HostServices/SharedFolders/shflhandle.cpp

	shflhandle.cpp revision 039cd2c4871a00e51af909222a34695d9cec3000
039cd2c4871a00e51af909222a34695d9cec3000vboxsync/** @file
039cd2c4871a00e51af909222a34695d9cec3000vboxsync *
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * Shared Folders:
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * Handles helper functions.
039cd2c4871a00e51af909222a34695d9cec3000vboxsync */
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync/*
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * Copyright (C) 2006-2007 innotek GmbH
039cd2c4871a00e51af909222a34695d9cec3000vboxsync *
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * This file is part of VirtualBox Open Source Edition (OSE), as
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * available from http://www.virtualbox.org. This file is free software;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * you can redistribute it and/or modify it under the terms of the GNU
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * General Public License as published by the Free Software Foundation,
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * distribution. VirtualBox OSE is distributed in the hope that it will
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * be useful, but WITHOUT ANY WARRANTY of any kind.
039cd2c4871a00e51af909222a34695d9cec3000vboxsync *
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * If you received this file as part of a commercial VirtualBox
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * distribution, then only the terms of your commercial VirtualBox
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * license agreement apply instead of the previous paragraph.
039cd2c4871a00e51af909222a34695d9cec3000vboxsync */
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync#include "shflhandle.h"
039cd2c4871a00e51af909222a34695d9cec3000vboxsync#include <iprt/alloc.h>
039cd2c4871a00e51af909222a34695d9cec3000vboxsync#include <iprt/assert.h>
039cd2c4871a00e51af909222a34695d9cec3000vboxsync#include <iprt/critsect.h>
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync/*
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * Very basic and primitive handle management. Should be sufficient for our needs.
039cd2c4871a00e51af909222a34695d9cec3000vboxsync * Handle allocation can be rather slow, but at least lookup is fast.
039cd2c4871a00e51af909222a34695d9cec3000vboxsync *
039cd2c4871a00e51af909222a34695d9cec3000vboxsync */
039cd2c4871a00e51af909222a34695d9cec3000vboxsynctypedef struct
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    uint32_t    uFlags;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    uintptr_t   pvUserData;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync} SHFLINTHANDLE, *PSHFLINTHANDLE;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncstatic SHFLINTHANDLE *pHandles = NULL;
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncstatic int32_t        lastHandleIndex = 0;
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncstatic RTCRITSECT     lock = {0};
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncint vbsfInitHandleTable()
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    pHandles = (SHFLINTHANDLE *)RTMemAllocZ (sizeof (SHFLINTHANDLE) * SHFLHANDLE_MAX);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (pHandles == NULL)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        AssertFailed();
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        return VERR_NO_MEMORY;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    /* Never return handle 0 */
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    pHandles[0].uFlags = SHFL_HF_TYPE_DONTUSE;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    lastHandleIndex    = 1;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return RTCritSectInit(&lock);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncint vbsfFreeHandleTable()
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (pHandles)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        RTMemFree(pHandles);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    pHandles = NULL;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (RTCritSectIsInitialized(&lock))
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        RTCritSectDelete(&lock);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return VINF_SUCCESS;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncSHFLHANDLE  vbsfAllocHandle(uint32_t uType, uintptr_t pvUserData)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    SHFLHANDLE handle;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    Assert((uType & SHFL_HF_TYPE_MASK) != 0 && pvUserData);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    RTCritSectEnter(&lock);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    /* Find next free handle */
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if(lastHandleIndex >= SHFLHANDLE_MAX-1)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        lastHandleIndex = 1;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    /* Nice linear search */
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    for(handle=lastHandleIndex;handle<SHFLHANDLE_MAX;handle++)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        if(pHandles[handle].pvUserData == 0)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            lastHandleIndex = handle;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            break;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if(handle == SHFLHANDLE_MAX)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        /* Try once more from the start */
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        for(handle=1;handle<SHFLHANDLE_MAX;handle++)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            if(pHandles[handle].pvUserData == 0)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync                lastHandleIndex = handle;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync                break;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        if(handle == SHFLHANDLE_MAX)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        { /* Out of handles */
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            RTCritSectLeave(&lock);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            AssertFailed();
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            return SHFL_HANDLE_NIL;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    pHandles[handle].uFlags     = (uType & SHFL_HF_TYPE_MASK) | SHFL_HF_VALID;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    pHandles[handle].pvUserData = pvUserData;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    lastHandleIndex++;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    RTCritSectLeave(&lock);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return handle;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncint vbsfFreeHandle(SHFLHANDLE handle)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (handle < SHFLHANDLE_MAX && (pHandles[handle].uFlags & SHFL_HF_VALID))
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        pHandles[handle].uFlags     = 0;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        pHandles[handle].pvUserData = 0;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        return VINF_SUCCESS;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return VERR_INVALID_HANDLE;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncuintptr_t vbsfQueryHandle(SHFLHANDLE handle, uint32_t uType)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (handle < SHFLHANDLE_MAX && (pHandles[handle].uFlags & SHFL_HF_VALID))
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        Assert((uType & SHFL_HF_TYPE_MASK) != 0);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        if (pHandles[handle].uFlags & uType)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync            return pHandles[handle].pvUserData;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return 0;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncSHFLHANDLE vbsfAllocDirHandle (void)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    SHFLFILEHANDLE *pHandle = (SHFLFILEHANDLE *)RTMemAllocZ (sizeof (SHFLFILEHANDLE));
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (pHandle)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        pHandle->Header.u32Flags = SHFL_HF_TYPE_DIR;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        return vbsfAllocHandle(pHandle->Header.u32Flags, (uintptr_t)pHandle);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return SHFL_HANDLE_NIL;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncSHFLHANDLE vbsfAllocFileHandle (void)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    SHFLFILEHANDLE *pHandle = (SHFLFILEHANDLE *)RTMemAllocZ (sizeof (SHFLFILEHANDLE));
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (pHandle)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        pHandle->Header.u32Flags = SHFL_HF_TYPE_FILE;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        return vbsfAllocHandle(pHandle->Header.u32Flags, (uintptr_t)pHandle);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return SHFL_HANDLE_NIL;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsyncvoid vbsfFreeFileHandle (SHFLHANDLE hHandle)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync{
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    SHFLFILEHANDLE *pHandle = (SHFLFILEHANDLE *)vbsfQueryHandle(hHandle, SHFL_HF_TYPE_DIR|SHFL_HF_TYPE_FILE);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    if (pHandle)
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    {
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        vbsfFreeHandle(hHandle);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        RTMemFree (pHandle);
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    }
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    else
039cd2c4871a00e51af909222a34695d9cec3000vboxsync        AssertFailed();
039cd2c4871a00e51af909222a34695d9cec3000vboxsync
039cd2c4871a00e51af909222a34695d9cec3000vboxsync    return;
039cd2c4871a00e51af909222a34695d9cec3000vboxsync}