Eukaryotes. Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus (that holds genetic material) as well as membrane-bound organelles. Genetic material in eukaryotes is contained within a nucleus within the cell and DNA is organized into chromosomes. Eukaryotic organisms may be multicellular or single-celled organisms. All animals are eukaryotes. Other eukaryotes include plants, fungi, and protists. A typical eukaryotic cell might contain the following parts: plasma membrane; nucleolus
A unique_lock can be created without immediately locking, can unlock at any point in its existence, and can transfer ownership of the lock from one instance to another. So you always use lock_guard, unless you need the capabilities of unique_lock. A condition_variable needs a unique_lock.
A lock is a variable associated with a data item that describes the status of the item with respect to possible operations that can be applied to it. Generally, there is one lock for each data item in the database.Locks are used as a means of synchronizing the access by concurrent transactions to the database item. Types of Locks. Several types of locks are used in concurrency control.inary Locks. A binary lock can have two states or values: locked and unlocked. A distinct lock is associated with each database item A. If the value of the lock on A is 1, item A cannot be accessed by a database operation that requests the item.