1.diff

diff --git a/include/uv.h b/include/uv.h
index d6485e5..d1da997 100644
--- a/include/uv.h
+++ b/include/uv.h
@@ -681,7 +681,9 @@ UV_EXTERN int uv_write2(uv_write_t* req,
  * - zero - if queued write is needed
  * - negative error code
  */
-UV_EXTERN int uv_try_write(uv_stream_t* handle, const char* buf, size_t length);
+UV_EXTERN int uv_try_write(uv_stream_t* handle,
+                           const uv_buf_t bufs[],
+                           unsigned int nbufs);
 
 /* uv_write_t is a subclass of uv_req_t */
 struct uv_write_s {
diff --git a/src/unix/stream.c b/src/unix/stream.c
index afd2a05..a9d174a 100644
--- a/src/unix/stream.c
+++ b/src/unix/stream.c
@@ -1305,13 +1305,15 @@ void uv_try_write_cb(uv_write_t* req, int status) {
 }
 
 
-int uv_try_write(uv_stream_t* stream, const char* buf, size_t size) {
+int uv_try_write(uv_stream_t* stream,
+                 const uv_buf_t bufs[],
+                 unsigned int nbufs) {
   int r;
   int has_pollout;
+  unsigned int i;
   size_t written;
   size_t req_size;
   uv_write_t req;
-  uv_buf_t bufstruct;
 
   /* Connecting or already writing some data */
   if (stream->connect_req != NULL || stream->write_queue_size != 0)
@@ -1319,13 +1321,14 @@ int uv_try_write(uv_stream_t* stream, const char* buf, size_t size) {
 
   has_pollout = uv__io_active(&stream->io_watcher, UV__POLLOUT);
 
-  bufstruct = uv_buf_init((char*) buf, size);
-  r = uv_write(&req, stream, &bufstruct, 1, uv_try_write_cb);
+  r = uv_write(&req, stream, bufs, nbufs, uv_try_write_cb);
   if (r != 0)
     return r;
 
   /* Remove not written bytes from write queue size */
-  written = size;
+  written = 0;
+  for (i = 0; i < nbufs; i++)
+    written += bufs[i].len;
   if (req.bufs != NULL)
     req_size = uv__write_req_size(&req);
   else
diff --git a/src/win/stream.c b/src/win/stream.c
index da62883..0bd261a 100644
--- a/src/win/stream.c
+++ b/src/win/stream.c
@@ -202,7 +202,9 @@ int uv_write2(uv_write_t* req,
 }
 
 
-int uv_try_write(uv_stream_t* handle, const char* buf, size_t length) {
+int uv_try_write(uv_stream_t* handle,
+                 const uv_buf_t bufs[],
+                 unsigned int nbufs) {
   /* NOTE: Won't work with overlapped writes */
   return UV_ENOSYS;
 }
diff --git a/test/test-tcp-try-write.c b/test/test-tcp-try-write.c
index 3fd6166..f4f4fb5 100644
--- a/test/test-tcp-try-write.c
+++ b/test/test-tcp-try-write.c
@@ -61,7 +61,8 @@ static void connect_cb(uv_connect_t* req, int status) {
   connect_cb_called++;
 
   do {
-    r = uv_try_write((uv_stream_t*) &client, zeroes, sizeof(zeroes));
+    buf = uv_buf_init(zeroes, sizeof(zeroes));
+    r = uv_try_write((uv_stream_t*) &client, &buf, 1);
     ASSERT(r >= 0);
     bytes_written += r;
 

You can use uv_count_bufs here https://gist.github.com/indutny/1d6fcf3da45540e160ea#file-1-diff-L51