threadpreempt-r0drv-darwin.cpp revision ed85baab9ddb62c27569ca61545c8232e8251383
/* $Id$ */
/** @file
* IPRT - Thread Preemption, Ring-0 Driver, Darwin.
*/
/*
* Copyright (C) 2009 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.
*
* 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.
*
* 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 "the-darwin-kernel.h"
/*******************************************************************************
* Structures and Typedefs *
*******************************************************************************/
typedef struct RTDARWINPREEMPTHACK
{
/** The spinlock we exploit for disabling preemption. */
/** The preemption count for this CPU, to guard against nested calls. */
typedef RTDARWINPREEMPTHACK *PRTDARWINPREEMPTHACK;
/*******************************************************************************
* Global Variables *
*******************************************************************************/
/**
* Allocates the per-cpu spin locks used to disable preemption.
*
* Called by rtR0InitNative.
*/
int rtThreadPreemptDarwinInit(void)
{
{
if (!g_aPreemptHacks[i].pSpinLock)
return VERR_NO_MEMORY; /* (The caller will invoke rtThreadPreemptDarwinTerm) */
}
return VINF_SUCCESS;
}
/**
* Frees the per-cpu spin locks used to disable preemption.
*
* Called by rtR0TermNative.
*/
void rtThreadPreemptDarwinTerm(void)
{
if (g_aPreemptHacks[i].pSpinLock)
{
}
}
{
return preemption_enabled();
}
{
/* HACK ALERT! This ASSUMES that the cpu_pending_ast member of cpu_data_t doesn't move. */
#if 1
__asm__ volatile("movl %%gs:%P1,%0\n\t"
: "=r" (ast_pending)
: "i" (7*sizeof(void*) + 7*sizeof(int)));
#else
#endif
}
{
/*
* Disable to prevent preemption while we grab the per-cpu spin lock.
* Note! Only take the lock on the first call or we end up spinning for ever.
*/
{
{
if (pSpinLock)
else
AssertFailed();
}
}
}
{
{
{
if (pSpinLock)
else
AssertFailed();
}
}
}