/* $Id$ */
/** @file
* IPRT - Low Resolution Timers, Generic.
*
* This code is more or less identical to timer-generic.cpp, so
* bugfixes goes into both files.
*/
/*
* Copyright (C) 2006-2012 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/timer.h>
#include "internal/iprt.h"
#include <iprt/thread.h>
#include <iprt/err.h>
#include <iprt/assert.h>
#include <iprt/alloc.h>
#include <iprt/asm.h>
#include <iprt/semaphore.h>
#include <iprt/time.h>
#include <iprt/log.h>
#include "internal/magics.h"
/*******************************************************************************
* Structures and Typedefs *
*******************************************************************************/
/**
* The internal representation of a timer handle.
*/
typedef struct RTTIMERLRINT
{
/** Magic.
* This is RTTIMERRT_MAGIC, but changes to something else before the timer
* is destroyed to indicate clearly that thread should exit. */
uint32_t volatile u32Magic;
/** Flag indicating the timer is suspended. */
bool volatile fSuspended;
/** Flag indicating that the timer has been destroyed. */
bool volatile fDestroyed;
/** Callback. */
PFNRTTIMERLR pfnTimer;
/** User argument. */
void *pvUser;
/** The timer thread. */
RTTHREAD hThread;
/** Event semaphore on which the thread is blocked. */
RTSEMEVENT hEvent;
/** The timer interval. 0 if one-shot. */
uint64_t u64NanoInterval;
/** The start of the current run (ns).
* This is used to calculate when the timer ought to fire the next time. */
uint64_t volatile u64StartTS;
/** The start of the current run (ns).
* This is used to calculate when the timer ought to fire the next time. */
uint64_t volatile u64NextTS;
/** The current tick number (since u64StartTS). */
uint64_t volatile iTick;
} RTTIMERLRINT;
typedef RTTIMERLRINT *PRTTIMERLRINT;
/*******************************************************************************
* Internal Functions *
*******************************************************************************/
static DECLCALLBACK(int) rtTimerLRThread(RTTHREAD hThread, void *pvUser);
RTDECL(int) RTTimerLRCreateEx(RTTIMERLR *phTimerLR, uint64_t u64NanoInterval, uint32_t fFlags, PFNRTTIMERLR pfnTimer, void *pvUser)
{
AssertPtr(phTimerLR);
*phTimerLR = NIL_RTTIMERLR;
/*
* We don't support the fancy MP features, nor intervals lower than 100 ms.
*/
if (fFlags & RTTIMER_FLAGS_CPU_SPECIFIC)
return VERR_NOT_SUPPORTED;
if (u64NanoInterval && u64NanoInterval < 100*1000*1000)
return VERR_INVALID_PARAMETER;
/*
* Allocate and initialize the timer handle.
*/
PRTTIMERLRINT pThis = (PRTTIMERLRINT)RTMemAlloc(sizeof(*pThis));
if (!pThis)
return VERR_NO_MEMORY;
pThis->u32Magic = RTTIMERLR_MAGIC;
pThis->fSuspended = true;
pThis->fDestroyed = false;
pThis->pfnTimer = pfnTimer;
pThis->pvUser = pvUser;
pThis->hThread = NIL_RTTHREAD;
pThis->hEvent = NIL_RTSEMEVENT;
pThis->u64NanoInterval = u64NanoInterval;
pThis->u64StartTS = 0;
int rc = RTSemEventCreate(&pThis->hEvent);
if (RT_SUCCESS(rc))
{
rc = RTThreadCreate(&pThis->hThread, rtTimerLRThread, pThis, 0, RTTHREADTYPE_TIMER, RTTHREADFLAGS_WAITABLE, "TimerLR");
if (RT_SUCCESS(rc))
{
*phTimerLR = pThis;
return VINF_SUCCESS;
}
pThis->u32Magic = 0;
RTSemEventDestroy(pThis->hEvent);
pThis->hEvent = NIL_RTSEMEVENT;
}
RTMemFree(pThis);
return rc;
}
RT_EXPORT_SYMBOL(RTTimerLRCreateEx);
RTDECL(int) RTTimerLRDestroy(RTTIMERLR hTimerLR)
{
/*
* Validate input, NIL is fine though.
*/
if (hTimerLR == NIL_RTTIMERLR)
return VINF_SUCCESS;
PRTTIMERLRINT pThis = hTimerLR;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertReturn(pThis->u32Magic == RTTIMERLR_MAGIC, VERR_INVALID_HANDLE);
AssertReturn(!pThis->fDestroyed, VERR_INVALID_HANDLE);
/*
* If the timer is active, we stop and destruct it in one go, to avoid
* unnecessary waiting for the next tick. If it's suspended we can safely
* set the destroy flag and signal it.
*/
RTTHREAD hThread = pThis->hThread;
if (!pThis->fSuspended)
ASMAtomicWriteBool(&pThis->fSuspended, true);
ASMAtomicWriteBool(&pThis->fDestroyed, true);
int rc = RTSemEventSignal(pThis->hEvent);
if (rc == VERR_ALREADY_POSTED)
rc = VINF_SUCCESS;
AssertRC(rc);
RTThreadWait(hThread, 250, NULL);
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTTimerLRDestroy);
RTDECL(int) RTTimerLRStart(RTTIMERLR hTimerLR, uint64_t u64First)
{
/*
* Validate input.
*/
PRTTIMERLRINT pThis = hTimerLR;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertReturn(pThis->u32Magic == RTTIMERLR_MAGIC, VERR_INVALID_HANDLE);
AssertReturn(!pThis->fDestroyed, VERR_INVALID_HANDLE);
if (u64First && u64First < 100*1000*1000)
return VERR_INVALID_PARAMETER;
if (!pThis->fSuspended)
return VERR_TIMER_ACTIVE;
/*
* Calc when it should start firing and give the thread a kick so it get going.
*/
u64First += RTTimeNanoTS();
ASMAtomicWriteU64(&pThis->iTick, 0);
ASMAtomicWriteU64(&pThis->u64StartTS, u64First);
ASMAtomicWriteU64(&pThis->u64NextTS, u64First);
ASMAtomicWriteBool(&pThis->fSuspended, false);
int rc = RTSemEventSignal(pThis->hEvent);
if (rc == VERR_ALREADY_POSTED)
rc = VINF_SUCCESS;
AssertRC(rc);
return rc;
}
RT_EXPORT_SYMBOL(RTTimerLRStart);
RTDECL(int) RTTimerLRStop(RTTIMERLR hTimerLR)
{
/*
* Validate input.
*/
PRTTIMERLRINT pThis = hTimerLR;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertReturn(pThis->u32Magic == RTTIMERLR_MAGIC, VERR_INVALID_HANDLE);
AssertReturn(!pThis->fDestroyed, VERR_INVALID_HANDLE);
if (pThis->fSuspended)
return VERR_TIMER_SUSPENDED;
/*
* Mark it as suspended and kick the thread.
*/
ASMAtomicWriteBool(&pThis->fSuspended, true);
int rc = RTSemEventSignal(pThis->hEvent);
if (rc == VERR_ALREADY_POSTED)
rc = VINF_SUCCESS;
AssertRC(rc);
return rc;
}
RT_EXPORT_SYMBOL(RTTimerLRStop);
RTDECL(int) RTTimerLRChangeInterval(RTTIMERLR hTimerLR, uint64_t u64NanoInterval)
{
PRTTIMERLRINT pThis = hTimerLR;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertReturn(pThis->u32Magic == RTTIMERLR_MAGIC, VERR_INVALID_HANDLE);
AssertReturn(!pThis->fDestroyed, VERR_INVALID_HANDLE);
if (u64NanoInterval && u64NanoInterval < 100*1000*1000)
return VERR_INVALID_PARAMETER;
#if 0
if (!pThis->fSuspended)
{
int rc = RTTimerLRStop(hTimerLR);
if (RT_FAILURE(rc))
return rc;
ASMAtomicWriteU64(&pThis->u64NanoInterval, u64NanoInterval);
rc = RTTimerLRStart(hTimerLR, 0);
if (RT_FAILURE(rc))
return rc;
}
else
#endif
{
uint64_t u64Now = RTTimeNanoTS();
ASMAtomicWriteU64(&pThis->iTick, 0);
ASMAtomicWriteU64(&pThis->u64StartTS, u64Now);
ASMAtomicWriteU64(&pThis->u64NextTS, u64Now);
ASMAtomicWriteU64(&pThis->u64NanoInterval, u64NanoInterval);
int rc = RTSemEventSignal(pThis->hEvent);
}
return VINF_SUCCESS;
}
RT_EXPORT_SYMBOL(RTTimerLRChangeInterval);
static DECLCALLBACK(int) rtTimerLRThread(RTTHREAD hThreadSelf, void *pvUser)
{
PRTTIMERLRINT pThis = (PRTTIMERLRINT)pvUser;
NOREF(hThreadSelf);
/*
* The loop.
*/
while (!ASMAtomicUoReadBool(&pThis->fDestroyed))
{
if (ASMAtomicUoReadBool(&pThis->fSuspended))
{
int rc = RTSemEventWait(pThis->hEvent, RT_INDEFINITE_WAIT);
if (RT_FAILURE(rc) && rc != VERR_INTERRUPTED)
{
AssertRC(rc);
RTThreadSleep(1000); /* Don't cause trouble! */
}
}
else
{
uint64_t cNanoSeconds;
const uint64_t u64NanoTS = RTTimeNanoTS();
if (u64NanoTS >= pThis->u64NextTS)
{
pThis->iTick++;
pThis->pfnTimer(pThis, pThis->pvUser, pThis->iTick);
/* status changed? */
if ( ASMAtomicUoReadBool(&pThis->fSuspended)
|| ASMAtomicUoReadBool(&pThis->fDestroyed))
continue;
/* one shot? */
if (!pThis->u64NanoInterval)
{
ASMAtomicWriteBool(&pThis->fSuspended, true);
continue;
}
/*
* Calc the next time we should fire.
*
* If we're more than 60 intervals behind, just skip ahead. We
* don't want the timer thread running wild just because the
* clock changed in an unexpected way. As seen in @bugref{3611} this
* does happen during suspend/resume, but it may also happen
* if we're using a non-monotonic clock as time source.
*/
pThis->u64NextTS = pThis->u64StartTS + pThis->iTick * pThis->u64NanoInterval;
if (RT_LIKELY(pThis->u64NextTS > u64NanoTS))
cNanoSeconds = pThis->u64NextTS - u64NanoTS;
else
{
uint64_t iActualTick = (u64NanoTS - pThis->u64StartTS) / pThis->u64NanoInterval;
if (iActualTick - pThis->iTick > 60)
pThis->iTick = iActualTick - 1;
#ifdef IN_RING0
cNanoSeconds = RTTimerGetSystemGranularity() / 2;
#else
cNanoSeconds = 1000000; /* 1ms */
#endif
pThis->u64NextTS = u64NanoTS + cNanoSeconds;
}
}
else
cNanoSeconds = pThis->u64NextTS - u64NanoTS;
/* block. */
int rc = RTSemEventWait(pThis->hEvent,
(RTMSINTERVAL)(cNanoSeconds < 1000000 ? 1 : cNanoSeconds / 1000000));
if (RT_FAILURE(rc) && rc != VERR_INTERRUPTED && rc != VERR_TIMEOUT)
{
AssertRC(rc);
RTThreadSleep(1000); /* Don't cause trouble! */
}
}
}
/*
* Release the timer resources.
*/
ASMAtomicWriteU32(&pThis->u32Magic, ~RTTIMERLR_MAGIC); /* make the handle invalid. */
int rc = RTSemEventDestroy(pThis->hEvent); AssertRC(rc);
pThis->hEvent = NIL_RTSEMEVENT;
pThis->hThread = NIL_RTTHREAD;
RTMemFree(pThis);
return VINF_SUCCESS;
}