X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fio%2Fio.h;h=a93c6ed49941580efc4741ca58687b062d63c472;hb=580457bd3e4af60d5367412589d2aa1bb0289eed;hp=c9ab228c7a046b3c3575d0c1aa40d1255b15f5d7;hpb=7082f7d0e81911acb26787949c251dfb298cbdd8;p=ccan

diff --git a/ccan/io/io.h b/ccan/io/io.h
index c9ab228c..a93c6ed4 100644
--- a/ccan/io/io.h
+++ b/ccan/io/io.h
@@ -223,7 +223,8 @@ struct io_plan *io_write_(struct io_conn *conn,
  *
  * This creates a plan to read data into a buffer.  Once it's all
  * read, the @next function will be called: on an error, the finish
- * function is called instead.
+ * function is called instead.  If read() returns 0 (EOF) errno is set
+ * to 0.
  *
  * Note that the I/O may actually be done immediately.
  *
@@ -256,7 +257,8 @@ struct io_plan *io_read_(struct io_conn *conn,
  *
  * This creates a plan to read data into a buffer.  Once any data is
  * read, @len is updated and the @next function will be called: on an
- * error, the finish function is called instead.
+ * error, the finish function is called instead.  If read() returns 0 (EOF)
+ * errno is set to 0.
  *
  * Note that the I/O may actually be done immediately.
  *
@@ -720,6 +722,35 @@ bool io_plan_out_started(const struct io_conn *conn);
  */
 bool io_flush_sync(struct io_conn *conn);
 
+/**
+ * io_conn_exclusive - set/unset an io_conn to exclusively serviced
+ * @conn: the connection
+ * @exclusive: whether to be exclusive or not
+ *
+ * If any io_conn is set exclusive, then no non-exclusive io_conn (or
+ * io_listener) will be serviced by io_loop().  If it's a io_duplex io_conn(),
+ * then io_conn_exclusive() makes the read-side exclusive; io_conn_out_exclusive()
+ * makes the write-side exclusive.
+ *
+ * This allows you to temporarily service only one (or several) fds.
+ * For example, you might want to flush out one io_conn and not
+ * receive any new connections or read any otherninput.
+ *
+ * Returns true of there any exclusive io_conn remain, otherwise false.
+ * (This is useful for checking your own logic: dangling exclusive io_conn
+ * are dangerous!).
+ */
+bool io_conn_exclusive(struct io_conn *conn, bool exclusive);
+
+/**
+ * io_conn_out_exclusive - set/unset exclusive on the write-side of a duplex
+ * @conn: the connection, post io_duplex
+ * @exclusive: whether to be exclusive or not
+ *
+ * See io_conn_exclusive() above.
+ */
+bool io_conn_out_exclusive(struct io_conn *conn, bool exclusive);
+
 /**
  * io_fd_block - helper to set an fd blocking/nonblocking.
  * @fd: the file descriptor