rust / expert
Snippet
Intercepting Thread Panics Using Custom Global Panic Hooks
In advanced testing or multi-threaded diagnostics, default panic handling might not capture sufficient contextual telemetry or increment test metric counters. By registering a custom panic hook, you can intercept panicking threads, record thread metadata, update atomic diagnostics counters, and chain back to the standard panic output.
snippet.rs
rust
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use std::panic;use std::thread;use std::sync::atomic::{AtomicUsize, Ordering};static PANIC_COUNT: AtomicUsize = AtomicUsize::new(0);pub fn setup_diagnostic_panic_hook() {let default_hook = panic::take_hook();panic::set_hook(Box::new(move |panic_info| {PANIC_COUNT.fetch_add(1, Ordering::SeqCst);let thread = thread::current();let thread_name = thread.name().unwrap_or("<unnamed>");eprintln!("Thread '{}' encountered panic. Hook state: {:?}",thread_name, panic_info);default_hook(panic_info);}));}
Breakdown
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let default_hook = panic::take_hook();
Retrieves the current panic hook wrapper, allowing the custom hook to chain execution back to default behavior.
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panic::set_hook(Box::new(move |panic_info| {
Registers a new global closure as the handler for thread panics across the entire application lifetime.
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PANIC_COUNT.fetch_add(1, Ordering::SeqCst);
Uses atomic ordering to safely increment the global panic tracker in a thread-safe manner.