win,udp: implements uv_udp_try_send

PR-URL: https://github.com/libuv/libuv/pull/1385
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>

src/win/udp.c

@@ -922,5 +922,40 @@ int uv__udp_try_send(uv_udp_t* handle,
                      unsigned int nbufs,
                      const struct sockaddr* addr,
                      unsigned int addrlen) {
-  return UV_ENOSYS;
+  DWORD bytes;
+  const struct sockaddr* bind_addr;
+  int err;
+
+  assert(nbufs > 0);
+
+  /* Already sending a message.*/
+  if (handle->send_queue_count != 0)
+    return UV_EAGAIN;
+
+  if (!(handle->flags & UV_HANDLE_BOUND)) {
+    if (addrlen == sizeof(uv_addr_ip4_any_))
+      bind_addr = (const struct sockaddr*) &uv_addr_ip4_any_;
+    else if (addrlen == sizeof(uv_addr_ip6_any_))
+      bind_addr = (const struct sockaddr*) &uv_addr_ip6_any_;
+    else
+      abort();
+    err = uv_udp_maybe_bind(handle, bind_addr, addrlen, 0);
+    if (err)
+      return uv_translate_sys_error(err);
+  }
+
+  err = WSASendTo(handle->socket,
+                  (WSABUF*)bufs,
+                  nbufs,
+                  &bytes,
+                  0,
+                  addr,
+                  addrlen,
+                  NULL,
+                  NULL);
+
+  if (err)
+    return uv_translate_sys_error(WSAGetLastError());
+
+  return bytes;
 }

test/test-udp-try-send.c

@@ -26,16 +26,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#ifdef _WIN32
-
-TEST_IMPL(udp_try_send) {
-
-  MAKE_VALGRIND_HAPPY();
-  return 0;
-}
-
-#else  /* !_WIN32 */
-
 #define CHECK_HANDLE(handle) \
   ASSERT((uv_udp_t*)(handle) == &server || (uv_udp_t*)(handle) == &client)
 
@@ -129,5 +119,3 @@ TEST_IMPL(udp_try_send) {
   MAKE_VALGRIND_HAPPY();
   return 0;
 }
-
-#endif  /* !_WIN32 */