Operating Systems W1 - W2 Concurrency Flashcards
concurrency
multiple tasks which start, run, and complete in overlapping time periods, in no specific order. (one chef in the kitchen)
Parallelism
multiple tasks of the same task that literally run at the same time on a hardware with multiple computing resources like multi-core processor. (e.g Another chef in the kitchen)
Distributed system
computing environment in which various components are spread across multiple computers (or other computing devices) on a network
address space
This is the area of contiguous virtual addresses available for executing instructions and storing data.
thread libraries
provides the programmer with an Application program interface for creating and managing thread
non-determinism
an algorithm that, even for the same input, can exhibit different behaviours on different runs, as opposed to a deterministic algorithm.
critical section
a section of code that must not overlap.
Interference/race conditions
when concurrent threads affect one another’s behaviour, which is called interference.
What are the registers?
A piece of memory can only be found in the CPU to allow the CPU faster access to the memory and quickly retrieve the information
program status word (PSW)
register that performs the function of a status register and program counter, and sometimes more.
What are privileged instructions?
Code that runs in the kernel mode can use privileged instructions (IN, OUT).
Machine code
Runs while the CPU is in user mode, it cannot use privileged instructions.
Kernel mode
a computer program at the core of the computer’s operating system and has complete control over everything in the system.
Sequential system
Computations - or parts of the computation are executed to completion, one after the other.
Data race
It can occur when two or more threads concurrently access the same memory location.
