new file mode 100644
--- /dev/null
+++ b/src/os/unix/ngx_freebsd_rfork_thread.h
@@ -0,0 +1,93 @@
+#ifndef _NGX_FREEBSD_RFORK_THREAD_H_INCLUDED_
+#define _NGX_FREEBSD_RFORK_THREAD_H_INCLUDED_
+
+
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <sched.h>
+
+typedef pid_t  ngx_tid_t;
+
+#undef ngx_log_pid
+#define ngx_log_pid    ngx_thread_self()
+#define ngx_log_tid    0
+
+#define TID_T_FMT      PID_T_FMT
+    
+
+#define NGX_MUTEX_LIGHT      1
+
+#define NGX_MUTEX_LOCK_BUSY  0x80000000
+
+typedef volatile struct {
+    ngx_atomic_t  lock;
+    ngx_log_t    *log;
+    int           semid;
+} ngx_mutex_t;
+
+
+#define NGX_CV_SIGNAL        64
+
+typedef struct {
+    int           signo;
+    int           kq;
+    ngx_tid_t     tid;
+    ngx_log_t    *log;
+} ngx_cond_t;
+
+
+#define ngx_thread_sigmask(how, set, oset)                         \
+            (sigprocmask(how, set, oset) == -1) ? ngx_errno : 0
+
+#define ngx_thread_sigmask_n   "sigprocmask()"
+
+#define ngx_thread_join(t, p)
+
+#define ngx_setthrtitle(n)     setproctitle(n)
+
+
+extern char    *ngx_freebsd_kern_usrstack;
+extern size_t   ngx_thread_stack_size;
+
+
+static inline int ngx_gettid()
+{
+    char  *sp;
+
+    if (ngx_thread_stack_size == 0) {
+        return 0;
+    }
+
+#if ( __i386__ )
+
+    __asm__ volatile ("mov %%esp, %0" : "=q" (sp));
+
+#elif ( __amd64__ )
+
+    __asm__ volatile ("mov %%rsp, %0" : "=q" (sp));
+
+#else
+
+#error "rfork()ed threads are not supported on this platform"
+
+#endif
+
+    return (ngx_freebsd_kern_usrstack - sp) / ngx_thread_stack_size;
+}
+
+
+ngx_tid_t ngx_thread_self();
+#define ngx_thread_main()   (ngx_gettid() == 0)
+
+
+#define ngx_mutex_trylock(m)  ngx_mutex_dolock(m, 1)
+#define ngx_mutex_lock(m)     ngx_mutex_dolock(m, 0)
+ngx_int_t ngx_mutex_dolock(ngx_mutex_t *m, ngx_int_t try);
+ngx_int_t ngx_mutex_unlock(ngx_mutex_t *m);
+
+
+typedef int (*ngx_rfork_thread_func_pt)(void *arg);
+
+
+
+#endif /* _NGX_FREEBSD_RFORK_THREAD_H_INCLUDED_ */