jerenkrantz 01/07/24 09:53:40
Modified: network_io/unix sendrecv.c
Log:
Move the blocking logic on FreeBSD to match everyone else to be after the
sendfile() call rather than before.
Redid the comment to make a bit more sense given its new location.
Someone who has FreeBSD will need to make sure this still works as expected.
Revision Changes Path
1.70 +21 -20 apr/network_io/unix/sendrecv.c
Index: sendrecv.c
===================================================================
RCS file: /home/cvs/apr/network_io/unix/sendrecv.c,v
retrieving revision 1.69
retrieving revision 1.70
diff -u -r1.69 -r1.70
--- sendrecv.c 2001/07/24 16:37:23 1.69
+++ sendrecv.c 2001/07/24 16:53:40 1.70
@@ -410,26 +410,6 @@
headerstruct.trl_cnt = hdtr->numtrailers;
/* FreeBSD can send the headers/footers as part of the system call */
- if (sock->timeout >= 0) {
- /* On FreeBSD, it is possible for the first call to sendfile to
- * get EAGAIN, but still send some data. This means that we cannot
- * call sendfile and then check for EAGAIN, and then wait and call
- * sendfile again. If we do that, then we are likely to send the
- * first chunk of data twice, once in the first call and once in the
- * second. If we are using a timed write, then we check to make sure
- * we can send data before trying to send it.
- *
- * JLT: doing this first doesn't eliminate the possibility that
- * we get -1/EAGAIN/nbytes>0; AFAICT it just means extra
syscalls
- * from time to time
- */
- apr_status_t arv = apr_wait_for_io_or_timeout(sock, 0);
- if (arv != APR_SUCCESS) {
- *len = 0;
- return arv;
- }
- }
-
do {
if (bytes_to_send) {
/* We won't dare call sendfile() if we don't have
@@ -466,6 +446,27 @@
}
}
} while (rv == -1 && errno == EINTR);
+
+ /* On FreeBSD, it is possible that sendfile will return EAGAIN, but
+ * still send some data. This means that we cannot call sendfile
+ * and then check for EAGAIN, and then wait and call sendfile again.
+ * If we do that, then we are likely to send the first chunk of data
+ * twice, once in the first call and once in the second.
+ *
+ * When we are dealing with a non-blocking or timeout socket, the
+ * caller must already be aware that we may not be able to write
+ * everything in one call. Therefore, we should return back to
+ * the caller with how much we actually sent (as specified from EAGAIN).
+ *
+ * If we are using a timed write, we will now block until we are clear.
+ */
+ if (errno == EAGAIN && nbytes && sock->timeout >= 0) {
+ apr_status_t arv = apr_wait_for_io_or_timeout(sock, 0);
+ if (arv != APR_SUCCESS) {
+ *len = 0;
+ return arv;
+ }
+ }
(*len) = nbytes;
if (rv == -1) {
