new file mode 100644
--- /dev/null
+++ b/src/os/unix/ngx_channel.h
@@ -0,0 +1,33 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#ifndef _NGX_CHANNEL_H_INCLUDED_
+#define _NGX_CHANNEL_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+
+
+typedef struct {
+     ngx_uint_t  command;
+     ngx_pid_t   pid;
+     ngx_int_t   slot;
+     ngx_fd_t    fd;
+} ngx_channel_t;
+
+
+ngx_int_t ngx_write_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size,
+                            ngx_log_t *log);
+ngx_int_t ngx_read_channel(ngx_socket_t s, ngx_channel_t *ch, size_t size,
+                           ngx_log_t *log);
+ngx_int_t ngx_add_channel_event(ngx_cycle_t *cycle, ngx_fd_t fd,
+                                ngx_int_t event, ngx_event_handler_pt handler);
+void ngx_close_channel(ngx_fd_t *fd, ngx_log_t *log);
+
+
+#endif /* _NGX_CHANNEL_H_INCLUDED_ */