/* $Id: semfastmutex-r0drv-darwin.cpp $ */
/** @file
 * IPRT - Fast Mutex Semaphores, Ring-0 Driver, Darwin.
 */

/*
 * Copyright (C) 2006-2023 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, in version 3 of the
 * License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <https://www.gnu.org/licenses>.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
 * in the VirtualBox 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.
 *
 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
 */


/*********************************************************************************************************************************
*   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/errcore.h>
#include <iprt/mem.h>
#include <iprt/mp.h>
#include <iprt/thread.h>

#include "internal/magics.h"


/*********************************************************************************************************************************
*   Structures and Typedefs                                                                                                      *
*********************************************************************************************************************************/
/**
 * Wrapper for the darwin semaphore structure.
 */
typedef struct RTSEMFASTMUTEXINTERNAL
{
    /** Magic value (RTSEMFASTMUTEX_MAGIC). */
    uint32_t            u32Magic;
    /** The mutex. */
    lck_mtx_t          *pMtx;
} RTSEMFASTMUTEXINTERNAL, *PRTSEMFASTMUTEXINTERNAL;



RTDECL(int)  RTSemFastMutexCreate(PRTSEMFASTMUTEX phFastMtx)
{
    AssertCompile(sizeof(RTSEMFASTMUTEXINTERNAL) > sizeof(void *));
    AssertPtrReturn(phFastMtx, VERR_INVALID_POINTER);
    RT_ASSERT_PREEMPTIBLE();
    IPRT_DARWIN_SAVE_EFL_AC();

    PRTSEMFASTMUTEXINTERNAL pThis = (PRTSEMFASTMUTEXINTERNAL)RTMemAlloc(sizeof(*pThis));
    if (pThis)
    {
        pThis->u32Magic = RTSEMFASTMUTEX_MAGIC;
        Assert(g_pDarwinLockGroup);
        pThis->pMtx = lck_mtx_alloc_init(g_pDarwinLockGroup, LCK_ATTR_NULL);
        if (pThis->pMtx)
        {
            *phFastMtx = pThis;
            IPRT_DARWIN_RESTORE_EFL_AC();
            return VINF_SUCCESS;
        }

        RTMemFree(pThis);
    }
    IPRT_DARWIN_RESTORE_EFL_AC();
    return VERR_NO_MEMORY;
}


RTDECL(int)  RTSemFastMutexDestroy(RTSEMFASTMUTEX hFastMtx)
{
    PRTSEMFASTMUTEXINTERNAL pThis = hFastMtx;
    if (pThis == NIL_RTSEMFASTMUTEX)
        return VINF_SUCCESS;
    AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
    AssertMsgReturn(pThis->u32Magic == RTSEMFASTMUTEX_MAGIC, ("%p: u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_HANDLE);
    RT_ASSERT_INTS_ON();
    IPRT_DARWIN_SAVE_EFL_AC();

    ASMAtomicWriteU32(&pThis->u32Magic, RTSEMFASTMUTEX_MAGIC_DEAD);
    Assert(g_pDarwinLockGroup);
    lck_mtx_free(pThis->pMtx, g_pDarwinLockGroup);
    pThis->pMtx = NULL;
    RTMemFree(pThis);

    IPRT_DARWIN_RESTORE_EFL_AC();
    return VINF_SUCCESS;
}


RTDECL(int)  RTSemFastMutexRequest(RTSEMFASTMUTEX hFastMtx)
{
    PRTSEMFASTMUTEXINTERNAL pThis = hFastMtx;
    AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
    AssertMsgReturn(pThis->u32Magic == RTSEMFASTMUTEX_MAGIC, ("%p: u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_HANDLE);
    RT_ASSERT_PREEMPTIBLE();
    IPRT_DARWIN_SAVE_EFL_AC();

    lck_mtx_lock(pThis->pMtx);

    IPRT_DARWIN_RESTORE_EFL_ONLY_AC();
    return VINF_SUCCESS;
}


RTDECL(int)  RTSemFastMutexRelease(RTSEMFASTMUTEX hFastMtx)
{
    PRTSEMFASTMUTEXINTERNAL pThis = hFastMtx;
    AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
    AssertMsgReturn(pThis->u32Magic == RTSEMFASTMUTEX_MAGIC, ("%p: u32Magic=%RX32\n", pThis, pThis->u32Magic), VERR_INVALID_HANDLE);
    RT_ASSERT_PREEMPTIBLE();
    IPRT_DARWIN_SAVE_EFL_AC();

    lck_mtx_unlock(pThis->pMtx);

    IPRT_DARWIN_RESTORE_EFL_ONLY_AC();
    return VINF_SUCCESS;
}

