prock

Fast, low-overhead CPU statistics for process trees.

Uses direct syscalls for minimal overhead (~1-5µs per process):

• macOS: proc_pid_rusage via libproc
• Linux: /proc/[pid]/stat filesystem reads

Features

• CPU time (user + system) in nanoseconds
• Memory usage (RSS and virtual)
• Disk I/O statistics
• Process tree discovery (parent/child relationships)
• Tree-wide aggregation (sum stats across process + all descendants)

Usage

use prock::{get_cpu_time, get_memory, get_all_stats};

// Get CPU time for a single process
if let Some(cpu) = get_cpu_time(pid) {
    println!("CPU: {}ns user, {}ns system", cpu.user_ns, cpu.system_ns);
}

// Get memory for a single process
if let Some(mem) = get_memory(pid) {
    println!("Memory: {} bytes", mem);
}

// Get all stats at once (more efficient for multiple metrics)
if let Some(stats) = get_all_stats(pid) {
    println!("CPU: {:?}, Memory: {}", stats.cpu_time, stats.memory_bytes);
}

Platform Support