sendto

Signed-off-by: Loris Cro <kappaloris@gmail.com>

lib/std/event/loop.zig

@@ -1088,6 +1088,27 @@ pub const Loop = struct {
         }
     }
 
+    pub fn sendto(
+        self: *Loop,
+        /// The file descriptor of the sending socket.
+        sockfd: os.fd_t,
+        /// Message to send.
+        buf: []const u8,
+        flags: u32,
+        dest_addr: ?*const os.sockaddr,
+        addrlen: os.socklen_t,
+    ) os.SendError!usize {
+        while (true) {
+            return os.sendto(sockfd, buf, flags, dest_addr, addrlen) catch |err| switch (err) {
+                error.WouldBlock => {
+                    self.waitUntilFdWritable(sockfd);
+                    continue;
+                },
+                else => return err,
+            };
+        }
+    }
+
     /// Performs an async `os.faccessatZ` using a separate thread.
     /// `fd` must block and not return EAGAIN.
     pub fn faccessatZ(

lib/std/net.zig

@@ -1435,10 +1435,14 @@ fn resMSendRc(
                 if (answers[i].len == 0) {
                     var j: usize = 0;
                     while (j < ns.len) : (j += 1) {
+                        if (std.io.is_async) {
+                            _ = std.event.Loop.instance.?.sendto(fd, queries[i], os.MSG_NOSIGNAL, &ns[j].any, sl) catch undefined;
+                        } else {
                             _ = os.sendto(fd, queries[i], os.MSG_NOSIGNAL, &ns[j].any, sl) catch undefined;
                         }
                     }
                 }
+            }
             t1 = t2;
             servfail_retry = 2 * queries.len;
         }
@@ -1476,7 +1480,11 @@ fn resMSendRc(
                 0, 3 => {},
                 2 => if (servfail_retry != 0) {
                     servfail_retry -= 1;
+                    if (std.io.is_async) {
+                        _ = std.event.Loop.instance.?.sendto(fd, queries[i], os.MSG_NOSIGNAL, &ns[j].any, sl) catch undefined;
+                    } else {
                         _ = os.sendto(fd, queries[i], os.MSG_NOSIGNAL, &ns[j].any, sl) catch undefined;
+                    }
                 },
                 else => continue,
             }

lib/std/os.zig

@@ -4571,14 +4571,8 @@ pub fn sendto(
         const rc = system.sendto(sockfd, buf.ptr, buf.len, flags, dest_addr, addrlen);
         switch (errno(rc)) {
             0 => return @intCast(usize, rc),
-
             EACCES => return error.AccessDenied,
-            EAGAIN => if (std.event.Loop.instance) |loop| {
-                loop.waitUntilFdWritable(sockfd);
-                continue;
-            } else {
-                return error.WouldBlock;
-            },
+            EAGAIN => return error.WouldBlock,
             EALREADY => return error.FastOpenAlreadyInProgress,
             EBADF => unreachable, // always a race condition
             ECONNRESET => return error.ConnectionResetByPeer,