From 71d8586e614fcb8f44f11b70f968273c2c717477 Mon Sep 17 00:00:00 2001
From: bpaunescu <bogdan.paunescu@r3.com>
Date: Mon, 4 Jun 2018 10:14:53 +0100
Subject: [PATCH] =?UTF-8?q?ENT-1962:=20throw=20a=20clearer=20exception=20w?=
 =?UTF-8?q?hen=20starting=20RPC=20flow=20while=20SMM=20is=20stopped=20?=
 =?UTF-8?q?=E2=80=A6=20(#912)?=
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* ENT-1962: throw a clearer exception when starting RPC flow while SMM is stopped.

* ENT-1962: update exception constructor
---
 .../main/kotlin/net/corda/core/internal/LifeCycle.kt  | 11 +++++++++++
 .../kotlin/net/corda/node/internal/CordaRPCOpsImpl.kt |  7 ++++++-
 .../exceptions/StateMachineStoppedException.kt        |  7 +++++++
 .../statemachine/MultiThreadedStateMachineManager.kt  |  3 ++-
 4 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 node/src/main/kotlin/net/corda/node/internal/exceptions/StateMachineStoppedException.kt

diff --git a/core/src/main/kotlin/net/corda/core/internal/LifeCycle.kt b/core/src/main/kotlin/net/corda/core/internal/LifeCycle.kt
index 4e71271875..e7e08908f7 100644
--- a/core/src/main/kotlin/net/corda/core/internal/LifeCycle.kt
+++ b/core/src/main/kotlin/net/corda/core/internal/LifeCycle.kt
@@ -39,6 +39,17 @@ class LifeCycle<S : Enum<S>>(initial: S) {
     }
     fun requireState(requiredState: S) = requireState(requiredState) {}
 
+    fun <A> requireState(
+            requiredState: S,
+            throwable: Throwable,
+            block: () -> A
+    ): A {
+        return lock.readLock().withLock {
+           if (requiredState != state) { throw throwable }
+            block()
+        }
+    }
+
     /** Assert something about the current state atomically. */
     fun <A> requireState(
             errorMessage: (S) -> String,
diff --git a/node/src/main/kotlin/net/corda/node/internal/CordaRPCOpsImpl.kt b/node/src/main/kotlin/net/corda/node/internal/CordaRPCOpsImpl.kt
index b686c2fcaa..f883606ee8 100644
--- a/node/src/main/kotlin/net/corda/node/internal/CordaRPCOpsImpl.kt
+++ b/node/src/main/kotlin/net/corda/node/internal/CordaRPCOpsImpl.kt
@@ -50,6 +50,7 @@ import net.corda.core.node.services.vault.Sort
 import net.corda.core.serialization.serialize
 import net.corda.core.transactions.SignedTransaction
 import net.corda.core.utilities.getOrThrow
+import net.corda.node.internal.exceptions.StateMachineStoppedException
 import net.corda.node.services.api.FlowStarter
 import net.corda.node.services.api.ServiceHubInternal
 import net.corda.node.services.messaging.context
@@ -185,7 +186,11 @@ internal class CordaRPCOpsImpl(
         if (isFlowsDrainingModeEnabled()) {
             throw RejectedCommandException("Node is draining before shutdown. Cannot start new flows through RPC.")
         }
-        return flowStarter.invokeFlowAsync(logicType, context(), *args).getOrThrow()
+        try {
+            return flowStarter.invokeFlowAsync(logicType, context(), *args).getOrThrow()
+        } catch (e: StateMachineStoppedException) {
+            throw RejectedCommandException("Node is shutting down. Cannot start new flows through RPC.")
+        }
     }
 
     override fun attachmentExists(id: SecureHash): Boolean {
diff --git a/node/src/main/kotlin/net/corda/node/internal/exceptions/StateMachineStoppedException.kt b/node/src/main/kotlin/net/corda/node/internal/exceptions/StateMachineStoppedException.kt
new file mode 100644
index 0000000000..88a5bcb31a
--- /dev/null
+++ b/node/src/main/kotlin/net/corda/node/internal/exceptions/StateMachineStoppedException.kt
@@ -0,0 +1,7 @@
+package net.corda.node.internal.exceptions
+
+import net.corda.core.CordaRuntimeException
+
+class StateMachineStoppedException(message: String, cause: Throwable?) : CordaRuntimeException(message, cause) {
+    constructor(msg: String) : this(msg, null)
+}
diff --git a/node/src/main/kotlin/net/corda/node/services/statemachine/MultiThreadedStateMachineManager.kt b/node/src/main/kotlin/net/corda/node/services/statemachine/MultiThreadedStateMachineManager.kt
index eaeee67788..8aa56cf475 100644
--- a/node/src/main/kotlin/net/corda/node/services/statemachine/MultiThreadedStateMachineManager.kt
+++ b/node/src/main/kotlin/net/corda/node/services/statemachine/MultiThreadedStateMachineManager.kt
@@ -34,6 +34,7 @@ import net.corda.core.utilities.Try
 import net.corda.core.utilities.contextLogger
 import net.corda.core.utilities.debug
 import net.corda.node.internal.InitiatedFlowFactory
+import net.corda.node.internal.exceptions.StateMachineStoppedException
 import net.corda.node.services.api.CheckpointStorage
 import net.corda.node.services.api.ServiceHubInternal
 import net.corda.node.services.config.shouldCheckCheckpoints
@@ -196,7 +197,7 @@ class MultiThreadedStateMachineManager(
             ourIdentity: Party?,
             deduplicationHandler: DeduplicationHandler?
     ): CordaFuture<FlowStateMachine<A>> {
-        return lifeCycle.requireState(State.STARTED) {
+        return lifeCycle.requireState(State.STARTED, StateMachineStoppedException("Flow cannot be started. State machine is stopped.")) {
             startFlowInternal(
                     invocationContext = context,
                     flowLogic = flowLogic,