[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH RFC 1/4] 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 | 118 +++++++++++++++++------------- tools/xenstore/xenstored_core.h | 16 ++-- tools/xenstore/xenstored_domain.c | 11 ++- 3 files changed, 85 insertions(+), 60 deletions(-) diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index 65ecdd0568..c89f5202fe 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; @@ -1520,8 +1520,8 @@ 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; @@ -1546,8 +1546,8 @@ 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; @@ -1570,7 +1570,7 @@ 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; @@ -1580,8 +1580,7 @@ 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); @@ -1622,6 +1621,16 @@ int readfd(struct connection *conn, void *data, unsigned int len) errno = EBADF; return -1; } + +static bool socket_can_write(struct connection *conn) +{ + return false; +} + +static bool socket_can_read(struct connection *conn) +{ + return false; +} #else int writefd(struct connection *conn, const void *data, unsigned int len) { @@ -1661,6 +1670,32 @@ int readfd(struct connection *conn, void *data, unsigned int len) return rc; } +static bool socket_can_write(struct connection *conn) +{ + 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 & POLLOUT; +} + +static bool socket_can_read(struct connection *conn) +{ + 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 & POLLIN; +} + static void accept_connection(int sock) { int fd; @@ -1670,7 +1705,7 @@ 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 @@ -1678,6 +1713,13 @@ static void accept_connection(int sock) } #endif +struct interface_funcs socket_funcs = { + .write = writefd, + .read = readfd, + .can_write = socket_can_write, + .can_read = socket_can_read, +}; + static int tdb_flags; /* We create initial nodes manually. */ @@ -2280,47 +2322,19 @@ 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 589699e833..84b364d82c 100644 --- a/tools/xenstore/xenstored_core.h +++ b/tools/xenstore/xenstored_core.h @@ -87,8 +87,13 @@ 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 { @@ -132,9 +137,8 @@ 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; @@ -197,7 +201,7 @@ 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, ...); diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c index 3d4d0649a2..04f2a974e4 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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