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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH] tools/xenstore: simplify xenstored main loop
The main loop of xenstored is rather complicated due to different
handling of socket and ring-page interfaces. Unify that handling by
introducing interface type specific functions can_read() and
can_write().
Put the interface type specific functions in an own structure and let
struct connection contain only a pointer to that new function vector.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
tools/xenstore/xenstored_core.c | 117 ++++++++++++++----------------
tools/xenstore/xenstored_core.h | 19 ++---
tools/xenstore/xenstored_domain.c | 11 ++-
3 files changed, 73 insertions(+), 74 deletions(-)
diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 4b7b71cfb3..b66d119a98 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -226,8 +226,8 @@ static bool write_messages(struct connection *conn)
sockmsg_string(out->hdr.msg.type),
out->hdr.msg.len,
out->buffer, conn);
- ret = conn->write(conn, out->hdr.raw + out->used,
- sizeof(out->hdr) - out->used);
+ ret = conn->funcs->write(conn, out->hdr.raw + out->used,
+ sizeof(out->hdr) - out->used);
if (ret < 0)
return false;
@@ -243,8 +243,8 @@ static bool write_messages(struct connection *conn)
return true;
}
- ret = conn->write(conn, out->buffer + out->used,
- out->hdr.msg.len - out->used);
+ ret = conn->funcs->write(conn, out->buffer + out->used,
+ out->hdr.msg.len - out->used);
if (ret < 0)
return false;
@@ -1531,8 +1531,8 @@ static void handle_input(struct connection *conn)
/* Not finished header yet? */
if (in->inhdr) {
if (in->used != sizeof(in->hdr)) {
- bytes = conn->read(conn, in->hdr.raw + in->used,
- sizeof(in->hdr) - in->used);
+ bytes = conn->funcs->read(conn, in->hdr.raw + in->used,
+ sizeof(in->hdr) - in->used);
if (bytes < 0)
goto bad_client;
in->used += bytes;
@@ -1557,8 +1557,8 @@ static void handle_input(struct connection *conn)
in->inhdr = false;
}
- bytes = conn->read(conn, in->buffer + in->used,
- in->hdr.msg.len - in->used);
+ bytes = conn->funcs->read(conn, in->buffer + in->used,
+ in->hdr.msg.len - in->used);
if (bytes < 0)
goto bad_client;
@@ -1581,7 +1581,7 @@ static void handle_output(struct connection *conn)
ignore_connection(conn);
}
-struct connection *new_connection(connwritefn_t *write, connreadfn_t *read)
+struct connection *new_connection(struct interface_funcs *funcs)
{
struct connection *new;
@@ -1591,8 +1591,7 @@ struct connection *new_connection(connwritefn_t *write,
connreadfn_t *read)
new->fd = -1;
new->pollfd_idx = -1;
- new->write = write;
- new->read = read;
+ new->funcs = funcs;
new->is_ignored = false;
new->transaction_started = 0;
INIT_LIST_HEAD(&new->out_list);
@@ -1622,17 +1621,7 @@ static void accept_connection(int sock)
{
}
-int writefd(struct connection *conn, const void *data, unsigned int len)
-{
- errno = EBADF;
- return -1;
-}
-
-int readfd(struct connection *conn, void *data, unsigned int len)
-{
- errno = EBADF;
- return -1;
-}
+struct interface_funcs socket_funcs;
#else
int writefd(struct connection *conn, const void *data, unsigned int len)
{
@@ -1672,6 +1661,29 @@ int readfd(struct connection *conn, void *data, unsigned
int len)
return rc;
}
+static bool socket_can_process(struct connection *conn, int mask)
+{
+ if (conn->pollfd_idx == -1)
+ return false;
+
+ if (fds[conn->pollfd_idx].revents & ~(POLLIN | POLLOUT)) {
+ talloc_free(conn);
+ return false;
+ }
+
+ return (fds[conn->pollfd_idx].revents & mask) && !conn->is_ignored;
+}
+
+static bool socket_can_write(struct connection *conn)
+{
+ return socket_can_process(conn, POLLOUT);
+}
+
+static bool socket_can_read(struct connection *conn)
+{
+ return socket_can_process(conn, POLLIN);
+}
+
static void accept_connection(int sock)
{
int fd;
@@ -1681,12 +1693,19 @@ static void accept_connection(int sock)
if (fd < 0)
return;
- conn = new_connection(writefd, readfd);
+ conn = new_connection(&socket_funcs);
if (conn)
conn->fd = fd;
else
close(fd);
}
+
+struct interface_funcs socket_funcs = {
+ .write = writefd,
+ .read = readfd,
+ .can_write = socket_can_write,
+ .can_read = socket_can_read,
+};
#endif
static int tdb_flags;
@@ -2304,47 +2323,19 @@ int main(int argc, char *argv[])
if (&next->list != &connections)
talloc_increase_ref_count(next);
- if (conn->domain) {
- if (domain_can_read(conn))
- handle_input(conn);
- if (talloc_free(conn) == 0)
- continue;
-
- talloc_increase_ref_count(conn);
- if (domain_can_write(conn) &&
- !list_empty(&conn->out_list))
- handle_output(conn);
- if (talloc_free(conn) == 0)
- continue;
- } else {
- if (conn->pollfd_idx != -1) {
- if (fds[conn->pollfd_idx].revents
- & ~(POLLIN|POLLOUT))
- talloc_free(conn);
- else if ((fds[conn->pollfd_idx].revents
- & POLLIN) &&
- !conn->is_ignored)
- handle_input(conn);
- }
- if (talloc_free(conn) == 0)
- continue;
-
- talloc_increase_ref_count(conn);
-
- if (conn->pollfd_idx != -1) {
- if (fds[conn->pollfd_idx].revents
- & ~(POLLIN|POLLOUT))
- talloc_free(conn);
- else if ((fds[conn->pollfd_idx].revents
- & POLLOUT) &&
- !conn->is_ignored)
- handle_output(conn);
- }
- if (talloc_free(conn) == 0)
- continue;
+ if (conn->funcs->can_read(conn))
+ handle_input(conn);
+ if (talloc_free(conn) == 0)
+ continue;
- conn->pollfd_idx = -1;
- }
+ talloc_increase_ref_count(conn);
+
+ if (conn->funcs->can_write(conn))
+ handle_output(conn);
+ if (talloc_free(conn) == 0)
+ continue;
+
+ conn->pollfd_idx = -1;
}
if (delayed_requests) {
diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 6a6d0448e8..1467270476 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -86,8 +86,13 @@ struct delayed_request {
};
struct connection;
-typedef int connwritefn_t(struct connection *, const void *, unsigned int);
-typedef int connreadfn_t(struct connection *, void *, unsigned int);
+
+struct interface_funcs {
+ int (*write)(struct connection *, const void *, unsigned int);
+ int (*read)(struct connection *, void *, unsigned int);
+ bool (*can_write)(struct connection *);
+ bool (*can_read)(struct connection *);
+};
struct connection
{
@@ -131,9 +136,8 @@ struct connection
/* My watches. */
struct list_head watches;
- /* Methods for communicating over this connection: write can be NULL */
- connwritefn_t *write;
- connreadfn_t *read;
+ /* Methods for communicating over this connection. */
+ struct interface_funcs *funcs;
/* Support for live update: connection id. */
unsigned int conn_id;
@@ -196,7 +200,7 @@ int write_node_raw(struct connection *conn, TDB_DATA *key,
struct node *node,
struct node *read_node(struct connection *conn, const void *ctx,
const char *name);
-struct connection *new_connection(connwritefn_t *write, connreadfn_t *read);
+struct connection *new_connection(struct interface_funcs *funcs);
struct connection *get_connection_by_id(unsigned int conn_id);
void check_store(void);
void corrupt(struct connection *conn, const char *fmt, ...);
@@ -254,9 +258,6 @@ void finish_daemonize(void);
/* Open a pipe for signal handling */
void init_pipe(int reopen_log_pipe[2]);
-int writefd(struct connection *conn, const void *data, unsigned int len);
-int readfd(struct connection *conn, void *data, unsigned int len);
-
extern struct interface_funcs socket_funcs;
extern xengnttab_handle **xgt_handle;
diff --git a/tools/xenstore/xenstored_domain.c
b/tools/xenstore/xenstored_domain.c
index 0c17937c0f..6e0fa6e861 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -172,6 +172,13 @@ static int readchn(struct connection *conn, void *data,
unsigned int len)
return len;
}
+static struct interface_funcs domain_funcs = {
+ .write = writechn,
+ .read = readchn,
+ .can_write = domain_can_write,
+ .can_read = domain_can_read,
+};
+
static void *map_interface(domid_t domid)
{
return xengnttab_map_grant_ref(*xgt_handle, domid,
@@ -389,7 +396,7 @@ static int new_domain(struct domain *domain, int port, bool
restore)
domain->introduced = true;
- domain->conn = new_connection(writechn, readchn);
+ domain->conn = new_connection(&domain_funcs);
if (!domain->conn) {
errno = ENOMEM;
return errno;
@@ -1288,7 +1295,7 @@ void read_state_connection(const void *ctx, const void
*state)
struct domain *domain, *tdomain;
if (sc->conn_type == XS_STATE_CONN_TYPE_SOCKET) {
- conn = new_connection(writefd, readfd);
+ conn = new_connection(&socket_funcs);
if (!conn)
barf("error restoring connection");
conn->fd = sc->spec.socket_fd;
--
2.26.2
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