diff --git a/src/lib.rs b/src/lib.rs index ed7cc58..6ac37b0 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -28,7 +28,7 @@ //! I/O panic: //! //! ```rust -//! use fail::fail_point; +//! use fail::{fail_point, FailScenario}; //! //! fn do_fallible_work() { //! fail_point!("read-dir"); @@ -36,9 +36,9 @@ //! // ... do some work on the directory ... //! } //! -//! fail::setup(); +//! let scenario = FailScenario::setup(); //! do_fallible_work(); -//! fail::teardown(); +//! scenario.teardown(); //! println!("done"); //! ``` //! @@ -116,7 +116,9 @@ //! Here's a example to show the process： //! //! ```rust -//! fail::setup(); +//! use fail::FailScenario; +//! +//! let _scenario = FailScenario::setup(); //! fail::cfg("p1", "sleep(100)").unwrap(); //! println!("Global registry: {:?}", fail::list()); //! { @@ -165,7 +167,7 @@ //! function we used earlier to return a `Result`: //! //! ```rust -//! use fail::fail_point; +//! use fail::{fail_point, FailScenario}; //! use std::io; //! //! fn do_fallible_work() -> io::Result<()> { @@ -176,9 +178,9 @@ //! } //! //! fn main() -> io::Result<()> { -//! fail::setup(); +//! let scenario = FailScenario::setup(); //! do_fallible_work()?; -//! fail::teardown(); +//! scenario.teardown(); //! println!("done"); //! Ok(()) //! } @@ -264,6 +266,7 @@ use std::env::VarError; use std::fmt::Debug; use std::str::FromStr; use std::sync::atomic::{AtomicUsize, Ordering}; +use std::sync::MutexGuard; use std::sync::{Arc, Condvar, Mutex, RwLock, TryLockError}; use std::time::{Duration, Instant}; use std::{env, thread}; @@ -588,63 +591,80 @@ impl FailPointRegistry { lazy_static::lazy_static! { static ref REGISTRY_GROUP: RwLock>>> = Default::default(); static ref REGISTRY_GLOBAL: FailPointRegistry = Default::default(); + static ref SCENARIO: Mutex<&'static FailPointRegistry> = Mutex::new(®ISTRY_GLOBAL); } -/// Set up the global fail points registry. -/// -/// Configures global fail points specified in the `FAILPOINTS` environment variable. -/// It does not otherwise change any existing fail point configuration. -/// -/// The format of `FAILPOINTS` is `failpoint=actions;...`, where -/// `failpoint` is the name of the fail point. For more information -/// about fail point actions see the [`cfg`](fn.cfg.html) function and -/// the [`fail_point`](macro.fail_point.html) macro. -/// -/// `FAILPOINTS` may configure fail points that are not actually defined. In -/// this case the configuration has no effect. -/// -/// This function should generally be called prior to running a test with fail -/// points, and afterward paired with [`teardown`](fn.teardown.html). -/// -/// # Panics -/// -/// Panics if an action is not formatted correctly. -pub fn setup() { - let mut registry = REGISTRY_GLOBAL.registry.write().unwrap(); - cleanup(&mut registry); - - let failpoints = match env::var("FAILPOINTS") { - Ok(s) => s, - Err(VarError::NotPresent) => return, - Err(e) => panic!("invalid failpoints: {:?}", e), - }; - for mut cfg in failpoints.trim().split(';') { - cfg = cfg.trim(); - if cfg.is_empty() { - continue; - } - let (name, order) = partition(cfg, '='); - match order { - None => panic!("invalid failpoint: {:?}", cfg), - Some(order) => { - if let Err(e) = set(&mut registry, name.to_owned(), order) { - panic!("unable to configure failpoint \"{}\": {}", name, e); +/// Test scenario with configured fail points. +#[derive(Debug)] +pub struct FailScenario<'a> { + scenario_guard: MutexGuard<'a, &'static FailPointRegistry>, +} + +impl<'a> FailScenario<'a> { + /// Set up the global fail points registry. + /// + /// Configures global fail points specified in the `FAILPOINTS` environment variable. + /// It does not otherwise change any existing fail point configuration. + /// + /// The format of `FAILPOINTS` is `failpoint=actions;...`, where + /// `failpoint` is the name of the fail point. For more information + /// about fail point actions see the [`cfg`](fn.cfg.html) function and + /// the [`fail_point`](macro.fail_point.html) macro. + /// + /// `FAILPOINTS` may configure fail points that are not actually defined. In + /// this case the configuration has no effect. + /// + /// This function should generally be called prior to running a test with fail + /// points, and afterward paired with [`teardown`](fn.teardown.html). + /// + /// # Panics + /// + /// Panics if an action is not formatted correctly. + pub fn setup() -> Self { + let scenario_guard = SCENARIO.lock().unwrap_or_else(|e| e.into_inner()); + let mut registry = scenario_guard.registry.write().unwrap(); + cleanup(&mut registry); + + let failpoints = match env::var("FAILPOINTS") { + Ok(s) => s, + Err(VarError::NotPresent) => return Self { scenario_guard }, + Err(e) => panic!("invalid failpoints: {:?}", e), + }; + for mut cfg in failpoints.trim().split(';') { + cfg = cfg.trim(); + if cfg.is_empty() { + continue; + } + let (name, order) = partition(cfg, '='); + match order { + None => panic!("invalid failpoint: {:?}", cfg), + Some(order) => { + if let Err(e) = set(&mut registry, name.to_owned(), order) { + panic!("unable to configure failpoint \"{}\": {}", name, e); + } } } } + Self { scenario_guard } + } + + /// Tear down the global fail points registry. + /// + /// Clears the configuration of global fail points. Any paused fail + /// points will be notified before they are deactivated. + /// + /// This function should generally be called after running a test with fail points. + /// Calling `teardown` without previously calling `setup` results in a no-op. + pub fn teardown(self) { + drop(self); } } -/// Tear down the global fail points registry. -/// -/// Clears the configuration of global fail points. Any paused fail -/// points will be notified before they are deactivated. -/// -/// This function should generally be called after running a test with fail points. -/// Calling `teardown` without previously calling `setup` results in a no-op. -pub fn teardown() { - let mut registry = REGISTRY_GLOBAL.registry.write().unwrap(); - cleanup(&mut registry); +impl<'a> Drop for FailScenario<'a> { + fn drop(&mut self) { + let mut registry = self.scenario_guard.registry.write().unwrap(); + cleanup(&mut registry); + } } /// Clean all registered fail points. @@ -1099,7 +1119,7 @@ mod tests { "FAILPOINTS", "setup_and_teardown1=return;setup_and_teardown2=pause;", ); - setup(); + let scenario = FailScenario::setup(); let group = FailPointRegistry::new(); let handler = thread::spawn(move || { @@ -1130,7 +1150,7 @@ mod tests { }); assert!(rx.recv_timeout(Duration::from_millis(500)).is_err()); - teardown(); + scenario.teardown(); assert_eq!(rx.recv_timeout(Duration::from_millis(500)).unwrap(), 0); assert_eq!(f1(), 0); }