PDMAsyncCompletionFileInternal.h revision 1d650736ebf4152a341805561a3a86d79769171b
/* $Id$ */
/** @file
* PDM Async I/O - Transport data asynchronous in R3 using EMT.
*/
/*
* Copyright (C) 2006-2008 Sun Microsystems, Inc.
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* 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.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 USA or visit http://www.sun.com if you need
* additional information or have any questions.
*/
#include <iprt/semaphore.h>
#include "PDMAsyncCompletionInternal.h"
/** @todo: Revise the caching of tasks. We have currently four caches:
* Per endpoint task cache
* Per class cache
* Per endpoint task segment cache
* Per class task segment cache
*
* We could use the RT heap for this probably or extend MMR3Heap (uses RTMemAlloc
* instead of managing larger blocks) to have this global for the whole VM.
*/
/**
* A few forward declerations.
*/
typedef struct PDMASYNCCOMPLETIONENDPOINTFILE *PPDMASYNCCOMPLETIONENDPOINTFILE;
/** Pointer to a request segment. */
typedef struct PDMACTASKFILESEG *PPDMACTASKFILESEG;
/** Pointer to the endpoint class data. */
typedef struct PDMASYNCCOMPLETIONTASKFILE *PPDMASYNCCOMPLETIONTASKFILE;
/**
* Blocking event types.
*/
typedef enum PDMACEPFILEAIOMGRBLOCKINGEVENT
{
/** Invalid tye */
/** An endpoint is added to the manager. */
/** An endpoint is removed from the manager. */
/** An endpoint is about to be closed. */
/** The manager is requested to terminate */
/** The manager is requested to suspend */
/** 32bit hack */
PDMACEPFILEAIOMGRBLOCKINGEVENT_32BIT_HACK = 0x7fffffff
/**
* State of a async I/O manager.
*/
typedef struct PDMACEPFILEMGR
{
/** Next Aio manager in the list. */
/** Previous Aio manager in the list. */
/** Event semaphore the manager sleeps on when waiting for new requests. */
/** Flag whether the thread waits in the event semaphore. */
volatile bool fWaitingEventSem;
/** Flag whether this manager uses the failsafe method. */
bool fFailsafe;
/** Thread data */
/** The async I/O context for this manager. */
/** Flag whether the I/O manager is requested to terminate */
volatile bool fShutdown;
/** Flag whether the I/O manager was woken up. */
volatile bool fWokenUp;
/** List of endpoints assigned to this manager. */
/** Number of requests active currently. */
unsigned cRequestsActive;
/** Critical section protecting the blocking event handling. */
/** Event sempahore for blocking external events.
* The caller waits on it until the async I/O manager
* finished processing the event. */
/** Flag whether a blocking event is pending and needs
* processing by the I/O manager. */
volatile bool fBlockingEventPending;
/** Blocking event type */
/** Event type data */
union
{
/** Add endpoint event. */
struct
{
/** The endpoint to be added */
volatile PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint;
} AddEndpoint;
/** Remove endpoint event. */
struct
{
/** The endpoint to be removed */
volatile PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint;
/** Close endpoint event. */
struct
{
/** The endpoint to be closed */
volatile PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint;
/** Pointer to a async I/O manager state. */
typedef PDMACEPFILEMGR *PPDMACEPFILEMGR;
/** Pointer to a async I/O manager state pointer. */
typedef PPDMACEPFILEMGR *PPPDMACEPFILEMGR;
/**
* Global data for the file endpoint class.
*/
typedef struct PDMASYNCCOMPLETIONEPCLASSFILE
{
/** Common data. */
/** Flag whether we use the failsafe method. */
bool fFailsafe;
/** Critical section protecting the list of async I/O managers. */
/** Pointer to the head of the async I/O managers. */
/** Number of async I/O managers currently running. */
unsigned cAioMgrs;
/** Maximum number of segments to cache per endpoint */
unsigned cSegmentsCacheMax;
/** Maximum number of simultaneous outstandingrequests. */
/** Bitmask for checking the alignment of a buffer. */
/** Pointer to the endpoint class data. */
typedef enum PDMACEPFILEBLOCKINGEVENT
{
/** The invalid event type */
/** A task is about to be canceled */
/** Usual 32bit hack */
PDMACEPFILEBLOCKINGEVENT_32BIT_HACK = 0x7fffffff
/**
* Data for the file endpoint.
*/
typedef struct PDMASYNCCOMPLETIONENDPOINTFILE
{
/** Common data. */
/** async I/O manager this endpoint is assigned to. */
/** Filename */
char *pszFilename;
/** Flags for opening the file. */
unsigned fFlags;
/** File handle. */
/** Flag whether caching is enabled for this file. */
bool fCaching;
/** List of new tasks. */
/** Head of the small cache for allocated task segments for exclusive
* use by this endpoint. */
/** Tail of the small cache for allocated task segments for exclusive
* use by this endpoint. */
/** Number of elements in the cache. */
volatile uint32_t cSegmentsCached;
/** Flag whether a flush request is currently active */
/** Flag whether the endpoint is currently closed or removed from
* the active endpoint. */
bool fRemovedOrClosed;
/** Event sempahore for blocking external events.
* The caller waits on it until the async I/O manager
* finished processing the event. */
/** Flag whether a blocking event is pending and needs
* processing by the I/O manager. */
bool fBlockingEventPending;
/** Blocking event type */
/** Additional data needed for the event types. */
union
{
/** Cancelation event. */
struct
{
/** The task to cancel. */
} Cancel;
/** Data for exclusive use by the assigned async I/O manager. */
struct
{
/** Pointer to the next endpoint assigned to the manager. */
/** Pointer to the previous endpoint assigned to the manager. */
/** List of pending requests (not submitted due to usage restrictions
* or a pending flush request) */
/** Tail of pending requests. */
/** Number of requests currently being processed for this endpoint
* (excluded flush requests). */
unsigned cRequestsActive;
} AioMgr;
/** Pointer to the endpoint class data. */
/**
* Segment data of a request.
*/
typedef struct PDMACTASKFILESEG
{
/** Pointer to the next segment in the list. */
/** Pointer to the previous segment in the list. */
/** Pointer to the task owning the segment. */
/** Data segment. */
/** Flag whether this segment uses a bounce buffer
* because the provided buffer doesn't meet host requirements. */
bool fBounceBuffer;
/** Pointer to the used bounce buffer if any. */
void *pvBounceBuffer;
/** AIO request */
/**
* Transfer type.
*/
typedef enum PDMACTASKFILETRANSFER
{
/** Invalid. */
/** Read transfer. */
/** Write transfer. */
/** Flush transfer. */
/**
* Per task data.
*/
typedef struct PDMASYNCCOMPLETIONTASKFILE
{
/** Common data. */
/** Transfer type. */
/** Type dependent data. */
union
{
/** Data for a data transfer */
struct
{
/** Start offset. */
/** Number of bytes to transfer. */
/** Number of segments which still needs to be processed before the task
* completes. */
unsigned cSegments;
/** Head of the request segments list for read and write requests. */
} DataTransfer;
} u;
#endif