From a8968330aff45e0b8cf278f49fa337d5fcb9bfd8 Mon Sep 17 00:00:00 2001 From: Alex AUVOLAT Date: Fri, 28 Mar 2014 17:09:15 +0100 Subject: Import and compile code for article 6.5 --- sos-code-article6.5/sos/time.h | 222 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 222 insertions(+) create mode 100644 sos-code-article6.5/sos/time.h (limited to 'sos-code-article6.5/sos/time.h') diff --git a/sos-code-article6.5/sos/time.h b/sos-code-article6.5/sos/time.h new file mode 100644 index 0000000..7d3a90b --- /dev/null +++ b/sos-code-article6.5/sos/time.h @@ -0,0 +1,222 @@ +/* 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 +#include +#include + + +/* ======================================================================= + * 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_ */ -- cgit v1.2.3