1 files changed, 30 insertions, 5 deletions

diff --git a/src/uv_link_t.c b/src/uv_link_t.c
index 0e2111e..548d638 100644
--- a/src/uv_link_t.c
+++ b/src/uv_link_t.c
@@ -1,9 +1,33 @@
+#include <stdlib.h>
 #include <string.h>
 
 #include "common.h"
 
+static void uv_link_def_alloc_cb(uv_link_t* link,
+                                 size_t suggested_size,
+                                 uv_buf_t* buf) {
+  static const size_t kBufferSize = 16 * 1024;
+
+  buf->base = malloc(kBufferSize);
+  buf->len = kBufferSize;
+
+  CHECK_NE(buf->base, NULL, "uv_link_t: alloc_cb failure");
+}
+
+
+static void uv_link_def_read_cb(uv_link_t* link,
+                                ssize_t nread,
+                                const uv_buf_t* buf) {
+  free(buf->base);
+}
+
+
 int uv_link_init(uv_loop_t* loop, uv_link_t* link) {
   memset(link, 0, sizeof(*link));
+
+  link->alloc_cb = uv_link_def_alloc_cb;
+  link->read_cb = uv_link_def_read_cb;
+
   return 0;
 }
 
@@ -19,12 +43,11 @@ int uv_link_chain(uv_link_t* from,
   if (from->child != NULL || to->parent != NULL)
     return UV_EINVAL;
 
-  if (from->alloc_cb != NULL || from->read_cb != NULL)
-    return UV_EINVAL;
-
   from->child = to;
   to->parent = from;
 
+  from->saved_alloc_cb = from->alloc_cb;
+  from->saved_read_cb = from->read_cb;
   from->alloc_cb = alloc_cb;
   from->read_cb = read_cb;
 
@@ -39,8 +62,10 @@ int uv_link_unchain(uv_link_t* from, uv_link_t* to) {
   from->child = NULL;
   to->parent = NULL;
 
-  from->alloc_cb = NULL;
-  from->read_cb = NULL;
+  from->alloc_cb = from->saved_alloc_cb;
+  from->read_cb = from->saved_read_cb;
+  from->saved_alloc_cb = NULL;
+  from->saved_read_cb = NULL;
 
   return from->read_stop(from);
 }