new file mode 100644
--- /dev/null
+++ b/src/os/unix/freebsd/ngx_rfork_thread.h
@@ -0,0 +1,24 @@
+#ifndef _NGX_OS_THREAD_H_INCLUDED_
+#define _NGX_OS_THREAD_H_INCLUDED_
+
+
+typedef int  ngx_os_tid_t;
+typedef int  ngx_tid_t;
+
+
+extern char   *ngx_stacks_start;
+extern char   *ngx_stacks_end;
+extern size_t  ngx_stack_size;
+
+
+static inline ngx_tid_t ngx_gettid()
+{   
+    char *sp;
+
+    __asm__ ("mov %%esp,%0" : "=r" (sp));
+    return (sp > ngx_stacks_end) ? 0:
+           (sp - ngx_stacks_start) / ngx_stack_size + 1;
+}
+
+
+#endif /* _NGX_OS_THREAD_H_INCLUDED_ */