semevent-r0drv-darwin.cpp revision a8f65e585466d1267633cea76b4f97a69b7f1cc0
/* $Id$ */
/** @file
* IPRT - Event Semaphores, Ring-0 Driver, Darwin.
*/
/*
* Copyright (C) 2006-2010 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-darwin-kernel.h"
#include "internal/iprt.h"
#include <iprt/semaphore.h>
#include <iprt/assert.h>
#include <iprt/asm.h>
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
# include <iprt/asm-amd64-x86.h>
#endif
#include <iprt/err.h>
#include <iprt/mem.h>
#include <iprt/mp.h>
#include <iprt/thread.h>
#include "internal/magics.h"
/*******************************************************************************
* Structures and Typedefs *
*******************************************************************************/
/**
* Darwin event semaphore.
*/
typedef struct RTSEMEVENTINTERNAL
{
/** Magic value (RTSEMEVENT_MAGIC). */
uint32_t volatile u32Magic;
/** The number of waiting threads. */
uint32_t volatile cWaiters;
/** Set if the event object is signaled. */
uint8_t volatile fSignaled;
/** The number of threads in the process of waking up. */
uint32_t volatile cWaking;
/** The spinlock protecting us. */
lck_spin_t *pSpinlock;
} RTSEMEVENTINTERNAL, *PRTSEMEVENTINTERNAL;
RTDECL(int) RTSemEventCreate(PRTSEMEVENT phEventSem)
{
return RTSemEventCreateEx(phEventSem, 0 /*fFlags*/, NIL_RTLOCKVALCLASS, NULL);
}
RTDECL(int) RTSemEventCreateEx(PRTSEMEVENT phEventSem, uint32_t fFlags, RTLOCKVALCLASS hClass, const char *pszNameFmt, ...)
{
AssertCompile(sizeof(RTSEMEVENTINTERNAL) > sizeof(void *));
AssertReturn(!(fFlags & ~RTSEMEVENT_FLAGS_NO_LOCK_VAL), VERR_INVALID_PARAMETER);
AssertPtrReturn(phEventSem, VERR_INVALID_POINTER);
RT_ASSERT_PREEMPTIBLE();
PRTSEMEVENTINTERNAL pThis = (PRTSEMEVENTINTERNAL)RTMemAlloc(sizeof(*pThis));
if (pThis)
{
pThis->u32Magic = RTSEMEVENT_MAGIC;
pThis->cWaiters = 0;
pThis->cWaking = 0;
pThis->fSignaled = 0;
Assert(g_pDarwinLockGroup);
pThis->pSpinlock = lck_spin_alloc_init(g_pDarwinLockGroup, LCK_ATTR_NULL);
if (pThis->pSpinlock)
{
*phEventSem = pThis;
return VINF_SUCCESS;
}
pThis->u32Magic = 0;
RTMemFree(pThis);
}
return VERR_NO_MEMORY;
}
RTDECL(int) RTSemEventDestroy(RTSEMEVENT hEventSem)
{
PRTSEMEVENTINTERNAL pThis = hEventSem;
if (pThis == NIL_RTSEMEVENT)
return VINF_SUCCESS;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertMsgReturn(pThis->u32Magic == RTSEMEVENT_MAGIC, ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), VERR_INVALID_HANDLE);
RT_ASSERT_INTS_ON();
lck_spin_lock(pThis->pSpinlock);
ASMAtomicIncU32(&pThis->u32Magic); /* make the handle invalid */
if (pThis->cWaiters > 0)
{
/* abort waiting thread, last man cleans up. */
ASMAtomicXchgU32(&pThis->cWaking, pThis->cWaking + pThis->cWaiters);
thread_wakeup_prim((event_t)pThis, FALSE /* all threads */, THREAD_RESTART);
lck_spin_unlock(pThis->pSpinlock);
}
else if (pThis->cWaking)
/* the last waking thread is gonna do the cleanup */
lck_spin_unlock(pThis->pSpinlock);
else
{
lck_spin_unlock(pThis->pSpinlock);
lck_spin_destroy(pThis->pSpinlock, g_pDarwinLockGroup);
RTMemFree(pThis);
}
return VINF_SUCCESS;
}
RTDECL(int) RTSemEventSignal(RTSEMEVENT hEventSem)
{
PRTSEMEVENTINTERNAL pThis = (PRTSEMEVENTINTERNAL)hEventSem;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertMsgReturn(pThis->u32Magic == RTSEMEVENT_MAGIC,
("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic),
VERR_INVALID_HANDLE);
RT_ASSERT_PREEMPT_CPUID_VAR();
RT_ASSERT_INTS_ON();
/** @todo should probably disable interrupts here... update
* semspinmutex-r0drv-generic.c when done. */
lck_spin_lock(pThis->pSpinlock);
if (pThis->cWaiters > 0)
{
ASMAtomicDecU32(&pThis->cWaiters);
ASMAtomicIncU32(&pThis->cWaking);
thread_wakeup_prim((event_t)pThis, TRUE /* one thread */, THREAD_AWAKENED);
/** @todo this isn't safe. a scheduling interrupt on the other cpu while we're in here
* could cause the thread to be timed out before we manage to wake it up and the event
* ends up in the wrong state. ditto for posix signals.
* Update: check the return code; it will return KERN_NOT_WAITING if no one is around. */
}
else
ASMAtomicXchgU8(&pThis->fSignaled, true);
lck_spin_unlock(pThis->pSpinlock);
RT_ASSERT_PREEMPT_CPUID();
return VINF_SUCCESS;
}
static int rtSemEventWait(RTSEMEVENT hEventSem, RTMSINTERVAL cMillies, wait_interrupt_t fInterruptible)
{
PRTSEMEVENTINTERNAL pThis = (PRTSEMEVENTINTERNAL)hEventSem;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertMsgReturn(pThis->u32Magic == RTSEMEVENT_MAGIC, ("pThis=%p u32Magic=%#x\n", pThis, pThis->u32Magic), VERR_INVALID_HANDLE);
if (cMillies)
RT_ASSERT_PREEMPTIBLE();
lck_spin_lock(pThis->pSpinlock);
int rc;
if (pThis->fSignaled)
{
Assert(!pThis->cWaiters);
ASMAtomicXchgU8(&pThis->fSignaled, false);
rc = VINF_SUCCESS;
}
else if (!cMillies)
rc = VERR_TIMEOUT;
else
{
ASMAtomicIncU32(&pThis->cWaiters);
wait_result_t rcWait;
if (cMillies == RT_INDEFINITE_WAIT)
rcWait = lck_spin_sleep(pThis->pSpinlock, LCK_SLEEP_DEFAULT, (event_t)pThis, fInterruptible);
else
{
uint64_t u64AbsTime;
nanoseconds_to_absolutetime(cMillies * UINT64_C(1000000), &u64AbsTime);
u64AbsTime += mach_absolute_time();
rcWait = lck_spin_sleep_deadline(pThis->pSpinlock, LCK_SLEEP_DEFAULT,
(event_t)pThis, fInterruptible, u64AbsTime);
}
switch (rcWait)
{
case THREAD_AWAKENED:
Assert(pThis->cWaking > 0);
if ( !ASMAtomicDecU32(&pThis->cWaking)
&& pThis->u32Magic != RTSEMEVENT_MAGIC)
{
/* the event was destroyed after we woke up, as the last thread do the cleanup. */
lck_spin_unlock(pThis->pSpinlock);
Assert(g_pDarwinLockGroup);
lck_spin_destroy(pThis->pSpinlock, g_pDarwinLockGroup);
RTMemFree(pThis);
return VINF_SUCCESS;
}
rc = VINF_SUCCESS;
break;
case THREAD_TIMED_OUT:
Assert(cMillies != RT_INDEFINITE_WAIT);
ASMAtomicDecU32(&pThis->cWaiters);
rc = VERR_TIMEOUT;
break;
case THREAD_INTERRUPTED:
Assert(fInterruptible);
ASMAtomicDecU32(&pThis->cWaiters);
rc = VERR_INTERRUPTED;
break;
case THREAD_RESTART:
/* Last one out does the cleanup. */
if (!ASMAtomicDecU32(&pThis->cWaking))
{
lck_spin_unlock(pThis->pSpinlock);
Assert(g_pDarwinLockGroup);
lck_spin_destroy(pThis->pSpinlock, g_pDarwinLockGroup);
RTMemFree(pThis);
return VERR_SEM_DESTROYED;
}
rc = VERR_SEM_DESTROYED;
break;
default:
AssertMsgFailed(("rcWait=%d\n", rcWait));
rc = VERR_GENERAL_FAILURE;
break;
}
}
lck_spin_unlock(pThis->pSpinlock);
return rc;
}
RTDECL(int) RTSemEventWait(RTSEMEVENT hEventSem, RTMSINTERVAL cMillies)
{
return rtSemEventWait(hEventSem, cMillies, THREAD_UNINT);
}
RTDECL(int) RTSemEventWaitNoResume(RTSEMEVENT hEventSem, RTMSINTERVAL cMillies)
{
return rtSemEventWait(hEventSem, cMillies, THREAD_ABORTSAFE);
}