From fd9693b9611438deb1c1e85237c25053283e04ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Garc=C3=ADa?=
<dani-garcia@users.noreply.github.com>
Date: Mon, 22 Nov 2021 00:01:23 +0100
Subject: [PATCH] await the mutex in db_run and use block_in_place for it's
contents
---
src/db/mod.rs | 99 +++++++++++++++------------------------------------
1 file changed, 28 insertions(+), 71 deletions(-)
diff --git a/src/db/mod.rs b/src/db/mod.rs
index aeceda5a..6fcb63e5 100644
--- a/src/db/mod.rs
+++ b/src/db/mod.rs
@@ -206,87 +206,44 @@ macro_rules! db_run {
// Different code for each db
( $conn:ident: $( $($db:ident),+ $body:block )+ ) => {{
#[allow(unused)] use diesel::prelude::*;
+ #[allow(unused)] use crate::db::FromDb;
- // It is important that this inner Arc<Mutex<>> (or the OwnedMutexGuard
- // derived from it) never be a variable on the stack at an await point,
- // where Drop might be called at any time. This causes (synchronous)
- // Drop to be called from asynchronous code, which some database
- // wrappers do not or can not handle.
let conn = $conn.conn.clone();
+ let mut conn = conn.lock_owned().await;
+ match conn.as_mut().expect("internal invariant broken: self.connection is Some") {
+ $($(
+ #[cfg($db)]
+ crate::db::DbConnInner::$db($conn) => {
+ paste::paste! {
+ #[allow(unused)] use crate::db::[<__ $db _schema>]::{self as schema, *};
+ #[allow(unused)] use [<__ $db _model>]::*;
+ }
- // Since connection can't be on the stack in an async fn during an
- // await, we have to spawn a new blocking-safe thread...
- /*
- run_blocking(move || {
- // And then re-enter the runtime to wait on the async mutex, but in
- // a blocking fashion.
- let mut conn = tokio::runtime::Handle::current().block_on(conn.lock_owned());
- let conn = conn.as_mut().expect("internal invariant broken: self.connection is Some");
- */
- let mut __conn_mutex = conn.try_lock_owned().unwrap();
- let conn = __conn_mutex.as_mut().unwrap();
- match conn {
- $($(
- #[cfg($db)]
- crate::db::DbConnInner::$db($conn) => {
- paste::paste! {
- #[allow(unused)] use crate::db::[<__ $db _schema>]::{self as schema, *};
- #[allow(unused)] use [<__ $db _model>]::*;
- #[allow(unused)] use crate::db::FromDb;
- }
-
- /*
- // Since connection can't be on the stack in an async fn during an
- // await, we have to spawn a new blocking-safe thread...
- run_blocking(move || {
- // And then re-enter the runtime to wait on the async mutex, but in
- // a blocking fashion.
- let mut conn = tokio::runtime::Handle::current().block_on(async {
- conn.lock_owned().await
- });
-
- let conn = conn.as_mut().expect("internal invariant broken: self.connection is Some");
- f(conn)
- }).await;*/
-
- $body
- },
- )+)+
- }
- // }).await
+ tokio::task::block_in_place(move || { $body }) // Run blocking can't be used due to the 'static limitation, use block_in_place instead
+ },
+ )+)+
+ }
}};
( @raw $conn:ident: $( $($db:ident),+ $body:block )+ ) => {{
#[allow(unused)] use diesel::prelude::*;
+ #[allow(unused)] use crate::db::FromDb;
- // It is important that this inner Arc<Mutex<>> (or the OwnedMutexGuard
- // derived from it) never be a variable on the stack at an await point,
- // where Drop might be called at any time. This causes (synchronous)
- // Drop to be called from asynchronous code, which some database
- // wrappers do not or can not handle.
let conn = $conn.conn.clone();
+ let mut conn = conn.lock_owned().await;
+ match conn.as_mut().expect("internal invariant broken: self.connection is Some") {
+ $($(
+ #[cfg($db)]
+ crate::db::DbConnInner::$db($conn) => {
+ paste::paste! {
+ #[allow(unused)] use crate::db::[<__ $db _schema>]::{self as schema, *};
+ // @ RAW: #[allow(unused)] use [<__ $db _model>]::*;
+ }
- // Since connection can't be on the stack in an async fn during an
- // await, we have to spawn a new blocking-safe thread...
- run_blocking(move || {
- // And then re-enter the runtime to wait on the async mutex, but in
- // a blocking fashion.
- let mut conn = tokio::runtime::Handle::current().block_on(conn.lock_owned());
- match conn.as_mut().expect("internal invariant broken: self.connection is Some") {
- $($(
- #[cfg($db)]
- crate::db::DbConnInner::$db($conn) => {
- paste::paste! {
- #[allow(unused)] use crate::db::[<__ $db _schema>]::{self as schema, *};
- // @RAW: #[allow(unused)] use [<__ $db _model>]::*;
- #[allow(unused)] use crate::db::FromDb;
- }
-
- $body
- },
- )+)+
- }
- }).await
+ tokio::task::block_in_place(move || { $body }) // Run blocking can't be used due to the 'static limitation, use block_in_place instead
+ },
+ )+)+
+ }
}};
}