diff --git a/src/os/unix/ngx_atomic.h b/src/os/unix/ngx_atomic.h
index 50d6354..c505027 100644
--- a/src/os/unix/ngx_atomic.h
+++ b/src/os/unix/ngx_atomic.h
@@ -34,6 +34,7 @@
 /* the code in src/os/unix/ngx_sunpro_x86.il */
 
 #define ngx_memory_barrier()        __asm (".volatile"); __asm (".nonvolatile")
+#define ngx_cpu_pause()             __asm ("pause")
 
 
 #else /* ( __GNUC__ || __INTEL_COMPILER ) */
@@ -67,6 +68,7 @@
 /* the code in src/os/unix/ngx_sunpro_amd64.il */
 
 #define ngx_memory_barrier()        __asm (".volatile"); __asm (".nonvolatile")
+#define ngx_cpu_pause()             __asm ("pause")
 
 
 #else /* ( __GNUC__ || __INTEL_COMPILER ) */
@@ -175,10 +177,11 @@
 }
 
 #define ngx_memory_barrier()
+#define ngx_cpu_pause()
 
 #endif
 
-void ngx_spinlock(ngx_atomic_t *lock, ngx_uint_t spin);
+void ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin);
 
 #define ngx_trylock(lock)  (*(lock) == 0 && ngx_atomic_cmp_set(lock, 0, 1))
 #define ngx_unlock(lock)    *(lock) = 0
diff --git a/src/os/unix/ngx_files.c b/src/os/unix/ngx_files.c
index b5a807b..f89147d 100644
--- a/src/os/unix/ngx_files.c
+++ b/src/os/unix/ngx_files.c
@@ -235,59 +235,58 @@
 }
 
 
-ngx_int_t
-ngx_lock_file(ngx_file_t *file)
+ngx_err_t
+ngx_trylock_fd(ngx_fd_t fd)
 {
-    ngx_err_t     err;
     struct flock  fl;
 
-    fl.l_whence = SEEK_SET;
+    fl.l_start = 0;
     fl.l_len = 0;
     fl.l_pid = 0;
     fl.l_type = F_WRLCK;
-    fl.l_start = 0;
+    fl.l_whence = SEEK_SET;
 
-    if (fcntl(file->fd, F_SETLK, &fl) == -1) {
-        err = ngx_errno;
-
-        if (err == NGX_EAGAIN) {
-            return NGX_BUSY;
-        }
-
-        ngx_log_error(NGX_LOG_ALERT, file->log, err,
-                      "fcntl(%s, F_SETLK, F_WRLCK) failed", file->name.data);
-
-        return NGX_ERROR;
+    if (fcntl(fd, F_SETLK, &fl) == -1) {
+        return ngx_errno;
     }
 
-    return NGX_OK;
+    return 0;
 }
 
 
-ngx_int_t
-ngx_unlock_file(ngx_file_t *file)
+ngx_err_t
+ngx_lock_fd(ngx_fd_t fd)
 {
-    ngx_err_t     err;
     struct flock  fl;
 
+    fl.l_start = 0;
+    fl.l_len = 0;
+    fl.l_pid = 0;
+    fl.l_type = F_WRLCK;
     fl.l_whence = SEEK_SET;
+
+    if (fcntl(fd, F_SETLKW, &fl) == -1) {
+        return ngx_errno;
+    }
+
+    return 0;
+}
+
+
+ngx_err_t
+ngx_unlock_fd(ngx_fd_t fd)
+{
+    struct flock  fl;
+
+    fl.l_start = 0;
     fl.l_len = 0;
     fl.l_pid = 0;
     fl.l_type = F_UNLCK;
-    fl.l_start = 0;
+    fl.l_whence = SEEK_SET;
 
-    if (fcntl(file->fd, F_SETLK, &fl) == -1) {
-        err = ngx_errno;
-
-        if (err == NGX_EAGAIN) {
-            return NGX_BUSY;
-        }
-
-        ngx_log_error(NGX_LOG_ALERT, file->log, err,
-                      "fcntl(%s, F_SETLK, F_UNLCK) failed", file->name.data);
-
-        return NGX_ERROR;
+    if (fcntl(fd, F_SETLK, &fl) == -1) {
+        return  ngx_errno;
     }
 
-    return NGX_OK;
+    return 0;
 }
diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index a361fe4..fcf5da4 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -119,4 +119,13 @@
 #define ngx_de_mtime(dir)        (dir)->info.st_mtime
 
 
+ngx_err_t ngx_trylock_fd(ngx_fd_t fd);
+ngx_err_t ngx_lock_fd(ngx_fd_t fd);
+ngx_err_t ngx_unlock_fd(ngx_fd_t fd);
+
+#define ngx_trylock_fd_n         "fcntl(F_SETLK, F_WRLCK)"
+#define ngx_lock_fd_n            "fcntl(F_SETLKW, F_WRLCK)"
+#define ngx_unlock_fd_n          "fcntl(F_SETLK, F_UNLCK)"
+
+
 #endif /* _NGX_FILES_H_INCLUDED_ */
diff --git a/src/os/unix/ngx_gcc_atomic_amd64.h b/src/os/unix/ngx_gcc_atomic_amd64.h
index 2183e73..289cd61 100644
--- a/src/os/unix/ngx_gcc_atomic_amd64.h
+++ b/src/os/unix/ngx_gcc_atomic_amd64.h
@@ -74,4 +74,6 @@
 }
 
 
-#define ngx_memory_barrier()       __asm__ volatile ("" ::: "memory")
+#define ngx_memory_barrier()    __asm__ volatile ("" ::: "memory")
+
+#define ngx_cpu_pause()         __asm__ ("pause")
diff --git a/src/os/unix/ngx_gcc_atomic_ppc.h b/src/os/unix/ngx_gcc_atomic_ppc.h
index a6bbb39..5339ba9 100644
--- a/src/os/unix/ngx_gcc_atomic_ppc.h
+++ b/src/os/unix/ngx_gcc_atomic_ppc.h
@@ -71,3 +71,5 @@
 #else
 #define ngx_memory_barrier()   __asm__ volatile ("" ::: "memory")
 #endif
+
+#define ngx_cpu_pause()
diff --git a/src/os/unix/ngx_gcc_atomic_sparc64.h b/src/os/unix/ngx_gcc_atomic_sparc64.h
index fc6bace..e5a6254 100644
--- a/src/os/unix/ngx_gcc_atomic_sparc64.h
+++ b/src/os/unix/ngx_gcc_atomic_sparc64.h
@@ -77,3 +77,5 @@
 #else
 #define ngx_memory_barrier()   __asm__ volatile ("" ::: "memory")
 #endif
+
+#define ngx_cpu_pause()
diff --git a/src/os/unix/ngx_gcc_atomic_x86.h b/src/os/unix/ngx_gcc_atomic_x86.h
index 8e3480d..1e15825 100644
--- a/src/os/unix/ngx_gcc_atomic_x86.h
+++ b/src/os/unix/ngx_gcc_atomic_x86.h
@@ -118,3 +118,6 @@
  */
 
 #define ngx_memory_barrier()    __asm__ volatile ("" ::: "memory")
+
+/* old as does not support "pause" opcode */
+#define ngx_cpu_pause()         __asm__ (".byte 0xf3, 0x90")
diff --git a/src/os/unix/ngx_posix_init.c b/src/os/unix/ngx_posix_init.c
index 83d5f30..a44a89c 100644
--- a/src/os/unix/ngx_posix_init.c
+++ b/src/os/unix/ngx_posix_init.c
@@ -45,6 +45,8 @@
         ngx_ncpu = 1;
     }
 
+    ngx_cpuinfo();
+
     if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
         ngx_log_error(NGX_LOG_ALERT, log, errno,
                       "getrlimit(RLIMIT_NOFILE) failed)");
diff --git a/src/os/unix/ngx_sunpro_atomic_sparc64.h b/src/os/unix/ngx_sunpro_atomic_sparc64.h
index 691e94e..db85211 100644
--- a/src/os/unix/ngx_sunpro_atomic_sparc64.h
+++ b/src/os/unix/ngx_sunpro_atomic_sparc64.h
@@ -56,3 +56,5 @@
         __asm (".volatile");                                                  \
         __asm ("membar #LoadLoad | #LoadStore | #StoreStore | #StoreLoad");   \
         __asm (".nonvolatile")
+
+#define ngx_cpu_pause()