A mailbox is a built-in class around a queue that uses semaphores to control access to the ends of a queue. A mailbox only has FIFO element ordering whereas you can access the head, tail, or middle elements of a queue. … However, if there is more than one thread, a mailbox is a convenient class to use.
Mailboxes are a message-based process synchronization and communication mechanism provided in SV. It allows messages to be exchanged between processes. Conceptually, mailboxes behave like real mailboxes with delivery and retrieval of messages
An associative array is one of the aggregate data types available in the system Verilog. … When the size of the collection is unknown or the data space is sparse, an associative array is used, which does not have any storage allocated until it is used. That means, it is dynamically allocated but has non-contiguous elements.
Randomization is the process of making something random; SystemVerilog randomization is the process of generating random values to a variable. Verilog has a $random method for generating the random integer values.