* [Qemu-devel] [PATCH 1/3] util: remove the obsolete non-blocking connect
2016-07-28 7:39 [Qemu-devel] [PATCH 0/3] Remove obsolete non-blocking connect Cao jin
@ 2016-07-28 7:39 ` Cao jin
2016-07-28 8:07 ` Daniel P. Berrange
2016-07-28 7:39 ` [Qemu-devel] [PATCH 2/3] util: fix some coding style issue Cao jin
2016-07-28 7:39 ` [Qemu-devel] [PATCH 3/3] migration/socket: fix typo in file header Cao jin
2 siblings, 1 reply; 8+ messages in thread
From: Cao jin @ 2016-07-28 7:39 UTC (permalink / raw)
To: qemu-devel; +Cc: Daniel P. Berrange, Gerd Hoffmann, Paolo Bonzini
The non-blocking connect mechanism is obsolete, and it doesn't work well
in inet connection, because it will call getaddrinfo first and getaddrinfo
will blocks on DNS lookups. Since commit e65c67e4 & d984464e, the non-blocking
connect of migration goes through QIOChannel in a different manner(using a
thread), and nobody use this old non-blocking connect anymore.
Any newly written code which needs a non-blocking connect should use the
QIOChannel code, so we can just rip out NonBlockingConnectHandler as a
concept entirely.
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
---
include/qemu/sockets.h | 7 +--
io/channel-socket.c | 2 +-
net/socket.c | 2 +-
util/qemu-sockets.c | 163 +++++--------------------------------------------
4 files changed, 19 insertions(+), 155 deletions(-)
diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
index 9eb2470..9e7c322 100644
--- a/include/qemu/sockets.h
+++ b/include/qemu/sockets.h
@@ -27,10 +27,6 @@ int socket_set_fast_reuse(int fd);
#define SHUT_RDWR 2
#endif
-/* callback function for nonblocking connect
- * valid fd on success, negative error code on failure
- */
-typedef void NonBlockingConnectHandler(int fd, Error *err, void *opaque);
InetSocketAddress *inet_parse(const char *str, Error **errp);
int inet_connect(const char *str, Error **errp);
@@ -41,8 +37,7 @@ int unix_listen(const char *path, char *ostr, int olen, Error **errp);
int unix_connect(const char *path, Error **errp);
SocketAddress *socket_parse(const char *str, Error **errp);
-int socket_connect(SocketAddress *addr, Error **errp,
- NonBlockingConnectHandler *callback, void *opaque);
+int socket_connect(SocketAddress *addr, Error **errp);
int socket_listen(SocketAddress *addr, Error **errp);
void socket_listen_cleanup(int fd, Error **errp);
int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp);
diff --git a/io/channel-socket.c b/io/channel-socket.c
index 196a4f1..6aa0ad2 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -147,7 +147,7 @@ int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
int fd;
trace_qio_channel_socket_connect_sync(ioc, addr);
- fd = socket_connect(addr, errp, NULL, NULL);
+ fd = socket_connect(addr, errp);
if (fd < 0) {
trace_qio_channel_socket_connect_fail(ioc);
return -1;
diff --git a/net/socket.c b/net/socket.c
index ae6f921..8037b3c 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -541,7 +541,7 @@ static int net_socket_connect_init(NetClientState *peer,
qemu_set_nonblock(fd);
connected = 0;
for(;;) {
- ret = socket_connect(saddr, &local_error, NULL, NULL);
+ ret = socket_connect(saddr, &local_error);
if (ret < 0) {
if (errno == EINTR || errno == EWOULDBLOCK) {
/* continue */
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index b4314ca..cd4ed55 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -239,96 +239,18 @@ listen:
return slisten;
}
-#ifdef _WIN32
-#define QEMU_SOCKET_RC_INPROGRESS(rc) \
- ((rc) == -EINPROGRESS || (rc) == -EWOULDBLOCK || (rc) == -WSAEALREADY)
-#else
-#define QEMU_SOCKET_RC_INPROGRESS(rc) \
- ((rc) == -EINPROGRESS)
-#endif
-
-/* Struct to store connect state for non blocking connect */
-typedef struct ConnectState {
- int fd;
- struct addrinfo *addr_list;
- struct addrinfo *current_addr;
- NonBlockingConnectHandler *callback;
- void *opaque;
-} ConnectState;
-
-static int inet_connect_addr(struct addrinfo *addr, bool *in_progress,
- ConnectState *connect_state, Error **errp);
-
-static void wait_for_connect(void *opaque)
-{
- ConnectState *s = opaque;
- int val = 0, rc = 0;
- socklen_t valsize = sizeof(val);
- bool in_progress;
- Error *err = NULL;
-
- qemu_set_fd_handler(s->fd, NULL, NULL, NULL);
-
- do {
- rc = qemu_getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &val, &valsize);
- } while (rc == -1 && errno == EINTR);
-
- /* update rc to contain error */
- if (!rc && val) {
- rc = -1;
- errno = val;
- }
-
- /* connect error */
- if (rc < 0) {
- error_setg_errno(&err, errno, "Error connecting to socket");
- closesocket(s->fd);
- s->fd = rc;
- }
-
- /* try to connect to the next address on the list */
- if (s->current_addr) {
- while (s->current_addr->ai_next != NULL && s->fd < 0) {
- s->current_addr = s->current_addr->ai_next;
- s->fd = inet_connect_addr(s->current_addr, &in_progress, s, NULL);
- if (s->fd < 0) {
- error_free(err);
- err = NULL;
- error_setg_errno(&err, errno, "Unable to start socket connect");
- }
- /* connect in progress */
- if (in_progress) {
- goto out;
- }
- }
-
- freeaddrinfo(s->addr_list);
- }
- if (s->callback) {
- s->callback(s->fd, err, s->opaque);
- }
- g_free(s);
-out:
- error_free(err);
-}
-
-static int inet_connect_addr(struct addrinfo *addr, bool *in_progress,
- ConnectState *connect_state, Error **errp)
+static int inet_connect_addr(struct addrinfo *addr, Error **errp)
{
int sock, rc;
- *in_progress = false;
-
sock = qemu_socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
if (sock < 0) {
error_setg_errno(errp, errno, "Failed to create socket");
return -1;
}
socket_set_fast_reuse(sock);
- if (connect_state != NULL) {
- qemu_set_nonblock(sock);
- }
+
/* connect to peer */
do {
rc = 0;
@@ -337,15 +259,12 @@ static int inet_connect_addr(struct addrinfo *addr, bool *in_progress,
}
} while (rc == -EINTR);
- if (connect_state != NULL && QEMU_SOCKET_RC_INPROGRESS(rc)) {
- connect_state->fd = sock;
- qemu_set_fd_handler(sock, NULL, wait_for_connect, connect_state);
- *in_progress = true;
- } else if (rc < 0) {
+ if (rc < 0) {
error_setg_errno(errp, errno, "Failed to connect socket");
closesocket(sock);
return -1;
}
+
return sock;
}
@@ -403,43 +322,25 @@ static struct addrinfo *inet_parse_connect_saddr(InetSocketAddress *saddr,
*
* @saddr: Inet socket address specification
* @errp: set on error
- * @callback: callback function for non-blocking connect
- * @opaque: opaque for callback function
*
* Returns: -1 on error, file descriptor on success.
- *
- * If @callback is non-null, the connect is non-blocking. If this
- * function succeeds, callback will be called when the connection
- * completes, with the file descriptor on success, or -1 on error.
*/
-static int inet_connect_saddr(InetSocketAddress *saddr, Error **errp,
- NonBlockingConnectHandler *callback, void *opaque)
+static int inet_connect_saddr(InetSocketAddress *saddr, Error **errp)
{
Error *local_err = NULL;
struct addrinfo *res, *e;
int sock = -1;
- bool in_progress;
- ConnectState *connect_state = NULL;
res = inet_parse_connect_saddr(saddr, errp);
if (!res) {
return -1;
}
- if (callback != NULL) {
- connect_state = g_malloc0(sizeof(*connect_state));
- connect_state->addr_list = res;
- connect_state->callback = callback;
- connect_state->opaque = opaque;
- }
-
for (e = res; e != NULL; e = e->ai_next) {
error_free(local_err);
local_err = NULL;
- if (connect_state != NULL) {
- connect_state->current_addr = e;
- }
- sock = inet_connect_addr(e, &in_progress, connect_state, &local_err);
+
+ sock = inet_connect_addr(e, &local_err);
if (sock >= 0) {
break;
}
@@ -447,16 +348,10 @@ static int inet_connect_saddr(InetSocketAddress *saddr, Error **errp,
if (sock < 0) {
error_propagate(errp, local_err);
- } else if (in_progress) {
- /* wait_for_connect() will do the rest */
- return sock;
- } else {
- if (callback) {
- callback(sock, NULL, opaque);
- }
}
- g_free(connect_state);
+
freeaddrinfo(res);
+
return sock;
}
@@ -640,7 +535,7 @@ int inet_connect(const char *str, Error **errp)
addr = inet_parse(str, errp);
if (addr != NULL) {
- sock = inet_connect_saddr(addr, errp, NULL, NULL);
+ sock = inet_connect_saddr(addr, errp);
qapi_free_InetSocketAddress(addr);
}
return sock;
@@ -716,11 +611,9 @@ err:
return -1;
}
-static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp,
- NonBlockingConnectHandler *callback, void *opaque)
+static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
{
struct sockaddr_un un;
- ConnectState *connect_state = NULL;
int sock, rc;
if (saddr->path == NULL) {
@@ -733,12 +626,6 @@ static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp,
error_setg_errno(errp, errno, "Failed to create socket");
return -1;
}
- if (callback != NULL) {
- connect_state = g_malloc0(sizeof(*connect_state));
- connect_state->callback = callback;
- connect_state->opaque = opaque;
- qemu_set_nonblock(sock);
- }
memset(&un, 0, sizeof(un));
un.sun_family = AF_UNIX;
@@ -752,24 +639,12 @@ static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp,
}
} while (rc == -EINTR);
- if (connect_state != NULL && QEMU_SOCKET_RC_INPROGRESS(rc)) {
- connect_state->fd = sock;
- qemu_set_fd_handler(sock, NULL, wait_for_connect, connect_state);
- return sock;
- } else if (rc >= 0) {
- /* non blocking socket immediate success, call callback */
- if (callback != NULL) {
- callback(sock, NULL, opaque);
- }
- }
-
if (rc < 0) {
error_setg_errno(errp, -rc, "Failed to connect socket");
close(sock);
sock = -1;
}
- g_free(connect_state);
return sock;
}
@@ -784,8 +659,7 @@ static int unix_listen_saddr(UnixSocketAddress *saddr,
return -1;
}
-static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp,
- NonBlockingConnectHandler *callback, void *opaque)
+static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
{
error_setg(errp, "unix sockets are not available on windows");
errno = ENOTSUP;
@@ -829,7 +703,7 @@ int unix_connect(const char *path, Error **errp)
saddr = g_new0(UnixSocketAddress, 1);
saddr->path = g_strdup(path);
- sock = unix_connect_saddr(saddr, errp, NULL, NULL);
+ sock = unix_connect_saddr(saddr, errp);
qapi_free_UnixSocketAddress(saddr);
return sock;
}
@@ -872,26 +746,21 @@ fail:
return NULL;
}
-int socket_connect(SocketAddress *addr, Error **errp,
- NonBlockingConnectHandler *callback, void *opaque)
+int socket_connect(SocketAddress *addr, Error **errp)
{
int fd;
switch (addr->type) {
case SOCKET_ADDRESS_KIND_INET:
- fd = inet_connect_saddr(addr->u.inet.data, errp, callback, opaque);
+ fd = inet_connect_saddr(addr->u.inet.data, errp);
break;
case SOCKET_ADDRESS_KIND_UNIX:
- fd = unix_connect_saddr(addr->u.q_unix.data, errp, callback, opaque);
+ fd = unix_connect_saddr(addr->u.q_unix.data, errp);
break;
case SOCKET_ADDRESS_KIND_FD:
fd = monitor_get_fd(cur_mon, addr->u.fd.data->str, errp);
- if (fd >= 0 && callback) {
- qemu_set_nonblock(fd);
- callback(fd, NULL, opaque);
- }
break;
default:
--
2.1.0
^ permalink raw reply related [flat|nested] 8+ messages in thread