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Make dns callbacks run deferred

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svn:r1205
This commit is contained in:
Nick Mathewson 2009-04-19 01:59:09 +00:00
parent 327165b339
commit 2d9619d78f
1 changed files with 69 additions and 31 deletions
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100
evdns.c
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@ -109,6 +109,7 @@
#include <event2/event_struct.h>
#include <event2/thread.h>
#include "defer-internal.h"
#include "log-internal.h"
#include "mm-internal.h"
#include "strlcpy-internal.h"
@ -735,40 +736,77 @@ evdns_requests_pump_waiting_queue(struct evdns_base *base) {
}
}
/* TODO(nickm) document */
struct deferred_reply_callback {
struct deferred_cb deferred;
u8 request_type;
u8 have_reply;
u32 ttl;
u32 err;
evdns_callback_type user_callback;
struct reply reply;
};
static void
reply_callback(struct evdns_request *const req, u32 ttl, u32 err, struct reply *reply) {
/* TODO(nickm) This nees to be deferred. */
switch (req->request_type) {
reply_run_callback(struct deferred_cb *d, void *user_pointer)
{
struct deferred_reply_callback *cb =
EVUTIL_UPCAST(d, struct deferred_reply_callback, deferred);
switch (cb->request_type) {
case TYPE_A:
if (reply)
req->user_callback(DNS_ERR_NONE, DNS_IPv4_A,
reply->data.a.addrcount, ttl,
reply->data.a.addresses,
req->user_pointer);
if (cb->have_reply)
cb->user_callback(DNS_ERR_NONE, DNS_IPv4_A,
cb->reply.data.a.addrcount, cb->ttl,
cb->reply.data.a.addresses,
user_pointer);
else
req->user_callback(err, 0, 0, 0, NULL, req->user_pointer);
return;
cb->user_callback(cb->err, 0, 0, 0, NULL, user_pointer);
break;
case TYPE_PTR:
if (reply) {
char *name = reply->data.ptr.name;
req->user_callback(DNS_ERR_NONE, DNS_PTR, 1, ttl,
&name, req->user_pointer);
if (cb->have_reply) {
char *name = cb->reply.data.ptr.name;
cb->user_callback(DNS_ERR_NONE, DNS_PTR, 1, cb->ttl,
&name, user_pointer);
} else {
req->user_callback(err, 0, 0, 0, NULL,
req->user_pointer);
cb->user_callback(cb->err, 0, 0, 0, NULL, user_pointer);
}
return;
break;
case TYPE_AAAA:
if (reply)
req->user_callback(DNS_ERR_NONE, DNS_IPv6_AAAA,
reply->data.aaaa.addrcount, ttl,
reply->data.aaaa.addresses,
req->user_pointer);
if (cb->have_reply)
cb->user_callback(DNS_ERR_NONE, DNS_IPv6_AAAA,
cb->reply.data.aaaa.addrcount, cb->ttl,
cb->reply.data.aaaa.addresses,
user_pointer);
else
req->user_callback(err, 0, 0, 0, NULL, req->user_pointer);
return;
cb->user_callback(cb->err, 0, 0, 0, NULL, user_pointer);
break;
default:
assert(0);
}
assert(0);
mm_free(cb);
}
static void
reply_schedule_callback(struct evdns_request *const req, u32 ttl, u32 err, struct reply *reply)
{
struct deferred_reply_callback *d = mm_calloc(1, sizeof(*d));
ASSERT_LOCKED(req->base);
d->request_type = req->request_type;
d->user_callback = req->user_callback;
d->ttl = ttl;
d->err = err;
if (reply) {
d->have_reply = 1;
memcpy(&d->reply, reply, sizeof(struct reply));
}
event_deferred_cb_init(&d->deferred, reply_run_callback,
req->user_pointer);
event_deferred_cb_schedule(req->base->event_base, &d->deferred);
}
/* this processes a parsed reply packet */
@ -837,11 +875,11 @@ reply_handle(struct evdns_request *const req, u16 flags, u32 ttl, struct reply *
}
/* all else failed. Pass the failure up */
reply_callback(req, 0, error, NULL);
reply_schedule_callback(req, 0, error, NULL);
request_finished(req, &REQ_HEAD(req->base, req->trans_id));
} else {
/* all ok, tell the user */
reply_callback(req, ttl, 0, reply);
reply_schedule_callback(req, ttl, 0, reply);
nameserver_up(req->ns);
request_finished(req, &REQ_HEAD(req->base, req->trans_id));
}
@ -2082,7 +2120,7 @@ evdns_request_timeout_callback(evutil_socket_t fd, short events, void *arg) {
if (req->tx_count >= req->base->global_max_retransmits) {
/* this request has failed */
reply_callback(req, 0, DNS_ERR_TIMEOUT, NULL);
reply_schedule_callback(req, 0, DNS_ERR_TIMEOUT, NULL);
request_finished(req, &REQ_HEAD(req->base, req->trans_id));
} else {
/* retransmit it */
@ -2627,7 +2665,7 @@ evdns_cancel_request(struct evdns_base *base, struct evdns_request *req)
base = req->base;
EVDNS_LOCK(base);
reply_callback(req, 0, DNS_ERR_CANCEL, NULL);
reply_schedule_callback(req, 0, DNS_ERR_CANCEL, NULL);
if (req->ns) {
/* remove from inflight queue */
request_finished(req, &REQ_HEAD(base, req->trans_id));
@ -3606,13 +3644,13 @@ evdns_base_free(struct evdns_base *base, int fail_requests)
for (i = 0; i < base->n_req_heads; ++i) {
while (base->req_heads[i]) {
if (fail_requests)
reply_callback(base->req_heads[i], 0, DNS_ERR_SHUTDOWN, NULL);
reply_schedule_callback(base->req_heads[i], 0, DNS_ERR_SHUTDOWN, NULL);
request_finished(base->req_heads[i], &REQ_HEAD(base, base->req_heads[i]->trans_id));
}
}
while (base->req_waiting_head) {
if (fail_requests)
reply_callback(base->req_waiting_head, 0, DNS_ERR_SHUTDOWN, NULL);
reply_schedule_callback(base->req_waiting_head, 0, DNS_ERR_SHUTDOWN, NULL);
request_finished(base->req_waiting_head, &base->req_waiting_head);
}
base->global_requests_inflight = base->global_requests_waiting = 0;