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/* $Id: thread-r0drv-nt.cpp $ */
/** @file
* IPRT - Threads, Ring-0 Driver, NT.
*/
/*
* Copyright (C) 2006-2019 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 "the-nt-kernel.h"
#include "internal/iprt.h"
#include <iprt/thread.h>
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
# include <iprt/asm-amd64-x86.h>
#endif
#include <iprt/assert.h>
#include <iprt/errcore.h>
#include <iprt/mp.h>
#include "internal-r0drv-nt.h"
RTDECL(RTNATIVETHREAD) RTThreadNativeSelf(void)
{
return (RTNATIVETHREAD)PsGetCurrentThread();
}
static int rtR0ThreadNtSleepCommon(RTMSINTERVAL cMillies)
{
LARGE_INTEGER Interval;
Interval.QuadPart = -(int64_t)cMillies * 10000;
NTSTATUS rcNt = KeDelayExecutionThread(KernelMode, TRUE, &Interval);
switch (rcNt)
{
case STATUS_SUCCESS:
return VINF_SUCCESS;
case STATUS_ALERTED:
case STATUS_USER_APC:
return VERR_INTERRUPTED;
default:
return RTErrConvertFromNtStatus(rcNt);
}
}
RTDECL(int) RTThreadSleep(RTMSINTERVAL cMillies)
{
return rtR0ThreadNtSleepCommon(cMillies);
}
RTDECL(bool) RTThreadYield(void)
{
return ZwYieldExecution() != STATUS_NO_YIELD_PERFORMED;
}
RTDECL(bool) RTThreadPreemptIsEnabled(RTTHREAD hThread)
{
Assert(hThread == NIL_RTTHREAD); RT_NOREF1(hThread);
KIRQL Irql = KeGetCurrentIrql();
if (Irql > APC_LEVEL)
return false;
if (!ASMIntAreEnabled())
return false;
return true;
}
RTDECL(bool) RTThreadPreemptIsPending(RTTHREAD hThread)
{
Assert(hThread == NIL_RTTHREAD); RT_NOREF1(hThread);
/*
* The KeShouldYieldProcessor API introduced in Windows 10 looks like exactly
* what we want. But of course there is a snag. It may return with interrupts
* enabled when called with them disabled. Let's just hope it doesn't get upset
* by disabled interrupts in other ways...
*/
if (g_pfnrtKeShouldYieldProcessor)
{
RTCCUINTREG fSavedFlags = ASMGetFlags();
bool fReturn = g_pfnrtKeShouldYieldProcessor() != FALSE;
ASMSetFlags(fSavedFlags);
return fReturn;
}
/*
* Fallback approach for pre W10 kernels.
*
* If W10 is anything to go by, we should also check and yield when:
* - pPrcb->NextThread != NULL && pPrcb->NextThread != pPrcb->CurrentThread
* when QuantumEnd is zero.
* - pPrcb->DpcRequestSummary & 1
* - pPrcb->DpcRequestSummary & 0x1e
*/
/*
* Read the globals and check if they are useful.
*/
/** @todo Should we check KPRCB.InterruptRequest and KPRCB.DpcInterruptRequested (older kernels). */
uint32_t const offQuantumEnd = g_offrtNtPbQuantumEnd;
uint32_t const cbQuantumEnd = g_cbrtNtPbQuantumEnd;
uint32_t const offDpcQueueDepth = g_offrtNtPbDpcQueueDepth;
if (!offQuantumEnd && !cbQuantumEnd && !offDpcQueueDepth)
return false;
Assert((offQuantumEnd && cbQuantumEnd) || (!offQuantumEnd && !cbQuantumEnd));
/*
* Disable interrupts so we won't be messed around.
*/
bool fPending;
RTCCUINTREG fSavedFlags = ASMIntDisableFlags();
#ifdef RT_ARCH_X86
PKPCR pPcr = (PKPCR)__readfsdword(RT_UOFFSETOF(KPCR,SelfPcr));
uint8_t *pbPrcb = (uint8_t *)pPcr->Prcb;
#elif defined(RT_ARCH_AMD64)
/* HACK ALERT! The offset is from windbg/vista64. */
PKPCR pPcr = (PKPCR)__readgsqword(RT_UOFFSETOF(KPCR,Self));
uint8_t *pbPrcb = (uint8_t *)pPcr->CurrentPrcb;
#else
# error "port me"
#endif
/* Check QuantumEnd. */
if (cbQuantumEnd == 1)
{
uint8_t volatile *pbQuantumEnd = (uint8_t volatile *)(pbPrcb + offQuantumEnd);
fPending = *pbQuantumEnd == TRUE;
}
else if (cbQuantumEnd == sizeof(uint32_t))
{
uint32_t volatile *pu32QuantumEnd = (uint32_t volatile *)(pbPrcb + offQuantumEnd);
fPending = *pu32QuantumEnd != 0;
}
else
fPending = false;
/* Check DpcQueueDepth. */
if ( !fPending
&& offDpcQueueDepth)
{
uint32_t volatile *pu32DpcQueueDepth = (uint32_t volatile *)(pbPrcb + offDpcQueueDepth);
fPending = *pu32DpcQueueDepth > 0;
}
ASMSetFlags(fSavedFlags);
return fPending;
}
RTDECL(bool) RTThreadPreemptIsPendingTrusty(void)
{
if (g_pfnrtKeShouldYieldProcessor)
return true;
#if 0 /** @todo RTThreadPreemptIsPending isn't good enough on w7 and possibly elsewhere. */
/* RTThreadPreemptIsPending is only reliable if we've got both offsets and size. */
return g_offrtNtPbQuantumEnd != 0
&& g_cbrtNtPbQuantumEnd != 0
&& g_offrtNtPbDpcQueueDepth != 0;
#else
return false;
#endif
}
RTDECL(bool) RTThreadPreemptIsPossible(void)
{
/* yes, kernel preemption is possible. */
return true;
}
RTDECL(void) RTThreadPreemptDisable(PRTTHREADPREEMPTSTATE pState)
{
AssertPtr(pState);
Assert(pState->uchOldIrql == 255);
Assert(KeGetCurrentIrql() <= DISPATCH_LEVEL);
KeRaiseIrql(DISPATCH_LEVEL, &pState->uchOldIrql);
RT_ASSERT_PREEMPT_CPUID_DISABLE(pState);
}
RTDECL(void) RTThreadPreemptRestore(PRTTHREADPREEMPTSTATE pState)
{
AssertPtr(pState);
RT_ASSERT_PREEMPT_CPUID_RESTORE(pState);
KeLowerIrql(pState->uchOldIrql);
pState->uchOldIrql = 255;
}
RTDECL(bool) RTThreadIsInInterrupt(RTTHREAD hThread)
{
Assert(hThread == NIL_RTTHREAD); NOREF(hThread);
KIRQL CurIrql = KeGetCurrentIrql();
return CurIrql > PASSIVE_LEVEL; /** @todo Is there a more correct way? */
}
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