Being Rust
- Rust hype
- Memory management
- Rust history
- How I work with Rust
- How to learn Rust
- Beyond tech
- Guru notes
Also
- Q&A
- Stories
- Live mistake-making!
About me (brson)
- Rust since 2010
- Mozilla / Rust core team
- PingCAP since 2018
- talent-plan/rust
About you
- Self-motivated
- Some programming experience
- Have read The Rust Book
Hype!
Elevator Pitch
Rust is a programming language that does exactly what you tell it to. It is one of the fastest languages in the world, but it does not crash like comparable languages. It is suitable for the most performance- and safety-critical systems, as well as for daily software development, and it runs everywhere.
Key features
- Memory safety
- Deterministic memory management
- No runtime (no GC)
- Ownership and borrowing
- Platform support
Rust use cases
- CLI tools
- Operating systems
- Runtimes
- Multi-platform
- Databases
- Networking
- Microcontrollers
- Firmware
- Rendering
- Web backends
- Web frontends (WASM)
- Aerospace
- Blockchains
- Finance
Rust users
User: Mozilla
- Product: Firefox
- What: Web browser
- Why: Security
- Why: Performance
User: PingCAP
- Product: TiDB (TiKV)
- What: Database
- Why: Reliability
- Why: Performance
User: Cloudflare
- Product: TiDB (TiKV)
- What: Edge compute sandboxing
- Why: WASM
Rust quotes and press
TODO
https://github.com/brson/my-rust-lists/blob/master/rust-quotes-and-press.md
Questions?
Memory management
The CPU and RAM
+---------------+ +---------------+
| | | |
| I'm the | | I'm the |
| CPU +-----------+ RAM |
| | | |
| | ^ | |
+---------------+ | +---------------+
|
(this is slow)
The CPU and RAM
5b080 <alloc::box_free>:
5b080: 48 89 f0 mov %rsi, %rax
5b083: 48 8b 76 08 mov 0x8(%rsi), %rsi
5b087: 48 85 f6 test %rsi, %rsi
5b08a: 74 0a je 5b096 <alloc::box_free+0x16>
The callstack
Source code
fn main() {
let a = 1;
foo(&a);
}
Stack frames
|=============| 0x00
| fn main |
| a = 1 |
|=============|
Source code
fn main() {
let a = 1;
foo(&a);
}
fn foo(ptr_a: &i32) {
let b = 2;
bar(ptr_a, &b);
}
Stack frames
|=============| 0x00
| fn main |
| a = 1 |
|=============| 0x10
| fn foo |
| <main regs> |
| ptr_a = &a |
| b = 2 |
|=============|
Source code
fn foo(ptr_a: &i32) {
let b = 2;
bar(ptr_a, &b);
}
fn bar(ptr_a: &i32,
ptr_b: &i32) {
...
}
Stack frames
...
|=============| 0x10
| fn foo |
| <main regs> |
| ptr_a = &a |
| b = 2 |
|=============| 0x20
| fn bar |
| <foo regs> |
| ptr_a = &a |
| ptr_b = &b |
|=============|
Source code
fn main() {
let a = 1;
foo(&a);
}
fn foo(ptr_a: &i32) {
let b = 2;
bar(ptr_a, &b);
}
Stack frames
|=============| 0x00
| fn main |
| a = 1 |
|=============| 0x10
| fn foo |
| <main regs> |
| ptr_a = &a |
| b = 2 |
|=============|
Source code
fn main() {
let a = 1;
foo(&a);
}
Stack frames
|=============| 0x00
| fn main |
| a = 1 |
|=============|
The heap
- Not CPU registers
- Not the stack
- All the other RAM
- As allocated with
malloc
Questions?
Managing the heap
- manually with alloc / free (like C)
- garbage collection (like Go)
Heap management examples
https://github.com/brson/being-rust/blob/master/examples/Problems of malloc/free
- Use after free
- Double free
- Crashes == security bugs
Problems of garbage collection
- Bookeeping overhead
- CPU overhead
- Latency
- Runtime binary
- Mutable aliasing
Ownership in Rust
Questions?
Rust history
Questions?
How I work with Rust
Questions?
How to learn Rust
Rust mindset
- Be curious
- Write real projects
- Read real code
- Try again
- Ask for help
Rust mindset
- Be curious
- Write real projects
- Read real code
- Try again
- Ask for help
Rust resources
See README.md
Beyond tech
Relationships
Insecurity
Contributing
Inspiration
Questions?
Understand mutable aliasing
This is the thing Rust solves.
See README.md for links
Don't jump to lifetimes
Just clone stuff.
- `memcpy` is fast.
- `malloc` is fast.
`impl Drop` is a breaking change
struct Bar;
struct Foo(Bar);
impl Drop for Foo { fn drop(&mut self) { } }
fn main() {
// XXX can't destructure
let Foo(i) = Foo(Bar);
}
Know the `cargo` command line
The defaults are not always what you want. Save time by being precise with your `cargo` invocations.
cargo check --all
cargo test --all --no-run
cargo check --all --no-run --profile=dev
cargo test -p subproject
The "turbofish"
a::<B>();Alternate debug formatting
println!("{:?}", qux);
println!("{:#?}", qux);
Foo { bar: 0, baz: 1 }
Foo {
bar: 0,
baz: 1,
}
Building without the networking
cargo generate-lockfile
cargo fetch
cargo build --locked --offline
cargo test --locked --offline
Rust CI tools
cargo clippy
cargo fmt
cargo outdated
cargo audit
Questions?
