move rpc_server to drop() semantics instead of having its own thread

src/fullnode.rs

@@ -24,6 +24,7 @@ use window;
 pub struct Fullnode {
     exit: Arc<AtomicBool>,
     thread_hdls: Vec<JoinHandle<()>>,
+    _rpc_service: JsonRpcService,
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
@@ -190,14 +191,8 @@ impl Fullnode {
         let mut drone_addr = node.info.contact_info.tpu;
         drone_addr.set_port(DRONE_PORT);
         let rpc_addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::from(0)), RPC_PORT);
-        let rpc_service = JsonRpcService::new(
-            &bank,
-            node.info.contact_info.tpu,
-            drone_addr,
-            rpc_addr,
-            exit.clone(),
-        );
-        thread_hdls.extend(rpc_service.thread_hdls());
+        let _rpc_service =
+            JsonRpcService::new(&bank, node.info.contact_info.tpu, drone_addr, rpc_addr);
 
         let blob_recycler = BlobRecycler::default();
         let window =
@@ -266,7 +261,11 @@ impl Fullnode {
             }
         }
 
-        Fullnode { exit, thread_hdls }
+        Fullnode {
+            exit,
+            thread_hdls,
+            _rpc_service,
+        }
     }
 
     //used for notifying many nodes in parallel to exit

src/rpc.rs

@@ -5,13 +5,11 @@ use bincode::deserialize;
 use bs58;
 use jsonrpc_core::*;
 use jsonrpc_http_server::*;
-use service::Service;
 use signature::{Pubkey, Signature};
 use std::mem;
 use std::net::{SocketAddr, UdpSocket};
-use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
-use std::thread::{self, sleep, Builder, JoinHandle};
+use std::thread::sleep;
 use std::time::Duration;
 use std::time::Instant;
 use transaction::Transaction;
@@ -20,7 +18,7 @@ use wallet::request_airdrop;
 pub const RPC_PORT: u16 = 8899;
 
 pub struct JsonRpcService {
-    thread_hdl: JoinHandle<()>,
+    server: Option<Server>,
 }
 
 impl JsonRpcService {
@@ -29,51 +27,42 @@ impl JsonRpcService {
         transactions_addr: SocketAddr,
         drone_addr: SocketAddr,
         rpc_addr: SocketAddr,
-        exit: Arc<AtomicBool>,
     ) -> Self {
         let request_processor = JsonRpcRequestProcessor::new(bank.clone());
-        let thread_hdl = Builder::new()
-            .name("solana-jsonrpc".to_string())
-            .spawn(move || {
-                let mut io = MetaIoHandler::default();
-                let rpc = RpcSolImpl;
-                io.extend_with(rpc.to_delegate());
+        let mut io = MetaIoHandler::default();
+        let rpc = RpcSolImpl;
+        io.extend_with(rpc.to_delegate());
 
-                let server =
-                    ServerBuilder::with_meta_extractor(io, move |_req: &hyper::Request| Meta {
-                        request_processor: request_processor.clone(),
-                        transactions_addr,
-                        drone_addr,
-                    }).threads(4)
-                        .cors(DomainsValidation::AllowOnly(vec![
-                            AccessControlAllowOrigin::Any,
-                        ]))
-                        .start_http(&rpc_addr);
-                if server.is_err() {
-                    warn!("JSON RPC service unavailable: unable to bind to RPC port {}. \nMake sure this port is not already in use by another application", rpc_addr.port());
-                    return;
-                }
-                loop {
-                    if exit.load(Ordering::Relaxed) {
-                        server.unwrap().close();
-                        break;
-                    }
-                    sleep(Duration::from_millis(100));
-                }
-                ()
-            })
-            .unwrap();
-        JsonRpcService { thread_hdl }
-    }
-}
+        let server = ServerBuilder::with_meta_extractor(io, move |_req: &hyper::Request| Meta {
+            request_processor: request_processor.clone(),
+            transactions_addr,
+            drone_addr,
+        }).threads(4)
+            .cors(DomainsValidation::AllowOnly(vec![
+                AccessControlAllowOrigin::Any,
+            ]))
+            .start_http(&rpc_addr);
 
-impl Service for JsonRpcService {
-    fn thread_hdls(self) -> Vec<JoinHandle<()>> {
-        vec![self.thread_hdl]
+        let server = match server {
+            Ok(server) => Some(server),
+            Err(e) => {
+                warn!(
+                    "JSON RPC service unavailable: error {}. \n\
+                     Make sure the RPC port {} is not already in use by another application",
+                    e,
+                    rpc_addr.port()
+                );
+                None
+            }
+        };
+
+        JsonRpcService { server }
     }
 
-    fn join(self) -> thread::Result<()> {
-        self.thread_hdl.join()
+    pub fn close(self) {
+        if let Some(server) = self.server {
+            server.close();
+        }
     }
 }