Asterisk
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asterisk
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minor comment changes, code rearrangement and field renaming

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to minimize diffs with future modifications.

The current implementation is problematic for the following reasons:
+ all insertions are O(N) because the event list does not have a tail
  pointer;
+ there is only a single lock protecting both session and users queues.
+ the implementation of the queue itself is not documented.
  I think i have figured it out, more or less, but am unclear on
  whether there is proper locking in place

The rewrite (which i have working locally) uses a tailq so insertions
are O(1), separate locks for the event and session queues, and has
a documented implementation so hopefully we can figure out if/where
bug exist.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@45753 65c4cc65-6c06-0410-ace0-fbb531ad65f3
1.6.0
Luigi Rizzo 19 years ago
parent d6602b1b5e
commit edd8e11889
1 changed files with 27 additions and 29 deletions
Show Stats Download Patch File Download Diff File

56
main/manager.c
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@ -126,11 +126,13 @@ struct mansession {
char inbuf[AST_MAX_MANHEADER_LEN]; /*!< Buffer */
int inlen; /*!< number of buffered bytes */
int send_events; /*!< XXX what ? */
struct eventqent *eventq; /*!< last event processed. */
struct eventqent *last_ev; /*!< last event processed. */
int writetimeout; /*!< Timeout for ast_carefulwrite() */
AST_LIST_ENTRY(mansession) list;
};
#define NEW_EVENT(m) (m->last_ev->next)
static AST_LIST_HEAD_STATIC(sessions, mansession);
/*! \brief user descriptor, as read from the config file.
@ -512,7 +514,7 @@ static struct eventqent *unref_event(struct eventqent *e)
static void free_session(struct mansession *s)
{
struct eventqent *eqe = s->eventq;
struct eventqent *eqe = s->last_ev;
if (s->fd > -1)
close(s->fd);
if (s->outputstr)
@ -945,7 +947,6 @@ static int action_waitevent(struct mansession *s, struct message *m)
int x;
int needexit = 0;
time_t now;
struct eventqent *eqe;
char *id = astman_get_header(m,"ActionID");
char idText[256] = "";
@ -977,7 +978,7 @@ static int action_waitevent(struct mansession *s, struct message *m)
ast_log(LOG_DEBUG, "Starting waiting for an event!\n");
for (x=0; ((x < timeout) || (timeout < 0)); x++) {
ast_mutex_lock(&s->__lock);
if (s->eventq && s->eventq->next)
if (s->last_ev && s->last_ev->next)
needexit = 1;
if (s->waiting_thread != pthread_self())
needexit = 1;
@ -997,16 +998,14 @@ static int action_waitevent(struct mansession *s, struct message *m)
ast_log(LOG_DEBUG, "Finished waiting for an event!\n");
ast_mutex_lock(&s->__lock);
if (s->waiting_thread == pthread_self()) {
struct eventqent *eqe;
astman_send_response(s, m, "Success", "Waiting for Event...");
/* Only show events if we're the most recent waiter */
while(s->eventq->next) {
eqe = s->eventq->next;
while ( (eqe = NEW_EVENT(s)) ) {
if (((s->readperm & eqe->category) == eqe->category) &&
((s->send_events & eqe->category) == eqe->category)) {
astman_append(s, "%s", eqe->eventdata);
}
unref_event(s->eventq);
s->eventq = eqe;
s->last_ev = unref_event(s->last_ev);
}
astman_append(s,
"Event: WaitEventComplete\r\n"
@ -1708,16 +1707,16 @@ static int process_events(struct mansession *s)
if (s->fd > -1) {
struct eventqent *eqe;
if (!s->eventq)
s->eventq = master_eventq;
while( (eqe = s->eventq->next) ) {
if (!s->last_ev)
s->last_ev = master_eventq;
while ( (eqe = NEW_EVENT(s)) ) {
if ((s->authenticated && (s->readperm & eqe->category) == eqe->category) &&
((s->send_events & eqe->category) == eqe->category)) {
if (!ret && ast_carefulwrite(s->fd, eqe->eventdata, strlen(eqe->eventdata), s->writetimeout) < 0)
if (!ret && ast_carefulwrite(s->fd, eqe->eventdata,
strlen(eqe->eventdata), s->writetimeout) < 0)
ret = -1;
}
unref_event(s->eventq); /* XXX why not eqe ? */
s->eventq = eqe;
s->last_ev = unref_event(s->last_ev);
}
}
ast_mutex_unlock(&s->__lock);
@ -1886,7 +1885,7 @@ static void *session_do(void *data)
memset(&m, 0, sizeof(m));
} else if (m.hdrcount < AST_MAX_MANHEADERS - 1)
m.hdrcount++;
} else if (s->eventq->next) {
} else if (s->last_ev->next) {
if (process_events(s))
break;
}
@ -1948,7 +1947,6 @@ static void *accept_thread(void *ignore)
AST_LIST_TRAVERSE_SAFE_END
/* Purge master event queue of old, unused events, but make sure we
always keep at least one in the queue */
/* XXX why do we need one entry in the queue ? */
while (master_eventq->next && !master_eventq->usecount) {
struct eventqent *eqe = master_eventq;
master_eventq = master_eventq->next;
@ -2000,13 +1998,12 @@ static void *accept_thread(void *ignore)
ast_atomic_fetchadd_int(&num_sessions, 1);
AST_LIST_LOCK(&sessions);
AST_LIST_INSERT_HEAD(&sessions, s, list);
/* Find the last place in the master event queue and hook ourselves
in there */
s->eventq = master_eventq;
while(s->eventq->next)
s->eventq = s->eventq->next;
/* Hook to the tail of the event queue */
s->last_ev = master_eventq;
while(s->last_ev->next)
s->last_ev = s->last_ev->next;
AST_LIST_UNLOCK(&sessions);
ast_atomic_fetchadd_int(&s->eventq->usecount, 1);
ast_atomic_fetchadd_int(&s->last_ev->usecount, 1);
if (ast_pthread_create_background(&s->ms_t, &attr, session_do, s))
destroy_session(s);
}
@ -2028,6 +2025,7 @@ static int append_event(const char *str, int category)
/* need to init all fields, because ast_malloc() does not */
tmp->next = NULL;
tmp->usecount = num_sessions;
tmp->category = category;
strcpy(tmp->eventdata, str);
@ -2040,7 +2038,6 @@ static int append_event(const char *str, int category)
master_eventq = tmp;
}
tmp->usecount = num_sessions;
return 0;
}
@ -2078,9 +2075,10 @@ int manager_event(int category, const char *event, const char *fmt, ...)
ast_dynamic_str_thread_append(&buf, 0, &manager_event_buf, "\r\n");
/* Append event to master list and wake up any sleeping sessions */
AST_LIST_LOCK(&sessions);
append_event(buf->str, category);
/* Wake up any sleeping sessions */
AST_LIST_TRAVERSE(&sessions, s, list) {
ast_mutex_lock(&s->__lock);
if (s->waiting_thread != AST_PTHREADT_NULL)
@ -2447,11 +2445,11 @@ static char *generic_http_callback(enum output_format format,
AST_LIST_LOCK(&sessions);
AST_LIST_INSERT_HEAD(&sessions, s, list);
/* Hook into the last spot in the event queue */
s->eventq = master_eventq;
while (s->eventq->next)
s->eventq = s->eventq->next;
s->last_ev = master_eventq;
while (s->last_ev->next)
s->last_ev = s->last_ev->next;
AST_LIST_UNLOCK(&sessions);
ast_atomic_fetchadd_int(&s->eventq->usecount, 1);
ast_atomic_fetchadd_int(&s->last_ev->usecount, 1);
ast_atomic_fetchadd_int(&num_sessions, 1);
}

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