From ded6a8bfd446ccc322daf2b5ceb6f82d7be8d66c Mon Sep 17 00:00:00 2001
From: arya2 <aryasolhi@gmail.com>
Date: Wed, 21 Sep 2022 18:09:53 -0400
Subject: [PATCH 1/2] use spawn_blocking to run zebra_state::init from start
 cmd

---
 zebra-state/src/lib.rs       |  2 +-
 zebra-state/src/service.rs   | 16 ++++++++++++++++
 zebrad/src/commands/start.rs |  5 ++++-
 zebrad/tests/acceptance.rs   | 25 +++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/zebra-state/src/lib.rs b/zebra-state/src/lib.rs
index 7b81d554f33..89505af7acf 100644
--- a/zebra-state/src/lib.rs
+++ b/zebra-state/src/lib.rs
@@ -34,7 +34,7 @@ pub use request::{FinalizedBlock, HashOrHeight, PreparedBlock, ReadRequest, Requ
 pub use response::{ReadResponse, Response};
 pub use service::{
     chain_tip::{ChainTipChange, LatestChainTip, TipAction},
-    init, OutputIndex, OutputLocation, TransactionLocation,
+    init, spawn_init, OutputIndex, OutputLocation, TransactionLocation,
 };
 
 #[cfg(any(test, feature = "proptest-impl"))]
diff --git a/zebra-state/src/service.rs b/zebra-state/src/service.rs
index 5e7859bdb22..77853984bf7 100644
--- a/zebra-state/src/service.rs
+++ b/zebra-state/src/service.rs
@@ -1292,6 +1292,22 @@ pub fn init(
     )
 }
 
+/// Calls [`init`] with the provided [`Config`] and [`Network`] from a blocking task.
+/// 
+/// Returns a [`tokio::task::JoinHandle`] with a boxed state service,
+/// a read state service, and receivers for state chain tip updates.
+pub fn spawn_init(
+    config: Config,
+    network: Network,
+) -> tokio::task::JoinHandle<(
+    BoxService<Request, Response, BoxError>,
+    ReadStateService,
+    LatestChainTip,
+    ChainTipChange,
+)> {
+    tokio::task::spawn_blocking(move || init(config, network))
+}
+
 /// Returns a [`StateService`] with an ephemeral [`Config`] and a buffer with a single slot.
 ///
 /// This can be used to create a state service for testing.
diff --git a/zebrad/src/commands/start.rs b/zebrad/src/commands/start.rs
index b22a82df7ce..455397598c8 100644
--- a/zebrad/src/commands/start.rs
+++ b/zebrad/src/commands/start.rs
@@ -103,8 +103,11 @@ impl StartCmd {
         info!(?config);
 
         info!("initializing node state");
+        info!("opening database, this may take a couple minutes");
+
         let (state_service, read_only_state_service, latest_chain_tip, chain_tip_change) =
-            zebra_state::init(config.state.clone(), config.network.network);
+            zebra_state::spawn_init(config.state.clone(), config.network.network).await?;
+
         let state = ServiceBuilder::new()
             .buffer(Self::state_buffer_bound())
             .service(state_service);
diff --git a/zebrad/tests/acceptance.rs b/zebrad/tests/acceptance.rs
index 11793002628..cc99d535658 100644
--- a/zebrad/tests/acceptance.rs
+++ b/zebrad/tests/acceptance.rs
@@ -313,6 +313,31 @@ fn start_args() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn db_init_outside_future_executor() -> Result<()> {
+    use std::time::{Duration, Instant};
+
+    let _init_guard = zebra_test::init();
+    let config = default_test_config()?;
+
+    let start = Instant::now();
+
+    let db_init_handle = zebra_state::spawn_init(config.state.clone(), config.network.network);
+
+    // it's faster to panic if it takes longer than expected, since the executor
+    // will wait indefinitely for blocking operation to finish once started
+    let block_duration = start.elapsed();
+    assert!(
+        block_duration < Duration::from_millis(5),
+        "futures executor was blocked longer than expected ({:?})",
+        block_duration,
+    );
+
+    db_init_handle.await?;
+
+    Ok(())
+}
+
 #[test]
 fn persistent_mode() -> Result<()> {
     let _init_guard = zebra_test::init();

From 84be95432a327af7a7faa367206173793c5695e3 Mon Sep 17 00:00:00 2001
From: arya2 <aryasolhi@gmail.com>
Date: Wed, 21 Sep 2022 19:12:09 -0400
Subject: [PATCH 2/2] uses zebra_state::spawn_init in copy-state command

---
 zebra-state/src/service.rs        | 1 -
 zebrad/src/commands/copy_state.rs | 4 ++--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/zebra-state/src/service.rs b/zebra-state/src/service.rs
index 77853984bf7..f69017728db 100644
--- a/zebra-state/src/service.rs
+++ b/zebra-state/src/service.rs
@@ -1293,7 +1293,6 @@ pub fn init(
 }
 
 /// Calls [`init`] with the provided [`Config`] and [`Network`] from a blocking task.
-/// 
 /// Returns a [`tokio::task::JoinHandle`] with a boxed state service,
 /// a read state service, and receivers for state chain tip updates.
 pub fn spawn_init(
diff --git a/zebrad/src/commands/copy_state.rs b/zebrad/src/commands/copy_state.rs
index 36e71d97588..ee87c68c46a 100644
--- a/zebrad/src/commands/copy_state.rs
+++ b/zebrad/src/commands/copy_state.rs
@@ -117,7 +117,7 @@ impl CopyStateCmd {
             _source_read_only_state_service,
             _source_latest_chain_tip,
             _source_chain_tip_change,
-        ) = old_zs::init(source_config.clone(), network);
+        ) = old_zs::spawn_init(source_config.clone(), network).await?;
 
         let elapsed = source_start_time.elapsed();
         info!(?elapsed, "finished initializing source state service");
@@ -136,7 +136,7 @@ impl CopyStateCmd {
             _target_read_only_state_service,
             _target_latest_chain_tip,
             _target_chain_tip_change,
-        ) = new_zs::init(target_config.clone(), network);
+        ) = new_zs::spawn_init(target_config.clone(), network).await?;
 
         let elapsed = target_start_time.elapsed();
         info!(?elapsed, "finished initializing target state service");