Mon Nov 24 15:34:51 2008

Asterisk developer's documentation


sched.h File Reference

Scheduler Routines (derived from cheops). More...

Go to the source code of this file.

Defines

#define ast_sched_add_object(obj, con, when, callback)   ast_sched_add((con),(when),(callback), ASTOBJ_REF((obj)))
 Convenience macro for objects and reference (add).
#define AST_SCHED_CB(a)   ((ast_sched_cb)(a))
#define AST_SCHED_DEL(sched, id)
 a loop construct to ensure that the scheduled task get deleted. The idea is that if we loop attempting to remove the scheduled task, then whatever callback had been running will complete and reinsert the task into the scheduler.
#define ast_sched_del_object(obj, destructor, con, id)
 Convenience macro for objects and reference (del).
#define AST_SCHED_DEL_SPINLOCK(sched, id, lock)
#define SCHED_MAX_CACHE   128
 Max num of schedule structs.

Typedefs

typedef int(*) ast_sched_cb (const void *data)
 callback for a cheops scheduler A cheops scheduler callback takes a pointer with callback data and

Functions

int ast_sched_add (struct sched_context *con, int when, ast_sched_cb callback, const void *data)
 Adds a scheduled event Schedule an event to take place at some point in the future. callback will be called with data as the argument, when milliseconds into the future (approximately) If callback returns 0, no further events will be re-scheduled.
int ast_sched_add_variable (struct sched_context *con, int when, ast_sched_cb callback, const void *data, int variable)
 Schedule callback(data) to happen when ms into the future.
int ast_sched_del (struct sched_context *con, int id)
 Deletes a scheduled event Remove this event from being run. A procedure should not remove its own event, but return 0 instead.
void ast_sched_dump (const struct sched_context *con)
 Dumps the scheduler contents Debugging: Dump the contents of the scheduler to stderr.
int ast_sched_runq (struct sched_context *con)
 Runs the queue.
int ast_sched_wait (struct sched_context *con)
 Determines number of seconds until the next outstanding event to take place Determine the number of seconds until the next outstanding event should take place, and return the number of milliseconds until it needs to be run. This value is perfect for passing to the poll call.
long ast_sched_when (struct sched_context *con, int id)
 Returns the number of seconds before an event takes place.
sched_contextsched_context_create (void)
 New schedule context.
void sched_context_destroy (struct sched_context *c)
 destroys a schedule context Destroys (free's) the given sched_context structure


Detailed Description

Scheduler Routines (derived from cheops).

Definition in file sched.h.


Define Documentation

#define ast_sched_add_object ( obj,
con,
when,
callback   )     ast_sched_add((con),(when),(callback), ASTOBJ_REF((obj)))

Convenience macro for objects and reference (add).

Definition at line 180 of file sched.h.

#define AST_SCHED_CB (  )     ((ast_sched_cb)(a))

Definition at line 100 of file sched.h.

#define AST_SCHED_DEL ( sched,
id   ) 

a loop construct to ensure that the scheduled task get deleted. The idea is that if we loop attempting to remove the scheduled task, then whatever callback had been running will complete and reinsert the task into the scheduler.

Since macro expansion essentially works like pass-by-name parameter passing, this macro will still work correctly even if the id of the task to delete changes. This holds as long as the name of the id which could change is passed to the macro and not a copy of the value of the id.

Definition at line 50 of file sched.h.

Referenced by __oh323_destroy(), __oh323_update_info(), __sip_destroy(), __sip_semi_ack(), ack_trans(), ast_closestream(), ast_rtcp_write_rr(), ast_rtcp_write_sr(), ast_rtp_destroy(), ast_rtp_stop(), auth_fail(), build_gateway(), build_peer(), destroy_packet(), destroy_packets(), destroy_peer(), dnsmgr_start_refresh(), do_reload(), handle_command_response(), handle_request_invite(), handle_response_invite(), handle_response_peerpoke(), handle_response_register(), iax2_ack_registry(), iax2_destroy_helper(), iax2_do_register(), iax2_dprequest(), iax2_frame_free(), iax2_provision(), make_trunk(), mgcpsock_read(), misdn_tasks_remove(), parse_register_contact(), qualify_peer(), receive_digit(), reg_source_db(), schedule_delivery(), sip_call(), sip_hangup(), sip_poke_all_peers(), sip_poke_noanswer(), sip_poke_peer(), sip_registry_destroy(), sip_scheddestroy(), sip_send_all_registers(), socket_process(), submit_unscheduled_batch(), transmit_register(), and update_jbsched().

#define ast_sched_del_object ( obj,
destructor,
con,
id   ) 

Convenience macro for objects and reference (del).

Definition at line 186 of file sched.h.

#define AST_SCHED_DEL_SPINLOCK ( sched,
id,
lock   ) 

Definition at line 63 of file sched.h.

Referenced by iax2_destroy().

#define SCHED_MAX_CACHE   128

Max num of schedule structs.

Note:
The max number of schedule structs to keep around for use. Undefine to disable schedule structure caching. (Only disable this on very low memory machines)

Definition at line 36 of file sched.h.

Referenced by sched_release().


Typedef Documentation

typedef int(*) ast_sched_cb(const void *data)

callback for a cheops scheduler A cheops scheduler callback takes a pointer with callback data and

Returns:
returns a 0 if it should not be run again, or non-zero if it should be rescheduled to run again

Definition at line 99 of file sched.h.


Function Documentation

int ast_sched_add ( struct sched_context con,
int  when,
ast_sched_cb  callback,
const void *  data 
)

Adds a scheduled event Schedule an event to take place at some point in the future. callback will be called with data as the argument, when milliseconds into the future (approximately) If callback returns 0, no further events will be re-scheduled.

Parameters:
con Scheduler context to add
when how many milliseconds to wait for event to occur
callback function to call when the amount of time expires
data data to pass to the callback
Returns:
Returns a schedule item ID on success, -1 on failure

Definition at line 247 of file sched.c.

References ast_sched_add_variable().

Referenced by __oh323_update_info(), ast_readaudio_callback(), ast_readvideo_callback(), ast_rtp_raw_write(), ast_rtp_read(), do_register(), do_reload(), dundi_discover(), dundi_query(), dundi_send(), handle_command_response(), handle_response_invite(), handle_response_peerpoke(), handle_response_register(), iax2_sched_add(), mgcp_postrequest(), parse_register_contact(), populate_addr(), precache_trans(), qualify_peer(), receive_digit(), reg_source_db(), sip_call(), sip_poke_all_peers(), sip_poke_noanswer(), sip_poke_peer(), sip_scheddestroy(), sip_send_all_registers(), submit_scheduled_batch(), submit_unscheduled_batch(), and transmit_register().

00248 {
00249    return ast_sched_add_variable(con, when, callback, data, 0);
00250 }

int ast_sched_add_variable ( struct sched_context con,
int  when,
ast_sched_cb  callback,
const void *  data,
int  variable 
)

Schedule callback(data) to happen when ms into the future.

Adds a scheduled event with rescheduling support

Parameters:
con Scheduler context to add
when how many milliseconds to wait for event to occur
callback function to call when the amount of time expires
data data to pass to the callback
variable If true, the result value of callback function will be used for rescheduling Schedule an event to take place at some point in the future. Callback will be called with data as the argument, when milliseconds into the future (approximately) If callback returns 0, no further events will be re-scheduled
Returns:
Returns a schedule item ID on success, -1 on failure

Definition at line 214 of file sched.c.

References ast_log(), ast_mutex_lock(), ast_mutex_unlock(), ast_sched_dump(), DEBUG, sched_context::eventcnt, sched_context::lock, LOG_DEBUG, LOG_NOTICE, option_debug, sched_alloc(), sched_release(), sched_settime(), and schedule().

Referenced by __sip_reliable_xmit(), _misdn_tasks_add_variable(), ast_sched_add(), dnsmgr_start_refresh(), and do_reload().

00215 {
00216    struct sched *tmp;
00217    int res = -1;
00218    DEBUG(ast_log(LOG_DEBUG, "ast_sched_add()\n"));
00219    if (!when) {
00220       ast_log(LOG_NOTICE, "Scheduled event in 0 ms?\n");
00221       return -1;
00222    }
00223    ast_mutex_lock(&con->lock);
00224    if ((tmp = sched_alloc(con))) {
00225       tmp->id = con->eventcnt++;
00226       tmp->callback = callback;
00227       tmp->data = data;
00228       tmp->resched = when;
00229       tmp->variable = variable;
00230       tmp->when = ast_tv(0, 0);
00231       if (sched_settime(&tmp->when, when)) {
00232          sched_release(con, tmp);
00233       } else {
00234          schedule(con, tmp);
00235          res = tmp->id;
00236       }
00237    }
00238 #ifdef DUMP_SCHEDULER
00239    /* Dump contents of the context while we have the lock so nothing gets screwed up by accident. */
00240    if (option_debug)
00241       ast_sched_dump(con);
00242 #endif
00243    ast_mutex_unlock(&con->lock);
00244    return res;
00245 }

int ast_sched_del ( struct sched_context con,
int  id 
)

Deletes a scheduled event Remove this event from being run. A procedure should not remove its own event, but return 0 instead.

Parameters:
con scheduling context to delete item from
id ID of the scheduled item to delete
Returns:
Returns 0 on success, -1 on failure

Definition at line 259 of file sched.c.

References ast_assert, AST_LIST_REMOVE_CURRENT, AST_LIST_TRAVERSE_SAFE_BEGIN, AST_LIST_TRAVERSE_SAFE_END, ast_log(), ast_mutex_lock(), ast_mutex_unlock(), ast_sched_dump(), DEBUG, LOG_DEBUG, option_debug, s, and sched_release().

Referenced by __sip_ack(), delete_users(), iax2_poke_peer(), reg_source_db(), sip_cancel_destroy(), socket_process(), unlink_peer(), and update_registry().

00263 {
00264    struct sched *s;
00265 
00266    DEBUG(ast_log(LOG_DEBUG, "ast_sched_del()\n"));
00267    
00268    ast_mutex_lock(&con->lock);
00269    AST_LIST_TRAVERSE_SAFE_BEGIN(&con->schedq, s, list) {
00270       if (s->id == id) {
00271          AST_LIST_REMOVE_CURRENT(&con->schedq, list);
00272          con->schedcnt--;
00273          sched_release(con, s);
00274          break;
00275       }
00276    }
00277    AST_LIST_TRAVERSE_SAFE_END
00278 
00279 #ifdef DUMP_SCHEDULER
00280    /* Dump contents of the context while we have the lock so nothing gets screwed up by accident. */
00281    if (option_debug)
00282       ast_sched_dump(con);
00283 #endif
00284    ast_mutex_unlock(&con->lock);
00285 
00286    if (!s) {
00287       if (option_debug)
00288          ast_log(LOG_DEBUG, "Attempted to delete nonexistent schedule entry %d!\n", id);
00289 #ifndef AST_DEVMODE
00290       ast_assert(s != NULL);
00291 #else
00292       _ast_assert(0, "s != NULL", file, line, function);
00293 #endif
00294       return -1;
00295    }
00296    
00297    return 0;
00298 }

void ast_sched_dump ( const struct sched_context con  ) 

Dumps the scheduler contents Debugging: Dump the contents of the scheduler to stderr.

Parameters:
con Context to dump

Definition at line 301 of file sched.c.

References AST_LIST_TRAVERSE, ast_log(), ast_tvsub(), sched_context::eventcnt, LOG_DEBUG, and sched_context::schedcnt.

Referenced by ast_sched_add_variable(), and ast_sched_del().

00302 {
00303    struct sched *q;
00304    struct timeval tv = ast_tvnow();
00305 #ifdef SCHED_MAX_CACHE
00306    ast_log(LOG_DEBUG, "Asterisk Schedule Dump (%d in Q, %d Total, %d Cache)\n", con->schedcnt, con->eventcnt - 1, con->schedccnt);
00307 #else
00308    ast_log(LOG_DEBUG, "Asterisk Schedule Dump (%d in Q, %d Total)\n", con->schedcnt, con->eventcnt - 1);
00309 #endif
00310 
00311    ast_log(LOG_DEBUG, "=============================================================\n");
00312    ast_log(LOG_DEBUG, "|ID    Callback          Data              Time  (sec:ms)   |\n");
00313    ast_log(LOG_DEBUG, "+-----+-----------------+-----------------+-----------------+\n");
00314    AST_LIST_TRAVERSE(&con->schedq, q, list) {
00315       struct timeval delta = ast_tvsub(q->when, tv);
00316 
00317       ast_log(LOG_DEBUG, "|%.4d | %-15p | %-15p | %.6ld : %.6ld |\n", 
00318          q->id,
00319          q->callback,
00320          q->data,
00321          delta.tv_sec,
00322          (long int)delta.tv_usec);
00323    }
00324    ast_log(LOG_DEBUG, "=============================================================\n");
00325    
00326 }

int ast_sched_runq ( struct sched_context con  ) 

Runs the queue.

Parameters:
con Scheduling context to run Run the queue, executing all callbacks which need to be performed at this time.
con context to act upon
Returns:
Returns the number of events processed.

Definition at line 331 of file sched.c.

References AST_LIST_EMPTY, AST_LIST_FIRST, AST_LIST_REMOVE_HEAD, ast_log(), ast_mutex_lock(), ast_mutex_unlock(), ast_tvadd(), DEBUG, sched_context::lock, LOG_DEBUG, sched_release(), sched_settime(), sched_context::schedcnt, and schedule().

Referenced by background_detect_exec(), do_cdr(), do_monitor(), do_refresh(), misdn_tasks_thread_func(), network_thread(), reload_config(), sched_thread(), speech_background(), wait_for_winner(), and waitstream_core().

00332 {
00333    struct sched *current;
00334    struct timeval tv;
00335    int numevents;
00336    int res;
00337 
00338    DEBUG(ast_log(LOG_DEBUG, "ast_sched_runq()\n"));
00339       
00340    ast_mutex_lock(&con->lock);
00341 
00342    for (numevents = 0; !AST_LIST_EMPTY(&con->schedq); numevents++) {
00343       /* schedule all events which are going to expire within 1ms.
00344        * We only care about millisecond accuracy anyway, so this will
00345        * help us get more than one event at one time if they are very
00346        * close together.
00347        */
00348       tv = ast_tvadd(ast_tvnow(), ast_tv(0, 1000));
00349       if (ast_tvcmp(AST_LIST_FIRST(&con->schedq)->when, tv) != -1)
00350          break;
00351       
00352       current = AST_LIST_REMOVE_HEAD(&con->schedq, list);
00353       con->schedcnt--;
00354 
00355       /*
00356        * At this point, the schedule queue is still intact.  We
00357        * have removed the first event and the rest is still there,
00358        * so it's permissible for the callback to add new events, but
00359        * trying to delete itself won't work because it isn't in
00360        * the schedule queue.  If that's what it wants to do, it 
00361        * should return 0.
00362        */
00363          
00364       ast_mutex_unlock(&con->lock);
00365       res = current->callback(current->data);
00366       ast_mutex_lock(&con->lock);
00367          
00368       if (res) {
00369          /*
00370           * If they return non-zero, we should schedule them to be
00371           * run again.
00372           */
00373          if (sched_settime(&current->when, current->variable? res : current->resched)) {
00374             sched_release(con, current);
00375          } else
00376             schedule(con, current);
00377       } else {
00378          /* No longer needed, so release it */
00379          sched_release(con, current);
00380       }
00381    }
00382 
00383    ast_mutex_unlock(&con->lock);
00384    
00385    return numevents;
00386 }

int ast_sched_wait ( struct sched_context con  ) 

Determines number of seconds until the next outstanding event to take place Determine the number of seconds until the next outstanding event should take place, and return the number of milliseconds until it needs to be run. This value is perfect for passing to the poll call.

Parameters:
con context to act upon
Returns:
Returns "-1" if there is nothing there are no scheduled events (and thus the poll should not timeout)

Definition at line 148 of file sched.c.

References AST_LIST_EMPTY, AST_LIST_FIRST, ast_log(), ast_mutex_lock(), ast_mutex_unlock(), DEBUG, sched_context::lock, and LOG_DEBUG.

Referenced by background_detect_exec(), do_cdr(), do_monitor(), do_refresh(), misdn_tasks_thread_func(), network_thread(), sched_thread(), speech_background(), wait_for_winner(), and waitstream_core().

00149 {
00150    int ms;
00151 
00152    DEBUG(ast_log(LOG_DEBUG, "ast_sched_wait()\n"));
00153 
00154    ast_mutex_lock(&con->lock);
00155    if (AST_LIST_EMPTY(&con->schedq)) {
00156       ms = -1;
00157    } else {
00158       ms = ast_tvdiff_ms(AST_LIST_FIRST(&con->schedq)->when, ast_tvnow());
00159       if (ms < 0)
00160          ms = 0;
00161    }
00162    ast_mutex_unlock(&con->lock);
00163 
00164    return ms;
00165 }

long ast_sched_when ( struct sched_context con,
int  id 
)

Returns the number of seconds before an event takes place.

Parameters:
con Context to use
id Id to dump

Definition at line 388 of file sched.c.

References AST_LIST_TRAVERSE, ast_log(), ast_mutex_lock(), ast_mutex_unlock(), DEBUG, sched_context::lock, LOG_DEBUG, and s.

Referenced by _sip_show_peer(), handle_cli_status(), and parse_register_contact().

00389 {
00390    struct sched *s;
00391    long secs = -1;
00392    DEBUG(ast_log(LOG_DEBUG, "ast_sched_when()\n"));
00393 
00394    ast_mutex_lock(&con->lock);
00395    AST_LIST_TRAVERSE(&con->schedq, s, list) {
00396       if (s->id == id)
00397          break;
00398    }
00399    if (s) {
00400       struct timeval now = ast_tvnow();
00401       secs = s->when.tv_sec - now.tv_sec;
00402    }
00403    ast_mutex_unlock(&con->lock);
00404    
00405    return secs;
00406 }

struct sched_context* sched_context_create ( void   ) 

New schedule context.

Note:
Create a scheduling context
Returns:
Returns a malloc'd sched_context structure, NULL on failure

Definition at line 75 of file sched.c.

References ast_calloc, and ast_mutex_init().

Referenced by ast_cdr_engine_init(), ast_channel_alloc(), dnsmgr_init(), load_module(), and misdn_tasks_init().

00076 {
00077    struct sched_context *tmp;
00078 
00079    if (!(tmp = ast_calloc(1, sizeof(*tmp))))
00080       return NULL;
00081 
00082    ast_mutex_init(&tmp->lock);
00083    tmp->eventcnt = 1;
00084    
00085    return tmp;
00086 }

void sched_context_destroy ( struct sched_context c  ) 

destroys a schedule context Destroys (free's) the given sched_context structure

Parameters:
c Context to free
Returns:
Returns 0 on success, -1 on failure

Definition at line 88 of file sched.c.

References AST_LIST_REMOVE_HEAD, ast_mutex_destroy(), ast_mutex_lock(), ast_mutex_unlock(), free, sched_context::lock, and s.

Referenced by __unload_module(), ast_channel_alloc(), ast_channel_free(), ast_hangup(), load_module(), misdn_tasks_destroy(), and unload_module().

00089 {
00090    struct sched *s;
00091 
00092    ast_mutex_lock(&con->lock);
00093 
00094 #ifdef SCHED_MAX_CACHE
00095    /* Eliminate the cache */
00096    while ((s = AST_LIST_REMOVE_HEAD(&con->schedc, list)))
00097       free(s);
00098 #endif
00099 
00100    /* And the queue */
00101    while ((s = AST_LIST_REMOVE_HEAD(&con->schedq, list)))
00102       free(s);
00103    
00104    /* And the context */
00105    ast_mutex_unlock(&con->lock);
00106    ast_mutex_destroy(&con->lock);
00107    free(con);
00108 }


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