From 3f627790f8644580d5ab4f1cfb446622ebc90352 Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Tue, 17 May 2022 16:40:21 +0200
Subject: [PATCH] [proving] Ensure that proving is completely stopped

---
 dagger/contracts/interactions.nim |  4 ++--
 dagger/proving.nim                | 18 ++++++++++++------
 tests/dagger/testproving.nim      |  4 ++--
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/dagger/contracts/interactions.nim b/dagger/contracts/interactions.nim
index 26e32b6e..347ce33e 100644
--- a/dagger/contracts/interactions.nim
+++ b/dagger/contracts/interactions.nim
@@ -66,8 +66,8 @@ proc new*(_: type ContractInteractions): ?ContractInteractions =
 
 proc start*(interactions: ContractInteractions) {.async.} =
   interactions.sales.start()
-  interactions.proving.start()
+  await interactions.proving.start()
 
 proc stop*(interactions: ContractInteractions) {.async.} =
   interactions.sales.stop()
-  interactions.proving.stop()
+  await interactions.proving.stop()
diff --git a/dagger/proving.nim b/dagger/proving.nim
index 90347d57..f711decf 100644
--- a/dagger/proving.nim
+++ b/dagger/proving.nim
@@ -11,7 +11,7 @@ export proofs
 type
   Proving* = ref object
     proofs: Proofs
-    stopped: bool
+    loop: ?Future[void]
     contracts*: HashSet[ContractId]
     onProofRequired: ?OnProofRequired
   OnProofRequired* = proc (id: ContractId) {.gcsafe, upraises:[].}
@@ -35,7 +35,7 @@ proc removeEndedContracts(proving: Proving) {.async.} =
 
 proc run(proving: Proving) {.async.} =
   try:
-    while not proving.stopped:
+    while true:
       let currentPeriod = await proving.proofs.getCurrentPeriod()
       await proving.removeEndedContracts()
       for id in proving.contracts:
@@ -47,11 +47,17 @@ proc run(proving: Proving) {.async.} =
   except CatchableError as e:
     error "Proving failed", msg = e.msg
 
-proc start*(proving: Proving) =
-  asyncSpawn proving.run()
+proc start*(proving: Proving) {.async.} =
+  if proving.loop.isSome:
+    return
 
-proc stop*(proving: Proving) =
-  proving.stopped = true
+  proving.loop = some proving.run()
+
+proc stop*(proving: Proving) {.async.} =
+  if loop =? proving.loop:
+    proving.loop = Future[void].none
+    if not loop.finished:
+      await loop.cancelAndWait()
 
 proc submitProof*(proving: Proving, id: ContractId, proof: seq[byte]) {.async.} =
   await proving.proofs.submitProof(id, proof)
diff --git a/tests/dagger/testproving.nim b/tests/dagger/testproving.nim
index 159fb732..29e000f7 100644
--- a/tests/dagger/testproving.nim
+++ b/tests/dagger/testproving.nim
@@ -13,10 +13,10 @@ suite "Proving":
   setup:
     proofs = MockProofs.new()
     proving = Proving.new(proofs)
-    proving.start()
+    await proving.start()
 
   teardown:
-    proving.stop()
+    await proving.stop()
 
   proc advanceToNextPeriod(proofs: MockProofs) {.async.} =
     let current = await proofs.getCurrentPeriod()