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/* $Id: term.cpp $ */
/** @file
* IPRT - Common Termination Code.
*/
/*
* Copyright (C) 2009-2020 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 *
*********************************************************************************************************************************/
#include <iprt/initterm.h>
#include "internal/iprt.h"
#include <iprt/asm.h>
#include <iprt/assert.h>
#include <iprt/errcore.h>
#include <iprt/mem.h>
#include <iprt/once.h>
#include <iprt/semaphore.h>
#include <iprt/thread.h>
/*********************************************************************************************************************************
* Structures and Typedefs *
*********************************************************************************************************************************/
/** Pointer to a termination callback record. */
typedef struct RTTERMCALLBACKREC *PRTTERMCALLBACKREC;
/**
* Termination callback record.
*/
typedef struct RTTERMCALLBACKREC
{
/** Pointer to the next record. */
PRTTERMCALLBACKREC pNext;
/** Pointer to the callback. */
PFNRTTERMCALLBACK pfnCallback;
/** The user argument. */
void *pvUser;
} RTTERMCALLBACKREC;
/*********************************************************************************************************************************
* Global Variables *
*********************************************************************************************************************************/
/** Execute once construct protecting lazy callback initialization. */
static RTONCE g_InitTermCallbacksOnce = RTONCE_INITIALIZER;
/** Mutex protecting the callback globals. */
static RTSEMFASTMUTEX g_hFastMutex = NIL_RTSEMFASTMUTEX;
/** Number of registered callbacks. */
static uint32_t g_cCallbacks = 0;
/** The callback head. */
static PRTTERMCALLBACKREC g_pCallbackHead = NULL;
/**
* Initializes the globals.
*
* @returns IPRT status code
* @param pvUser Ignored.
*/
static DECLCALLBACK(int32_t) rtTermInitOnce(void *pvUser)
{
RTSEMFASTMUTEX hFastMutex;
int rc;
Assert(!g_cCallbacks);
Assert(!g_pCallbackHead);
Assert(g_hFastMutex == NIL_RTSEMFASTMUTEX);
rc = RTSemFastMutexCreate(&hFastMutex);
if (RT_SUCCESS(rc))
g_hFastMutex = hFastMutex;
NOREF(pvUser);
return rc;
}
RTDECL(int) RTTermRegisterCallback(PFNRTTERMCALLBACK pfnCallback, void *pvUser)
{
int rc;
PRTTERMCALLBACKREC pNew;
/*
* Validation and lazy init.
*/
AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
rc = RTOnce(&g_InitTermCallbacksOnce, rtTermInitOnce, NULL);
if (RT_FAILURE(rc))
return rc;
/*
* Allocate and initialize a new callback record.
*/
pNew = (PRTTERMCALLBACKREC)RTMemAlloc(sizeof(*pNew));
if (!pNew)
return VERR_NO_MEMORY;
pNew->pfnCallback = pfnCallback;
pNew->pvUser = pvUser;
/*
* Insert into the list.
*/
rc = RTSemFastMutexRequest(g_hFastMutex);
if (RT_SUCCESS(rc))
{
g_cCallbacks++;
pNew->pNext = g_pCallbackHead;
g_pCallbackHead = pNew;
RTSemFastMutexRelease(g_hFastMutex);
}
else
RTMemFree(pNew);
return rc;
}
RT_EXPORT_SYMBOL(RTTermRegisterCallback);
RTDECL(int) RTTermDeregisterCallback(PFNRTTERMCALLBACK pfnCallback, void *pvUser)
{
/*
* g_hFastMutex will be NIL if we're not initialized.
*/
int rc;
RTSEMFASTMUTEX hFastMutex = g_hFastMutex;
if (hFastMutex == NIL_RTSEMFASTMUTEX)
return VERR_NOT_FOUND;
rc = RTSemFastMutexRequest(hFastMutex);
if (RT_SUCCESS(rc))
{
/*
* Search for the specified pfnCallback/pvUser pair.
*/
PRTTERMCALLBACKREC pPrev = NULL;
PRTTERMCALLBACKREC pCur = g_pCallbackHead;
while (pCur)
{
if ( pCur->pfnCallback == pfnCallback
&& pCur->pvUser == pvUser)
{
if (pPrev)
pPrev->pNext = pCur->pNext;
else
g_pCallbackHead = pCur->pNext;
g_cCallbacks--;
RTSemFastMutexRelease(hFastMutex);
pCur->pfnCallback = NULL;
RTMemFree(pCur);
return VINF_SUCCESS;
}
/* next */
pPrev = pCur;
pCur = pCur->pNext;
}
RTSemFastMutexRelease(hFastMutex);
rc = VERR_NOT_FOUND;
}
return rc;
}
RT_EXPORT_SYMBOL(RTTermDeregisterCallback);
RTDECL(void) RTTermRunCallbacks(RTTERMREASON enmReason, int32_t iStatus)
{
RTSEMFASTMUTEX hFastMutex;
Assert( enmReason == RTTERMREASON_EXIT
|| enmReason == RTTERMREASON_ABEND
|| enmReason == RTTERMREASON_SIGNAL
|| enmReason == RTTERMREASON_UNLOAD);
/*
* Run the callback list. This is a bit paranoid in order to guard against
* recursive calls to RTTermRunCallbacks.
*/
while (g_hFastMutex != NIL_RTSEMFASTMUTEX)
{
PRTTERMCALLBACKREC pCur;
RTTERMCALLBACKREC CurCopy;
int rc;
/* Unlink the head of the chain. */
rc = RTSemFastMutexRequest(g_hFastMutex);
AssertRCReturnVoid(rc);
pCur = g_pCallbackHead;
if (pCur)
{
g_pCallbackHead = pCur->pNext;
g_cCallbacks--;
}
RTSemFastMutexRelease(g_hFastMutex);
if (!pCur)
break;
/* Copy and free it. */
CurCopy = *pCur;
RTMemFree(pCur);
/* Make the call. */
CurCopy.pfnCallback(enmReason, iStatus, CurCopy.pvUser);
}
/*
* Free the lock.
*/
ASMAtomicXchgHandle(&g_hFastMutex, NIL_RTSEMFASTMUTEX, &hFastMutex);
RTSemFastMutexDestroy(hFastMutex);
RTOnceReset(&g_InitTermCallbacksOnce); /* for the testcase */
}
RT_EXPORT_SYMBOL(RTTermRunCallbacks);
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