diff --git a/src/os/unix/ngx_process.c b/src/os/unix/ngx_process.c
index e500408..e9de91e 100644
--- a/src/os/unix/ngx_process.c
+++ b/src/os/unix/ngx_process.c
@@ -8,6 +8,14 @@
 ngx_uint_t     ngx_last_process;
 ngx_process_t  ngx_processes[NGX_MAX_PROCESSES];
 
+sigset_t  ngx_sigmask;
+
+
+void ngx_wait_events()
+{
+    sigsuspend(&ngx_sigmask);
+}
+
 
 ngx_int_t ngx_spawn_process(ngx_cycle_t *cycle,
                             ngx_spawn_proc_pt proc, void *data,
diff --git a/src/os/unix/ngx_process.h b/src/os/unix/ngx_process.h
index 5b7e37c..c63ff52 100644
--- a/src/os/unix/ngx_process.h
+++ b/src/os/unix/ngx_process.h
@@ -29,7 +29,9 @@
 } ngx_exec_ctx_t;
 
 
-#define ngx_getpid  getpid
+#define NGX_PROCESS_SINGLE  0
+#define NGX_PROCESS_MASTER  1
+#define NGX_PROCESS_WORKER  2
 
 #define NGX_MAX_PROCESSES  1024
 
@@ -38,6 +40,8 @@
 #define NGX_PROCESS_DETACHED   -3
 
 
+#define ngx_getpid  getpid
+
 ngx_int_t ngx_spawn_process(ngx_cycle_t *cycle,
                             ngx_spawn_proc_pt proc, void *data,
                             char *name, ngx_int_t respawn);