/* Copyright (C) 2004 David Decotigny
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 _SOS_TIME_H_
#define _SOS_TIME_H_
/**
* @file time.h
*
* Primitives and callbacks related to kernel time management (timer
* IRQ)
*/
#include <sos/types.h>
#include <sos/errno.h>
#include <sos/klibc.h>
/* =======================================================================
* Library of time manipulation functions
*/
struct sos_time
{
sos_ui32_t sec;
sos_ui32_t nanosec;
};
sos_ret_t sos_time_inc(struct sos_time *dest,
const struct sos_time *to_add);
sos_ret_t sos_time_dec(struct sos_time *dest,
const struct sos_time *to_dec);
int sos_time_cmp(const struct sos_time *t1,
const struct sos_time *t2);
sos_bool_t sos_time_is_zero(const struct sos_time *tm);
/* =======================================================================
* Kernel time management. This is not the same as the "system-time",
* ie it does not not take into account the system-time adjustments
* (NTP, daylight saving times, etc...): this is the job of a
* system-time subsystem.
*/
/**
* Initialize kernel time subsystem.
*
* @param initial_resolution The initial time resolution. MUST be
* consistent with that of the hardware timer
*/
sos_ret_t sos_time_subsysem_setup(const struct sos_time *initial_resolution);
/**
* Value of the interval between 2 time ticks. Should be consistent
* with the configuration of the hardware timer.
*/
sos_ret_t sos_time_get_tick_resolution(struct sos_time *resolution);
/**
* Change the value of the interval between 2 time ticks. Must be
* called each time the hardware timer is reconfigured.
*
* @note MUST be consistent with that of the hardware timer
*/
sos_ret_t sos_time_set_tick_resolution(const struct sos_time *resolution);
/**
* Get the time elapsed since system boot. Does not take into account
* the system-time adjustment (NTP, daylight saving times, etc...):
* this is the job of a system-time subsystem.
*/
sos_ret_t sos_time_get_now(struct sos_time *now);
/* =======================================================================
* Routines to schedule future execution of routines: "timeout" actions
*/
/* Forward declaration */
struct sos_timeout_action;
/**
* Prototype of a timeout routine. Called with IRQ disabled !
*/
typedef void (sos_timeout_routine_t)(struct sos_timeout_action *);
/**
* The structure of a timeout action. This structure should have been
* opaque to the other parts of the kernel. We keep it public here so
* that struct sos_timeout_action can be allocated on the stack from
* other source files in the kernel. However, all the fields should be
* considered read-only for modules others than time.{ch}.
*
* @note After an action has been allocated (on the stack or kmalloc),
* it MUST be initialized with sos_time_init_action below !
*/
struct sos_timeout_action
{
/** PUBLIC: Address of the timeout routine */
sos_timeout_routine_t *routine;
/** PUBLIC: (Custom) data available for this routine */
void *routine_data;
/** PUBLIC: 2 meanings:
* - before and while in the timeout list: absolute due date of the
* timeout action
* - once removed from timeout list: the time remaining in the
* initial timeout (might be 0 if timeout expired) at removal
* time
*/
struct sos_time timeout;
/** PRIVATE: To chain the timeout actions */
struct sos_timeout_action *tmo_prev, *tmo_next;
};
/**
* Initialize a timeout action. MUST be called immediately after
* (stack or kmalloc) allocation of the action.
*
* @param ptr_act Pointer to the action to initialize.
*/
#define sos_time_init_action(ptr_act) \
({ (ptr_act)->tmo_prev = (ptr_act)->tmo_next = NULL; /* return */ SOS_OK; })
/**
* Add the given action in the timeout list, so that it will be
* triggered after the specified delay RELATIVE to the time when the
* function gets called. The action is always inserted in the list.
*
* @param act The action to be initialized by the function upon
* insertion in the timeout list.
*
* @param delay Delay until the action is fired. If 0, then it is
* fired at next timer IRQ. The action will be fired in X ticks, with
* X integer and >= delay.
*
* @param routine The timeout routine to call when the timeout will be
* triggered.
*
* @param routine_data The data available to the routine when it will
* be called.
*
* @note 'act' MUST remain valid until it is either fired or removed
* (with sos_time_remove_action)
*/
sos_ret_t
sos_time_register_action_relative(struct sos_timeout_action *act,
const struct sos_time *delay,
sos_timeout_routine_t *routine,
void *routine_data);
/**
* Add the given action in the timeout list, so that it will be
* triggered after the specified ABSOLUTE date (relative to system
* boot time). The action is always inserted in the list.
*
* @param act The action to be initialized by the function upon
* insertion in the timeout list.
*
* @param date Absolute date (relative to system boot time) when the
* action will be triggered.
*
* @param routine The timeout routine to call when the timeout will be
* triggered.
*
* @param routine_data The data available to the routine when it will
* be called.
*
* @note 'act' MUST remain valid until it is either fired or removed
* (with sos_time_remove_action)
*/
sos_ret_t
sos_time_register_action_absolute(struct sos_timeout_action *act,
const struct sos_time *date,
sos_timeout_routine_t *routine,
void *routine_data);
/**
* The action is removed and its timeout is updated to reflect the
* time remaining.
*/
sos_ret_t sos_time_unregister_action(struct sos_timeout_action *act);
/**
* Timer IRQ callback. Call and remove expired actions from the list.
*
* @note The use of this function is RESERVED (to timer IRQ)
*/
sos_ret_t sos_time_do_tick();
#endif /* _SOS_TIME_H_ */
