fix some issues with apr_sendfile() for FreeBSD

1) checking when to call wait_for_io_or_timeout()
   it checked errno without checking rv
   it required that we already sent bytes (nbytes != 0)
   it checked timeout != 0 instead of timeout > 0
2) it didn't retry the sendfile() (or writev()) after
   a successful wait_for_io_or_timeout()


git-svn-id: http://svn.apache.org/repos/asf/apr/apr/trunk@62022 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 41 insertions, 14 deletions

diff --git a/network_io/unix/sendrecv.c b/network_io/unix/sendrecv.c
index d74c3d6cf..59fc96bc0 100644
--- a/network_io/unix/sendrecv.c
+++ b/network_io/unix/sendrecv.c
@@ -447,25 +447,52 @@ apr_status_t apr_sendfile(apr_socket_t * sock, apr_file_t * file,
         }
     } 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) {
+    if (rv == -1 &&
+        errno == EAGAIN && 
+        sock->timeout > 0) {
         apr_status_t arv = apr_wait_for_io_or_timeout(sock, 0);
         if (arv != APR_SUCCESS) {
             *len = 0;
             return arv;
         }
+        else {
+            do {
+                if (bytes_to_send) {
+                    /* We won't dare call sendfile() if we don't have
+                     * header or file bytes to send because bytes_to_send == 0
+                     * means send the whole file.
+                     */
+                    rv = sendfile(file->filedes, /* file to be sent */
+                                  sock->socketdes, /* socket */
+                                  *offset,       /* where in the file to start */
+                                  bytes_to_send, /* number of bytes to send */
+                                  &headerstruct, /* Headers/footers */
+                                  &nbytes,       /* number of bytes written */
+                                  flags);        /* undefined, set to 0 */
+                    /* FreeBSD's sendfile can return -1/EAGAIN even if it
+                     * sent bytes.  Sanitize the result so we get normal EAGAIN
+                     * semantics w.r.t. bytes sent.
+                     */
+                    if (rv == -1 && errno == EAGAIN && nbytes) {
+                        rv = 0;
+                    }
+                }
+                else {
+                    /* just trailer bytes... use writev()
+                     */
+                    rv = writev(sock->socketdes,
+                                hdtr->trailers,
+                                hdtr->numtrailers);
+                    if (rv > 0) {
+                        nbytes = rv;
+                        rv = 0;
+                    }
+                    else {
+                        nbytes = 0;
+                    }
+                }
+            } while (rv == -1 && errno == EINTR);
+        }
     }
 
     (*len) = nbytes;