1. Ch 3

2. Shared memory programming: threads
You will learn
Create threads
Run threads
Kill threads
Semaphores
Race conditions
Deadlocks
Synchronization issues
Control thread execution
Debug threaded programs

3. Concurrent execution Processes compete for the CPU
Fork creates processes that compete with each other for the cpu
Child gets a copy of parents code
Concurrent execution

4. Threads Operate within the parent process Benefits of threads
Improve performance
Background tasks
Asynchronous processing
Improving program structure

5. Make a multithreaded pgm behave like a sequential one
Design Concerns

6. Set of rules that force a system to behave in a specific way
Example: sequential consistency model
All events that work on shared memory happen in a 1 at a time order
Problematic when combining 2 sequentially consistent events, resulting in inconsistent. Figure 3.6
Example: linearizability
Events appear to happen in a one at a time order
Appear to take place instantly, done by linearization points (when they take effect)
Consistency Model

7. Implications of linearization points
Methods can be totally ordered by linearization points
Locking has the effect of taking place instantly as far as others are concerned.
Discuss page 68, 69, 70
Implications of linearization points

8. semaphores

9. Producer / Consumer