streamWrapper::stream_lock
(PHP 5, PHP 7)
streamWrapper::stream_lock — Advisory file locking
说明
   public streamWrapper::stream_lock
    ( int 
  $operation
   ) : bool
   This method is called in response to flock(), when
   file_put_contents() (when flags
   contains LOCK_EX),
   stream_set_blocking() and when closing the stream
   (LOCK_UN).
  
参数
- 
operation
- 
      operationis one of the following:- 
         
          LOCK_SHto acquire a shared lock (reader).
- 
         
          LOCK_EXto acquire an exclusive lock (writer).
- 
         
          LOCK_UNto release a lock (shared or exclusive).
- 
         
          LOCK_NBif you don't want flock() to block while locking. (not supported on Windows)
 
- 
         
          
返回值
   成功时返回 TRUE, 或者在失败时返回 FALSE。
  
错误/异常
   Emits E_WARNING if call to this method fails (i.e. not implemented).