I/O messages

There are some 64-bit I/O messages that are used with resource managers:

• _IO_READ64 and _IO_WRITE64 have repurposed a zero field to allow the specification of the high 32 bits of length. There are _IO_READ_GET_NBYTES() and _IO_WRITE_GET_NBYTES() macros that calculate the number of bytes specified by _IO_READ, _IO_READ64, _IO_WRITE, and _IO_WRITE64 messages. For more information, see the Handling Read and Write Messages chapter in Writing a Resource Manager.
• _IO_UTIME64 defines a structure to handle 64-bit time_ts and to support futimens() and utimensat(). For more information, see iofunc_utime().
• _IO_NOTIFY64 extends the structure to handle 64-bit sigevent structures; see iofunc_notify().
• _IO_STAT repurposed a zero field to identify which format of stat structure is requested:

  #define _STAT_FORM_UNSET	0
  #define _STAT_FORM_T32_2001	1
  #define _STAT_FORM_T32_2008	2
  #define _STAT_FORM_T64_2008	3
  #if __PTR_BITS__ == 32
  #define _STAT_FORM_SYS_2008		(_STAT_FORM_T32_2008)
  #define _STAT_FORM_PREFERRED	(_STAT_FORM_T32_2001)
  #else
  #define _STAT_FORM_SYS_2008		(_STAT_FORM_T64_2008)
  #define _STAT_FORM_PREFERRED	(_STAT_FORM_T64_2008)
  #endif
    

  and uses the MsgReply() status parameter to indicate which format was generated. See iofunc_stat_default().