void
ipc_port_destroy(
ipc_port_t port)
{
ipc_port_t pdrequest, nsrequest;
ipc_mqueue_t mqueue;
ipc_kmsg_t kmsg;
#if IMPORTANCE_INHERITANCE
task_t release_imp_task = TASK_NULL;
thread_t self = current_thread();
boolean_t top = (self->ith_assertions == 0);
natural_t assertcnt = 0;
#endif /* IMPORTANCE_INHERITANCE */
assert(ip_active(port));
/* port->ip_receiver_name is garbage */
/* port->ip_receiver/port->ip_destination is garbage */
assert(port->ip_pset_count == 0);
assert(port->ip_mscount == 0);
/* check for a backup port */
pdrequest = port->ip_pdrequest;
#if IMPORTANCE_INHERITANCE
/* determine how may assertions to drop and from whom */
if (port->ip_tempowner != 0) {
assert(top);
if (port->ip_taskptr != 0) {
release_imp_task = port->ip_imp_task;
port->ip_imp_task = TASK_NULL;
port->ip_taskptr = 0;
assertcnt = port->ip_impcount;
}
/* Otherwise, nothing to drop */
} else {
assert(port->ip_taskptr == 0);
assertcnt = port->ip_impcount;
if (pdrequest != IP_NULL)
/* mark in limbo for the journey */
port->ip_tempowner = 1;
}
if (top)
self->ith_assertions = assertcnt;
#endif /* IMPORTANCE_INHERITANCE */
if (pdrequest != IP_NULL) {
/* we assume the ref for pdrequest */
port->ip_pdrequest = IP_NULL;
/* make port be in limbo */
port->ip_receiver_name = MACH_PORT_NULL;
port->ip_destination = IP_NULL;
ip_unlock(port);
/* consumes our refs for port and pdrequest */
ipc_notify_port_destroyed(pdrequest, port);
goto drop_assertions;
}
/* once port is dead, we don't need to keep it locked */
port->ip_object.io_bits &= ~IO_BITS_ACTIVE;
port->ip_timestamp = ipc_port_timestamp();
/*
* If the port has a preallocated message buffer and that buffer
* is not inuse, free it. If it has an inuse one, then the kmsg
* free will detect that we freed the association and it can free it
* like a normal buffer.
*/
if (IP_PREALLOC(port)) {
ipc_port_t inuse_port;
kmsg = port->ip_premsg;
assert(kmsg != IKM_NULL);
inuse_port = ikm_prealloc_inuse_port(kmsg);
IP_CLEAR_PREALLOC(port, kmsg);
ip_unlock(port);
if (inuse_port != IP_NULL) {
assert(inuse_port == port);
} else {
ipc_kmsg_free(kmsg);
}
} else {
ip_unlock(port);
}
/* throw away no-senders request */
nsrequest = port->ip_nsrequest;
if (nsrequest != IP_NULL)
ipc_notify_send_once(nsrequest); /* consumes ref */
/* destroy any queued messages */
mqueue = &port->ip_messages;
ipc_mqueue_destroy(mqueue);
/* generate dead-name notifications */
ipc_port_dnnotify(port);
ipc_kobject_destroy(port);
ip_release(port); /* consume caller's ref */
drop_assertions:
#if IMPORTANCE_INHERITANCE
if (release_imp_task != TASK_NULL) {
if (assertcnt > 0) {
assert(top);
self->ith_assertions = 0;
assert(release_imp_task->imp_receiver != 0);
task_importance_drop_internal_assertion(release_imp_task, assertcnt);
}
task_deallocate(release_imp_task);
} else if (assertcnt > 0) {
if (top) {
self->ith_assertions = 0;
release_imp_task = current_task();
if (release_imp_task->imp_receiver != 0) {
task_importance_drop_internal_assertion(release_imp_task, assertcnt);
}
} else {
/* the port chain we are enqueued on should cover our assertions */
assert(assertcnt <= self->ith_assertions);
}
}
#endif /* IMPORTANCE_INHERITANCE */
}
void
ipc_port_destroy(
ipc_port_t port)
{
ipc_port_t pdrequest, nsrequest;
ipc_mqueue_t mqueue;
ipc_kmsg_t kmsg;
ipc_port_request_t dnrequests;
assert(ip_active(port));
/* port->ip_receiver_name is garbage */
/* port->ip_receiver/port->ip_destination is garbage */
assert(port->ip_pset_count == 0);
assert(port->ip_mscount == 0);
/* first check for a backup port */
pdrequest = port->ip_pdrequest;
if (pdrequest != IP_NULL) {
/* we assume the ref for pdrequest */
port->ip_pdrequest = IP_NULL;
/* make port be in limbo */
port->ip_receiver_name = MACH_PORT_NULL;
port->ip_destination = IP_NULL;
ip_unlock(port);
/* consumes our refs for port and pdrequest */
ipc_notify_port_destroyed(pdrequest, port);
return;
}
/* once port is dead, we don't need to keep it locked */
port->ip_object.io_bits &= ~IO_BITS_ACTIVE;
port->ip_timestamp = ipc_port_timestamp();
/* save for later */
dnrequests = port->ip_dnrequests;
port->ip_dnrequests = IPR_NULL;
/*
* If the port has a preallocated message buffer and that buffer
* is not inuse, free it. If it has an inuse one, then the kmsg
* free will detect that we freed the association and it can free it
* like a normal buffer.
*/
if (IP_PREALLOC(port)) {
kmsg = port->ip_premsg;
assert(kmsg != IKM_NULL);
IP_CLEAR_PREALLOC(port, kmsg);
if (!ikm_prealloc_inuse(kmsg))
ipc_kmsg_free(kmsg);
}
ip_unlock(port);
/* throw away no-senders request */
nsrequest = port->ip_nsrequest;
if (nsrequest != IP_NULL)
ipc_notify_send_once(nsrequest); /* consumes ref */
/* destroy any queued messages */
mqueue = &port->ip_messages;
ipc_mqueue_destroy(mqueue);
/* generate dead-name notifications */
if (dnrequests != IPR_NULL) {
ipc_port_dnnotify(port, dnrequests);
}
ipc_kobject_destroy(port);
ipc_port_release(port); /* consume caller's ref */
}