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/*

 * Project: S.Ha.R.K.

 *

 * Coordinators:

 *   Giorgio Buttazzo    <giorgio@sssup.it>

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *

 * Authors     :

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *   Massimiliano Giorgi <massy@gandalf.sssup.it>

 *   Luca Abeni          <luca@gandalf.sssup.it>

 *   (see the web pages for full authors list)

 *

 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)

 *

 * http://www.sssup.it

 * http://retis.sssup.it

 * http://shark.sssup.it

 */

/**

 ------------

 CVS :        $Id: descr.h,v 1.2 2002-11-11 08:36:01 pj Exp $

 File:        $File$

 Revision:    $Revision: 1.2 $

 Last update: $Date: 2002-11-11 08:36:01 $

 ------------

Kernel main data structures

This file declare:

- the descriptors

  - cleanup handlers

  - levels

  - mutexes

  - mutex attributes

  - resource levels

**/

/*

 * Copyright (C) 2000 Paolo Gai

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#ifndef __KERNEL_DESCR_H__

#define __KERNEL_DESCR_H__

#include <ll/ll.h>

#include <kernel/model.h>

#include <kernel/types.h>

#include <kernel/iqueue.h>

#include <limits.h>

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  CLEANUP HANDLER STRUCTURES

  Derived directly from posix standard, B.18.2.3

  This structure implements the task cleanup functions queue...

  look at kern.c!

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

struct _task_handler_rec {

  void (*f)(void *);

  void *a;

  struct _task_handler_rec *next;

};

struct condition_struct;

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  GENERAL TASK DESCRIPTOR

  In this type definition there is all the basic information for

  handling a task in the system.

  All the informations scheduler-dependent (like deadline, priority,

  and so on) are put in the level module files.

  In any case, a priority field is inserted to simplify the implementation

  of most of the scheduling algorithms

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

typedef struct {

        DWORD   task_ID;      /*+ progressive task counter ID +*/

        LEVEL   task_level;   /*+ the "real" level that owns the task     +*/

        CONTEXT context;      /*+ Context area pointer (see vm.h)         +*/

        BYTE    *stack;       /*+ Pointer to stack area base              +*/

        TASK    (*body)();    /*+ Pointer to the code of the task

                                  (starting address)                      +*/

        char    name[MAX_TASKNAME]; /*+ Text identifing the process name  +*/

        WORD    status;       /*+ actual task status

                                  (it could be EXE, SLEEP, IDLE, ...)     +*/

        WORD    pclass;       /*+ The code number of the task model used  +*/

        WORD    group;        /*+ 0 if task is single, else group id      +*/

        WORD    stacksize;    /*+ Task stack size                         +*/

        DWORD   control;      /*+ Control task operating mode

                                 Refer to the TASK_MODEL type for its use +*/

        int     frozen_activations; /*+ number of frozen activation;

                                        see kern.c, task_block_activations

                                        see model.h,flag in control field +*/

        /* sigset_t!!! */

        int sigmask;          /*+ The task signal mask                    +*/

        int sigpending;       /*+ The signal pending mask                 +*/

        int sigwaiting;       /*+ The signal waiting mask                 +*/

        struct timespec request_time;

                              /*+ Last request time for the task          +*/

        int     avail_time;   /*+ the time the task can execute before a

                                  timer fire. see also the control field

                                  and bits related in model.h             +*/

        PID     shadow;       /*+ Shadow task                             +*/

        struct _task_handler_rec *cleanup_stack;

                              /*+ The cleanup stack                       +*/

        int     errnumber;

        /* Job Execution Time fields */

        TIME    jet_table[JET_TABLE_DIM];

                              /*+ Execution time of the last

                                  activations of the task.                +*/

        int     jet_tvalid;   /*+ number of valid entry in the jet_table  +*/

        int     jet_curr;     /*+ Current entry in the jet_table          +*/

        TIME    jet_max;      /*+ Maximum Execution time since task_create

                                  or last jet_delstat                     +*/

        TIME    jet_sum;      /*+ Mean Execution time since task_create

                                  or last jet_delstat                     +*/

        TIME    jet_n;        /*+ Number of instances on witch the mean

                                  time have to be computed                +*/

        /* task_join fields */

        PID waiting_for_me;   /*+ the task that waits my dead,

                                  NIL if there aren't                     +*/

        void *return_value;   /*+ task return value                       +*/

        /* task specific data (it uses directly POSIX constant) */

        void *keys[PTHREAD_KEYS_MAX];

        /* condition variable field */

        struct condition_struct *cond_waiting;

                              /*+ the condition on that the task is

                                  waiting +*/

        /* stuff used in most algorithms; they are not used directly in

         * the generic kernel, with exclusion of delay_timer that is used

         * also in cond_timedwait

         */

        int     delay_timer;  /*+ A field useful to store the delay timer +*/

        int     wcet;         /*+ a worst case time execution             +*/

} proc_des;

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  LEVEL DESCRIPTOR

  In this type definition there is all the basic information for

  handling a scheduling level in the system.

  All the informations that depends on the particular module are put

  in the level module files.

  The initialization of a level is splitted in two parts:

  - the registration -> called before the system initialization, typically

                        AFTER the resource registration

  - the level_init   -> called during the system initialization,

                        BEFORE the resource_init(s)

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

typedef struct {

  char level_name[MAX_LEVELNAME]; /*+ for statistical pourposes          +*/

  WORD level_code;              /*+ level identification code            +*/

  BYTE level_version;           /*+ level version                        +*/

  /* LEVEL CALLS */

  int (*level_accept_task_model)(LEVEL l, TASK_MODEL *m);

                                /*+ models that a task can manage. returns

                                    -1 if not                            +*/

  int (*level_accept_guest_model)(LEVEL l, TASK_MODEL *m);

                                /*+ models that a task can manage as guest

                                    tasks. returns

                                    -1 if not                            +*/

  void (*level_status)(LEVEL l);/*+ print level statistics...            +*/

  PID  (*level_scheduler)(LEVEL l);

                                /*+ the level scheduler returns a task

                                    chosen among those belonging to the

                                    level                                +*/

  int (*level_guarantee)(LEVEL l, bandwidth_t *freebandwidth);

                                /*+ 0 if the level is guaranteed, -1 if not

                                    no guarantee if (*f)()=null

                                    the function updates the parameter

                                    (see guarantee() )                   +*/

  /* TASK CALLS */

  int  (*task_create)(LEVEL l, PID p, TASK_MODEL *m);

                                /*+ the task p is created into the level

                                    returns 0->ok, -1->error             +*/

  void (*task_detach)(LEVEL l, PID p);

                                /*+ there is an error in the task_create

                                    after the task call task_create.

                                    The function delete all the informations

                                    about the task in the level.

                                    For the resources levels there is the

                                    res_detach: res_detach is called also

                                    when killing a task                  +*/

  int (*task_eligible)(LEVEL l, PID p);

                                /*+ correctness control when a task is

                                    chosen by a level scheduler (used with

                                    aperiodic servers) 0->ok, -1->no     +*/

  void (*task_dispatch)(LEVEL l, PID p, int nostop);

                                /*+ a task go in the EXEC status (called

                                    by dispatch() )                      +*/

  void (*task_epilogue)(LEVEL l, PID p);

                                /*+ a task has finished the current slice+*/

  void (*task_activate)(LEVEL l, PID p);

                                /*+ the task is activated...             +*/

  void (*task_insert)(LEVEL l, PID p);

                                /*+ opposite to task_extract             +*/

  void (*task_extract)(LEVEL l, PID p);

                                /*+ remove the task from the "ready" (if any)

                                    queue                                +*/

  void (*task_endcycle)(LEVEL l, PID p);

                                /*+ the (periodic) task finish the cycle +*/

  void (*task_end)(LEVEL l, PID p);

                                /*+ the task is killed; we have to remove

                                    it from the level queues, test if it

                                    is in the exec state, etc... it can

                                    modify the state of the task (-> FREE,

                                    ZOMBIE...), but

                                    cannot call the scheduler directly (it

                                    is called by the task_makefree.

                                    Note: the task can be in a state

                                    different from those managed by the

                                    level because the task may be blocked.

                                    the res_detach is in any case called

                                    AFTER the task_end.                  +*/

  void (*task_sleep)(LEVEL l, PID p);

                                /*+ this function will fall asleep the

                                    task in the EXE state. +*/

  /* guest CALLS:

     these functions are called from an Aperiodic Server Level for the task

     that are inserted in the local queues */

  int  (*guest_create)(LEVEL l, PID p, TASK_MODEL *m);

                                /*+ the task is already created in another

                                    level and it is inserted in the current

                                    level; returns 0->ok, -1->error      +*/

  void (*guest_detach)(LEVEL l, PID p);

                                /*+ there is an error in a task creation

                                    of a task made by an aperiodic server

                                    The function delete all the informations

                                    about the task in the level.         +*/

  void (*guest_dispatch)(LEVEL l, PID p, int nostop);

                                /*+ a task belonging to another level but

                                    inserted in the current level go in the

                                    EXEC status (called by dispatch() )  +*/

  void (*guest_epilogue)(LEVEL l, PID p);

                                /*+ a task has finished the current slice+*/

  void (*guest_activate)(LEVEL l, PID p);

                                /*+ the task is activated...             +*/

  void (*guest_insert)(LEVEL l, PID p);

                                /*+ remove the task from the "ready" (if any)

                                    queue                                +*/

  void (*guest_extract)(LEVEL l, PID p);

                                /*+ opposite to guest_insert             +*/

  void (*guest_endcycle)(LEVEL l, PID p);

                                /*+ the task finish the cycle +*/

  void (*guest_end)(LEVEL l, PID p);

                                /*+ the task is killed                   +*/

  void (*guest_sleep)(LEVEL l, PID p);

} level_des;

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  RESOURCE DESCRIPTOR

  In this type definition there is all the basic information for

  handling a resource module in the system.

  All the informations protocol-dependent (like ceiling, task that use

  a particular resource, and so on) are put in the resource module files.

  In general, the initialization of a resource module is splitted in two

  parts:

  - the registration   -> tipically done with a finction called

                          XXX_register_module. It is called before the

                          system initialization, in

                          the function __kernel_register_levels__().

  - the initialization -> called during the system initialization,

                          This is done posting some init functions with

                          the sys_at_init()

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

typedef struct {

  char res_name[MAX_MODULENAME];/*+ for statistical pourposes            +*/

  WORD res_code;                /*+ resource module identification code  +*/

  BYTE res_version;             /*+ resource module version              +*/

  int rtype;                    /*+ resource module extented interface

                                    code (see model.h)                   +*/

  void (*resource_status)();    /*+ print resource protocol statistics...+*/

  int  (*level_accept_resource_model)(RLEVEL l, RES_MODEL *r);

                                /*+ this function is called when the process

                                    is created. it returns 0 if the RES_MODEL

                                    can be managed by the level,-1 if not+*/

  void (*res_register)(RLEVEL l, PID p, RES_MODEL *r);

                                /*+ When the system knows that a resource

                                    model can be registered by a level,

                                    it calls this function. It registers all

                                    the information about the task and the

                                    model. +*/

  void (*res_detach)(RLEVEL l, PID p);

                                /*+ this function is called when the task

                                    is killed or some error is occurred

                                    in the task_create. It have to unlink

                                    the task from the module... If the task

                                    is already unlinked from the protocol

                                    no action is done                    +*/

} resource_des;

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  MUTEX DESCRIPTOR

  In this type definition there is all the basic fields for

  handling a mutex in the system

  Many of the informations protocol-dependent (like ceiling, and so on)

  are put in the resource module or are pointef by the field opt.

  The opt field is used because in this way a mutex can be allocated in

  a dynamic way (in this case opt points to a dynamically allocated

  structure) or in a static way (in this case opt can be an index or a

  pointer to a static structure)

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

typedef struct {

  RLEVEL mutexlevel;  /*+ protocol used by the mutex. +*/

  int use;            /*+ the mutex is used in a condition wait... +*/

  void *opt;

} mutex_t;

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  MUTEX RESOURCE DESCRIPTOR

  This object is a resource_des object with a set of functions used to

  implement the mutex behaviour.

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

typedef struct {

  resource_des r;

  int  (*level_accept_mutexattr)(RLEVEL l, const mutexattr_t *a);

                                /*+ this function is called when a mutex

                                    is created. it returns 0 if the

                                    mutexattr_t

                                    can be managed by the level,-1 if not+*/

  int (*init)   (RLEVEL l, mutex_t *m, const mutexattr_t *a);

  int (*destroy)(RLEVEL l, mutex_t *m);

  int (*lock)   (RLEVEL l, mutex_t *m);

  int (*trylock)(RLEVEL l, mutex_t *m);

  int (*unlock) (RLEVEL l, mutex_t *m);

} mutex_resource_des;

/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  CONDITION VARIABLE DESCRIPTOR

  This is the condition variable descriptor.

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

typedef struct condition_struct {

  IQUEUE waiters; /*+ queue for tasks waiting on the condition +*/

  mutex_t *used_for_waiting;

} cond_t;

#endif /* __TYPE_H__ */