The mi_lo_unlock() function

Syntax

mi_integer mi_lo_unlock(conn, LO_fd, offset, whence, nbytes)
   MI_CONNECTION *conn;
   MI_LO_FD LO_fd;
   mi_int8 *offset;
   mi_integer whence;
   mi_int8 *nbytes;

conn

This value is one of the following connection values:

A pointer to a connection descriptor established by a previous call to mi_open(), mi_server_connect(), or mi_server_reconnect().

A NULL-valued pointer (database server only)

LO_fd

An LO file descriptor for the open smart large object whose bytes you want to unlock.

offset

A pointer to the eight-byte integer (mi_int8) that identifies the offset at which the unlock of the smart-large-object bytes begins.

whence

An integer value that identifies the starting LO seek position.

nbytes

A pointer to the eight-byte integer (mi_int8) that specifies the number of bytes to unlock. This value cannot exceed 2 GB.

Usage

The mi_lo_unlock() function removes a byte-range lock on the open smart large object that LO_fd indicates. This unlock request applies to nbytes number of bytes beginning at the LO seek location that the whence and offset arguments specify.

When the mi_lo_unlock() function requests the release of a byte-range lock, the database server attempts to unlock a locked smart large object if it has a share-mode or update-mode lock. For exclusive locks, the database server does not permit the release of the lock until the end of the transaction.

For more information about locks for smart large objects or on how to use byte-range locks, see the Informix® DataBlade® API Programmer's Guide.

Return values

MI_OK

The function was successful; the requested lock was successfully released.

MI_ERROR

The function was not successful; the requested lock cannot be released or the smart large object has not been opened for byte-range locking.