multsk.h

一个操作系统源代码 用于嵌入式设备 在Vc++环境下仿真 成功移植到多款处理器上

#ifndef _FS_MULTSK_H
#define _FS_MULTSK_H

/*
 * This macro decides max number of files one task can open at same time.
 */
#define MAX_OPENED_FILE_NUM_PER_TASK 5


/*
 * Structure of multi-task part in file system:
 * It contains a flag to distinguish files the task is opening, 
 * and a read/write pointer.
 */
typedef struct {
	unsigned int fp;	/* file's flag */
	unsigned int curp;	/* current read/write pointer */
} T_FSCB_ITEM;


/*
 * Array of multi-task part in file system:
 * It will be included in structure 'T_TSKCB'(asixos/kernel/internel.h).
 */
typedef struct {
	T_FSCB_ITEM items[MAX_OPENED_FILE_NUM_PER_TASK];
	int opened_num;
} T_FSCB;


/*
 * Public Functions:
 */
extern void init_fscb( T_FSCB *pfscb );
extern unsigned int get_curp( unsigned int fp );
extern unsigned int set_curp( unsigned int fp, unsigned int curp );
extern int get_fscb_item( unsigned int fp );
extern int remove_fscb_item( unsigned int fp );
extern int check_opened_file_num( void );

#endif /* _FS_MULTSK_H */