Implement basic connection teardown
I finally understand the codebase again. It's rather complicated.
This commit is contained in:
parent
efd500ca3c
commit
a3ec0942f8
GPG Key ID:
A0420B94F92B9493
|
|
@ -47,10 +47,10 @@ enum { PIPE_READ, PIPE_WRITE };
|
|||
#define FIND_CONTAINER(name, pointer, type, member) \
|
||||
type *name = CONTAINER_OF (pointer, type, member)
|
||||
|
||||
// --- libev helpers -----------------------------------------------------------
|
||||
// --- Utilities ---------------------------------------------------------------
|
||||
|
||||
static bool
|
||||
flush_queue (struct write_queue *queue, ev_io *watcher)
|
||||
flush_queue (struct write_queue *queue, int fd)
|
||||
{
|
||||
struct iovec vec[queue->len], *vec_iter = vec;
|
||||
LIST_FOR_EACH (struct write_req, iter, queue->head)
|
||||
|
|
@ -58,24 +58,17 @@ flush_queue (struct write_queue *queue, ev_io *watcher)
|
|||
|
||||
ssize_t written;
|
||||
again:
|
||||
written = writev (watcher->fd, vec, N_ELEMENTS (vec));
|
||||
if (written < 0)
|
||||
if ((written = writev (fd, vec, N_ELEMENTS (vec))) >= 0)
|
||||
{
|
||||
if (errno == EAGAIN)
|
||||
goto skip;
|
||||
if (errno == EINTR)
|
||||
goto again;
|
||||
return false;
|
||||
write_queue_processed (queue, written);
|
||||
return true;
|
||||
}
|
||||
if (errno == EINTR)
|
||||
goto again;
|
||||
if (errno == EAGAIN)
|
||||
return true;
|
||||
|
||||
write_queue_processed (queue, written);
|
||||
|
||||
skip:
|
||||
if (write_queue_is_empty (queue))
|
||||
ev_io_stop (EV_DEFAULT_ watcher);
|
||||
else
|
||||
ev_io_start (EV_DEFAULT_ watcher);
|
||||
return true;
|
||||
return false;
|
||||
}
|
||||
|
||||
// --- Logging -----------------------------------------------------------------
|
||||
|
|
@ -135,16 +128,17 @@ struct fcgi_muxer
|
|||
/// Write data to the underlying transport
|
||||
void (*write_cb) (struct fcgi_muxer *, const void *data, size_t len);
|
||||
|
||||
/// Close the underlying transport
|
||||
// TODO: consider half-close and the subsequent handling
|
||||
/// Close the underlying transport. You are allowed to destroy the muxer
|
||||
/// directly from within the callback.
|
||||
void (*close_cb) (struct fcgi_muxer *);
|
||||
|
||||
/// Start processing a request. Return false if no further action is
|
||||
/// to be done and the request should be finished.
|
||||
bool (*request_start_cb) (struct fcgi_muxer *, struct fcgi_request *);
|
||||
bool (*request_start_cb) (struct fcgi_request *);
|
||||
|
||||
/// Handle incoming data. "len == 0" means EOF.
|
||||
void (*request_push_cb)
|
||||
/// Handle incoming data. "len == 0" means EOF. Returns false if
|
||||
/// the underlying transport should be closed, this being the last request.
|
||||
bool (*request_push_cb)
|
||||
(struct fcgi_request *, const void *data, size_t len);
|
||||
|
||||
/// Destroy the handler's data stored in the request object
|
||||
|
|
@ -230,7 +224,7 @@ fcgi_request_push_params
|
|||
{
|
||||
// TODO: probably check the state of the header parser
|
||||
// TODO: request_start() can return false, end the request here?
|
||||
(void) self->muxer->request_start_cb (self->muxer, self);
|
||||
(void) self->muxer->request_start_cb (self);
|
||||
self->state = FCGI_REQUEST_STDIN;
|
||||
}
|
||||
}
|
||||
|
|
@ -282,7 +276,9 @@ fcgi_request_write (struct fcgi_request *self, const void *data, size_t len)
|
|||
}
|
||||
}
|
||||
|
||||
static void
|
||||
/// Mark the request as done. Returns false if the underlying transport
|
||||
/// should be closed, this being the last request.
|
||||
static bool
|
||||
fcgi_request_finish (struct fcgi_request *self)
|
||||
{
|
||||
fcgi_request_flush (self);
|
||||
|
|
@ -292,14 +288,26 @@ fcgi_request_finish (struct fcgi_request *self)
|
|||
0 /* TODO app_status, although ignored */,
|
||||
FCGI_REQUEST_COMPLETE /* TODO protocol_status, may be different */);
|
||||
|
||||
if (!(self->flags & FCGI_KEEP_CONN))
|
||||
{
|
||||
// TODO: tear down (shut down) the connection
|
||||
}
|
||||
bool should_close = !(self->flags & FCGI_KEEP_CONN);
|
||||
|
||||
self->muxer->active_requests--;
|
||||
self->muxer->requests[self->request_id] = NULL;
|
||||
fcgi_request_destroy (self);
|
||||
|
||||
// TODO: tear down (shut down) the connection. This is called from:
|
||||
//
|
||||
// 1. client_fcgi_request_push <- request_push_cb
|
||||
// <- fcgi_request_push_stdin <- fcgi_muxer_on_stdin
|
||||
// <- fcgi_muxer_on_message <- fcgi_parser_push <- fcgi_muxer_push
|
||||
// <- client_fcgi_push <- client_read_loop
|
||||
// => in this case no close_cb may be called
|
||||
// -> need to pass a false boolean aaall the way up,
|
||||
// then client_fcgi_finalize eventually cleans up the rest
|
||||
//
|
||||
// 2. client_fcgi_request_close_cb <- request_finish
|
||||
// => our direct caller must call fcgi_muxer::close_cb
|
||||
// -> not very nice to delegate it there
|
||||
return !should_close;
|
||||
}
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
|
@ -418,6 +426,7 @@ fcgi_muxer_on_abort_request
|
|||
|
||||
// TODO: abort the request: let it somehow produce FCGI_END_REQUEST,
|
||||
// make sure to send an stdout EOF record
|
||||
// TODO: and if that was not a FCGI_KEEP_CONN request, close the transport
|
||||
}
|
||||
|
||||
static void
|
||||
|
|
@ -1841,23 +1850,24 @@ struct client
|
|||
{
|
||||
LIST_HEADER (struct client)
|
||||
|
||||
// XXX: do we really need this here?
|
||||
struct server_context *ctx; ///< Server context
|
||||
struct client_vtable *vtable; ///< Client behaviour
|
||||
|
||||
int socket_fd; ///< The TCP socket
|
||||
int socket_fd; ///< The network socket
|
||||
bool received_eof; ///< Whether EOF has been received yet
|
||||
bool closing; ///< Whether we're just flushing buffers
|
||||
bool half_closed; ///< Transport half-closed while closing
|
||||
struct write_queue write_queue; ///< Write queue
|
||||
ev_timer flush_timeout_watcher; ///< Write queue flush timer
|
||||
|
||||
ev_io read_watcher; ///< The socket can be read from
|
||||
ev_io write_watcher; ///< The socket can be written to
|
||||
|
||||
struct client_vtable *vtable; ///< Client behaviour
|
||||
};
|
||||
|
||||
/// The concrete behaviour to serve a particular client's requests
|
||||
struct client_vtable
|
||||
{
|
||||
/// Process incoming data; "len == 0" means EOF.
|
||||
/// If the method returns false, the client is destroyed by caller.
|
||||
/// If the method returns false, client_close() is called by the caller.
|
||||
bool (*push) (struct client *client, const void *data, size_t len);
|
||||
|
||||
// TODO: optional push_error() to inform about network I/O errors
|
||||
|
|
@ -1885,8 +1895,8 @@ client_write (struct client *self, const void *data, size_t len)
|
|||
static void
|
||||
client_destroy (struct client *self)
|
||||
{
|
||||
struct server_context *ctx = self->ctx;
|
||||
|
||||
// XXX: this codebase halfway pretends there could be other contexts
|
||||
struct server_context *ctx = ev_userdata (EV_DEFAULT);
|
||||
LIST_UNLINK (ctx->clients, self);
|
||||
ctx->n_clients--;
|
||||
|
||||
|
|
@ -1897,63 +1907,111 @@ client_destroy (struct client *self)
|
|||
ev_io_stop (EV_DEFAULT_ &self->write_watcher);
|
||||
xclose (self->socket_fd);
|
||||
write_queue_free (&self->write_queue);
|
||||
ev_timer_stop (EV_DEFAULT_ &self->flush_timeout_watcher);
|
||||
free (self);
|
||||
|
||||
try_finish_quit (ctx);
|
||||
}
|
||||
|
||||
/// Try to cleanly close the connection, waiting for the remote client to close
|
||||
/// its own side of the connection as a sign that it has processed all the data
|
||||
/// it wanted to. The client implementation will not receive any further data.
|
||||
/// May directly call client_destroy().
|
||||
static void
|
||||
client_close (struct client *self)
|
||||
{
|
||||
if (self->closing)
|
||||
return;
|
||||
|
||||
self->closing = true;
|
||||
ev_timer_start (EV_DEFAULT_ &self->flush_timeout_watcher);
|
||||
ev_feed_event (EV_DEFAULT_ &self->write_watcher, EV_WRITE);
|
||||
|
||||
// We assume the remote client doesn't want our data if it half-closes
|
||||
if (self->received_eof)
|
||||
client_destroy (self);
|
||||
}
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
static bool
|
||||
client_read_loop (EV_P_ struct client *client, ev_io *watcher)
|
||||
{
|
||||
char buf[8192];
|
||||
while (true)
|
||||
ssize_t n_read;
|
||||
again:
|
||||
while ((n_read = recv (watcher->fd, buf, sizeof buf, 0)) >= 0)
|
||||
{
|
||||
ssize_t n_read = recv (watcher->fd, buf, sizeof buf, 0);
|
||||
if (n_read >= 0)
|
||||
if (!n_read)
|
||||
{
|
||||
if (!client->vtable->push (client, buf, n_read))
|
||||
return false;
|
||||
if (!n_read)
|
||||
break;
|
||||
// Don't deliver the EOF condition repeatedly
|
||||
ev_io_stop (EV_A_ watcher);
|
||||
client->received_eof = true;
|
||||
}
|
||||
else if (errno == EAGAIN)
|
||||
return true;
|
||||
else if (errno != EINTR)
|
||||
if (!client->closing
|
||||
&& !client->vtable->push (client, buf, n_read))
|
||||
{
|
||||
client_close (client);
|
||||
return false;
|
||||
}
|
||||
if (!n_read)
|
||||
return true;
|
||||
}
|
||||
if (errno == EINTR)
|
||||
goto again;
|
||||
if (errno == EAGAIN)
|
||||
return true;
|
||||
|
||||
// Don't receive the EOF condition repeatedly
|
||||
ev_io_stop (EV_A_ watcher);
|
||||
|
||||
// We can probably still write, so let's just return
|
||||
// XXX: if there's nothing to be written, shouldn't we close the connection?
|
||||
return true;
|
||||
client_destroy (client);
|
||||
return false;
|
||||
}
|
||||
|
||||
static void
|
||||
on_client_ready (EV_P_ ev_io *watcher, int revents)
|
||||
on_client_readable (EV_P_ ev_io *watcher, int revents)
|
||||
{
|
||||
struct client *client = watcher->data;
|
||||
// XXX: although read and write are in a sequence, if we create response
|
||||
// data, we'll still likely need to go back to the event loop.
|
||||
(void) revents;
|
||||
|
||||
if (revents & EV_READ)
|
||||
if (!client_read_loop (EV_A_ client, watcher))
|
||||
goto close;
|
||||
if (revents & EV_WRITE)
|
||||
// TODO: add "closing link" functionality -> automatic shutdown
|
||||
// (half-close) once we manage to flush the write buffer,
|
||||
// which is logically followed by waiting for an EOF from the client
|
||||
// TODO: some sort of "on_buffers_flushed" callback for streaming huge
|
||||
// chunks of external (or generated) data.
|
||||
if (!flush_queue (&client->write_queue, watcher))
|
||||
goto close;
|
||||
return;
|
||||
if (client_read_loop (EV_A_ client, watcher)
|
||||
&& client->closing && client->received_eof)
|
||||
client_destroy (client);
|
||||
}
|
||||
|
||||
close:
|
||||
client_destroy (client);
|
||||
static void
|
||||
on_client_writable (EV_P_ ev_io *watcher, int revents)
|
||||
{
|
||||
struct client *client = watcher->data;
|
||||
(void) loop;
|
||||
(void) revents;
|
||||
|
||||
// TODO: some sort of "on_buffers_flushed" callback for streaming huge
|
||||
// chunks of external (or generated) data. That will need to be
|
||||
// forwarded to "struct request_handler".
|
||||
if (!flush_queue (&client->write_queue, watcher->fd))
|
||||
{
|
||||
client_destroy (client);
|
||||
return;
|
||||
}
|
||||
if (!write_queue_is_empty (&client->write_queue))
|
||||
return;
|
||||
|
||||
ev_io_stop (EV_A_ watcher);
|
||||
if (client->closing && !client->half_closed)
|
||||
{
|
||||
if (!shutdown (client->socket_fd, SHUT_WR))
|
||||
client->half_closed = true;
|
||||
else
|
||||
client_destroy (client);
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
on_client_timeout (EV_P_ ev_timer *watcher, int revents)
|
||||
{
|
||||
(void) loop;
|
||||
(void) revents;
|
||||
|
||||
client_destroy (watcher->data);
|
||||
}
|
||||
|
||||
/// Create a new instance of a subclass with the given size.
|
||||
|
|
@ -1964,14 +2022,15 @@ client_new (EV_P_ size_t size, int sock_fd)
|
|||
struct server_context *ctx = ev_userdata (loop);
|
||||
struct client *self = xcalloc (1, size);
|
||||
|
||||
self->ctx = ctx;
|
||||
self->write_queue = write_queue_make ();
|
||||
ev_timer_init (&self->flush_timeout_watcher, on_client_timeout, 5., 0.);
|
||||
self->flush_timeout_watcher.data = self;
|
||||
|
||||
set_blocking (sock_fd, false);
|
||||
self->socket_fd = sock_fd;
|
||||
|
||||
ev_io_init (&self->read_watcher, on_client_ready, sock_fd, EV_READ);
|
||||
ev_io_init (&self->write_watcher, on_client_ready, sock_fd, EV_WRITE);
|
||||
ev_io_init (&self->read_watcher, on_client_readable, sock_fd, EV_READ);
|
||||
ev_io_init (&self->write_watcher, on_client_writable, sock_fd, EV_WRITE);
|
||||
self->read_watcher.data = self;
|
||||
self->write_watcher.data = self;
|
||||
|
||||
|
|
@ -2010,37 +2069,36 @@ static void
|
|||
client_fcgi_request_close_cb (struct request *req)
|
||||
{
|
||||
FIND_CONTAINER (self, req, struct client_fcgi_request, request);
|
||||
// No more data to send, terminate the substream/request
|
||||
// XXX: this will most probably end up with client_fcgi_request_destroy(),
|
||||
// we might or might not need to defer this action
|
||||
fcgi_request_finish (self->fcgi_request);
|
||||
struct fcgi_muxer *muxer = self->fcgi_request->muxer;
|
||||
// No more data to send, terminate the substream/request,
|
||||
// and also the transport if the client didn't specifically ask to keep it
|
||||
if (!fcgi_request_finish (self->fcgi_request))
|
||||
muxer->close_cb (muxer);
|
||||
}
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
static bool
|
||||
client_fcgi_request_start
|
||||
(struct fcgi_muxer *mux, struct fcgi_request *fcgi_request)
|
||||
client_fcgi_request_start (struct fcgi_request *fcgi_request)
|
||||
{
|
||||
FIND_CONTAINER (self, mux, struct client_fcgi, muxer);
|
||||
|
||||
struct client_fcgi_request *request =
|
||||
fcgi_request->handler_data = xcalloc (1, sizeof *request);
|
||||
request->fcgi_request = fcgi_request;
|
||||
request_init (&request->request);
|
||||
request->request.ctx = self->client.ctx;
|
||||
request->request.ctx = ev_userdata (EV_DEFAULT);
|
||||
request->request.write_cb = client_fcgi_request_write_cb;
|
||||
request->request.close_cb = client_fcgi_request_close_cb;
|
||||
|
||||
return request_start (&request->request, &fcgi_request->headers);
|
||||
}
|
||||
|
||||
static void
|
||||
static bool
|
||||
client_fcgi_request_push
|
||||
(struct fcgi_request *req, const void *data, size_t len)
|
||||
{
|
||||
struct client_fcgi_request *request = req->handler_data;
|
||||
request_push (&request->request, data, len);
|
||||
return request_push (&request->request, data, len)
|
||||
|| fcgi_request_finish (req);
|
||||
}
|
||||
|
||||
static void
|
||||
|
|
@ -2064,9 +2122,7 @@ static void
|
|||
client_fcgi_close_cb (struct fcgi_muxer *mux)
|
||||
{
|
||||
FIND_CONTAINER (self, mux, struct client_fcgi, muxer);
|
||||
// FIXME: we should probably call something like client_shutdown(),
|
||||
// which may have an argument whether we should really use close()
|
||||
client_destroy (&self->client);
|
||||
client_close (&self->client);
|
||||
}
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
|
@ -2137,11 +2193,9 @@ client_scgi_write_cb (struct request *req, const void *data, size_t len)
|
|||
static void
|
||||
client_scgi_close_cb (struct request *req)
|
||||
{
|
||||
// NOTE: this rather really means "close me [the request]"
|
||||
FIND_CONTAINER (self, req, struct client_scgi, request);
|
||||
// FIXME: we should probably call something like client_shutdown(),
|
||||
// which may have an argument whether we should really use close()
|
||||
client_destroy (&self->client);
|
||||
// NOTE: this rather really means "close me [the request]"
|
||||
client_close (&self->client);
|
||||
}
|
||||
|
||||
static bool
|
||||
|
|
@ -2201,7 +2255,6 @@ client_scgi_create (EV_P_ int sock_fd)
|
|||
self->client.vtable = &client_scgi_vtable;
|
||||
|
||||
request_init (&self->request);
|
||||
self->request.ctx = self->client.ctx;
|
||||
self->request.write_cb = client_scgi_write_cb;
|
||||
self->request.close_cb = client_scgi_close_cb;
|
||||
|
||||
|
|
@ -2231,8 +2284,9 @@ client_ws_on_message (struct ws_handler *handler,
|
|||
return false;
|
||||
}
|
||||
|
||||
struct server_context *ctx = ev_userdata (EV_DEFAULT);
|
||||
struct str response = str_make ();
|
||||
process_json_rpc (self->client.ctx, data, len, &response);
|
||||
process_json_rpc (ctx, data, len, &response);
|
||||
if (response.len)
|
||||
ws_handler_send (&self->handler,
|
||||
WS_OPCODE_TEXT, response.str, response.len);
|
||||
|
|
|
|||
Loading…
Reference in New Issue