The mi_unlock_memory() function

The mi_unlock_memory() function unlocks a named-memory block specified by name and memory duration.

Syntax

mi_integer mi_unlock_memory(mem_name, duration)
   mi_string *mem_name;
   MI_MEMORY_DURATION duration;

mem_name

The null-terminated name of the named-memory block to unlock.

duration

A value that specifies the memory duration of the named-memory block to unlock. Valid values for duration are:

PER_ROUTINE: For the duration of one iteration of the UDR
PER_COMMAND: For the duration of the execution of the current subquery
PER_STATEMENT (Deprecated): For the duration of the current SQL statement
PER_STMT_EXEC: For the duration of the execution of the current SQL statement
PER_STMT_PREP: For the duration of the current prepared SQL statement
PER_TRANSACTION: For the duration of one transaction
PER_SESSION: For the duration of the current client session
PER_SYSTEM: For the duration of the database server execution

Valid in client LIBMI application?	Valid in user-defined routine?
No	Yes

Important: This advanced function can adversely affect your UDR if you use the function incorrectly. Use it only when no regular DataBlade API function can perform the task you need done.

Usage

The mi_unlock_memory() function releases a lock on the named-memory block based on its memory duration of duration and its name, which mem_name references. The database server does not release any locks you acquire on named memory. You must ensure that your code uses the mi_unlock_memory() function to release locks in the following cases:

Immediately after you are done accessing the named memory
Before you raise an exception with the mi_db_error_raise() function
Before you call another DataBlade API function that raises an exception internally (For more information, see the HCL Informix® DataBlade API Programmer's Guide.)
Before the session ends
Before the memory duration of the named memory expires
Before you attempt to free the named memory with the mi_named_free() function

Important: After you obtain a lock on a named-memory block, you must explicitly release it with the mi_unlock_memory() function. Failure to release a lock before one of the previous conditions occurs can severely impact the operation of the database server.

Return values

MI_OK: The function successfully unlocked the specified named-memory block.
MI_NO_SUCH_NAME: The requested named-memory block does not exist for the specified duration.
MI_ERROR: The function was not successful.