From fa8d079c729dbf991ebc61049b49132488ea77f3 Mon Sep 17 00:00:00 2001
From: Julian Orth <ju.orth@gmail.com>
Date: Tue, 3 May 2022 12:45:20 +0200
Subject: [PATCH] it: run tests in parallel

---
 src/it.rs             | 52 ++++++++++++++++++++++++++++++++++---------
 src/it/tests.rs       |  2 +-
 src/utils.rs          |  1 +
 src/utils/num_cpus.rs | 21 +++++++++++++++++
 4 files changed, 64 insertions(+), 12 deletions(-)
 create mode 100644 src/utils/num_cpus.rs

diff --git a/src/it.rs b/src/it.rs
index 4a552ff9..ae6ba474 100644
--- a/src/it.rs
+++ b/src/it.rs
@@ -6,17 +6,19 @@ use {
             testrun::TestRun,
             tests::TestCase,
         },
-        utils::errorfmt::ErrorFmt,
+        utils::{errorfmt::ErrorFmt, num_cpus::num_cpus},
     },
     ahash::AHashMap,
     futures_util::{future, future::Either},
     isnt::std_1::collections::IsntHashMapExt,
     log::Level,
     std::{
-        cell::{Cell, RefCell},
+        cell::Cell,
+        collections::VecDeque,
         future::pending,
         pin::Pin,
         rc::Rc,
+        sync::{Arc, Mutex},
         time::SystemTime,
     },
     uapi::c,
@@ -37,23 +39,51 @@ mod test_utils;
 mod testrun;
 mod tests;
 
+const SINGLE_THREAD: bool = false;
+
 pub fn run_tests() {
     test_logger::install();
     test_logger::set_level(Level::Trace);
-    let it_run = ItRun {
+    let it_run = Arc::new(ItRun {
         path: format!(
             "{}/testruns/{}",
             env!("CARGO_MANIFEST_DIR"),
             humantime::format_rfc3339_millis(SystemTime::now())
         ),
         failed: Default::default(),
-    };
-    for test in tests::tests() {
-        with_test_config(|cfg| {
-            run_test(&it_run, test, cfg);
-        })
+    });
+    if SINGLE_THREAD {
+        for test in tests::tests() {
+            with_test_config(|cfg| {
+                run_test(&it_run, test, cfg);
+            })
+        }
+    } else {
+        let queue = Arc::new(Mutex::new(VecDeque::from_iter(tests::tests())));
+        let mut threads = vec![];
+        let num_cpus = match num_cpus() {
+            Ok(n) => n,
+            Err(e) => fatal!("Could not determine the number of cpus: {}", ErrorFmt(e)),
+        };
+        log::info!("Running {} tests in parallel", num_cpus);
+        for _ in 0..num_cpus {
+            let queue = queue.clone();
+            let it_run = it_run.clone();
+            threads.push(std::thread::spawn(move || loop {
+                let test = match queue.lock().unwrap().pop_front() {
+                    Some(t) => t,
+                    _ => break,
+                };
+                with_test_config(|cfg| {
+                    run_test(&it_run, test, cfg);
+                })
+            }));
+        }
+        for thread in threads {
+            thread.join().unwrap();
+        }
     }
-    let failed = it_run.failed.borrow_mut();
+    let failed = it_run.failed.lock().unwrap();
     if failed.is_not_empty() {
         let mut failed: Vec<_> = failed.iter().collect();
         failed.sort_by_key(|f| f.0);
@@ -70,7 +100,7 @@ pub fn run_tests() {
 
 struct ItRun {
     path: String,
-    failed: RefCell<AHashMap<&'static str, Vec<String>>>,
+    failed: Mutex<AHashMap<&'static str, Vec<String>>>,
 }
 
 fn run_test(it_run: &ItRun, test: &'static dyn TestCase, cfg: Rc<TestConfig>) {
@@ -130,7 +160,7 @@ fn run_test(it_run: &ItRun, test: &'static dyn TestCase, cfg: Rc<TestConfig>) {
         for e in &errors {
             log::error!("    {}", e);
         }
-        it_run.failed.borrow_mut().insert(test.name(), errors);
+        it_run.failed.lock().unwrap().insert(test.name(), errors);
     }
     test_logger::unset_file();
 }
diff --git a/src/it/tests.rs b/src/it/tests.rs
index 6a1c7d04..8252a8a4 100644
--- a/src/it/tests.rs
+++ b/src/it/tests.rs
@@ -58,7 +58,7 @@ mod t0002_window;
 mod t0003_multi_window;
 mod t0004_quit;
 
-pub trait TestCase {
+pub trait TestCase: Sync {
     fn name(&self) -> &'static str;
     fn run(&self, testrun: Rc<TestRun>) -> Box<dyn Future<Output = Result<(), TestError>>>;
 }
diff --git a/src/utils.rs b/src/utils.rs
index 95be0c4e..9f700ab8 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -13,6 +13,7 @@ pub mod hex;
 pub mod linkedlist;
 pub mod log_on_drop;
 pub mod nonblock;
+pub mod num_cpus;
 pub mod numcell;
 pub mod oserror;
 pub mod ptr_ext;
diff --git a/src/utils/num_cpus.rs b/src/utils/num_cpus.rs
new file mode 100644
index 00000000..8f4ffa08
--- /dev/null
+++ b/src/utils/num_cpus.rs
@@ -0,0 +1,21 @@
+use {
+    crate::utils::oserror::OsError,
+    smallvec::{smallvec_inline, SmallVec},
+    uapi::{c, Errno},
+};
+
+#[allow(dead_code)]
+pub fn num_cpus() -> Result<u32, OsError> {
+    let mut buf: SmallVec<[usize; 32]> = smallvec_inline![0; 32];
+    loop {
+        match uapi::sched_getaffinity(0, &mut buf) {
+            Ok(_) => return Ok(count(&buf)),
+            Err(Errno(c::EINVAL)) => buf.extend_from_slice(&[0; 32][..]),
+            Err(e) => return Err(e.into()),
+        }
+    }
+}
+
+fn count(buf: &[usize]) -> u32 {
+    buf.iter().copied().map(|n| n.count_ones()).sum()
+}