || !cMillies) && ... */
+ if (ASMAtomicCmpXchgU32(&pThis->fSignalled, 0, 1))
+ return VINF_SUCCESS;
+
+ /*
+ * Convert the timeout value.
+ */
+ struct timespec ts;
+ struct timespec *pTimeout = NULL;
+ uint64_t u64End = 0; /* shut up gcc */
+ if (cMillies != RT_INDEFINITE_WAIT)
+ {
+ if (!cMillies)
+ return VERR_TIMEOUT;
+ ts.tv_sec = cMillies / 1000;
+ ts.tv_nsec = (cMillies % 1000) * UINT32_C(1000000);
+ u64End = RTTimeSystemNanoTS() + cMillies * UINT64_C(1000000);
+ pTimeout = &ts;
+ }
+
+ ASMAtomicIncS32(&pThis->cWaiters);
+
+ /*
+ * The wait loop.
+ */
+#ifdef RTSEMEVENT_STRICT
+ RTTHREAD hThreadSelf = !(pThis->fFlags & RTSEMEVENT_FLAGS_BOOTSTRAP_HACK)
+ ? RTThreadSelfAutoAdopt()
+ : RTThreadSelf();
+#else
+ RTTHREAD hThreadSelf = RTThreadSelf();
+#endif
+ int rc = VINF_SUCCESS;
+ for (;;)
+ {
+#ifdef RTSEMEVENT_STRICT
+ if (pThis->fEverHadSignallers)
+ {
+ rc = RTLockValidatorRecSharedCheckBlocking(&pThis->Signallers, hThreadSelf, pSrcPos, false,
+ cMillies, RTTHREADSTATE_EVENT, true);
+ if (RT_FAILURE(rc))
+ break;
+ }
+#endif
+ RTThreadBlocking(hThreadSelf, RTTHREADSTATE_EVENT, true);
+ long lrc = sys_futex(&pThis->fSignalled, FUTEX_WAIT, 0, pTimeout, NULL, 0);
+ RTThreadUnblocked(hThreadSelf, RTTHREADSTATE_EVENT);
+ if (RT_UNLIKELY(pThis->iMagic != RTSEMEVENT_MAGIC))
+ {
+ rc = VERR_SEM_DESTROYED;
+ break;
+ }
+
+ if (RT_LIKELY(lrc == 0 || lrc == -EWOULDBLOCK))
+ {
+ /* successful wakeup or fSignalled > 0 in the meantime */
+ if (ASMAtomicCmpXchgU32(&pThis->fSignalled, 0, 1))
+ break;
+ }
+ else if (lrc == -ETIMEDOUT)
+ {
+ rc = VERR_TIMEOUT;
+ break;
+ }
+ else if (lrc == -EINTR)
+ {
+ if (!fAutoResume)
+ {
+ rc = VERR_INTERRUPTED;
+ break;
+ }
+ }
+ else
+ {
+ /* this shouldn't happen! */
+ AssertMsgFailed(("rc=%ld errno=%d\n", lrc, errno));
+ rc = RTErrConvertFromErrno(lrc);
+ break;
+ }
+ /* adjust the relative timeout */
+ if (pTimeout)
+ {
+ int64_t i64Diff = u64End - RTTimeSystemNanoTS();
+ if (i64Diff < 1000)
+ {
+ rc = VERR_TIMEOUT;
+ break;
+ }
+ ts.tv_sec = (uint64_t)i64Diff / UINT32_C(1000000000);
+ ts.tv_nsec = (uint64_t)i64Diff % UINT32_C(1000000000);
+ }
+ }
+
+ ASMAtomicDecS32(&pThis->cWaiters);
+ return rc;
+}
+
+
+RTDECL(int) RTSemEventWait(RTSEMEVENT hEventSem, RTMSINTERVAL cMillies)
+{
+ int rc = rtSemEventWait(hEventSem, cMillies, true);
+ Assert(rc != VERR_INTERRUPTED);
+ Assert(rc != VERR_TIMEOUT || cMillies != RT_INDEFINITE_WAIT);
+ return rc;
+}
+
+
+RTDECL(int) RTSemEventWaitNoResume(RTSEMEVENT hEventSem, RTMSINTERVAL cMillies)
+{
+ return rtSemEventWait(hEventSem, cMillies, false);
+}
+
+
+RTDECL(void) RTSemEventSetSignaller(RTSEMEVENT hEventSem, RTTHREAD hThread)
+{
+#ifdef RTSEMEVENT_STRICT
+ struct RTSEMEVENTINTERNAL *pThis = hEventSem;
+ AssertPtrReturnVoid(pThis);
+ AssertReturnVoid(pThis->iMagic == RTSEMEVENT_MAGIC);
+
+ ASMAtomicWriteBool(&pThis->fEverHadSignallers, true);
+ RTLockValidatorRecSharedResetOwner(&pThis->Signallers, hThread, NULL);
+#else
+ RT_NOREF(hEventSem, hThread);
+#endif
+}
+
+
+RTDECL(void) RTSemEventAddSignaller(RTSEMEVENT hEventSem, RTTHREAD hThread)
+{
+#ifdef RTSEMEVENT_STRICT
+ struct RTSEMEVENTINTERNAL *pThis = hEventSem;
+ AssertPtrReturnVoid(pThis);
+ AssertReturnVoid(pThis->iMagic == RTSEMEVENT_MAGIC);
+
+ ASMAtomicWriteBool(&pThis->fEverHadSignallers, true);
+ RTLockValidatorRecSharedAddOwner(&pThis->Signallers, hThread, NULL);
+#else
+ RT_NOREF(hEventSem, hThread);
+#endif
+}
+
+
+RTDECL(void) RTSemEventRemoveSignaller(RTSEMEVENT hEventSem, RTTHREAD hThread)
+{
+#ifdef RTSEMEVENT_STRICT
+ struct RTSEMEVENTINTERNAL *pThis = hEventSem;
+ AssertPtrReturnVoid(pThis);
+ AssertReturnVoid(pThis->iMagic == RTSEMEVENT_MAGIC);
+
+ RTLockValidatorRecSharedRemoveOwner(&pThis->Signallers, hThread);
+#else
+ RT_NOREF(hEventSem, hThread);
+#endif
+}
+
+#endif /* glibc < 2.6 || IPRT_WITH_FUTEX_BASED_SEMS */
+