Initial support to spawn a process (module/function) outbound on a specified node. Also fix some bugs.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@11477 d0543943-73ff-0310-b7d9-9358b9ac24b2
This commit is contained in:
Andrew Thompson 2009-01-24 01:04:59 +00:00
parent e14c57ddd1
commit 5fe69d307b
4 changed files with 276 additions and 69 deletions

View File

@ -123,29 +123,29 @@ void ei_encode_switch_event_tag(ei_x_buff *ebuf, switch_event_t *event, char *ta
/* function to spawn a process on a remote node */
int ei_spawn(struct ei_cnode_s *ec, int sockfd, char *module, char *function, int argc, char **argv)
int ei_spawn(struct ei_cnode_s *ec, int sockfd, erlang_ref *ref, char *module, char *function, int argc, char **argv)
{
ei_x_buff buf;
ei_x_new_with_version(&buf);
erlang_ref ref;
int i;
ei_x_encode_tuple_header(&buf, 3);
ei_x_encode_atom(&buf, "$gen_call");
ei_x_encode_tuple_header(&buf, 2);
ei_x_encode_pid(&buf, ei_self(ec));
/* TODO - use this reference to determine the response */
ei_init_ref(ec, &ref);
ei_x_encode_ref(&buf, &ref);
ei_init_ref(ec, ref);
ei_x_encode_ref(&buf, ref);
ei_x_encode_tuple_header(&buf, 5);
ei_x_encode_atom(&buf, "spawn");
ei_x_encode_atom(&buf, module);
ei_x_encode_atom(&buf, function);
/* argument list */
ei_x_encode_list_header(&buf, argc);
for(i = 0; i < argc && argv[i]; i++) {
ei_x_encode_atom(&buf, argv[i]);
if (argc < 0) {
ei_x_encode_list_header(&buf, argc);
for(i = 0; i < argc && argv[i]; i++) {
ei_x_encode_atom(&buf, argv[i]);
}
}
ei_x_encode_empty_list(&buf);
@ -156,12 +156,11 @@ int ei_spawn(struct ei_cnode_s *ec, int sockfd, char *module, char *function, in
ei_x_encode_pid(&buf, ei_self(ec)); /* should really be a valid group leader */
char *pbuf = 0;
i = 1;
ei_s_print_term(&pbuf, buf.buff, &i);
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "spawn returning %s\n", pbuf);
#ifdef EI_DEBUG
ei_x_print_reg_msg(&buf, "net_kernel", 1);
#endif
return ei_reg_send(ec, sockfd, "net_kernel", buf.buff, buf.index);
}
@ -196,6 +195,69 @@ void ei_init_ref(ei_cnode *ec, erlang_ref *ref)
}
void ei_x_print_reg_msg(ei_x_buff *buf, char *dest, int send)
{
char *mbuf = NULL;
int i = 1;
ei_s_print_term(&mbuf, buf->buff, &i);
if (send) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Sending %s to %s\n", mbuf, dest);
} else {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Received %s from %s\n", mbuf, dest);
}
free(mbuf);
}
void ei_x_print_msg(ei_x_buff *buf, erlang_pid *pid, int send)
{
char *pbuf = NULL;
int i = 0;
ei_x_buff pidbuf;
ei_x_new(&pidbuf);
ei_x_encode_pid(&pidbuf, pid);
ei_s_print_term(&pbuf, pidbuf.buff, &i);
ei_x_print_reg_msg(buf, pbuf, send);
free(pbuf);
}
int ei_sendto(ei_cnode *ec, int fd, struct erlang_process *process, ei_x_buff *buf)
{
int ret;
if (process->type == ERLANG_PID) {
ret = ei_send(fd, &process->pid, buf->buff, buf->index);
#ifdef EI_DEBUG
ei_x_print_msg(buf, &process->pid, 1);
#endif
} else if (process->type == ERLANG_REG_PROCESS) {
ret = ei_reg_send(ec, fd, process->reg_name, buf->buff, buf->index);
#ifdef EI_DEBUG
ei_x_print_reg_msg(buf, process->reg_name, 1);
#endif
} else {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Invalid process type!\n");
/* wuh-oh */
ret = -1;
}
return ret;
}
/* convert an erlang reference to some kind of hashed string so we can store it as a hash key */
void ei_hash_ref(erlang_ref *ref, char *output)
{
/* very lazy */
sprintf(output, "%d.%d.%d@%s", ref->n[0], ref->n[1], ref->n[2], ref->node);
}
switch_status_t initialise_ei(struct ei_cnode_s *ec)
{
switch_status_t rv;

View File

@ -107,6 +107,9 @@ static void *SWITCH_THREAD_FUNC api_exec(switch_thread_t *thread, void *obj)
switch_mutex_lock(acs->listener->sock_mutex);
ei_send(acs->listener->sockfd, &acs->pid, ebuf.buff, ebuf.index);
switch_mutex_unlock(acs->listener->sock_mutex);
#ifdef EI_DEBUG
ei_x_print_msg(&ebuf, &acs->pid, 1);
#endif
ei_x_free(&ebuf);
}
@ -132,6 +135,9 @@ static void *SWITCH_THREAD_FUNC api_exec(switch_thread_t *thread, void *obj)
switch_mutex_lock(acs->listener->sock_mutex);
ei_send(acs->listener->sockfd, &acs->pid, rbuf.buff, rbuf.index);
switch_mutex_unlock(acs->listener->sock_mutex);
#ifdef EI_DEBUG
ei_x_print_msg(&rbuf, &acs->pid, 1);
#endif
ei_x_free(&rbuf);
}
@ -492,8 +498,6 @@ static switch_status_t handle_msg_bind(listener_t *listener, erlang_msg *msg, ei
binding->process.pid = msg->from;
binding->listener = listener;
switch_core_hash_init(&listener->fetch_reply_hash, listener->pool);
switch_mutex_lock(globals.listener_mutex);
for (ptr = bindings.head; ptr && ptr->next; ptr = ptr->next);
@ -532,7 +536,7 @@ static switch_status_t handle_msg_handlecall(listener_t *listener, int arity, ei
switch_core_session_t *session;
if (!switch_strlen_zero(uuid_str) && (session = switch_core_session_locate(uuid_str))) {
/* create a new session list element and attach it to this listener */
if (attach_call_to_listener(listener,reg_name,session)) {
if (attach_call_to_registered_process(listener, reg_name, session)) {
ei_x_encode_atom(rbuf, "ok");
} else {
ei_x_encode_tuple_header(rbuf, 2);
@ -660,9 +664,48 @@ static switch_status_t handle_msg_atom(listener_t *listener, erlang_msg *msg, e
return ret;
}
static switch_status_t handle_ref_tuple(listener_t *listener, erlang_msg *msg, ei_x_buff *buf, ei_x_buff *rbuf)
{
erlang_ref ref;
erlang_pid *pid2, *pid = switch_core_alloc(listener->pool, sizeof(erlang_pid));
char hash[100];
int arity;
ei_decode_tuple_header(buf->buff, &buf->index, &arity);
if (ei_decode_ref(buf->buff, &buf->index, &ref)) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Invalid reference\n");
return SWITCH_STATUS_FALSE;
}
if (ei_decode_pid(buf->buff, &buf->index, pid)) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Invalid pid in a reference/pid tuple\n");
return SWITCH_STATUS_FALSE;
}
ei_hash_ref(&ref, hash);
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Hashed ref to %s\n", hash);
if ((pid2 = (erlang_pid *) switch_core_hash_find(listener->spawn_pid_hash, hash))) {
if (pid2 == NULL) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Found unfilled slot for %s\n", hash);
} else {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Found filled slot for %s\n", hash);
}
} else {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "No slot for %s\n", hash);
switch_core_hash_insert(listener->spawn_pid_hash, hash, pid);
}
return SWITCH_STATUS_SUCCESS;
}
int handle_msg(listener_t *listener, erlang_msg *msg, ei_x_buff *buf, ei_x_buff *rbuf)
{
int type, size, version;
int type, type2, size, version, arity, tmpindex;
switch_status_t ret = SWITCH_STATUS_SUCCESS;
buf->index = 0;
@ -672,7 +715,27 @@ int handle_msg(listener_t *listener, erlang_msg *msg, ei_x_buff *buf, ei_x_buff
switch(type) {
case ERL_SMALL_TUPLE_EXT :
case ERL_LARGE_TUPLE_EXT :
ret = handle_msg_tuple(listener,msg,buf,rbuf);
tmpindex = buf->index;
ei_decode_tuple_header(buf->buff, &tmpindex, &arity);
ei_get_type(buf->buff, &tmpindex, &type2, &size);
switch(type2) {
case ERL_ATOM_EXT:
ret = handle_msg_tuple(listener,msg,buf,rbuf);
break;
case ERL_REFERENCE_EXT :
case ERL_NEW_REFERENCE_EXT :
handle_ref_tuple(listener, msg, buf, rbuf);
return 0;
default :
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "WEEEEEEEE %d\n", type);
/* some other kind of erlang term */
ei_x_encode_tuple_header(rbuf, 2);
ei_x_encode_atom(rbuf, "error");
ei_x_encode_atom(rbuf, "undef");
break;
}
break;
case ERL_ATOM_EXT :
@ -687,17 +750,23 @@ int handle_msg(listener_t *listener, erlang_msg *msg, ei_x_buff *buf, ei_x_buff
break;
}
if (SWITCH_STATUS_FALSE==ret)
if (SWITCH_STATUS_FALSE==ret) {
return 0;
else {
} else if (rbuf->index > 1) {
switch_mutex_lock(listener->sock_mutex);
ei_send(listener->sockfd, &msg->from, rbuf->buff, rbuf->index);
switch_mutex_unlock(listener->sock_mutex);
#ifdef EI_DEBUG
ei_x_print_msg(rbuf, &msg->from, 1);
#endif
if (SWITCH_STATUS_SUCCESS==ret)
return 0;
else /* SWITCH_STATUS_TERM */
return 1;
} else {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Empty reply, supressing\n");
return 0;
}
}

View File

@ -346,7 +346,7 @@ static switch_xml_t erlang_fetch(const char *sectionstr, const char *tag_name, c
/*switch_core_hash_insert(ptr->reply_hash, uuid_str, );*/
switch_mutex_lock(ptr->listener->sock_mutex);
ei_send(ptr->listener->sockfd, &ptr->process.pid, buf.buff, buf.index);
ei_sendto(ptr->listener->ec, ptr->listener->sockfd, &ptr->process, &buf);
switch_mutex_unlock(ptr->listener->sock_mutex);
int i = 0;
@ -418,16 +418,13 @@ static switch_status_t notify_new_session(listener_t *listener, switch_core_sess
ei_encode_switch_event(&lbuf, call_event);
switch_mutex_lock(listener->sock_mutex);
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Sending initial call event\n");
if (process.type == ERLANG_PID) {
result = ei_send(listener->sockfd, &process.pid, lbuf.buff, lbuf.index);
} else {
result = ei_reg_send(listener->ec, listener->sockfd, process.reg_name, lbuf.buff, lbuf.index);
}
result = ei_sendto(listener->ec, listener->sockfd, &process, &lbuf);
switch_mutex_unlock(listener->sock_mutex);
if (result) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to send call event\n");
}
switch_mutex_unlock(listener->sock_mutex);
ei_x_free(&lbuf);
return SWITCH_STATUS_SUCCESS;
@ -467,11 +464,7 @@ static switch_status_t check_attached_sessions(listener_t *listener)
ei_encode_switch_event(&ebuf, pevent);
switch_mutex_lock(listener->sock_mutex);
if (sp->process.type == ERLANG_PID) {
ei_send(listener->sockfd, &sp->process.pid, ebuf.buff, ebuf.index);
} else {
ei_reg_send(listener->ec, listener->sockfd, sp->process.reg_name, ebuf.buff, ebuf.index);
}
ei_sendto(listener->ec, listener->sockfd, &sp->process, &ebuf);
switch_mutex_unlock(listener->sock_mutex);
/* event is a hangup, so this session can be removed */
@ -484,8 +477,11 @@ static switch_status_t check_attached_sessions(listener_t *listener)
else
listener->session_list = sp->next;
switch_channel_clear_flag(switch_core_session_get_channel(sp->session), CF_CONTROLLED);
/* this allows the application threads to exit */
switch_clear_flag_locked(sp, LFLAG_SESSION_ALIVE);
switch_clear_flag_locked(sp, LFLAG_SESSION_ALIVE);
switch_core_session_rwunlock(sp->session);
/* TODO
if this listener was created outbound, and the last session has been detached
@ -546,11 +542,7 @@ static void check_log_queue(listener_t *listener)
ei_x_encode_empty_list(&lbuf);
switch_mutex_lock(listener->sock_mutex);
if (listener->log_process.type == ERLANG_PID) {
ei_send(listener->sockfd, &listener->log_process.pid, lbuf.buff, lbuf.index);
} else {
ei_reg_send(listener->ec, listener->sockfd, listener->log_process.reg_name, lbuf.buff, lbuf.index);
}
ei_sendto(listener->ec, listener->sockfd, &listener->log_process, &lbuf);
switch_mutex_unlock(listener->sock_mutex);
ei_x_free(&lbuf);
@ -576,11 +568,7 @@ static void check_event_queue(listener_t *listener)
ei_encode_switch_event(&ebuf, pevent);
switch_mutex_lock(listener->sock_mutex);
if (listener->log_process.type == ERLANG_PID) {
ei_send(listener->sockfd, &listener->log_process.pid, ebuf.buff, ebuf.index);
} else {
ei_reg_send(listener->ec, listener->sockfd, listener->log_process.reg_name, ebuf.buff, ebuf.index);
}
ei_sendto(listener->ec, listener->sockfd, &listener->log_process, &ebuf);
switch_mutex_unlock(listener->sock_mutex);
ei_x_free(&ebuf);
@ -592,8 +580,6 @@ static void check_event_queue(listener_t *listener)
static void listener_main_loop(listener_t *listener)
{
int status = 1;
/*int i = 1;*/
/*char *pbuf = 0;*/
while ((status >= 0 || erl_errno == ETIMEDOUT || erl_errno == EAGAIN) && !prefs.done) {
erlang_msg msg;
@ -614,20 +600,27 @@ static void listener_main_loop(listener_t *listener)
case ERL_MSG :
switch(msg.msgtype) {
case ERL_SEND :
/*switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "erl_send\n");*/
/*i = 1;*/
#ifdef EI_DEBUG
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "erl_send\n");
ei_x_print_msg(&buf, &msg.from, 0);
/*ei_s_print_term(&pbuf, buf.buff, &i);*/
/*switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "erl_send was message %s\n", pbuf);*/
#endif
if (handle_msg(listener, &msg, &buf, &rbuf)) {
return;
}
break;
case ERL_REG_SEND :
/*switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "erl_reg_send to %s\n", msg.toname);*/
#ifdef EI_DEBUG
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "erl_reg_send to %s\n", msg.toname);
ei_x_print_reg_msg(&buf, msg.toname, 0);
/*i = 1;*/
/*ei_s_print_term(&pbuf, buf.buff, &i);*/
/*switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "erl_reg_send was message %s\n", pbuf);*/
#endif
if (handle_msg(listener, &msg, &buf, &rbuf)) {
return;
@ -695,6 +688,9 @@ static switch_bool_t check_inbound_acl(listener_t* listener)
ei_x_encode_atom(&rbuf, "acldeny");
ei_send(listener->sockfd, &msg.from, rbuf.buff, rbuf.index);
#ifdef EI_DEBUG
ei_x_print_msg(&rbuf, &msg.from, 1);
#endif
ei_x_free(&rbuf);
}
@ -718,6 +714,9 @@ static void *SWITCH_THREAD_FUNC listener_run(switch_thread_t *thread, void *obj)
prefs.threads++;
switch_mutex_unlock(globals.listener_mutex);
switch_core_hash_init(&listener->fetch_reply_hash, listener->pool);
switch_core_hash_init(&listener->spawn_pid_hash, listener->pool);
switch_assert(listener != NULL);
if (check_inbound_acl(listener)) {
@ -896,7 +895,7 @@ static listener_t* new_outbound_listener(char* node)
return listener;
}
session_elem_t* attach_call_to_listener(listener_t* listener, char* reg_name, switch_core_session_t *session)
session_elem_t* attach_call_to_registered_process(listener_t* listener, char* reg_name, switch_core_session_t *session)
{
/* create a session list element */
session_elem_t* session_element=NULL;
@ -922,32 +921,92 @@ session_elem_t* attach_call_to_listener(listener_t* listener, char* reg_name, sw
return session_element;
}
session_elem_t* attach_call_to_spawned_process(listener_t* listener, char *module, char *function, switch_core_session_t *session)
{
/* create a session list element */
session_elem_t* session_element=NULL;
if (!(session_element = switch_core_alloc(switch_core_session_get_pool(session), sizeof(*session_element)))) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to allocate session element\n");
}
else {
if (SWITCH_STATUS_SUCCESS != switch_core_session_read_lock(session)) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to get session read lock\n");
}
else {
char *argv[1], hash[100];
int i = 0;
session_element->session = session;
erlang_pid *pid;
erlang_ref ref;
ei_spawn(listener->ec, listener->sockfd, &ref, module, function, 0, argv);
ei_hash_ref(&ref, hash);
while (!(pid = (erlang_pid *) switch_core_hash_find(listener->spawn_pid_hash, hash))) {
if (i > 50) { /* half a second timeout */
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "timed out!\n");
return NULL;
}
i++;
switch_yield(10000); /* 10ms */
}
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "got pid!\n");
session_element->process.type = ERLANG_PID;
memcpy(&session_element->process.pid, pid, sizeof(erlang_pid));
switch_set_flag(session_element, LFLAG_SESSION_ALIVE);
switch_clear_flag(session_element, LFLAG_OUTBOUND_INIT);
switch_queue_create(&session_element->event_queue, SWITCH_CORE_QUEUE_LEN, switch_core_session_get_pool(session));
switch_mutex_init(&session_element->flag_mutex, SWITCH_MUTEX_NESTED, switch_core_session_get_pool(session));
/* attach the session to the listener */
add_session_elem_to_listener(listener,session_element);
}
}
return session_element;
}
/* Module Hooks */
/* Entry point for outbound mode */
SWITCH_STANDARD_APP(erlang_outbound_function)
{
char *reg_name, *node;
char *reg_name = NULL, *node, *module = NULL, *function = NULL;
listener_t *listener;
int argc = 0;
char *argv[80] = { 0 };
char *mydata;
int argc = 0, argc2=0;
char *argv[80] = { 0 }, *argv2[80] = { 0 };
char *mydata, *myarg;
switch_bool_t new_session = SWITCH_FALSE;
session_elem_t* session_element=NULL;
/* process app arguments */
if (data && (mydata = switch_core_session_strdup(session, data))) {
argc = switch_separate_string(mydata, ' ', argv, (sizeof(argv) / sizeof(argv[0])));
}
} /* XXX else? */
if (argc < 2) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Parse Error - need registered name and node!\n");
return;
}
reg_name = argv[0];
if (switch_strlen_zero(reg_name)) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing registered name!\n");
if (switch_strlen_zero(argv[0])) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing registered name or module:function!\n");
return;
}
if ((myarg = switch_core_session_strdup(session, argv[0]))) {
argc2 = switch_separate_string(myarg, ':', argv2, (sizeof(argv2) / sizeof(argv2[0])));
}
if (argc2 == 2) {
/* mod:fun style */
module = argv2[0];
function = argv2[1];
} else {
/* registered name style */
reg_name = argv[0];
}
node = argv[1];
if (switch_strlen_zero(node)) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing node name!\n");
@ -967,17 +1026,27 @@ SWITCH_STANDARD_APP(erlang_outbound_function)
else {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Using existing listener for session\n");
}
if (listener &&
(session_element=attach_call_to_listener(listener,reg_name,session)) != NULL) {
if (new_session)
launch_listener_thread(listener);
switch_ivr_park(session, NULL);
/* keep app thread running for lifetime of session */
if (switch_channel_get_state(switch_core_session_get_channel(session)) >= CS_HANGUP) {
while (switch_test_flag(session_element, LFLAG_SESSION_ALIVE)) {
switch_yield(100000);
if (listener) {
if (module && function) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Creating new spawned session for listener\n");
session_element=attach_call_to_spawned_process(listener, module, function, session);
} else {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Creating new registered session for listener\n");
session_element=attach_call_to_registered_process(listener, reg_name, session);
}
if (session_element) {
if (new_session)
launch_listener_thread(listener);
switch_ivr_park(session, NULL);
/* keep app thread running for lifetime of session */
if (switch_channel_get_state(switch_core_session_get_channel(session)) >= CS_HANGUP) {
while (switch_test_flag(session_element, LFLAG_SESSION_ALIVE)) {
switch_yield(100000);
}
}
}
}

View File

@ -32,6 +32,7 @@
*
*/
#define EI_DEBUG
typedef enum {
LFLAG_OUTBOUND_INIT = (1 << 0), /* Erlang peer has been notified of this session */
@ -93,6 +94,7 @@ struct listener {
uint8_t event_list[SWITCH_EVENT_ALL + 1];
switch_hash_t *event_hash;
switch_hash_t *fetch_reply_hash;
switch_hash_t *spawn_pid_hash;
switch_thread_rwlock_t *rwlock;
switch_mutex_t *session_mutex;
session_elem_t *session_list;
@ -186,13 +188,18 @@ int handle_msg(listener_t *listener, erlang_msg *msg, ei_x_buff *buf, ei_x_buff
void ei_link(listener_t *listener, erlang_pid *from, erlang_pid *to);
void ei_encode_switch_event_headers(ei_x_buff *ebuf, switch_event_t *event);
void ei_encode_switch_event_tag(ei_x_buff *ebuf, switch_event_t *event, char *tag);
int ei_spawn(struct ei_cnode_s *ec, int sockfd, char *module, char *function, int argc, char **argv);
int ei_spawn(struct ei_cnode_s *ec, int sockfd, erlang_ref *ref, char *module, char *function, int argc, char **argv);
void ei_init_ref(struct ei_cnode_s *ec, erlang_ref *ref);
void ei_x_print_reg_msg(ei_x_buff *buf, char *dest, int send);
void ei_x_print_msg(ei_x_buff *buf, erlang_pid *pid, int send);
int ei_sendto(ei_cnode *ec, int fd, struct erlang_process *process, ei_x_buff *buf);
void ei_hash_ref(erlang_ref *ref, char *output);
switch_status_t initialise_ei(struct ei_cnode_s *ec);
#define ei_encode_switch_event(_b, _e) ei_encode_switch_event_tag(_b, _e, "event")
/* mod_erlang_event.c */
session_elem_t* attach_call_to_listener(listener_t* listener, char* reg_name, switch_core_session_t *session);
session_elem_t* attach_call_to_registered_process(listener_t* listener, char* reg_name, switch_core_session_t *session);
session_elem_t* attach_call_to_spawned_process(listener_t* listener, char *module, char *function, switch_core_session_t *session);
/* For Emacs:
* Local Variables: