© Stewart Weiss. CC-BY-SA.

Table of Contents

Computer Systems
Operating System Overview
Processes
Threads

© Stewart Weiss. CC-BY-SA.

Threads

• Kernel level
• Thread libraries
• Implementations: 1:1, M:1, M:N, two-level
• Scheduler Activations
• Implicit Threading
• Parallelizing Compilers
• Types of Implicit Threading
• Thread Pools
• Fork-Join Parallelism
• OpenMP
• Grand Central Dispatch
• Threading Issues related to fork() and exec()
• Signals and Signal Handling

© Stewart Weiss. CC-BY-SA.

Scheduling

• FCFS
• Shortest Job First
• SRTF
• Round Robin
• Priority scheduling
• Priority queues
• Multilevel feedback queues
• System Contention Scope
• Process Contention Scope
• Multiprocessor Scheduling Issues
• Logical Versus Physical Processors
• Asymmetric Multiprocessing System Scheduling
• Symmetric Multiprocessor Scheduling
• Shared Ready Queues
• Per-Processor Ready Queues
• Load Balancing
• Migration Issues
• Processor Affinity
• NUMA Nodes
• Hardware Multithreading

© Stewart Weiss. CC-BY-SA.

Synchronization Tools

• Synchronization Mechanisms
• Race Conditions
• Race Conditions in the Kernel
• Preemptive Kernels
• Re-entrant Kernels
• The Critical Section Problem
• The Conditions A Solution Must Satisfy
• Peterson's Algorithm
• Limitations of Peterson's Algorithm
• Memory Barriers
• Hardware Support for Critical Section Solutions
• Bus locking
• Hardware Primitives
• The Test-and-Set Instruction
• Compare-and-Swap Instruction
• Implementing Test-and-Set With Compare-and-Swap
• Spinlocks
• Ensuring Bounded Waiting Using Locks
• Atomic Variables
• Mutex Locks
• Semaphores
• Binary Semaphores for Mutual Exclusion
• Counting Semaphores
• Liveness
• Priority Inversion

© Stewart Weiss. CC-BY-SA.

Synchronization Problems

• The Bounded Buffer Problem
• Producer and Consumer Problem
• The Readers-Writers Problem
• Alternative Preferences in Readers Writers Problem
• Reader-Writer Locks
• The Dining Philosophers Problem
• A Naive Solution Using Semaphores
• Synchronization in the Modern Linux Kernel
• Spinlocks in Linux
• Mutexes in Linux
• Semaphores in Linux

© Stewart Weiss. CC-BY-SA.

Deadlock

• Examples of Deadlock
• Formal Model of a Resource Allocation System
• Reusable Resource Graphs
• Characterizing Deadlock: Four Necessary Conditions
• Circular Waiting and Cycles: Theorems
• Prevention Methods
• Avoidance Algorithms
• Safe and Unsafe System States
• The Banker's Algorithm
• Deadlock Detection - ~