Merge pull request #1128 from spacejam/tyler_0.33

Cut 0.33. Fix atomicity bug in Tree::pop_min and Tree::pop_max

Author: spacejam

CHANGELOG.md

@@ -1,12 +1,17 @@
-# Unreleased
+# 0.33
 
 ## Breaking Changes
 
-* the backtrace crate has been made optional, which cuts
-  several seconds off compilation time, but may cause
+* #1125 the backtrace crate has been made optional, which
+  cuts several seconds off compilation time, but may cause
   breakage if you interacted with the backtrace field
   of corruption-related errors.
 
+## Bug Fixes
+
+* #1128 `Tree::pop_min` and `Tree::pop_max` had a bug where
+  they were not atomic.
+
 # 0.32.1
 
 ## New Features

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sled"
-version = "0.32.1"
+version = "0.33.0"
 authors = ["Tyler Neely <[email protected]>"]
 description = "a modern embedded database"
 license = "MIT/Apache-2.0"

src/tree.rs

@@ -1315,7 +1315,7 @@ impl Tree {
                         &first.0,
                         Some(&first.1),
                         None,
-                    )
+                    )?
                     .is_ok()
                 {
                     return Ok(Some(first));
@@ -1362,7 +1362,7 @@ impl Tree {
                         &first.0,
                         Some(&first.1),
                         None,
-                    )
+                    )?
                     .is_ok()
                 {
                     return Ok(Some(first));

tests/test_tree.rs

@@ -87,6 +87,41 @@ fn test_varied_compression_ratios() {
     let _ = std::fs::remove_dir_all("compression_db_test");
 }
 
+#[test]
+#[cfg(not(miri))] // can't create threads
+fn concurrent_tree_pops() -> sled::Result<()> {
+    use std::thread;
+
+    let db = sled::open("db")?;
+
+    // Insert values 0..5
+    for x in 0u32..5 {
+        db.insert(x.to_be_bytes(), &[])?;
+    }
+
+    let mut threads = vec![];
+
+    // Pop 5 values using multiple threads
+    for _ in 0..5 {
+        let db = db.clone();
+        threads.push(thread::spawn(move || {
+            db.pop_min().unwrap().unwrap();
+        }));
+    }
+
+    for thread in threads.into_iter() {
+        thread.join().unwrap();
+    }
+
+    assert!(
+        db.is_empty(),
+        "elements left in database: {:?}",
+        db.iter().collect::<Vec<_>>()
+    );
+
+    Ok(())
+}
+
 #[test]
 #[cfg(not(miri))] // can't create threads
 fn concurrent_tree_ops() {