From 176b159d70cb26b24ce928497ae269b294e503d8 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 20 Aug 2012 10:21:54 +0100 Subject: [PATCH] net: asynchronous send/receive infrastructure for net/socket.c The net/socket.c net client is not truly asynchronous. This patch borrows the qemu_set_fd_handler2() code from net/tap.c as the basis for proper asynchronous send/receive. Only read packets from the socket when the peer is able to receive. This avoids needless queuing. Later patches implement asynchronous send. Signed-off-by: Stefan Hajnoczi (cherry picked from commit 863f678fba4191f3b695620f41056cb7c124425d) Signed-off-by: Michael Roth --- net/socket.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 52 insertions(+), 6 deletions(-) diff --git a/net/socket.c b/net/socket.c index c172c24..54e32f0 100644 --- a/net/socket.c +++ b/net/socket.c @@ -42,9 +42,51 @@ typedef struct NetSocketState { unsigned int packet_len; uint8_t buf[4096]; struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */ + IOHandler *send_fn; /* differs between SOCK_STREAM/SOCK_DGRAM */ + bool read_poll; /* waiting to receive data? */ + bool write_poll; /* waiting to transmit data? */ } NetSocketState; static void net_socket_accept(void *opaque); +static void net_socket_writable(void *opaque); + +/* Only read packets from socket when peer can receive them */ +static int net_socket_can_send(void *opaque) +{ + NetSocketState *s = opaque; + + return qemu_can_send_packet(&s->nc); +} + +static void net_socket_update_fd_handler(NetSocketState *s) +{ + qemu_set_fd_handler2(s->fd, + s->read_poll ? net_socket_can_send : NULL, + s->read_poll ? s->send_fn : NULL, + s->write_poll ? net_socket_writable : NULL, + s); +} + +static void net_socket_read_poll(NetSocketState *s, bool enable) +{ + s->read_poll = enable; + net_socket_update_fd_handler(s); +} + +static void net_socket_write_poll(NetSocketState *s, bool enable) +{ + s->write_poll = enable; + net_socket_update_fd_handler(s); +} + +static void net_socket_writable(void *opaque) +{ + NetSocketState *s = opaque; + + net_socket_write_poll(s, false); + + qemu_flush_queued_packets(&s->nc); +} /* XXX: we consider we can send the whole packet without blocking */ static ssize_t net_socket_receive(NetClientState *nc, const uint8_t *buf, size_t size) @@ -81,7 +123,8 @@ static void net_socket_send(void *opaque) } else if (size == 0) { /* end of connection */ eoc: - qemu_set_fd_handler(s->fd, NULL, NULL, NULL); + net_socket_read_poll(s, false); + net_socket_write_poll(s, false); if (s->listen_fd != -1) { qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s); } @@ -152,7 +195,8 @@ static void net_socket_send_dgram(void *opaque) return; if (size == 0) { /* end of connection */ - qemu_set_fd_handler(s->fd, NULL, NULL, NULL); + net_socket_read_poll(s, false); + net_socket_write_poll(s, false); return; } qemu_send_packet(&s->nc, s->buf, size); @@ -243,7 +287,8 @@ static void net_socket_cleanup(NetClientState *nc) { NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc); if (s->fd != -1) { - qemu_set_fd_handler(s->fd, NULL, NULL, NULL); + net_socket_read_poll(s, false); + net_socket_write_poll(s, false); close(s->fd); s->fd = -1; } @@ -314,8 +359,8 @@ static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer, s->fd = fd; s->listen_fd = -1; - - qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s); + s->send_fn = net_socket_send_dgram; + net_socket_read_poll(s, true); /* mcast: save bound address as dst */ if (is_connected) { @@ -332,7 +377,8 @@ err: static void net_socket_connect(void *opaque) { NetSocketState *s = opaque; - qemu_set_fd_handler(s->fd, net_socket_send, NULL, s); + s->send_fn = net_socket_send; + net_socket_read_poll(s, true); } static NetClientInfo net_socket_info = {