Fix: nextest cleanup race condition

sqlx-core/Cargo.toml

@@ -52,6 +52,7 @@ mac_address = { workspace = true, optional = true }
 uuid = { workspace = true, optional = true }
 
 async-io = { version = "1.9.0", optional = true }
+base64 = { version = "0.22.0", default-features = false, features = ["std"] }
 bytes = "1.1.0"
 chrono = { version = "0.4.34", default-features = false, features = ["clock"], optional = true }
 crc = { version = "3", optional = true }

sqlx-core/src/testing/mod.rs

@@ -3,7 +3,9 @@ use std::time::Duration;
 
 use futures_core::future::BoxFuture;
 
+use base64::{engine::general_purpose::URL_SAFE, Engine as _};
 pub use fixtures::FixtureSnapshot;
+use sha2::{Digest, Sha512};
 
 use crate::connection::{ConnectOptions, Connection};
 use crate::database::Database;
@@ -41,6 +43,17 @@ pub trait TestSupport: Database {
     /// This snapshot can then be used to generate test fixtures.
     fn snapshot(conn: &mut Self::Connection)
         -> BoxFuture<'_, Result<FixtureSnapshot<Self>, Error>>;
+
+    /// Generate a unique database name for the given test path.
+    fn db_name(args: &TestArgs) -> String {
+        let mut hasher = Sha512::new();
+        hasher.update(args.test_path.as_bytes());
+        let hash = hasher.finalize();
+        let hash = URL_SAFE.encode(&hash[..39]);
+        let db_name = format!("_sqlx_test_{}", hash);
+        debug_assert!(db_name.len() == 63);
+        db_name
+    }
 }
 
 pub struct TestFixture {
@@ -217,7 +230,7 @@ where
         let res = test_fn(test_context.pool_opts, test_context.connect_opts).await;
 
         if res.is_success() {
-            if let Err(e) = DB::cleanup_test(&test_context.db_name).await {
+            if let Err(e) = DB::cleanup_test(&DB::db_name(&args)).await {
                 eprintln!(
                     "failed to delete database {:?}: {}",
                     test_context.db_name, e

sqlx-mysql/src/testing/mod.rs

@@ -1,29 +1,25 @@
-use std::fmt::Write;
 use std::ops::Deref;
 use std::str::FromStr;
-use std::sync::atomic::{AtomicBool, Ordering};
-use std::time::{Duration, SystemTime};
+use std::time::Duration;
 
 use futures_core::future::BoxFuture;
 
 use once_cell::sync::OnceCell;
-
-use crate::connection::Connection;
+use sqlx_core::connection::Connection;
+use sqlx_core::query_builder::QueryBuilder;
+use sqlx_core::query_scalar::query_scalar;
+use std::fmt::Write;
 
 use crate::error::Error;
 use crate::executor::Executor;
 use crate::pool::{Pool, PoolOptions};
 use crate::query::query;
-use crate::query_builder::QueryBuilder;
-use crate::query_scalar::query_scalar;
 use crate::{MySql, MySqlConnectOptions, MySqlConnection};
 
 pub(crate) use sqlx_core::testing::*;
 
 // Using a blocking `OnceCell` here because the critical sections are short.
 static MASTER_POOL: OnceCell<Pool<MySql>> = OnceCell::new();
-// Automatically delete any databases created before the start of the test binary.
-static DO_CLEANUP: AtomicBool = AtomicBool::new(true);
 
 impl TestSupport for MySql {
     fn test_context(args: &TestArgs) -> BoxFuture<'_, Result<TestContext<Self>, Error>> {
@@ -38,17 +34,7 @@ impl TestSupport for MySql {
                 .acquire()
                 .await?;
 
-            let db_id = db_id(db_name);
-
-            conn.execute(&format!("drop database if exists {db_name};")[..])
-                .await?;
-
-            query("delete from _sqlx_test_databases where db_id = ?")
-                .bind(db_id)
-                .execute(&mut *conn)
-                .await?;
-
-            Ok(())
+            do_cleanup(&mut conn, db_name).await
         })
     }
 
@@ -58,13 +44,55 @@ impl TestSupport for MySql {
 
             let mut conn = MySqlConnection::connect(&url).await?;
 
-            let now = SystemTime::now()
-                .duration_since(SystemTime::UNIX_EPOCH)
-                .unwrap();
+            let delete_db_names: Vec<String> =
+                query_scalar("select db_name from _sqlx_test_databases")
+                    .fetch_all(&mut conn)
+                    .await?;
+
+            if delete_db_names.is_empty() {
+                return Ok(None);
+            }
+
+            let mut deleted_db_names = Vec::with_capacity(delete_db_names.len());
+
+            let mut command = String::new();
+
+            for db_name in &delete_db_names {
+                command.clear();
+
+                let db_name = format!("_sqlx_test_database_{db_name}");
+
+                writeln!(command, "drop database if exists {db_name:?};").ok();
+                match conn.execute(&*command).await {
+                    Ok(_deleted) => {
+                        deleted_db_names.push(db_name);
+                    }
+                    // Assume a database error just means the DB is still in use.
+                    Err(Error::Database(dbe)) => {
+                        eprintln!("could not clean test database {db_name:?}: {dbe}")
+                    }
+                    // Bubble up other errors
+                    Err(e) => return Err(e),
+                }
+            }
+
+            if deleted_db_names.is_empty() {
+                return Ok(None);
+            }
+
+            let mut query =
+                QueryBuilder::new("delete from _sqlx_test_databases where db_name in (");
+
+            let mut separated = query.separated(",");
+
+            for db_name in &deleted_db_names {
+                separated.push_bind(db_name);
+            }
+
+            query.push(")").build().execute(&mut conn).await?;
 
-            let num_deleted = do_cleanup(&mut conn, now).await?;
             let _ = conn.close().await;
-            Ok(Some(num_deleted))
+            Ok(Some(delete_db_names.len()))
         })
     }
 
@@ -117,42 +145,27 @@ async fn test_context(args: &TestArgs) -> Result<TestContext<MySql>, Error> {
     conn.execute(
         r#"
         create table if not exists _sqlx_test_databases (
-            db_id bigint unsigned primary key auto_increment,
+            db_name text primary key,
             test_path text not null,
             created_at timestamp not null default current_timestamp
         );
     "#,
     )
     .await?;
 
-    // Record the current time _before_ we acquire the `DO_CLEANUP` permit. This
-    // prevents the first test thread from accidentally deleting new test dbs
-    // created by other test threads if we're a bit slow.
-    let now = SystemTime::now()
-        .duration_since(SystemTime::UNIX_EPOCH)
-        .unwrap();
-
-    // Only run cleanup if the test binary just started.
-    if DO_CLEANUP.swap(false, Ordering::SeqCst) {
-        do_cleanup(&mut conn, now).await?;
-    }
+    let db_name = MySql::db_name(args);
+    do_cleanup(&mut conn, &db_name).await?;
 
-    query("insert into _sqlx_test_databases(test_path) values (?)")
+    query("insert into _sqlx_test_databases(db_name, test_path) values (?, ?)")
+        .bind(&db_name)
         .bind(args.test_path)
         .execute(&mut *conn)
         .await?;
 
-    // MySQL doesn't have `INSERT ... RETURNING`
-    let new_db_id: u64 = query_scalar("select last_insert_id()")
-        .fetch_one(&mut *conn)
-        .await?;
-
-    let new_db_name = db_name(new_db_id);
-
-    conn.execute(&format!("create database {new_db_name}")[..])
+    conn.execute(&format!("create database {db_name:?}")[..])
         .await?;
 
-    eprintln!("created database {new_db_name}");
+    eprintln!("created database {db_name}");
 
     Ok(TestContext {
         pool_opts: PoolOptions::new()
@@ -167,74 +180,18 @@ async fn test_context(args: &TestArgs) -> Result<TestContext<MySql>, Error> {
             .connect_options()
             .deref()
             .clone()
-            .database(&new_db_name),
-        db_name: new_db_name,
+            .database(&db_name),
+        db_name,
     })
 }
 
-async fn do_cleanup(conn: &mut MySqlConnection, created_before: Duration) -> Result<usize, Error> {
-    // since SystemTime is not monotonic we added a little margin here to avoid race conditions with other threads
-    let created_before_as_secs = created_before.as_secs() - 2;
-    let delete_db_ids: Vec<u64> = query_scalar(
-        "select db_id from _sqlx_test_databases \
-            where created_at < from_unixtime(?)",
-    )
-    .bind(created_before_as_secs)
-    .fetch_all(&mut *conn)
-    .await?;
-
-    if delete_db_ids.is_empty() {
-        return Ok(0);
-    }
-
-    let mut deleted_db_ids = Vec::with_capacity(delete_db_ids.len());
-
-    let mut command = String::new();
-
-    for db_id in delete_db_ids {
-        command.clear();
-
-        let db_name = db_name(db_id);
-
-        writeln!(command, "drop database if exists {db_name}").ok();
-        match conn.execute(&*command).await {
-            Ok(_deleted) => {
-                deleted_db_ids.push(db_id);
-            }
-            // Assume a database error just means the DB is still in use.
-            Err(Error::Database(dbe)) => {
-                eprintln!("could not clean test database {db_id:?}: {dbe}")
-            }
-            // Bubble up other errors
-            Err(e) => return Err(e),
-        }
-    }
-
-    let mut query = QueryBuilder::new("delete from _sqlx_test_databases where db_id in (");
-
-    let mut separated = query.separated(",");
-
-    for db_id in &deleted_db_ids {
-        separated.push_bind(db_id);
-    }
-
-    query.push(")").build().execute(&mut *conn).await?;
-
-    Ok(deleted_db_ids.len())
-}
-
-fn db_name(id: u64) -> String {
-    format!("_sqlx_test_database_{id}")
-}
-
-fn db_id(name: &str) -> u64 {
-    name.trim_start_matches("_sqlx_test_database_")
-        .parse()
-        .unwrap_or_else(|_1| panic!("failed to parse ID from database name {name:?}"))
-}
+async fn do_cleanup(conn: &mut MySqlConnection, db_name: &str) -> Result<(), Error> {
+    let delete_db_command = format!("drop database if exists {db_name:?};");
+    conn.execute(&*delete_db_command).await?;
+    query("delete from _sqlx_test.databases where db_name = $1::text")
+        .bind(db_name)
+        .execute(&mut *conn)
+        .await?;
 
-#[test]
-fn test_db_name_id() {
-    assert_eq!(db_name(12345), "_sqlx_test_database_12345");
-    assert_eq!(db_id("_sqlx_test_database_12345"), 12345);
+    Ok(())
 }