execution is a is a function or action implemented as a sequence of one or more instructions that appears to be indivisible, no other process can see an intermediate state or interrupt the operations. is a programming language construct that encapsulates variables, access procedures, and initialization code within an abstract data type. 9 is a section of code within a process that requires access to shared resources and that must not be executed while another process is in a corresponding section of code 10) In the case of processes are sharing resources without being aware ofthe other processes is a mutual exclusion mechanism in II) which a process executes in an infinite loop waiting for the value of a lock variable to indicate availability. 12 Only three operations may be performed on a semaphore: initialize, increment, and 13 A monitor supports synchronization by the use of that are contained within the monitor and accessible only within the monitor. In the case of messages are not sent directly from sender to receiver but rather are sent to a shared data structure consisting of queues that can temporarily hold messages. IsyThe classic concurrency problem that involves multiple readers that can read from a shared data area when no single writer is exclusively writing to it is the