diff --git a/test/sys/test_lio_listio_resubmit.rs b/test/sys/test_lio_listio_resubmit.rs new file mode 100644 index 0000000000..87cb6a5a54 --- /dev/null +++ b/test/sys/test_lio_listio_resubmit.rs @@ -0,0 +1,108 @@ +// vim: tw=80 +extern crate nix; +#[cfg(target_os = "freebsd")] +extern crate sysctl; +extern crate tempfile; + +use nix::Error; +use nix::errno::*; +use nix::libc::off_t; +use nix::sys::aio::*; +use nix::sys::signal::SigevNotify; +use nix::unistd::{SysconfVar, sysconf}; +use std::os::unix::io::AsRawFd; +use std::{thread, time}; +use sysctl::CtlValue; +use tempfile::tempfile; + +const BYTES_PER_OP: usize = 512; + +/// Attempt to collect final status for all of `liocb`'s operations, freeing +/// system resources +fn finish_liocb(liocb: &mut LioCb) { + for j in 0..liocb.aiocbs.len() { + loop { + let e = liocb.error(j); + match e { + Ok(()) => break, + Err(Error::Sys(Errno::EINPROGRESS)) => + thread::sleep(time::Duration::from_millis(10)), + Err(x) => panic!("aio_error({:?})", x) + } + } + assert_eq!(liocb.aio_return(j).unwrap(), BYTES_PER_OP as isize); + } +} + +// Deliberately exceed system resource limits, causing lio_listio to return EIO. +// This test must run in its own process since it deliberately uses all AIO +// resources. ATM it is only enabled on FreeBSD, because I don't know how to +// check system AIO limits on other operating systems. +#[test] +#[cfg(target_os = "freebsd")] +fn test_lio_listio_resubmit() { + let mut resubmit_count = 0; + + // Lookup system resource limits + let alm = sysconf(SysconfVar::AIO_LISTIO_MAX) + .expect("sysconf").unwrap() as usize; + let maqpp = if let CtlValue::Int(x) = sysctl::value( + "vfs.aio.max_aio_queue_per_proc").unwrap(){ + x as usize + } else { + panic!("unknown sysctl"); + }; + + // Find lio_listio sizes that satisfy the AIO_LISTIO_MAX constraint and also + // result in a final lio_listio call that can only partially be queued + let target_ops = maqpp + alm / 2; + let num_listios = (target_ops + alm - 3) / (alm - 2); + let ops_per_listio = (target_ops + num_listios - 1) / num_listios; + assert!((num_listios - 1) * ops_per_listio < maqpp, + "the last lio_listio won't make any progress; fix the algorithm"); + println!("Using {:?} LioCbs of {:?} operations apiece", num_listios, + ops_per_listio); + + let f = tempfile().unwrap(); + let buffer_set = (0..num_listios).map(|_| { + (0..ops_per_listio).map(|_| { + vec![0u8; BYTES_PER_OP] + }).collect::>() + }).collect::>(); + + let mut liocbs = (0..num_listios).map(|i| { + let mut liocb = LioCb::with_capacity(ops_per_listio); + for j in 0..ops_per_listio { + let offset = (BYTES_PER_OP * (i * ops_per_listio + j)) as off_t; + let wcb = AioCb::from_slice( f.as_raw_fd(), + offset, + &buffer_set[i][j][..], + 0, //priority + SigevNotify::SigevNone, + LioOpcode::LIO_WRITE); + liocb.aiocbs.push(wcb); + } + let mut err = liocb.listio(LioMode::LIO_NOWAIT, SigevNotify::SigevNone); + while err == Err(Error::Sys(Errno::EIO)) || + err == Err(Error::Sys(Errno::EAGAIN)) || + err == Err(Error::Sys(Errno::EINTR)) { + // + thread::sleep(time::Duration::from_millis(10)); + resubmit_count += 1; + err = liocb.listio_resubmit(LioMode::LIO_NOWAIT, + SigevNotify::SigevNone); + } + liocb + }).collect::>(); + + // Ensure that every AioCb completed + for liocb in liocbs.iter_mut() { + finish_liocb(liocb); + } + + if resubmit_count > 0 { + println!("Resubmitted {:?} times, test passed", resubmit_count); + } else { + println!("Never resubmitted. Test ambiguous"); + } +}