How does work concurrency ?
Means that multiple tasks can be executed in an overlapping time period. One of the tasks can begin before the preceding one is completed; however, they won’t be running at the same time. The CPU will adjust time slices per task and appropriately switch contexts. That’s why this concept is quite complicated to implement and especially debug.
While the current thread or process is waiting for input-output operations, database transactions, or launching an external program, another process or thread receives the CPU allocation. On the kernel side, the OS sends an interrupt to the active task to stop it:
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How does work parallelism ?
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