/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The OpenAirInterface Software Alliance licenses this file to You under
* the OAI Public License, Version 1.1 (the "License"); you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.openairinterface.org/?page_id=698
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*-------------------------------------------------------------------------------
* For more information about the OpenAirInterface (OAI) Software Alliance:
* contact@openairinterface.org
*/
/*****************************************************************************
Source nas_timer.c
Version 0.1
Date 2012/10/09
Product NAS stack
Subsystem Utilities
Author Frederic Maurel
Description Timer utilities
*****************************************************************************/
#include <pthread.h>
#include <assert.h>
#include <stdint.h>
#include <string.h> // memset
#include <stdlib.h> // malloc, free
#include <sys/time.h> // setitimer
#if defined(ENABLE_ITTI)
# include "intertask_interface.h"
#else
# include <signal.h>
# include <time.h> // clock_gettime
#endif
#include "nas_timer.h"
#include "commonDef.h"
#include "msc.h"
/****************************************************************************/
/**************** E X T E R N A L D E F I N I T I O N S ****************/
/****************************************************************************/
/****************************************************************************/
/******************* L O C A L D E F I N I T I O N S *******************/
/****************************************************************************/
/* Structure of an interval timer entry
* ------------------------------------
* The callback function is scheduled to be executed upon expiration of
* the timer that has been previously setup to the initial interval time
* value when the timer entry was allocated.
*/
typedef struct {
#if defined(ENABLE_ITTI)
long timer_id; /* Timer id returned by the timer API from ITTI */
#else
pthread_t pid; /* Thread identifier of the callback */
#endif
struct timeval itv; /* Initial interval timer value */
struct timeval tv; /* Interval timer value */
nas_timer_callback_t cb; /* Callback executed at timer expiration */
void *args; /* Callback argument parameters */
} nas_timer_entry_t;
/* Structure of a timer queue - list of active interval timer entries
* ------------------------------------------------------------------
* At any time, the first entry of the queue is always associated to the
* first timer that will come to expire. Upon timer expiration, the first
* entry is removed from the queue and freed.
*/
typedef struct _nas_timer_queue_t {
int id; /* Identifier of the current timer entry */
nas_timer_entry_t *entry; /* The current timer entry */
struct _nas_timer_queue_t *prev;/* The previous timer entry in the queue */
struct _nas_timer_queue_t *next;/* The next timer entry in the queue */
} timer_queue_t;
/* Structure of a timer database
* -----------------------------
* The timer database is managed to provide unique identifier to timer at
* startup and to maintain an ordered queue of active timer entries.
*/
typedef struct {
int timer_id; /* Identifier of the first available timer entry */
#define TIMER_DATABASE_SIZE 256
timer_queue_t tq[TIMER_DATABASE_SIZE];
timer_queue_t *head;/* Pointer to the first timer entry to be fired */
#if !defined(ENABLE_ITTI)
pthread_mutex_t mutex;
#endif
} nas_timer_database_t;
/*
* The timer database
*/
static nas_timer_database_t _nas_timer_db = {
0,
{},
NULL
#if !defined(ENABLE_ITTI)
, PTHREAD_MUTEX_INITIALIZER
#endif
};
#if defined(ENABLE_ITTI)
#define nas_timer_lock_db()
#define nas_timer_unlock_db()
#else
#define nas_timer_lock_db() pthread_mutex_lock(&_nas_timer_db.mutex)
#define nas_timer_unlock_db() pthread_mutex_unlock(&_nas_timer_db.mutex)
#endif
/*
* The handler executed whenever the system timer expires
*/
#if !defined(ENABLE_ITTI)
static void _nas_timer_handler(int signal);
#endif
/*
* -----------------------------------------------------------------------------
* Functions used to manage the timer database
* -----------------------------------------------------------------------------
*/
static void _nas_timer_db_init(void);
static int _nas_timer_db_get_id(void);
static int _nas_timer_db_is_active(int id);
static nas_timer_entry_t *_nas_timer_db_create_entry(long sec,
nas_timer_callback_t cb, void *args);
static void _nas_timer_db_delete_entry(int id);
static void _nas_timer_db_insert_entry(int id, nas_timer_entry_t *te);
static int _nas_timer_db_insert(timer_queue_t *entry);
static nas_timer_entry_t *_nas_timer_db_remove_entry(int id);
static int _nas_timer_db_remove(timer_queue_t *entry);
/*
* -----------------------------------------------------------------------------
* Operator functions for timeval structures
* -----------------------------------------------------------------------------
*/
static int _nas_timer_cmp(const struct timeval *a, const struct timeval *b);
static void _nas_timer_add(const struct timeval *a, const struct timeval *b,
struct timeval *result);
static int _nas_timer_sub(const struct timeval *a, const struct timeval *b,
struct timeval *result);
/****************************************************************************/
/****************** E X P O R T E D F U N C T I O N S ******************/
/****************************************************************************/
/****************************************************************************
** **
** Name: timer_init() **
** **
** Description: Initializes internal data used to manage timers **
** **
** Inputs: None **
** Others: None **
** **
** Outputs: None **
** Return: RETURNok, RETURNerror **
** Others: _nas_timer_db **
** **
***************************************************************************/
int nas_timer_init(void)
{
/* Initialize the timer database */
_nas_timer_db_init();
#if !defined(ENABLE_ITTI)
/* Setup the timer database handler */
struct sigaction act;
(void) memset (&act, 0, sizeof (act));
(void) sigfillset (&act.sa_mask);
(void) sigdelset (&act.sa_mask, SIGHUP);
(void) sigdelset (&act.sa_mask, SIGINT);
(void) sigdelset (&act.sa_mask, SIGTERM);
(void) sigdelset (&act.sa_mask, SIGILL);
(void) sigdelset (&act.sa_mask, SIGTRAP);
(void) sigdelset (&act.sa_mask, SIGIOT);
# ifndef LINUX
(void) sigdelset (&act.sa_mask, SIGEMT);
# endif
(void) sigdelset (&act.sa_mask, SIGFPE);
(void) sigdelset (&act.sa_mask, SIGBUS);
(void) sigdelset (&act.sa_mask, SIGSEGV);
(void) sigdelset (&act.sa_mask, SIGSYS);
act.sa_handler = _nas_timer_handler;
if ( sigaction (SIGALRM, &act, 0) < 0 ) {
return (RETURNerror);
}
#endif
return (RETURNok);
}
/****************************************************************************
** **
** Name: timer_start() **
** **
** Description: Schedules the execution of the given callback function **
** upon expiration of the specified time interval **
** **
** Inputs: sec: The value of the time interval in seconds **
** cb: Function executed upon timer expiration **
** args: Callback argument parameters **
** Others: None **
** **
** Outputs: None **
** Return: The timer identifier when successfully **
** started; NAS_TIMER_INACTIVE_ID otherwise. **
** Others: None **
** **
***************************************************************************/
int nas_timer_start(long sec, nas_timer_callback_t cb, void *args)
{
int id;
nas_timer_entry_t *te;
#if defined(ENABLE_ITTI)
int ret;
long timer_id;
#endif
/* Do not start null timer */
if (sec == 0) {
return (NAS_TIMER_INACTIVE_ID);
}
/* Get an identifier for the new timer entry */
id = _nas_timer_db_get_id();
if (id < 0) {
/* No available timer entry found */
return (NAS_TIMER_INACTIVE_ID);
}
/* Create a new timer entry */
te = _nas_timer_db_create_entry(sec, cb, args);
if (te == NULL) {
return (NAS_TIMER_INACTIVE_ID);
}
/* Insert the new entry into the timer queue */
_nas_timer_db_insert_entry(id, te);
#if defined(ENABLE_ITTI)
# if defined(NAS_MME)
ret = timer_setup(sec, 0, TASK_NAS_MME, INSTANCE_DEFAULT, TIMER_PERIODIC, args, &timer_id);
# else
ret = timer_setup(sec, 0, TASK_NAS_UE, INSTANCE_DEFAULT, TIMER_PERIODIC, args, &timer_id);
# endif
if (ret == -1) {
return NAS_TIMER_INACTIVE_ID;
}
te->timer_id = timer_id;
#endif
return (id);
}
/****************************************************************************
** **
** Name: timer_stop() **
** **
** Description: Stop the timer with the specified identifier **
** **
** Inputs: id: The identifier of the timer to be stopped **
** Others: None **
** **
** Outputs: None **
** Return: NAS_TIMER_INACTIVE_ID when successfully stop- **
** ped; The timer identifier otherwise. **
** Others: None **
** **
***************************************************************************/
int nas_timer_stop(int id)
{
/* Check if the timer entry is active */
if (_nas_timer_db_is_active(id)) {
nas_timer_entry_t *entry;
/* Remove the entry from the timer queue */
entry = _nas_timer_db_remove_entry(id);
#if defined(ENABLE_ITTI)
timer_remove(entry->timer_id);
#else
(void)entry;
#endif
/* Delete the timer entry */
_nas_timer_db_delete_entry(id);
return (NAS_TIMER_INACTIVE_ID);
}
return (id);
}
/****************************************************************************
** **
** Name: timer_restart() **
** **
** Description: Restart the timer with the specified identifier. The ti- **
** mer is scheduled to expire after the same period of time **
** and will execute the callback function that has been set **
** when it was started. **
** **
** Inputs: id: The identifier of the timer to be started **
** again **
** Others: None **
** **
** Outputs: None **
** Return: The timer identifier when successfully **
** re-started; NAS_TIMER_INACTIVE_ID otherwise. **
** Others: None **
** **
***************************************************************************/
int nas_timer_restart(int id)
{
/* Check if the timer entry is active */
if (_nas_timer_db_is_active(id)) {
/* Remove the entry from the timer queue */
nas_timer_entry_t *te = _nas_timer_db_remove_entry(id);
/* Initialize its interval timer value */
te->tv = te->itv;
/* Insert again the entry into the timer queue */
_nas_timer_db_insert_entry(id, te);
return (id);
}
return (NAS_TIMER_INACTIVE_ID);
}
/****************************************************************************/
/********************* L O C A L F U N C T I O N S *********************/
/****************************************************************************/
/****************************************************************************
** **
** Name: _nas_timer_handler() **
** **
** Description: The timer handler is executed whenever the system deli- **
** vers signal SIGALARM. It starts execution of the callback **
** function of the first entry within the queue of active **
** timer entries. The entry is not removed from the queue of **
** active timer entries and shall be explicitly removed when **
** the timer expires. **
** **
** Inputs: None **
** Others: None **
** **
** Outputs: None **
** Return: None **
** Others: _nas_timer_db **
** **
***************************************************************************/
#if defined(ENABLE_ITTI)
void nas_timer_handle_signal_expiry(long timer_id, void *arg_p)
{
/* Get the timer entry for which the system timer expired */
nas_timer_entry_t *te = _nas_timer_db.head->entry;
te->cb(te->args);
}
#else
static void _nas_timer_handler(int signal)
{
/* At least one timer has been started */
assert( (_nas_timer_db.head != NULL) && (_nas_timer_db.head->entry != NULL) );
/* Get the timer entry for which the system timer expired */
nas_timer_entry_t *te = _nas_timer_db.head->entry;
threadCreate (&te->pid, te->cb, te->args, "nas-timer", -1, OAI_PRIORITY_RT_LOW);
void *result = NULL;
(void) pthread_join(te->pid, &result);
if (result) {
free(result);
}
}
#endif
/*
* -----------------------------------------------------------------------------
* Functions used to manage the timer database
* -----------------------------------------------------------------------------
*/
/****************************************************************************
** **
** Name: _nas_timer_db_init() **
** **
** Description: Initializes the timer database **
** **
** Inputs: None **
** Others: None **
** **
** Outputs: None **
** Return: None **
** Others: _nas_timer_db **
** **
***************************************************************************/
static void _nas_timer_db_init(void)
{
int i;
for (i = 0; i < TIMER_DATABASE_SIZE; i++) {
_nas_timer_db.tq[i].id = NAS_TIMER_INACTIVE_ID;
}
}
/****************************************************************************
** **
** Name: _nas_timer_db_get_id() **
** **
** Description: Gets the identifier of the first available timer entry in **
** the queue of active timer entries **
** **
** Inputs: None **
** Others: _nas_timer_db **
** **
** Outputs: None **
** Return: The identifier of the first available **
** timer entry if the queue of active timers **
** is not full; -1 otherwise. **
** Others: _nas_timer_db **
** **
***************************************************************************/
static int _nas_timer_db_get_id(void)
{
int i;
/* Search from the current timer entry to the last timer entry */
for (i = _nas_timer_db.timer_id; i < TIMER_DATABASE_SIZE; i++) {
if (_nas_timer_db.tq[i].id < 0 ) {
_nas_timer_db.timer_id = i+1;
return i;
}
}
/* Search from the first timer entry to the current timer entry */
for (i = 0; i < _nas_timer_db.timer_id; i++) {
if (_nas_timer_db.tq[i].id < 0 ) {
_nas_timer_db.timer_id = i+1;
return i;
}
}
/* No available timer entry found */
return (-1);
}
/****************************************************************************
** **
** Name: _nas_timer_db_is_active() **
** **
** Description: Checks whether the entry with the given identifier is **
** active within the queue of active timer entries **
** **
** Inputs: id: Identifier of the timer entry to check **
** Others: _nas_timer_db **
** **
** Outputs: None **
** Return: TRUE if the timer entry is active; FALSE **
** if it is not an active timer entry. **
** Others: None **
** **
***************************************************************************/
static int _nas_timer_db_is_active(int id)
{
return ( (id != NAS_TIMER_INACTIVE_ID) &&
(_nas_timer_db.tq[id].id != NAS_TIMER_INACTIVE_ID) );
}
/****************************************************************************
** **
** Name: _nas_timer_db_create_entry() **
** **
** Description: Creates a new timer entry **
** **
** Inputs: sec: Time interval value **
** cb: Function executed upon timer expiration **
** args: Callback argument parameters **
** Others: None **
** **
** Outputs: None **
** Return: A pointer to the new timer entry if **
** successfully allocated; NULL otherwise **
** Others: None **
** **
***************************************************************************/
static nas_timer_entry_t *_nas_timer_db_create_entry(
long sec, nas_timer_callback_t cb,
void *args)
{
nas_timer_entry_t *te = (nas_timer_entry_t *)malloc(sizeof(nas_timer_entry_t));
if (te != NULL) {
te->itv.tv_sec = sec;
te->itv.tv_usec = 0;
te->tv.tv_sec = te->itv.tv_sec;
te->tv.tv_usec = te->itv.tv_usec;
te->cb = cb;
te->args = args;
}
return (te);
}
/****************************************************************************
** **
** Name: _nas_timer_db_delete_entry() **
** **
** Description: Deletes the entry with the given identifier from the ti- **
** mer database. **
** **
** Inputs: id: Identifier of the entry to be deleted **
** Others: None **
** **
** Outputs: None **
** Return: None **
** Others: _nas_timer_db **
** **
***************************************************************************/
static void _nas_timer_db_delete_entry(int id)
{
/* The identifier of the timer is valid within the timer queue */
assert(_nas_timer_db.tq[id].id == id);
/* Delete the timer entry from the queue */
_nas_timer_db.tq[id].id = NAS_TIMER_INACTIVE_ID;
free(_nas_timer_db.tq[id].entry);
_nas_timer_db.tq[id].entry = NULL;
}
/****************************************************************************
** **
** Name: _nas_timer_db_insert_entry() **
** **
** Description: Inserts the entry with the given identifier into the **
** queue of active timer entries and restarts the system **
** timer if the new entry is the next entry for which the **
** timer should be scheduled to expire. **
** **
** Inputs: id: Identifier of the new entry **
** te: Pointer to the entry to be inserted **
** Others: None **
** **
** Outputs: None **
** Return: None **
** Others: _nas_timer_db **
** **
***************************************************************************/
static void _nas_timer_db_insert_entry(int id, nas_timer_entry_t *te)
{
struct itimerval it;
struct timespec ts;
struct timeval current_time;
int restart;
/* Enqueue the new timer entry */
_nas_timer_db.tq[id].id = id;
_nas_timer_db.tq[id].entry = te;
/* Save its interval timer value */
it.it_interval.tv_sec = it.it_interval.tv_usec = 0;
it.it_value = te->tv;
/* Update its interval timer value */
clock_gettime(CLOCK_MONOTONIC, &ts);
current_time.tv_sec = ts.tv_sec;
current_time.tv_usec = ts.tv_nsec/1000;
/* tv = tv + time() */
_nas_timer_add(&te->tv, ¤t_time, &te->tv);
/* Insert the new timer entry into the list of active entries */
nas_timer_lock_db();
restart = _nas_timer_db_insert(&_nas_timer_db.tq[id]);
nas_timer_unlock_db();
#if !defined(ENABLE_ITTI)
if (restart) {
/* The new entry is the first entry of the list;
* restart the system timer */
setitimer(ITIMER_REAL, &it, 0);
}
#else
(void)(restart);
#endif
}
static int _nas_timer_db_insert(timer_queue_t *entry)
{
timer_queue_t *prev, *next; /* previous and next entry in the list */
/*
* Search the list of timer entries for the first entry with an interval
* timer value greater than the interval timer value of the new timer entry
*/
for (prev = NULL, next = _nas_timer_db.head; next != NULL; next = next->next) {
if (_nas_timer_cmp(&next->entry->tv, &entry->entry->tv) > 0) {
break;
}
prev = next;
}
/* Insert the new entry in the list of active timer entries */
/* prev <-- entry --> next */
entry->prev = prev;
entry->next = next;
/* Update the pointer from the previous entry */
if (entry->next != NULL) {
/* prev <-- entry <--> next */
entry->next->prev = entry;
}
/* Update the pointer from the next entry */
if (entry->prev != NULL) {
/* prev <--> entry <--> next */
entry->prev->next = entry;
} else {
/* The new entry is the first entry of the list */
_nas_timer_db.head = entry;
return TRUE;
}
/* The new entry is NOT the first entry of the list */
return FALSE;
}
/****************************************************************************
** **
** Name: _nas_timer_db_remove_entry() **
** **
** Description: Removes the entry with the given identifier from the **
** queue of active timer entries and restarts the system **
** timer if the entry was the next entry for which the timer **
** was scheduled to expire. **
** **
** Inputs: id: Identifier of the entry to be removed **
** Others: None **
** **
** Outputs: None **
** Return: A pointer to the removed entry **
** Others: _nas_timer_db **
** **
***************************************************************************/
static nas_timer_entry_t *_nas_timer_db_remove_entry(int id)
{
int restart;
/* The identifier of the timer is valid within the timer queue */
assert(_nas_timer_db.tq[id].id == id);
/* Remove the timer entry from the list of active entries */
nas_timer_lock_db();
restart = _nas_timer_db_remove(&_nas_timer_db.tq[id]);
nas_timer_unlock_db();
if (restart) {
int rc;
/* The entry was the first entry of the list;
* the system timer needs to be restarted */
struct itimerval it;
struct timeval tv;
struct timespec ts;
it.it_interval.tv_sec = it.it_interval.tv_usec = 0;
clock_gettime(CLOCK_MONOTONIC, &ts);
tv.tv_sec = ts.tv_sec;
tv.tv_usec = ts.tv_nsec/1000;
/* tv = tv - time() */
rc = _nas_timer_sub(&_nas_timer_db.head->entry->tv, &tv, &it.it_value);
#if defined(ENABLE_ITTI)
timer_remove(_nas_timer_db.head->entry->timer_id);
(void) (rc);
#else
if (rc < 0) {
/* The system timer should have already expired */
_nas_timer_handler(SIGALRM);
} else {
/* Restart the system timer */
setitimer(ITIMER_REAL, &it, 0);
}
#endif
}
/* Return a pointer to the removed entry */
return (_nas_timer_db.tq[id].entry);
}
static int _nas_timer_db_remove(timer_queue_t *entry)
{
/* Update the pointer from the previous entry */
/* prev ---> entry ---> next */
/* prev <--- entry <--- next */
if (entry->next != NULL) {
/* prev ---> entry ---> next */
/* prev <-------------- next */
entry->next->prev = entry->prev;
}
/* Update the pointer from the next entry */
if (entry->prev != NULL) {
/* prev --------------> next */
/* prev <-------------- next */
entry->prev->next = entry->next;
} else {
/* The entry was the first entry of the list */
_nas_timer_db.head = entry->next;
if (_nas_timer_db.head != NULL) {
/* Other timers are scheduled to expire */
return TRUE;
}
#if !defined(ENABLE_ITTI)
{
/* No more timer is scheduled to expire; stop the system timer */
struct itimerval it;
it.it_interval.tv_sec = it.it_interval.tv_usec = 0;
it.it_value.tv_sec = it.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &it, 0);
return FALSE;
}
#endif
}
/* The entry was NOT the first entry of the list */
return FALSE;
}
/*
* -----------------------------------------------------------------------------
* Operator functions for timeval structures
* -----------------------------------------------------------------------------
*/
/****************************************************************************
** **
** Name: _nas_timer_cmp() **
** **
** Description: Performs timeval comparaison **
** **
** Inputs: a: The first timeval structure **
** b: The second timeval structure **
** Others: None **
** **
** Outputs: None **
** Return: -1 if a < b; 1 if a > b; 0 if a == b **
** Others: None **
** **
***************************************************************************/
static int _nas_timer_cmp(const struct timeval *a, const struct timeval *b)
{
if (a->tv_sec < b->tv_sec) {
return -1;
} else if (a->tv_sec > b->tv_sec) {
return 1;
} else if (a->tv_usec < b->tv_usec) {
return -1;
} else if (a->tv_usec > b->tv_usec) {
return 1;
}
return 0;
}
/****************************************************************************
** **
** Name: _nas_timer_add() **
** **
** Description: Performs timeval addition **
** **
** Inputs: a: The first timeval structure **
** b: The second timeval structure **
** Others: None **
** **
** Outputs: result: result = timeval(a + b) **
** Return: None **
** Others: None **
** **
***************************************************************************/
static void _nas_timer_add(const struct timeval *a, const struct timeval *b,
struct timeval *result)
{
result->tv_sec = a->tv_sec + b->tv_sec;
result->tv_usec = a->tv_usec + b->tv_usec;
if (result->tv_usec > 1000000) {
result->tv_sec++;
result->tv_usec -= 1000000;
}
}
/****************************************************************************
** **
** Name: _nas_timer_sub() **
** **
** Description: Performs timeval substraction **
** **
** Inputs: a: The first timeval structure **
** b: The second timeval structure **
** Others: None **
** **
** Outputs: result: a >= b, result = timeval(a - b) **
** Return: -1 if a < b; 0 otherwise **
** Others: None **
** **
***************************************************************************/
static int _nas_timer_sub(const struct timeval *a, const struct timeval *b,
struct timeval *result)
{
if (_nas_timer_cmp(a,b) > 0 ) {
result->tv_sec = a->tv_sec - b->tv_sec;
result->tv_usec = a->tv_usec - b->tv_usec;
if (result->tv_usec < 0) {
result->tv_sec--;
result->tv_usec += 1000000;
}
return 0;
}
return -1;
}