Module pool_pressure 

Memory pressure monitoring with threshold callbacks and eviction hooks.

A long-running allocator benefits from reacting before the device runs out of memory: trimming idle pool pages, evicting cached buffers, or throttling new work as free VRAM drops. This module models that control loop on the host side.

MemoryPressureMonitor holds configurable warning / critical thresholds (expressed as a used fraction of total device memory) and, on each sample, classifies the current state into a PressureLevel. Transitions into a more severe level fire user callbacks; entering the critical level fires an eviction hook that returns the number of bytes reclaimed so the loop can account for the relief.

Samples are supplied as crate::memory_info::MemoryInfo values. In production the MemoryPressureMonitor::poll method fetches a fresh sample via crate::memory_info::memory_info (requires a GPU); in tests the MemoryPressureMonitor::observe method feeds synthetic samples so the whole state machine is deterministic and hardware-free.

Example

let mut monitor = MemoryPressureMonitor::new(0.80, 0.95).expect("thresholds");

// 70% used -> nominal.
let lvl = monitor.observe(MemoryInfo { free: 30, total: 100 });
assert_eq!(lvl, PressureLevel::Nominal);

// 96% used -> critical.
let lvl = monitor.observe(MemoryInfo { free: 4, total: 100 });
assert_eq!(lvl, PressureLevel::Critical);

Structs

MemoryPressureMonitor

Monitors device memory pressure and drives reactive trim / eviction.

PressureSample

The outcome of classifying one memory sample.

Enums

PressureLevel

The classified memory-pressure state.

Functions

validate_thresholds

Validates a pair of (warning, critical) used-fraction thresholds without constructing a monitor.