filedes.h

T-kernel 的extension源代码

/*
 *----------------------------------------------------------------------
 *    T-Kernel / Standard Extension
 *
 *    Copyright (C) 2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel / Standard Extension is distributed 
 *      under the T-License for T-Kernel / Standard Extension.
 *----------------------------------------------------------------------
 *
 *    Version:   1.00.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/11.
 *
 *----------------------------------------------------------------------
 */

/*
 *	filedes.h (file)
 *
 *	File management
 *	Define the file descriptor.
 */

#ifndef _FM_FILEDES_H_
#define _FM_FILEDES_H_

#include "fsinfo.h"
#include "cmdpkt.h"

/* The maximum number of files that can be opened at a time in the whole system. */
#define	MaxOpenFile	( fmInfo.maxOpenFile )

/*
 * File descriptor
 *
 *	fs == NULL shows that the entry is free.
 */
typedef struct FD {
	QUEUE		q;

	FsInfo		*fs;		/* Supported file systems */
	PINFO		*pinfo;		/* Owner process */

	OFCB		*ofcb;		/* Open file */
	UW		omode;		/* Open mode */
	RCB		*crcb;		/* Current record */
	QUEUE		mcbq;		/* Queue of the record map information */

	FmCmdPkt	*waitReq;	/* Indeterminate wait request */
} FD;

/*
 * File descriptor table
 *	(Array that has MaxOpenFile entries)
 */
typedef FD	FDT[/*MaxOpenFile*/];

#define	SizeOfFDT	( MaxOpenFile * sizeof(FD) )

/*
 * File descriptor table management information
 */
typedef struct FDTInfo {
	FastLock	lock;		/* For exclusive access */

	FDT		*fdt;		/* First address of FDT */
	QUEUE		freeFD;		/* Free list */
} FDTInfo;


#include "fminfo.h"

/*
 * Lock at the file descriptor access
 */
#define	LockFD()	Lock(&fmInfo.fdtInfo.lock)
#define UnlockFD()	Unlock(&fmInfo.fdtInfo.lock)
#define	LOCK_FD(exp)	{ LockFD(); exp; UnlockFD(); }

/*
 * The file descriptor number starts from 1.
 */
#define	checkFDno(no)	( (UW)((no) - 1) < (UW)MaxOpenFile )
#define	getFDp(no)	( &(*fmInfo.fdtInfo.fdt)[(no) - 1] )
#define	getFDno(fd)	( ((fd) - getFDp(1)) + 1 )

/*
 * TRUE when some records of the file are mapped with fd.
 * (Note) One mapped with fd that is opened from other are not included.
 */
#define	isMapRecords(fd)	( !isQueEmpty(&(fd)->mcbq) )


IMPORT ER	fmInitFileDescriptorTable( void );
IMPORT void	fmDeleteFileDescriptorTable( void );
IMPORT FD*	fmGetFD( W no, PINFO *pinfo );

IMPORT FD*	fmpOpenFD( PINFO *pinfo, UW omode, OFCB *ofcb, ER *err );
IMPORT void	fmpCloseFD( FD *fd );
IMPORT ER	fmpCheckFileOpenMode( FD *fd, UW omode );
IMPORT void	fmpMoveCurRecord( FD *fd, RCB *new );

#endif