--- /dev/null
+/* $Id: semeventmulti-r0drv-linux.c $ */
+/** @file
+ * IPRT - Multiple Release Event Semaphores, Ring-0 Driver, Linux.
+ */
+
+/*
+ * Copyright (C) 2006-2017 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.
+ */
+
+
+/*********************************************************************************************************************************
+* Header Files *
+*********************************************************************************************************************************/
+#define RTSEMEVENTMULTI_WITHOUT_REMAPPING
+#include "the-linux-kernel.h"
+#include "internal/iprt.h"
+#include <iprt/semaphore.h>
+
+#include <iprt/assert.h>
+#include <iprt/asm.h>
+#include <iprt/err.h>
+#include <iprt/mem.h>
+#include <iprt/lockvalidator.h>
+
+#include "waitqueue-r0drv-linux.h"
+#include "internal/magics.h"
+
+
+/*********************************************************************************************************************************
+* Defined Constants And Macros *
+*********************************************************************************************************************************/
+/** @name fStateAndGen values
+ * @{ */
+/** The state bit number. */
+#define RTSEMEVENTMULTILNX_STATE_BIT 0
+/** The state mask. */
+#define RTSEMEVENTMULTILNX_STATE_MASK RT_BIT_32(RTSEMEVENTMULTILNX_STATE_BIT)
+/** The generation mask. */
+#define RTSEMEVENTMULTILNX_GEN_MASK ~RTSEMEVENTMULTILNX_STATE_MASK
+/** The generation shift. */
+#define RTSEMEVENTMULTILNX_GEN_SHIFT 1
+/** The initial variable value. */
+#define RTSEMEVENTMULTILNX_STATE_GEN_INIT UINT32_C(0xfffffffc)
+/** @} */
+
+
+/*********************************************************************************************************************************
+* Structures and Typedefs *
+*********************************************************************************************************************************/
+/**
+ * Linux event semaphore.
+ */
+typedef struct RTSEMEVENTMULTIINTERNAL
+{
+ /** Magic value (RTSEMEVENTMULTI_MAGIC). */
+ uint32_t volatile u32Magic;
+ /** The object state bit and generation counter.
+ * The generation counter is incremented every time the object is
+ * signalled. */
+ uint32_t volatile fStateAndGen;
+ /** Reference counter. */
+ uint32_t volatile cRefs;
+ /** The wait queue. */
+ wait_queue_head_t Head;
+} RTSEMEVENTMULTIINTERNAL, *PRTSEMEVENTMULTIINTERNAL;
+
+
+
+
+
+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, ...)
+{
+ PRTSEMEVENTMULTIINTERNAL pThis;
+ IPRT_LINUX_SAVE_EFL_AC();
+ RT_NOREF_PV(hClass); RT_NOREF_PV(pszNameFmt);
+
+ AssertReturn(!(fFlags & ~RTSEMEVENTMULTI_FLAGS_NO_LOCK_VAL), VERR_INVALID_PARAMETER);
+ pThis = (PRTSEMEVENTMULTIINTERNAL)RTMemAlloc(sizeof(*pThis));
+ if (pThis)
+ {
+ pThis->u32Magic = RTSEMEVENTMULTI_MAGIC;
+ pThis->fStateAndGen = RTSEMEVENTMULTILNX_STATE_GEN_INIT;
+ pThis->cRefs = 1;
+ init_waitqueue_head(&pThis->Head);
+
+ *phEventMultiSem = pThis;
+ IPRT_LINUX_RESTORE_EFL_AC();
+ return VINF_SUCCESS;
+ }
+ IPRT_LINUX_RESTORE_EFL_AC();
+ return VERR_NO_MEMORY;
+}
+RT_EXPORT_SYMBOL(RTSemEventMultiCreate);
+
+
+/**
+ * Retain a reference to the semaphore.
+ *
+ * @param pThis The semaphore.
+ */
+DECLINLINE(void) rtR0SemEventMultiLnxRetain(PRTSEMEVENTMULTIINTERNAL pThis)
+{
+ uint32_t cRefs = ASMAtomicIncU32(&pThis->cRefs);
+ NOREF(cRefs);
+ Assert(cRefs && cRefs < 100000);
+}
+
+
+/**
+ * Release a reference, destroy the thing if necessary.
+ *
+ * @param pThis The semaphore.
+ */
+DECLINLINE(void) rtR0SemEventMultiLnxRelease(PRTSEMEVENTMULTIINTERNAL pThis)
+{
+ if (RT_UNLIKELY(ASMAtomicDecU32(&pThis->cRefs) == 0))
+ {
+ Assert(pThis->u32Magic != RTSEMEVENTMULTI_MAGIC);
+ RTMemFree(pThis);
+ }
+}
+
+
+RTDECL(int) RTSemEventMultiDestroy(RTSEMEVENTMULTI hEventMultiSem)
+{
+ IPRT_LINUX_SAVE_EFL_AC();
+
+ /*
+ * Validate input.
+ */
+ PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)hEventMultiSem;
+ if (pThis == NIL_RTSEMEVENTMULTI)
+ return VINF_SUCCESS;
+ AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
+ AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
+ Assert(pThis->cRefs > 0);
+
+ /*
+ * Invalidate it and signal the object just in case.
+ */
+ ASMAtomicWriteU32(&pThis->u32Magic, ~RTSEMEVENTMULTI_MAGIC);
+ ASMAtomicAndU32(&pThis->fStateAndGen, RTSEMEVENTMULTILNX_GEN_MASK);
+ Assert(!waitqueue_active(&pThis->Head));
+ wake_up_all(&pThis->Head);
+ rtR0SemEventMultiLnxRelease(pThis);
+
+ IPRT_LINUX_RESTORE_EFL_AC();
+ return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTSemEventMultiDestroy);
+
+
+RTDECL(int) RTSemEventMultiSignal(RTSEMEVENTMULTI hEventMultiSem)
+{
+ IPRT_LINUX_SAVE_EFL_AC();
+ uint32_t fNew;
+ uint32_t fOld;
+
+ /*
+ * Validate input.
+ */
+ PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)hEventMultiSem;
+ if (!pThis)
+ return VERR_INVALID_PARAMETER;
+ AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
+ AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
+ rtR0SemEventMultiLnxRetain(pThis);
+
+ /*
+ * Signal the event object. The cause of the paranoia here is racing to try
+ * deal with racing RTSemEventMultiSignal calls (should probably be
+ * forbidden, but it's relatively easy to handle).
+ */
+ do
+ {
+ fNew = fOld = ASMAtomicUoReadU32(&pThis->fStateAndGen);
+ fNew += 1 << RTSEMEVENTMULTILNX_GEN_SHIFT;
+ fNew |= RTSEMEVENTMULTILNX_STATE_MASK;
+ }
+ while (!ASMAtomicCmpXchgU32(&pThis->fStateAndGen, fNew, fOld));
+
+ wake_up_all(&pThis->Head);
+
+ rtR0SemEventMultiLnxRelease(pThis);
+ IPRT_LINUX_RESTORE_EFL_AC();
+ return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTSemEventMultiSignal);
+
+
+RTDECL(int) RTSemEventMultiReset(RTSEMEVENTMULTI hEventMultiSem)
+{
+ /*
+ * Validate input.
+ */
+ PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)hEventMultiSem;
+ if (!pThis)
+ return VERR_INVALID_PARAMETER;
+ AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
+ AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
+ rtR0SemEventMultiLnxRetain(pThis);
+
+ /*
+ * Reset it.
+ */
+ ASMAtomicAndU32(&pThis->fStateAndGen, ~RTSEMEVENTMULTILNX_STATE_MASK);
+
+ rtR0SemEventMultiLnxRelease(pThis);
+ return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTSemEventMultiReset);
+
+
+/**
+ * Worker for RTSemEventMultiWaitEx and RTSemEventMultiWaitExDebug.
+ *
+ * @returns VBox status code.
+ * @param pThis The event semaphore.
+ * @param fFlags See RTSemEventMultiWaitEx.
+ * @param uTimeout See RTSemEventMultiWaitEx.
+ * @param pSrcPos The source code position of the wait.
+ */
+static int rtR0SemEventMultiLnxWait(PRTSEMEVENTMULTIINTERNAL pThis, uint32_t fFlags, uint64_t uTimeout,
+ PCRTLOCKVALSRCPOS pSrcPos)
+{
+ uint32_t fOrgStateAndGen;
+ int rc;
+ RT_NOREF_PV(pSrcPos);
+
+ /*
+ * Validate the input.
+ */
+ AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
+ AssertMsgReturn(pThis->u32Magic == RTSEMEVENTMULTI_MAGIC, ("%p u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_PARAMETER);
+ AssertReturn(RTSEMWAIT_FLAGS_ARE_VALID(fFlags), VERR_INVALID_PARAMETER);
+ rtR0SemEventMultiLnxRetain(pThis);
+
+ /*
+ * Is the event already signalled or do we have to wait?
+ */
+ fOrgStateAndGen = ASMAtomicUoReadU32(&pThis->fStateAndGen);
+ if (fOrgStateAndGen & RTSEMEVENTMULTILNX_STATE_MASK)
+ rc = VINF_SUCCESS;
+ else
+ {
+ /*
+ * We have to wait.
+ */
+ RTR0SEMLNXWAIT Wait;
+ IPRT_LINUX_SAVE_EFL_AC();
+ rc = rtR0SemLnxWaitInit(&Wait, fFlags, uTimeout, &pThis->Head);
+ if (RT_SUCCESS(rc))
+ {
+ IPRT_DEBUG_SEMS_STATE(pThis, 'E');
+ for (;;)
+ {
+ /* The destruction test. */
+ if (RT_UNLIKELY(pThis->u32Magic != RTSEMEVENTMULTI_MAGIC))
+ rc = VERR_SEM_DESTROYED;
+ else
+ {
+ rtR0SemLnxWaitPrepare(&Wait);
+
+ /* Check the exit conditions. */
+ if (RT_UNLIKELY(pThis->u32Magic != RTSEMEVENTMULTI_MAGIC))
+ rc = VERR_SEM_DESTROYED;
+ else if (ASMAtomicUoReadU32(&pThis->fStateAndGen) != fOrgStateAndGen)
+ rc = VINF_SUCCESS;
+ else if (rtR0SemLnxWaitHasTimedOut(&Wait))
+ rc = VERR_TIMEOUT;
+ else if (rtR0SemLnxWaitWasInterrupted(&Wait))
+ rc = VERR_INTERRUPTED;
+ else
+ {
+ /* Do the wait and then recheck the conditions. */
+ rtR0SemLnxWaitDoIt(&Wait);
+ continue;
+ }
+ }
+ break;
+ }
+
+ rtR0SemLnxWaitDelete(&Wait);
+ IPRT_DEBUG_SEMS_STATE_RC(pThis, 'E', rc);
+ }
+ IPRT_LINUX_RESTORE_EFL_AC();
+ }
+
+ rtR0SemEventMultiLnxRelease(pThis);
+ return rc;
+}
+
+
+RTDECL(int) RTSemEventMultiWaitEx(RTSEMEVENTMULTI hEventMultiSem, uint32_t fFlags, uint64_t uTimeout)
+{
+#ifndef RTSEMEVENT_STRICT
+ return rtR0SemEventMultiLnxWait(hEventMultiSem, fFlags, uTimeout, NULL);
+#else
+ RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_NORMAL_API();
+ return rtR0SemEventMultiLnxWait(hEventMultiSem, fFlags, uTimeout, &SrcPos);
+#endif
+}
+RT_EXPORT_SYMBOL(RTSemEventMultiWaitEx);
+
+
+RTDECL(int) RTSemEventMultiWaitExDebug(RTSEMEVENTMULTI hEventMultiSem, uint32_t fFlags, uint64_t uTimeout,
+ RTHCUINTPTR uId, RT_SRC_POS_DECL)
+{
+ RTLOCKVALSRCPOS SrcPos = RTLOCKVALSRCPOS_INIT_DEBUG_API();
+ return rtR0SemEventMultiLnxWait(hEventMultiSem, fFlags, uTimeout, &SrcPos);
+}
+RT_EXPORT_SYMBOL(RTSemEventMultiWaitExDebug);
+
+
+RTDECL(uint32_t) RTSemEventMultiGetResolution(void)
+{
+ return rtR0SemLnxWaitGetResolution();
+}
+RT_EXPORT_SYMBOL(RTSemEventMultiGetResolution);
+
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