Category : C Source Code
Archive   : CSWITCH.ZIP
Filename : TCB.H

/*
** Task Control Block (TCB) structure, along with other related
** memory structures for the Adept Multi-Tasker
**
** Copyright 1990 Herb Rose
**
*/

#define maxtasks 32
#define num_mcbs 512

struct tcb_rec {
int next_tcb; /* tcbs are arranged as a table, this is next index */
int base_pri; /* base priority */
int cur_pri; /* current priority */
unsigned int stackseg;
unsigned int stackptr;
int mcb_ptr; /* first mcb */
int emm_handle; /* handle for task if swapped out to ems */
int tcbflags; /* various state flags */
int cur_state; /* numerical value for task state */
int sem_wait_num;
int mcbs_in_use;
int mcbs_avail;
unsigned int dtaseg; /* this guys disk transfer area - segment */
unsigned int dtaoff; /* dta offset */
unsigned int pspseg; /* our psp segment */
char tcbname[10];
};

#define st_free -1 /* this tcb not being used */
#define st_active 0 /* the runner */
#define st_ready 1 /* ready to run */
#define st_sem_wait 2 /* waiting for a semaphore */
#define st_delay 3 /* task is delaying */
#define st_suspend 4 /* task is suspended - needs a wakeup signal */
#define st_msg_wait 5 /* task is waiting for a message */
#define st_stopping 6 /* task is terminating */

/* the following are bit values for the flags word */

#define fl_no_swap 1 /* when this task is the runner, do not task swap */
#define fl_in_dos 2 /* this task is in dos */
#define fl_in_emm 4 /* this task executes in emm */
#define fl_spawned 8 /* this task created with spawn */

struct mem_ctrl_block {
int fwd_link; /* index of next tcb */
unsigned int actlen; /* actual length of data (for message queues) */
unsigned int m_size; /* number of paragraphs */
unsigned int m_address; /* the segment address */
};

struct msgq_rec {
int mmcb[2]; /* hoq and toq mcbs for messages */
int mtcb[2]; /* same for tcbs */
};