38 lines
1.1 KiB
Rust
38 lines
1.1 KiB
Rust
use std::panic::AssertUnwindSafe;
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use crate::setup::{ParDatabase, ParDatabaseImpl};
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use salsa::{Cancelled, ParallelDatabase};
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/// Test where a read and a set are racing with one another.
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/// Should be atomic.
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#[test]
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fn in_par_get_set_race() {
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let mut db = ParDatabaseImpl::default();
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db.set_input('a', 100);
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db.set_input('b', 10);
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db.set_input('c', 1);
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let thread1 = std::thread::spawn({
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let db = db.snapshot();
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move || Cancelled::catch(AssertUnwindSafe(|| db.sum("abc")))
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});
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let thread2 = std::thread::spawn(move || {
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db.set_input('a', 1000);
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db.sum("a")
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});
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// If the 1st thread runs first, you get 111, otherwise you get
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// 1011; if they run concurrently and the 1st thread observes the
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// cancellation, it'll unwind.
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let result1 = thread1.join().unwrap();
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if let Ok(value1) = result1 {
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assert!(value1 == 111 || value1 == 1011, "illegal result {}", value1);
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}
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// thread2 can not observe a cancellation because it performs a
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// database write before running any other queries.
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assert_eq!(thread2.join().unwrap(), 1000);
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}
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