Message ID | 20210518061907.16374-3-jgross@suse.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | tools/xenstore: simplify xenstored main loop | expand |
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 <jgross@suse.com> Reviewed-by: Julien Grall <jgrall@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) >
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)
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 <jgross@suse.com> --- 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(-)