tests: Avoid 'do/while(false); ' in vhost-user-bridge

Use of a do/while(0) loop as a way to allow break statements in
the middle of execute-once code is unusual.  More typical is
the use of goto for early exits, with a label at the end of
the execute-once code, rather than nesting code in a scope;
however, the comment at the end of the existing code makes this
alternative a bit unpractical.

So, to avoid false positives from a future syntax check about
'while (false);', and to keep the loop form (in case someone
ever does add DONTWAIT support, where they can just as easily
manipulate the initial loop condition or add an if around the
final 'break'), I opted to use the form of a while(1) loop (the
break as an early exit is more idiomatic there), coupled with
a final break preserving the original comment.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171201232433.25193-6-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tests/vhost-user-bridge.c b/tests/vhost-user-bridge.c
index d820033a72b622e56feb75788224ce8b2389a628..e0605a529e1a1e58007e78f757ea10a8cdd67143 100644 (file)
--- a/tests/vhost-user-bridge.c
+++ b/tests/vhost-user-bridge.c
@@ -283,7 +283,7 @@ vubr_backend_recv_cb(int sock, void *ctx)
         return;
     }
 
-    do {
+    while (1) {
         struct iovec *sg;
         ssize_t ret, total = 0;
         unsigned int num;
@@ -343,7 +343,9 @@ vubr_backend_recv_cb(int sock, void *ctx)
 
         free(elem);
         elem = NULL;
-    } while (false); /* could loop if DONTWAIT worked? */
+
+        break;        /* could loop if DONTWAIT worked? */
+    }
 
     if (mhdr_cnt) {
         mhdr.num_buffers = i;