VBoxServiceBalloon.cpp revision 81734adca04af1298f2f31257f5880aa0028145a
/* $Id$ */
/** @file
* VBoxService - Memory Ballooning.
*/
/*
* Copyright (C) 2006-2010 Sun Microsystems, Inc.
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* 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.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 USA or visit http://www.sun.com if you need
* additional information or have any questions.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#include <iprt/semaphore.h>
#include <VBox/VBoxGuestLib.h>
#include "VBoxServiceInternal.h"
#include "VBoxServiceUtils.h"
/*******************************************************************************
* Global Variables *
*******************************************************************************/
/** The balloon size. */
static uint32_t g_cMemBalloonChunks = 0;
/** The semaphore we're blocking on. */
/** The array holding the R3 pointers of the balloon */
static void **g_pavBalloon = NULL;
/**
* Adapt the R0 memory balloon by granting/reclaiming 1MB chunks to/from R0.
*
* returns IPRT status code.
* @param cNewChunks The new number of 1MB chunks in the balloon.
*/
{
if (cNewChunks == g_cMemBalloonChunks)
return VINF_SUCCESS;
VBoxServiceVerbose(3, "VBoxServiceBalloonSetUser: cNewChunks=%u g_cMemBalloonChunks=%u\n", cNewChunks, g_cMemBalloonChunks);
int rc = VINF_SUCCESS;
if (cNewChunks > g_cMemBalloonChunks)
{
/* inflate */
uint32_t i;
for (i = g_cMemBalloonChunks; i < cNewChunks; i++)
{
/** @todo r=bird: this isn't safe on linux. See suplibOsPageAlloc in
* SUPLib-linux.cpp. We should probably just fail outright here if
* linux, just in case...
* frank: To be more specific, the problem is fork(). */
if (RT_SUCCESS(rc))
{
g_pavBalloon[i] = pv;
#ifndef RT_OS_SOLARIS
/*
* Protect against access by dangling pointers (ignore errors as it may fail).
* On Solaris it corrupts the address space leaving the process unkillable. This could
* perhaps be related to what the underlying segment driver does; currently just disable it.
*/
#endif
}
else
{
break;
}
}
}
else
{
/* deflate */
uint32_t i;
for (i = g_cMemBalloonChunks; i-- > cNewChunks;)
{
void *pv = g_pavBalloon[i];
if (RT_SUCCESS(rc))
{
#ifndef RT_OS_SOLARIS
/* unprotect */
#endif
g_pavBalloon[i] = NULL;
}
else
break;
}
}
return VINF_SUCCESS;
}
/** @copydoc VBOXSERVICE::pfnPreInit */
static DECLCALLBACK(int) VBoxServiceBalloonPreInit(void)
{
return VINF_SUCCESS;
}
/** @copydoc VBOXSERVICE::pfnOption */
static DECLCALLBACK(int) VBoxServiceBalloonOption(const char **ppszShort, int argc, char **argv, int *pi)
{
return VINF_SUCCESS;
}
/** @copydoc VBOXSERVICE::pfnInit */
static DECLCALLBACK(int) VBoxServiceBalloonInit(void)
{
g_cMemBalloonChunks = 0;
uint32_t cNewChunks = 0;
bool fHandleInR3;
/* Check balloon size */
if (RT_SUCCESS(rc))
{
if (fHandleInR3)
else
}
else
/* We shouldn't fail here if ballooning isn't available. This can have several reasons,
* for instance, host too old (which is not that fatal). */
return VINF_SUCCESS;
}
/**
* Query the size of the memory balloon, given as a count of chunks.
*
* @returns The number of chunks (VMMDEV_MEMORY_BALLOON_CHUNK_SIZE).
*/
{
return g_cMemBalloonChunks;
}
/** @copydoc VBOXSERVICE::pfnWorker */
{
/* Start monitoring of the stat event change event. */
if (RT_FAILURE(rc))
{
return rc;
}
/*
* Tell the control thread that it can continue
* spawning services.
*/
/*
* Now enter the loop retrieving runtime data continuously.
*/
for (;;)
{
/* Check if an update interval change is pending. */
if ( RT_SUCCESS(rc)
{
bool fHandleInR3;
if (RT_SUCCESS(rc))
{
if (fHandleInR3)
{
if (RT_FAILURE(rc))
{
}
else
VBoxServiceVerbose(3, "VBoxServiceBalloonWorker: successfully set requested balloon size %d.\n", cNewChunks);
}
else
}
else
}
/*
* Block for a while.
*
* The event semaphore takes care of ignoring interruptions and it
* allows us to implement service wakeup later.
*/
if (*pfShutdown)
break;
if (*pfShutdown)
break;
{
break;
}
}
/* Cancel monitoring of the memory balloon change event. */
if (RT_FAILURE(rc))
return 0;
}
/** @copydoc VBOXSERVICE::pfnTerm */
static DECLCALLBACK(void) VBoxServiceBalloonTerm(void)
{
return;
}
/** @copydoc VBOXSERVICE::pfnStop */
static DECLCALLBACK(void) VBoxServiceBalloonStop(void)
{
}
/**
* The 'memballoon' service description.
*/
{
/* pszName. */
"memballoon",
/* pszDescription. */
"Memory Ballooning",
/* pszUsage. */
NULL,
/* pszOptions. */
NULL,
/* methods */
};