io_lock()

int io_lock ( resmgr_context_t *ctp,
              io_lock_t *msg,
              RESMGR_OCB_T *ocb ) 

Classification: I/O

Default handler: iofunc_lock_default()

Helper functions: iofunc_lock()

Client functions: fcntl(), lockf(), flock()

Messages: _IO_LOCK

Data structure:

struct _io_lock {
  uint16_t              type;
  uint16_t              combine_len;
  uint32_t              subtype;
  uint32_t              nbytes;
};

struct _io_lock_reply {
  uint32_t              zero [3];
};

typedef union {
  struct _io_lock       i;
  struct _io_lock_reply o;
} io_lock_t;

Description: This provides advisory range-based file locking for a device. The default function is most likely sufficient for most resource managers.

Returns: The status via the helper macro _RESMGR_STATUS().