eh fixes (#926)

* work around improbable exceptions in metrics / chronos
* fix unnecessary lookup in block pool

beacon_chain/attestation_aggregation.nim

@@ -5,6 +5,8 @@
 #   * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
+{.push raises: [Defect].}
+
 import
   options,
   ./spec/[beaconstate, datatypes, crypto, digest, helpers, validator,

beacon_chain/attestation_pool.nim

@@ -1,3 +1,12 @@
+# beacon_chain
+# Copyright (c) 2018-2020 Status Research & Development GmbH
+# Licensed and distributed under either of
+#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
+#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
+# at your option. This file may not be copied, modified, or distributed except according to those terms.
+
+{.push raises: [Defect].}
+
 import
   deques, sequtils, tables, options,
   chronicles, stew/[bitseqs, byteutils], json_serialization/std/sets,

beacon_chain/beacon_node.nim

@@ -1,3 +1,10 @@
+# beacon_chain
+# Copyright (c) 2018-2020 Status Research & Development GmbH
+# Licensed and distributed under either of
+#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
+#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
+# at your option. This file may not be copied, modified, or distributed except according to those terms.
+
 import
   # Standard library
   os, tables, random, strutils, times,

beacon_chain/block_pool.nim

@@ -1,3 +1,12 @@
+# beacon_chain
+# Copyright (c) 2018-2020 Status Research & Development GmbH
+# Licensed and distributed under either of
+#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
+#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
+# at your option. This file may not be copied, modified, or distributed except according to those terms.
+
+{.push raises: [Defect].}
+
 import
   bitops, chronicles, options, tables,
   ssz, beacon_chain_db, state_transition, extras, kvstore,
@@ -336,13 +345,13 @@ proc add*(
   logScope: pcs = "block_addition"
 
   # Already seen this block??
-  if blockRoot in pool.blocks:
+  pool.blocks.withValue(blockRoot, blockRef):
     debug "Block already exists",
       blck = shortLog(blck),
       blockRoot = shortLog(blockRoot),
       cat = "filtering"
 
-    return pool.blocks[blockRoot]
+    return blockRef[]
 
   pool.missing.del(blockRoot)
 
@@ -547,7 +556,7 @@ func checkMissing*(pool: var BlockPool): seq[FetchRecord] =
 
 proc skipAndUpdateState(
     state: var HashedBeaconState, slot: Slot,
-    afterUpdate: proc (state: HashedBeaconState)) =
+    afterUpdate: proc (state: HashedBeaconState) {.gcsafe.}) =
   while state.data.slot < slot:
     # Process slots one at a time in case afterUpdate needs to see empty states
     process_slots(state, state.data.slot + 1)
@@ -555,7 +564,7 @@ proc skipAndUpdateState(
 
 proc skipAndUpdateState(
     state: var HashedBeaconState, signedBlock: SignedBeaconBlock, flags: UpdateFlags,
-    afterUpdate: proc (state: HashedBeaconState)): bool =
+    afterUpdate: proc (state: HashedBeaconState) {.gcsafe.}): bool =
 
   skipAndUpdateState(state, signedBlock.message.slot - 1, afterUpdate)
 
@@ -845,7 +854,10 @@ proc updateHead*(pool: BlockPool, newHead: BlockRef) =
       cat = "fork_choice"
 
     # A reasonable criterion for "reorganizations of the chain"
-    beacon_reorgs_total.inc()
+    try:
+      beacon_reorgs_total.inc()
+    except Exception as e: # TODO https://github.com/status-im/nim-metrics/pull/22
+      trace "Couldn't update metrics", msg = e.msg
   else:
     info "Updated head block",
       stateRoot = shortLog(pool.headState.data.root),

beacon_chain/time.nim

@@ -1,3 +1,5 @@
+{.push raises: [Defect].}
+
 import
   chronos,
   spec/datatypes
@@ -79,7 +81,13 @@ func saturate*(d: tuple[inFuture: bool, offset: Duration]): Duration =
   if d.inFuture: d.offset else: seconds(0)
 
 proc addTimer*(fromNow: Duration, cb: CallbackFunc, udata: pointer = nil) =
-  discard setTimer(Moment.now() + fromNow, cb, udata)
+  try:
+    discard setTimer(Moment.now() + fromNow, cb, udata)
+  except Exception as e:
+    # TODO https://github.com/status-im/nim-chronos/issues/94
+    # shouldn't happen because we should have initialized chronos by now
+    # https://github.com/nim-lang/Nim/issues/10288 - sigh
+    raiseAssert e.msg
 
 func shortLog*(d: Duration): string =
   let dd = int64(d.milliseconds())