Andy Pack
5f04cacd81
Affected files: .obsidian/workspace.json Projects/Dev Options.md Projects/Mixonomer.md Projects/NoteCrawler.md Projects/Selector.md Projects/To Do App.md STEM/CS/ABI.md STEM/CS/Calling Conventions.md STEM/CS/Code Types.md STEM/CS/Compilers.md STEM/CS/ISA.md STEM/CS/Language Binding.md STEM/CS/Languages/Assembly.md STEM/CS/Languages/C++.md STEM/CS/Languages/Javascript.md STEM/CS/Languages/Python.md STEM/CS/Languages/Rust.md STEM/CS/Languages/dotNet.md STEM/IOT/OS/Composition.md
54 lines
1.5 KiB
Markdown
54 lines
1.5 KiB
Markdown
---
|
|
tags:
|
|
- dev
|
|
---
|
|
# Threading
|
|
*Smallest sequence of programmed instructions that can be managed independently by a [scheduler](https://en.wikipedia.org/wiki/Scheduling_(computing))*
|
|
From <[https://en.wikipedia.org/wiki/Thread_(computing)](https://en.wikipedia.org/wiki/Thread_(computing))>
|
|
|
|
- Instructions run independently by scheduler
|
|
- Single address space
|
|
- One thread blocked for I/O
|
|
- Tasks run in other threads
|
|
- Need locks and mutexes
|
|
- Coordination between threads
|
|
- Complicated
|
|
- Deadlocks
|
|
|
|
# Protothreads
|
|
- Lightweight
|
|
- Stack-less
|
|
- Interruptible tasks for event-based
|
|
- Conditional blocking statement
|
|
- Blocks until given statement is true
|
|
- Use timer to manage
|
|
- Invoked whenever process receives message from another process or timer
|
|
|
|
# Events
|
|
*Action or occurrence recognized by software, often originating asynchronously from the external environment, that may be [handled](https://en.wikipedia.org/wiki/Event_handler) by the software*
|
|
From <[https://en.wikipedia.org/wiki/Event_(computing)](https://en.wikipedia.org/wiki/Event_(computing))>
|
|
|
|
- Event loop
|
|
- Waits for events
|
|
- Inputs
|
|
- On event
|
|
- Collects info
|
|
- Dispatches to call-back
|
|
- Register handlers with OS scheduler
|
|
- Kernel usually runs loop to poll for events
|
|
- Blocking operation
|
|
- Register call-back
|
|
- Return control to scheduler
|
|
|
|
# Radio Sleep
|
|
- Energy efficiency
|
|
- Congestion
|
|
|
|
## Event-based
|
|
|
|
|
|
## Thread-based
|
|
|
|
- Less complex
|
|
- Faster
|
|
- Pointer-based |