Struct PipeBufferSource 

pub struct PipeBufferSource {
    pub config: PipeBufferConfig,
}

Harvests timing jitter from pipe I/O with multiple pipes competing for kernel buffer space.

What it measures

Nanosecond timing of write() + read() cycles on a pool of pipes, with variable write sizes and periodic pipe creation/destruction for zone allocator churn.

Why it’s entropic

Multiple simultaneous pipes competing for kernel zone allocator resources amplifies nondeterminism:

• Zone allocator contention — multiple pipes allocating from the pipe zone simultaneously creates cross-CPU magazine transfer contention
• Variable buffer sizes — different write sizes exercise different mbuf allocation paths (small = inline storage, large = chained mbufs)
• Non-blocking I/O — EAGAIN on full pipe buffers follows a different kernel path with its own latency characteristics
• Cross-pipe interference — reading from one pipe while another has pending data creates wakeup scheduling interference

What makes it unique

Pipe buffers exercise the kernel’s zone allocator (magazine layer) in a way that no other entropy source does. The zone allocator’s per-CPU caching and cross-CPU transfers create timing that depends on every CPU’s allocation history.

Configuration

See PipeBufferConfig for tunable parameters. Key options:

• non_blocking: capture EAGAIN failure path timing (recommended: true)
• num_pipes: controls zone allocator contention level
• min_write_size/max_write_size: controls mbuf allocation path diversity

Fields

config: PipeBufferConfig

Source configuration. Use Default::default() for recommended settings.

Trait Implementations

impl Default for PipeBufferSource

fn default() -> PipeBufferSource

Returns the “default value” for a type.

impl EntropySource for PipeBufferSource

fn info(&self) -> &SourceInfo

Source metadata.

fn is_available(&self) -> bool

Check if this source can operate on the current machine.

fn collect(&self, n_samples: usize) -> Vec<u8>

Collect raw entropy samples. Returns a Vec<u8> of up to n_samples bytes.

fn name(&self) -> &'static str

Convenience: name from info.