14 releases (5 stable)
1.0.4 | Feb 11, 2019 |
---|---|
1.0.0 | Dec 15, 2018 |
0.7.1 | Dec 4, 2018 |
0.7.0 | Nov 19, 2018 |
#92 in #drop
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qadapt
debug_assert!
for your memory usage
Please note: This crate has been deprecated in favor of alloc-counter.
This allocator is a helper for writing high-performance code that is memory-sensitive;
a thread panic will be triggered if a function annotated with #[no_alloc]
,
or code inside an assert_no_alloc!
macro interacts with the allocator in any way.
Wanton allocations and unforeseen drops no more - this library lets you focus on
writing code without worrying if Rust properly managed to inline the variable into the stack.
Now, an allocator blowing up in production is a scary thought; that's why QADAPT
is designed to strip its own code out whenever you're running with a release build.
Just like the debug_assert!
macro
in Rust's standard library, it's safe to use without worrying about a unforeseen
circumstance causing your application to crash.
Usage
Actually making use of QADAPT is straight-forward. To set up the allocator, place the following snippet in either your program binaries (main.rs) or tests:
use qadapt::QADAPT;
#[global_allocator]
static Q: QADAPT = QADAPT;
fn main() {
# // Because `debug_assertions` are on for doctests in release mode
# // we have to add an extra guard.
# if qadapt::is_active() {
assert!(qadapt::is_active());
# }
}
After that, there are two ways of telling QADAPT that it should trigger a panic:
- Annotate functions with the
#[no_alloc]
proc macro:
use qadapt::no_alloc;
use qadapt::QADAPT;
use std::panic::catch_unwind;
#[global_allocator]
static Q: QADAPT = QADAPT;
// This function is fine, there are no allocations here
#[no_alloc]
fn do_math() -> u8 {
2 + 2
}
// This function will trigger a panic when called
#[no_alloc]
fn does_panic() -> Box<u32> {
Box::new(5)
}
fn main() {
do_math();
let err = catch_unwind(|| does_panic());
# if qadapt::is_active() {
assert!(err.is_err());
# }
}
- Evaluate expressions with the
assert_no_alloc!
macro
use qadapt::assert_no_alloc;
use qadapt::QADAPT;
#[global_allocator]
static Q: QADAPT = QADAPT;
fn main() {
// This code is allowed to trigger an allocation
let b = Box::new(8);
// This code would panic if an allocation occurred inside it
let x = assert_no_alloc!(*b + 2);
assert_eq!(x, 10);
}
Dependencies
~160–390KB