source: vbox/trunk/src/VBox/Runtime/r0drv/os2/spinlock-r0drv-os2.cpp@ 40806

/* $Id: spinlock-r0drv-os2.cpp 40806 2012-04-06 21:05:19Z vboxsync $ */
/** @file
 * IPRT - Spinlocks, Ring-0 Driver, OS/2.
 */

/*
 * Copyright (c) 2007 knut st. osmundsen <[email protected]>
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/*******************************************************************************
*   Header Files                                                               *
*******************************************************************************/
#include "the-os2-kernel.h"

#include <iprt/spinlock.h>
#include <iprt/err.h>
#include <iprt/alloc.h>
#include <iprt/assert.h>
#include <iprt/asm.h>

#include "internal/magics.h"


/*******************************************************************************
*   Structures and Typedefs                                                    *
*******************************************************************************/
/**
 * Wrapper for the SpinLock_t type.
 */
typedef struct RTSPINLOCKINTERNAL
{
    /** Spinlock magic value (RTSPINLOCK_MAGIC). */
    uint32_t volatile   u32Magic;
    /** Spinlock creation flags.  */
    uint32_t            fFlags;
    /** The OS/2 spinlock structure. */
    SpinLock_t          Spinlock;
} RTSPINLOCKINTERNAL, *PRTSPINLOCKINTERNAL;


RTDECL(int)  RTSpinlockCreate(PRTSPINLOCK pSpinlock, uint32_t fFlags, const char *pszName)
{
    AssertReturn(fFlags == RTSPINLOCK_FLAGS_INTERRUPT_SAFE || fFlags == RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, VERR_INVALID_PARAMETER);

    /*
     * Allocate.
     */
    AssertCompile(sizeof(RTSPINLOCKINTERNAL) > sizeof(void *));
    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)RTMemAlloc(sizeof(*pThis));
    if (!pThis)
        return VERR_NO_MEMORY;

    /*
     * Initialize & return.
     */
    pThis->u32Magic     = RTSPINLOCK_MAGIC;
    pThis->fFlags       = fFlags;
    pThis->fIntSaved    = 0;
    KernAllocSpinLock(&pThis->Spinlock);
    *pSpinlock = pThis;
    return VINF_SUCCESS;
}


RTDECL(int)  RTSpinlockDestroy(RTSPINLOCK Spinlock)
{
    /*
     * Validate input.
     */
    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
    if (!pThis)
        return VERR_INVALID_PARAMETER;
    AssertMsgReturn(pThis->u32Magic == RTSPINLOCK_MAGIC,
                    ("Invalid spinlock %p magic=%#x\n", pThis, pThis->u32Magic),
                    VERR_INVALID_PARAMETER);

    /*
     * Make the lock invalid and release the memory.
     */
    ASMAtomicIncU32(&pThis->u32Magic);
    KernFreeSpinLock(&pThis->Spinlock);
    RTMemFree(pThis);
    return VINF_SUCCESS;
}


RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock)
{
    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
    AssertPtr(pThis);
    Assert(pThis->u32Magic == RTSPINLOCK_MAGIC);

    KernAcquireSpinLock(&pThis->Spinlock);
    Assert(!ASMIntAreEnabled()); /** @todo verify that interrupts are disabled. */
}


RTDECL(void) RTSpinlockRelease(RTSPINLOCK Spinlock)
{
    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
    AssertPtr(pThis);
    Assert(pThis->u32Magic == RTSPINLOCK_MAGIC);

    KernReleaseSpinLock(&pThis->Spinlock);
}


RTDECL(void) RTSpinlockReleaseNoInts(RTSPINLOCK Spinlock)
{
#if 1
    if (RT_UNLIKELY(!(Spinlock->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)))
        RTAssertMsg2("RTSpinlockReleaseNoInts: %p (magic=%#x)\n", Spinlock, Spinlock->u32Magic);
#else
    AssertRelease(Spinlock->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE);
#endif
    RTSpinlockRelease(Spinlock);
}