#define _INTRPT_ 0x7f
/* This structure is used to hold status information
on a process */
struct _statusT
{
int kill_flag : 2;
int wait_flag : 2;
int fill_flag : 12;
};
/* This structure holds all of the information that
defines a processes context */
struct _simprocessT
{
struct _simprocessT *next;
struct _simprocessT *prev;
int init;
int proc_id;
struct _statusT status;
unsigned long start_time;
void *waitpost;
int reg_ax;
int reg_bx;
int reg_cx;
int reg_dx;
int reg_es;
int reg_ds;
int reg_si;
int reg_di;
int reg_bp;
int reg_sp;
int reg_ss;
int reg_cs;
int reg_ip;
int reg_flag;
};
typedef struct _simprocessT *pprocess;
/* this is the interprocess communications structure, for
communications and synchronization */
struct _postT
{
struct _postT *next;
struct _postT *prev;
char name[30];
int handle;
void *value;
pprocess *waiting;
};
/* Process header block list, which is circular */
struct _simprocessT *processlist;
/* This process responds to the keyboard */
struct _simprocessT *kbprocess;
int set_kb_process = 0;
/* Total number of process */
int totalprocs = 1;
/* List of all current posts */
struct _postT *postlist;
/* Total number of posts in the system */
int unsigned totalposts;
/* Storage for the original interrupt vector,
which is replaced by task_handler */
void interrupt (*old_vector)
();
/* Globals used by setup_task */
int _sim_init_val = 2;
int glbl_sp;
int glbl_ss;
int glbl_bp;
void (*glbl_fc)(void)=NULL;
/* Quick way to the system timer */
long unsigned *systimer = MK_FP(0x0040, 0x006c);
/* Simulation Time used by system */
long unsigned _sim_system_time;
long unsigned _last_update_time;
/* Simulation Time ratio used by system */
float _sim_time_ratio = 0;
/* Hidden routines handle installation of task
switcher, and actual task switching */
int install_handler(void);
void interrupt task_handler(unsigned bp, unsigned di,
unsigned si, unsigned ds,
unsigned es, unsigned dx,
unsigned cx, unsigned bx,
unsigned ax, unsigned ip,
unsigned cs, unsigned flags);
void sim_start(void);
/* Simulation time available to programmer */
long unsigned CurrentTime; /* Visible to programs */
/* Visible routine for process control */
int start_kb_process(void (*func)(void), int stacksize);
int start_process(void (*func)(void), int stacksize);
void stop_process(int process_id);
int my_process_id(void);
/* Visible routines for control of
process time utilivation */
int wait_until_time(long unsigned starttime);
int wait_for_time(float delaytime);
/* Sets the sim time to real time ratio - maximum running
speed. If this is set to 0.0, the system will run as
fast as possible */
int set_time_ratio(float ratio);
/* Visible routines for the handling of posts */
int init_post(char *postname);
int set_post(int posthandle, void *pointer);
void *get_post(int posthandle);
void *wait_post(int posthandle);
/* Exiting the system, and cleaning up the interrupts
reports the value of the exit condition before
exiting, useful for signalling certain errors */
void exit_processing(int condition);