ALL meanings of concurrency
con·cur·rence
C c - abbreviation Technical meaning of CONCURRENCY multitasking 3
- noun concurrency The property or an instance of being concurrent; something that happens at the same time as something else. 1
- noun Technical meaning of concurrency (computer, parallel) (Or "multi-tasking", "multiprogramming", "concurrent processing", "concurrency", "process scheduling") A technique used in an operating system for sharing a single processor between several independent jobs. The first multitasking operating systems were designed in the early 1960s. Under "cooperative multitasking" the running task decides when to give up the CPU and under "pre-emptive multitasking" (probably more common) a system process called the "scheduler" suspends the currently running task after it has run for a fixed period known as a "time-slice". In both cases the scheduler is responsible for selecting the next task to run and (re)starting it. The running task may relinquish control voluntarily even in a pre-emptive system if it is waiting for some external event. In either system a task may be suspended prematurely if a hardware interrupt occurs, especially if a higher priority task was waiting for this event and has therefore become runnable. The scheduling algorithm used by the scheduler determines which task will run next. Some common examples are round-robin scheduling, priority scheduling, shortest job first and guaranteed scheduling. Multitasking introduces overheads because the processor spends some time in choosing the next job to run and in saving and restoring tasks' state, but it reduces the worst-case time from job submission to completion compared with a simple batch system where each job must finish before the next one starts. Multitasking also means that while one task is waiting for some external event, the CPU to do useful work on other tasks. A multitasking operating system should provide some degree of protection of one task from another to prevent tasks from interacting in unexpected ways such as accidentally modifying the contents of each other's memory areas. The jobs in a multitasking system may belong to one or many users. This is distinct from parallel processing where one user runs several tasks on several processors. Time-sharing is almost synonymous but implies that there is more than one user. 1
- noun concurrency the act of concurring. 1
- noun concurrency accordance in opinion; agreement: With the concurrence of several specialists, our doctor recommended surgery. 1
- noun concurrency cooperation, as of agents or causes; combined action or effort. 1
- noun concurrency simultaneous occurrence; coincidence: the concurrence of several unusual events. 1
- noun concurrency Geometry. a point that is in three or more lines simultaneously. 1
- noun concurrency Law. a power equally held or a claim shared equally. 1
- noun concurrency Archaic. competition; rivalry. 1
- noun concurrency (computer science) a property of systems where several processes execute at the same time. 0