[Libguestfs] [PATCH libnbd] states: In recv_into_rbuf and send_from_wbuf loop until EAGAIN.
Previously we performed a single call to recv(2) or send(2) (or the
GnuTLS equivalents), and even if more data/space was immediately
available to receive/send we would return to poll. Instead of this,
loop until the socket returns EAGAIN.
---
generator/states.c | 91 ++++++++++++++++++++++------------------------
1 file changed, 43 insertions(+), 48 deletions(-)
diff --git a/generator/states.c b/generator/states.c
index 145e8c1..cde934a 100644
--- a/generator/states.c
+++ b/generator/states.c
@@ -46,43 +46,40 @@ recv_into_rbuf (struct nbd_handle *h)
void *rbuf;
size_t rlen;
- if (h->rlen == 0)
- return 0; /* move to next state */
+ while (h->rlen > 0) {
+ /* As a special case h->rbuf is allowed to be NULL, meaning
+ * throw away the data.
+ */
+ if (h->rbuf) {
+ rbuf = h->rbuf;
+ rlen = h->rlen;
+ }
+ else {
+ rbuf = &buf;
+ rlen = h->rlen > sizeof buf ? sizeof buf : h->rlen;
+ }
- /* As a special case h->rbuf is allowed to be NULL, meaning
- * throw away the data.
- */
- if (h->rbuf) {
- rbuf = h->rbuf;
- rlen = h->rlen;
- }
- else {
- rbuf = &buf;
- rlen = h->rlen > sizeof buf ? sizeof buf : h->rlen;
- }
-
- r = h->sock->ops->recv (h, h->sock, rbuf, rlen);
- if (r == -1) {
- if (errno == EAGAIN || errno == EWOULDBLOCK)
- return 1; /* more data */
- /* sock->ops->recv called set_error already. */
- return -1;
- }
- if (r == 0) {
- set_error (0, "recv: server disconnected unexpectedly");
- return -1;
- }
+ r = h->sock->ops->recv (h, h->sock, rbuf, rlen);
+ if (r == -1) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ return 1; /* more data */
+ /* sock->ops->recv called set_error already. */
+ return -1;
+ }
+ if (r == 0) {
+ set_error (0, "recv: server disconnected unexpectedly");
+ return -1;
+ }
#ifdef DUMP_PACKETS
- if (h->rbuf != NULL)
- nbd_internal_hexdump (h->rbuf, r, stderr);
+ if (h->rbuf != NULL)
+ nbd_internal_hexdump (h->rbuf, r, stderr);
#endif
- if (h->rbuf)
- h->rbuf += r;
- h->rlen -= r;
- if (h->rlen == 0)
- return 0; /* move to next state */
- else
- return 1; /* more data */
+ if (h->rbuf)
+ h->rbuf += r;
+ h->rlen -= r;
+ }
+
+ return 0; /* move to next state */
}
static int
@@ -90,21 +87,19 @@ send_from_wbuf (struct nbd_handle *h)
{
ssize_t r;
- if (h->wlen == 0)
- return 0; /* move to next state */
- r = h->sock->ops->send (h, h->sock, h->wbuf, h->wlen);
- if (r == -1) {
- if (errno == EAGAIN || errno == EWOULDBLOCK)
- return 1; /* more data */
- /* sock->ops->send called set_error already. */
- return -1;
+ while (h->wlen > 0) {
+ r = h->sock->ops->send (h, h->sock, h->wbuf, h->wlen);
+ if (r == -1) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ return 1; /* more data */
+ /* sock->ops->send called set_error already. */
+ return -1;
+ }
+ h->wbuf += r;
+ h->wlen -= r;
}
- h->wbuf += r;
- h->wlen -= r;
- if (h->wlen == 0)
- return 0; /* move to next state */
- else
- return 1; /* more data */
+
+ return 0; /* move to next state */
}
/*----- End of prologue. -----*/
--
2.21.0