support 0-length UDP packet for #604 #541

Author: ithewei

event/nio.c

@@ -323,15 +323,14 @@ static void nio_read(hio_t* io) {
             // goto read_done;
             return;
         } else if (err == EMSGSIZE) {
-            // ignore
-            return;
+            nread = len;
         } else {
             // perror("read");
             io->error = err;
             goto read_error;
         }
     }
-    if (nread == 0) {
+    if (nread == 0 && (io->io_type & HIO_TYPE_SOCK_STREAM)) {
         goto disconnect;
     }
     if (nread < len) {
@@ -385,7 +384,7 @@ static void nio_write(hio_t* io) {
             goto write_error;
         }
     }
-    if (nwrite == 0) {
+    if (nwrite == 0 && (io->io_type & HIO_TYPE_SOCK_STREAM)) {
         goto disconnect;
     }
     pbuf->offset += nwrite;
@@ -516,12 +515,12 @@ int hio_write (hio_t* io, const void* buf, size_t len) {
                 goto write_error;
             }
         }
-        if (nwrite == 0) {
-            goto disconnect;
-        }
         if (nwrite == len) {
             goto write_done;
         }
+        if (nwrite == 0 && (io->io_type & HIO_TYPE_SOCK_STREAM)) {
+            goto disconnect;
+        }
 enqueue:
         hio_add(io, hio_handle_events, HV_WRITE);
     }