Hi Juergen,
On 18/05/2021 07:19, Juergen Gross wrote:
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().
Take the opportunity to remove the empty list check before calling
write_messages() because the function is already able to cope with an
empty list.
Signed-off-by: Juergen Gross <jgr...@suse.com>
Reviewed-by: Julien Grall <jgr...@amazon.com>
I have also committed the series.
Cheers,
---
V2:
- split off function vector introduction (Julien Grall)
V3:
- expand commit message (Julien Grall)
---
tools/xenstore/xenstored_core.c | 77 +++++++++++++++----------------
tools/xenstore/xenstored_core.h | 2 +
tools/xenstore/xenstored_domain.c | 2 +
3 files changed, 41 insertions(+), 40 deletions(-)
diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 856f518075..883a1a582a 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -1659,9 +1659,34 @@ static 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);
+}
+
const struct interface_funcs socket_funcs = {
.write = writefd,
.read = readfd,
+ .can_write = socket_can_write,
+ .can_read = socket_can_read,
};
static void accept_connection(int sock)
@@ -2296,47 +2321,19 @@ 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 6c4845c196..bb36111ecc 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -90,6 +90,8 @@ struct connection;
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
diff --git a/tools/xenstore/xenstored_domain.c
b/tools/xenstore/xenstored_domain.c
index f3cd56050e..708bf68af0 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -175,6 +175,8 @@ static int readchn(struct connection *conn, void *data,
unsigned int len)
static const 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)
--
Julien Grall
