Add exit flag for bigtable upload operations

ledger/src/bigtable_upload.rs

@@ -2,7 +2,15 @@ use crate::blockstore::Blockstore;
 use log::*;
 use solana_measure::measure::Measure;
 use solana_sdk::clock::Slot;
-use std::{collections::HashSet, result::Result, sync::Arc, time::Duration};
+use std::{
+    collections::HashSet,
+    result::Result,
+    sync::{
+        atomic::{AtomicBool, Ordering},
+        Arc,
+    },
+    time::Duration,
+};
 use tokio::time::delay_for;
 
 // Attempt to upload this many blocks in parallel
@@ -17,6 +25,7 @@ pub async fn upload_confirmed_blocks(
     starting_slot: Slot,
     ending_slot: Option<Slot>,
     allow_missing_metadata: bool,
+    exit: Arc<AtomicBool>,
 ) -> Result<(), Box<dyn std::error::Error>> {
     let mut measure = Measure::start("entire upload");
 
@@ -120,11 +129,17 @@ pub async fn upload_confirmed_blocks(
 
     // Load the blocks out of blockstore in a separate thread to allow for concurrent block uploading
     let (_loader_thread, receiver) = {
+        let exit = exit.clone();
+
         let (sender, receiver) = std::sync::mpsc::sync_channel(BLOCK_READ_AHEAD_DEPTH);
         (
             std::thread::spawn(move || {
                 let mut measure = Measure::start("block loader thread");
                 for (i, slot) in blocks_to_upload.iter().enumerate() {
+                    if exit.load(Ordering::Relaxed) {
+                        break;
+                    }
+
                     let _ = match blockstore.get_confirmed_block(
                         *slot,
                         Some(solana_transaction_status::UiTransactionEncoding::Base64),
@@ -162,6 +177,10 @@ pub async fn upload_confirmed_blocks(
         tokio::stream::iter(receiver.into_iter()).chunks(NUM_BLOCKS_TO_UPLOAD_IN_PARALLEL);
 
     while let Some(blocks) = stream.next().await {
+        if exit.load(Ordering::Relaxed) {
+            break;
+        }
+
         let mut measure_upload = Measure::start("Upload");
         let mut num_blocks = blocks.len();
         info!("Preparing the next {} blocks for upload", num_blocks);