diff --git a/src/os/unix/ngx_thread.h b/src/os/unix/ngx_thread.h
index 2077b3d..9d5f724 100644
--- a/src/os/unix/ngx_thread.h
+++ b/src/os/unix/ngx_thread.h
@@ -111,9 +111,61 @@
 
 #define ngx_thread_volatile
 
+#if (NGX_THREADS)
+
+#include <pthread.h>
+
+
+typedef pthread_mutex_t  ngx_thread_mutex_t;
+
+ngx_int_t ngx_thread_mutex_create(ngx_thread_mutex_t *mtx, ngx_log_t *log);
+ngx_int_t ngx_thread_mutex_destroy(ngx_thread_mutex_t *mtx, ngx_log_t *log);
+ngx_int_t ngx_thread_mutex_lock(ngx_thread_mutex_t *mtx, ngx_log_t *log);
+ngx_int_t ngx_thread_mutex_unlock(ngx_thread_mutex_t *mtx, ngx_log_t *log);
+
+
+typedef pthread_cond_t  ngx_thread_cond_t;
+
+ngx_int_t ngx_thread_cond_create(ngx_thread_cond_t *cond, ngx_log_t *log);
+ngx_int_t ngx_thread_cond_destroy(ngx_thread_cond_t *cond, ngx_log_t *log);
+ngx_int_t ngx_thread_cond_signal(ngx_thread_cond_t *cond, ngx_log_t *log);
+ngx_int_t ngx_thread_cond_wait(ngx_thread_cond_t *cond, ngx_thread_mutex_t *mtx,
+    ngx_log_t *log);
+
+
+#if (NGX_LINUX)
+
+typedef pid_t      ngx_tid_t;
+#define NGX_TID_T_FMT         "%P"
+
+#elif (NGX_FREEBSD)
+
+typedef uint32_t   ngx_tid_t;
+#define NGX_TID_T_FMT         "%uD"
+
+#elif (NGX_DARWIN)
+
+typedef uint64_t   ngx_tid_t;
+#define NGX_TID_T_FMT         "%uA"
+
+#else
+
+typedef uint64_t   ngx_tid_t;
+#define NGX_TID_T_FMT         "%uA"
+
+#endif
+
+ngx_tid_t ngx_thread_tid(void);
+
+#define ngx_log_tid           ngx_thread_tid()
+
+#else
+
 #define ngx_log_tid           0
 #define NGX_TID_T_FMT         "%d"
 
+#endif
+
 #define ngx_mutex_trylock(m)  NGX_OK
 #define ngx_mutex_lock(m)
 #define ngx_mutex_unlock(m)