/**
   * @file event_buffer.h
   *
   * @remark Copyright 2002 OProfile authors
   * @remark Read the file COPYING
   *
   * @author John Levon <levon@movementarian.org>
   */
  
  #ifndef EVENT_BUFFER_H
  #define EVENT_BUFFER_H
  
  #include <linux/types.h>
  #include <linux/mutex.h>
  
  int alloc_event_buffer(void);
  
  void free_event_buffer(void);
  
  /**
   * Add data to the event buffer.
   * The data passed is free-form, but typically consists of
   * file offsets, dcookies, context information, and ESCAPE codes.
   */
  void add_event_entry(unsigned long data);
  
  /* wake up the process sleeping on the event file */
  void wake_up_buffer_waiter(void);
  
  #define INVALID_COOKIE ~0UL
  #define NO_COOKIE 0UL
  
  extern const struct file_operations event_buffer_fops;
  
  /* mutex between sync_cpu_buffers() and the
   * file reading code.
   */
  extern struct mutex buffer_mutex;
  
  #endif /* EVENT_BUFFER_H */