degesch: clean up the async code a bit

This commit is contained in:
Přemysl Eric Janouch 2015-07-03 23:30:54 +02:00
parent 2357f1382a
commit 7de1309421
1 changed files with 90 additions and 70 deletions

142
degesch.c
View File

@ -1065,9 +1065,9 @@ struct transport
void (*cleanup) (struct server *s); void (*cleanup) (struct server *s);
/// The underlying socket may have become readable, update `read_buffer' /// The underlying socket may have become readable, update `read_buffer'
enum transport_io_result (*on_readable) (struct server *s); enum transport_io_result (*try_read) (struct server *s);
/// The underlying socket may have become writeable, flush `write_buffer' /// The underlying socket may have become writeable, flush `write_buffer'
enum transport_io_result (*on_writeable) (struct server *s); enum transport_io_result (*try_write) (struct server *s);
/// Return event mask to use in the poller /// Return event mask to use in the poller
int (*get_poll_events) (struct server *s); int (*get_poll_events) (struct server *s);
@ -3203,7 +3203,9 @@ irc_send (struct server *s, const char *format, ...)
print_debug ("tried sending a message to a dead server connection"); print_debug ("tried sending a message to a dead server connection");
return; return;
} }
if (s->state == IRC_CLOSING)
if (s->state == IRC_CLOSING
|| s->state == IRC_HALF_CLOSED)
return; return;
va_list ap; va_list ap;
@ -3329,7 +3331,7 @@ initiate_quit (struct app_context *ctx)
} }
static void static void
on_irc_disconnected (struct server *s) irc_disconnect (struct server *s)
{ {
hard_assert (irc_is_connected (s)); hard_assert (irc_is_connected (s));
@ -3337,6 +3339,7 @@ on_irc_disconnected (struct server *s)
if (s->transport if (s->transport
&& s->transport->cleanup) && s->transport->cleanup)
s->transport->cleanup (s); s->transport->cleanup (s);
s->transport = NULL;
xclose (s->socket); xclose (s->socket);
s->socket = -1; s->socket = -1;
@ -3403,7 +3406,7 @@ on_irc_ping_timeout (void *user_data)
{ {
struct server *s = user_data; struct server *s = user_data;
log_server_error (s, s->buffer, "Connection timeout"); log_server_error (s, s->buffer, "Connection timeout");
on_irc_disconnected (s); irc_disconnect (s);
} }
static void static void
@ -3419,74 +3422,91 @@ on_irc_timeout (void *user_data)
static void irc_process_message static void irc_process_message
(const struct irc_message *msg, const char *raw, void *user_data); (const struct irc_message *msg, const char *raw, void *user_data);
static void static enum transport_io_result
on_irc_ready (const struct pollfd *pfd, struct server *s) irc_try_read (struct server *s)
{
enum transport_io_result result = s->transport->try_read (s);
if (result == TRANSPORT_IO_OK)
{ {
struct transport *transport = s->transport;
enum transport_io_result result;
if ((result = transport->on_readable (s)) == TRANSPORT_IO_ERROR)
goto error;
bool read_eof = result == TRANSPORT_IO_EOF;
if (s->read_buffer.len >= (1 << 20)) if (s->read_buffer.len >= (1 << 20))
{ {
// XXX: this is stupid; if anything, count it in dependence of time // XXX: this is stupid; if anything, count it in dependence of time
log_server_error (s, s->buffer, log_server_error (s, s->buffer,
"The IRC server seems to spew out data frantically"); "The IRC server seems to spew out data frantically");
goto disconnect; return TRANSPORT_IO_ERROR;
} }
if (s->read_buffer.len) if (s->read_buffer.len)
irc_process_buffer (&s->read_buffer, irc_process_message, s); irc_process_buffer (&s->read_buffer, irc_process_message, s);
}
if ((result = transport->on_writeable (s)) == TRANSPORT_IO_ERROR) return result;
goto error;
bool write_eof = result == TRANSPORT_IO_EOF;
// FIXME: this may probably fire multiple times if we're flushing after it,
// we should probably store this information next to the state
if (read_eof || write_eof)
log_server_error (s, s->buffer, "The IRC server closed the connection");
// It makes no sense to flush anything if the write needs to read
// and we receive an EOF -> disconnect right away
if (write_eof)
goto disconnect;
// If we've been asked to flush the write buffer and our job is complete,
// we send an EOF to the server, changing the state to IRC_HALF_CLOSED
if (s->state == IRC_CLOSING && !s->write_buffer.len)
irc_real_shutdown (s);
if (read_eof)
{
// Both ends closed, we're done
if (s->state == IRC_HALF_CLOSED)
goto disconnect;
// Otherwise we want to flush the write buffer
irc_shutdown (s);
// If that went well, we can disconnect now
if (s->state == IRC_HALF_CLOSED)
goto disconnect;
} }
static enum transport_io_result
irc_try_write (struct server *s)
{
enum transport_io_result result = s->transport->try_write (s);
if (result == TRANSPORT_IO_OK)
{
// If we're flushing the write buffer and our job is complete, we send
// an EOF to the server, changing the state to IRC_HALF_CLOSED
if (s->state == IRC_CLOSING && !s->write_buffer.len)
irc_real_shutdown (s);
}
return result;
}
static bool
irc_try_read_write (struct server *s)
{
enum transport_io_result read_result;
enum transport_io_result write_result;
if ((read_result = irc_try_read (s)) == TRANSPORT_IO_ERROR
|| (write_result = irc_try_write (s)) == TRANSPORT_IO_ERROR)
{
log_server_error (s, s->buffer, "Server connection failed");
return false;
}
// FIXME: this may probably fire multiple times when we're flushing,
// we should probably store a flag next to the state
if (read_result == TRANSPORT_IO_EOF
|| write_result == TRANSPORT_IO_EOF)
log_server_error (s, s->buffer, "Server closed the connection");
// If the write needs to read and we receive an EOF, we can't flush
if (write_result == TRANSPORT_IO_EOF)
return false;
if (read_result == TRANSPORT_IO_EOF)
{
// Eventually initiate shutdown to flush the write buffer
irc_shutdown (s);
// If there's nothing to write, we can disconnect now
if (s->state == IRC_HALF_CLOSED)
return false;
}
return true;
}
static void
on_irc_ready (const struct pollfd *pfd, struct server *s)
{
if (irc_try_read_write (s))
{
// XXX: shouldn't we rather wait for PONG messages? // XXX: shouldn't we rather wait for PONG messages?
irc_reset_connection_timeouts (s); irc_reset_connection_timeouts (s);
irc_update_poller (s, pfd); irc_update_poller (s, pfd);
return; }
else
error: // We don't want to keep the socket anymore
log_server_error (s, s->buffer, "Reading from the IRC server failed"); irc_disconnect (s);
disconnect:
on_irc_disconnected (s);
} }
// --- Plain transport --------------------------------------------------------- // --- Plain transport ---------------------------------------------------------
static enum transport_io_result static enum transport_io_result
transport_plain_on_readable (struct server *s) transport_plain_try_read (struct server *s)
{ {
struct str *buf = &s->read_buffer; struct str *buf = &s->read_buffer;
ssize_t n_read; ssize_t n_read;
@ -3516,7 +3536,7 @@ transport_plain_on_readable (struct server *s)
} }
static enum transport_io_result static enum transport_io_result
transport_plain_on_writeable (struct server *s) transport_plain_try_write (struct server *s)
{ {
struct str *buf = &s->write_buffer; struct str *buf = &s->write_buffer;
ssize_t n_written; ssize_t n_written;
@ -3552,8 +3572,8 @@ transport_plain_get_poll_events (struct server *s)
static struct transport g_transport_plain = static struct transport g_transport_plain =
{ {
.on_readable = transport_plain_on_readable, .try_read = transport_plain_try_read,
.on_writeable = transport_plain_on_writeable, .try_write = transport_plain_try_write,
.get_poll_events = transport_plain_get_poll_events, .get_poll_events = transport_plain_get_poll_events,
}; };
@ -3696,7 +3716,7 @@ transport_tls_cleanup (struct server *s)
} }
static enum transport_io_result static enum transport_io_result
transport_tls_on_readable (struct server *s) transport_tls_try_read (struct server *s)
{ {
struct transport_tls_data *data = s->transport_data; struct transport_tls_data *data = s->transport_data;
if (data->ssl_tx_want_rx) if (data->ssl_tx_want_rx)
@ -3733,7 +3753,7 @@ transport_tls_on_readable (struct server *s)
} }
static enum transport_io_result static enum transport_io_result
transport_tls_on_writeable (struct server *s) transport_tls_try_write (struct server *s)
{ {
struct transport_tls_data *data = s->transport_data; struct transport_tls_data *data = s->transport_data;
if (data->ssl_rx_want_tx) if (data->ssl_rx_want_tx)
@ -3794,8 +3814,8 @@ static struct transport g_transport_tls =
{ {
.init = transport_tls_init, .init = transport_tls_init,
.cleanup = transport_tls_cleanup, .cleanup = transport_tls_cleanup,
.on_readable = transport_tls_on_readable, .try_read = transport_tls_try_read,
.on_writeable = transport_tls_on_writeable, .try_write = transport_tls_try_write,
.get_poll_events = transport_tls_get_poll_events, .get_poll_events = transport_tls_get_poll_events,
.in_before_shutdown = transport_tls_in_before_shutdown, .in_before_shutdown = transport_tls_in_before_shutdown,
}; };