UML supports concurrency, and makes it possible to represent the concept in different kinds of diagrams. This article covers the three most commonly used – the activity diagram, sequence …

We just looked at a shared memory model of concurrency: different threads could concurrently access the same memory locations. A shared memory model is commonly used in many programming …

Concurrency A version of the program that executes multiple tasks simultaneously Example: Our web server could execute multiple queries at the same time While one is waiting for I/O, another can be …

What Is a Thread? What Is “Concurrency?” Two events are said to be concurrent if they occur within the same time interval. Two or more tasks executing over the same time interval are said to execute …

This chapter has set up the problem of concurrency as if only one type of interaction occurs between threads, that of accessing shared variables and the need to support atomicity for critical sections.

Run a computation on all cores on 100K machines! Concurrency is Inevitable! Inconsistent replicas! What to Do? Handle one client at a time? How to enforce a consistent order? Based on wall-clock time?

3 Concurrency, CS314 Fall019© BGRyder 5 Concurrency as Interleaving • Interleaving of threads - possible orderings that maintain relative order of events within one thread { a; b} {x; y; z} a x b y z …