add test for init once

src/tools/miri/tests/pass/concurrency/windows_init_once.rs

@@ -0,0 +1,138 @@
+//@only-target-windows: Uses win32 api functions
+// We are making scheduler assumptions here.
+//@compile-flags: -Zmiri-preemption-rate=0
+
+use std::ffi::c_void;
+use std::ptr::null_mut;
+use std::thread;
+
+#[derive(Copy, Clone)]
+struct SendPtr<T>(*mut T);
+
+unsafe impl<T> Send for SendPtr<T> {}
+
+extern "system" {
+    fn InitOnceBeginInitialize(
+        init: *mut *mut c_void,
+        flags: u32,
+        pending: *mut i32,
+        context: *mut c_void,
+    ) -> i32;
+
+    fn InitOnceComplete(init: *mut *mut c_void, flags: u32, context: *mut c_void) -> i32;
+}
+
+const TRUE: i32 = 1;
+const FALSE: i32 = 0;
+
+const INIT_ONCE_INIT_FAILED: u32 = 4;
+
+fn single_thread() {
+    let mut init_once = null_mut();
+    let mut pending = 0;
+
+    unsafe {
+        assert_eq!(InitOnceBeginInitialize(&mut init_once, 0, &mut pending, null_mut()), TRUE);
+        assert_eq!(pending, TRUE);
+
+        assert_eq!(InitOnceComplete(&mut init_once, 0, null_mut()), TRUE);
+
+        assert_eq!(InitOnceBeginInitialize(&mut init_once, 0, &mut pending, null_mut()), TRUE);
+        assert_eq!(pending, FALSE);
+    }
+
+    let mut init_once = null_mut();
+
+    unsafe {
+        assert_eq!(InitOnceBeginInitialize(&mut init_once, 0, &mut pending, null_mut()), TRUE);
+        assert_eq!(pending, TRUE);
+
+        assert_eq!(InitOnceComplete(&mut init_once, INIT_ONCE_INIT_FAILED, null_mut()), TRUE);
+
+        assert_eq!(InitOnceBeginInitialize(&mut init_once, 0, &mut pending, null_mut()), TRUE);
+        assert_eq!(pending, TRUE);
+    }
+}
+
+fn block_until_complete() {
+    let mut init_once = null_mut();
+    let mut pending = 0;
+
+    unsafe {
+        assert_eq!(InitOnceBeginInitialize(&mut init_once, 0, &mut pending, null_mut()), TRUE);
+        assert_eq!(pending, TRUE);
+    }
+
+    let init_once_ptr = SendPtr(&mut init_once);
+
+    let waiter = move || unsafe {
+        let mut pending = 0;
+
+        assert_eq!(InitOnceBeginInitialize(init_once_ptr.0, 0, &mut pending, null_mut()), TRUE);
+        assert_eq!(pending, FALSE);
+
+        println!("finished waiting for initialization");
+    };
+
+    let waiter1 = thread::spawn(waiter);
+    let waiter2 = thread::spawn(waiter);
+
+    // this yield ensures `waiter1` & `waiter2` are blocked on the main thread
+    thread::yield_now();
+
+    println!("completing initialization");
+
+    unsafe {
+        assert_eq!(InitOnceComplete(init_once_ptr.0, 0, null_mut()), TRUE);
+    }
+
+    waiter1.join().unwrap();
+    waiter2.join().unwrap();
+}
+
+fn retry_on_fail() {
+    let mut init_once = null_mut();
+    let mut pending = 0;
+
+    unsafe {
+        assert_eq!(InitOnceBeginInitialize(&mut init_once, 0, &mut pending, null_mut()), TRUE);
+        assert_eq!(pending, TRUE);
+    }
+
+    let init_once_ptr = SendPtr(&mut init_once);
+
+    let waiter = move || unsafe {
+        let mut pending = 0;
+
+        assert_eq!(InitOnceBeginInitialize(init_once_ptr.0, 0, &mut pending, null_mut()), TRUE);
+
+        if pending == 1 {
+            println!("retrying initialization");
+
+            assert_eq!(InitOnceComplete(init_once_ptr.0, 0, null_mut()), TRUE);
+        } else {
+            println!("finished waiting for initialization");
+        }
+    };
+
+    let waiter1 = thread::spawn(waiter);
+    let waiter2 = thread::spawn(waiter);
+
+    // this yield ensures `waiter1` & `waiter2` are blocked on the main thread
+    thread::yield_now();
+
+    println!("failing initialization");
+
+    unsafe {
+        assert_eq!(InitOnceComplete(init_once_ptr.0, INIT_ONCE_INIT_FAILED, null_mut()), TRUE);
+    }
+
+    waiter1.join().unwrap();
+    waiter2.join().unwrap();
+}
+
+fn main() {
+    single_thread();
+    block_until_complete();
+    retry_on_fail();
+}

src/tools/miri/tests/pass/concurrency/windows_init_once.stdout

@@ -0,0 +1,6 @@
+completing initialization
+finished waiting for initialization
+finished waiting for initialization
+failing initialization
+retrying initialization
+finished waiting for initialization