socket: sendmsg/recvmsg only retries blocking on errors

* ext/socket/ancdata.c (bsock_sendmsg_internal): only retry on error
  (bsock_recvmsg_internal): ditto
* test/socket/test_unix.rb: test above for infinite loop

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45066 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 8 insertions, 10 deletions

diff --git a/ext/socket/ancdata.c b/ext/socket/ancdata.c
index 7054d654ea..218085d5ce 100644
--- a/ext/socket/ancdata.c
+++ b/ext/socket/ancdata.c
@@ -1282,12 +1282,11 @@ bsock_sendmsg_internal(int argc, VALUE *argv, VALUE sock, int nonblock)
 
     ss = rb_sendmsg(fptr->fd, &mh, flags);
 
-    if (!nonblock && rb_io_wait_writable(fptr->fd)) {
-        rb_io_check_closed(fptr);
-        goto retry;
-    }
-
     if (ss == -1) {
+        if (!nonblock && rb_io_wait_writable(fptr->fd)) {
+            rb_io_check_closed(fptr);
+            goto retry;
+        }
         if (nonblock && (errno == EWOULDBLOCK || errno == EAGAIN))
             rb_readwrite_sys_fail(RB_IO_WAIT_WRITABLE, "sendmsg(2) would block");
 	rb_sys_fail("sendmsg(2)");
@@ -1601,12 +1600,11 @@ bsock_recvmsg_internal(int argc, VALUE *argv, VALUE sock, int nonblock)
 
     ss = rb_recvmsg(fptr->fd, &mh, flags);
 
-    if (!nonblock && rb_io_wait_readable(fptr->fd)) {
-        rb_io_check_closed(fptr);
-        goto retry;
-    }
-
     if (ss == -1) {
+        if (!nonblock && rb_io_wait_readable(fptr->fd)) {
+            rb_io_check_closed(fptr);
+            goto retry;
+        }
         if (nonblock && (errno == EWOULDBLOCK || errno == EAGAIN))
             rb_readwrite_sys_fail(RB_IO_WAIT_READABLE, "recvmsg(2) would block");
 #if defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL)