semeventmulti-r0drv-linux.c revision 9197680d465154232353e065bfc7e7b0fe026b97
/* $Id$ */
/** @file
* innotek Portable Runtime - Multiple Release Event Semaphores, Ring-0 Driver, Linux.
*/
/*
* Copyright (C) 2006-2007 innotek GmbH
*
* 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 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.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#include "the-linux-kernel.h"
#include <iprt/semaphore.h>
#include <iprt/alloc.h>
#include <iprt/assert.h>
#include <iprt/asm.h>
#include <iprt/err.h>
#include "internal/magics.h"
/*******************************************************************************
* Structures and Typedefs *
*******************************************************************************/
/**
* Linux event semaphore.
*/
typedef struct RTSEMEVENTMULTIINTERNAL
{
/** Magic value (RTSEMEVENTMULTI_MAGIC). */
uint32_t volatile u32Magic;
/** The object status - !0 when signaled and 0 when reset. */
uint32_t volatile fState;
/** The wait queue. */
wait_queue_head_t Head;
} RTSEMEVENTMULTIINTERNAL, *PRTSEMEVENTMULTIINTERNAL;
RTDECL(int) RTSemEventMultiCreate(PRTSEMEVENTMULTI pEventMultiSem)
{
PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)RTMemAlloc(sizeof(*pThis));
if (pThis)
{
pThis->u32Magic = RTSEMEVENTMULTI_MAGIC;
init_waitqueue_head(&pThis->Head);
*pEventMultiSem = pThis;
return VINF_SUCCESS;
}
return VERR_NO_MEMORY;
}
RTDECL(int) RTSemEventMultiDestroy(RTSEMEVENTMULTI EventMultiSem)
{
/*
* Validate input.
*/
PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)EventMultiSem;
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);
/*
* Invalidate it and signal the object just in case.
*/
ASMAtomicIncU32(&pThis->u32Magic);
ASMAtomicXchgU32(&pThis->fState, 0);
Assert(!waitqueue_active(&pThis->Head));
wake_up_all(&pThis->Head);
RTMemFree(pThis);
return VINF_SUCCESS;
}
RTDECL(int) RTSemEventMultiSignal(RTSEMEVENTMULTI EventMultiSem)
{
/*
* Validate input.
*/
PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)EventMultiSem;
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);
/*
* Signal the event object.
*/
ASMAtomicXchgU32(&pThis->fState, 1);
wake_up_all(&pThis->Head);
return VINF_SUCCESS;
}
RTDECL(int) RTSemEventMultiReset(RTSEMEVENTMULTI EventMultiSem)
{
/*
* Validate input.
*/
PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)EventMultiSem;
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);
/*
* Reset it.
*/
ASMAtomicXchgU32(&pThis->fState, 0);
return VINF_SUCCESS;
}
/**
* Worker for RTSemEventMulti and RTSemEventMultiNoResume.
*
* @returns VBox status code.
* @param pThis The event semaphore.
* @param cMillies The number of milliseconds to wait.
* @param fInterruptible Whether it's an interruptible wait or not.
*/
static int rtSemEventWait(PRTSEMEVENTMULTIINTERNAL pThis, unsigned cMillies, bool fInterruptible)
{
/*
* Ok wait for it.
*/
DEFINE_WAIT(Wait);
int rc = VINF_SUCCESS;
long lTimeout = cMillies == RT_INDEFINITE_WAIT ? MAX_SCHEDULE_TIMEOUT : msecs_to_jiffies(cMillies);
for (;;)
{
/* make everything thru schedule() atomic scheduling wise. */
prepare_to_wait(&pThis->Head, &Wait, fInterruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
/* check the condition. */
if (pThis->fState)
break;
/* check for pending signals. */
if (fInterruptible && signal_pending(current))
{
rc = VERR_INTERRUPTED;
break;
}
/* wait */
lTimeout = schedule_timeout(lTimeout);
/* Check if someone destroyed the semaphore while we were waiting. */
if (pThis->u32Magic != RTSEMEVENTMULTI_MAGIC)
{
rc = VERR_SEM_DESTROYED;
break;
}
/* check for timeout. */
if (!lTimeout)
{
rc = VERR_TIMEOUT;
break;
}
}
finish_wait(&pThis->Head, &Wait);
return rc;
}
RTDECL(int) RTSemEventMultiWait(RTSEMEVENTMULTI EventMultiSem, unsigned cMillies)
{
PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)EventMultiSem;
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);
if (pThis->fState)
return VINF_SUCCESS;
return rtSemEventWait(pThis, cMillies, false /* fInterruptible */);
}
RTDECL(int) RTSemEventMultiWaitNoResume(RTSEMEVENTMULTI EventMultiSem, unsigned cMillies)
{
PRTSEMEVENTMULTIINTERNAL pThis = (PRTSEMEVENTMULTIINTERNAL)EventMultiSem;
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);
if (pThis->fState)
return VINF_SUCCESS;
return rtSemEventWait(pThis, cMillies, true /* fInterruptible */);
}