GC-safety for Nimbus (#63)

eth_p2p/blockchain_utils.nim

@@ -4,7 +4,7 @@ import
 # TODO: Perhaps we can move this to eth-common
 
 proc getBlockHeaders*(db: AbstractChainDb,
-                      req: BlocksRequest): seq[BlockHeader] =
+                      req: BlocksRequest): seq[BlockHeader] {.gcsafe.} =
   result = newSeqOfCap[BlockHeader](req.maxResults)
 
   var foundBlock: BlockHeader
@@ -18,7 +18,7 @@ proc getBlockHeaders*(db: AbstractChainDb,
 
 template fetcher*(fetcherName, fetchingFunc, InputType, ResultType: untyped) =
   proc fetcherName*(db: AbstractChainDb,
-                    lookups: openarray[InputType]): seq[ResultType] =
+                    lookups: openarray[InputType]): seq[ResultType] {.gcsafe.} =
     for lookup in lookups:
       let fetched = fetchingFunc(db, lookup)
       if fetched.hasData:

eth_p2p/rlpx_protocols/eth_protocol.nim

@@ -75,7 +75,7 @@ p2pProtocol eth(version = protocolVersion,
     discard
 
   requestResponse:
-    proc getBlockHeaders(peer: Peer, request: BlocksRequest) =
+    proc getBlockHeaders(peer: Peer, request: BlocksRequest) {.gcsafe.} =
       if request.maxResults > uint64(maxHeadersFetch):
         await peer.disconnect(BreachOfProtocol)
         return
@@ -85,7 +85,7 @@ p2pProtocol eth(version = protocolVersion,
     proc blockHeaders(p: Peer, headers: openarray[BlockHeader])
 
   requestResponse:
-    proc getBlockBodies(peer: Peer, hashes: openarray[KeccakHash]) =
+    proc getBlockBodies(peer: Peer, hashes: openarray[KeccakHash]) {.gcsafe.} =
       if hashes.len > maxBodiesFetch:
         await peer.disconnect(BreachOfProtocol)
         return

eth_p2p/rlpx_protocols/les_protocol.nim

@@ -301,7 +301,7 @@ p2pProtocol les(version = lesVersion,
     proc getBlockBodies(
            peer: Peer,
            blocks: openarray[KeccakHash]) {.
-           costQuantity(blocks.len, max = maxBodiesFetch).} =
+           costQuantity(blocks.len, max = maxBodiesFetch), gcsafe.} =
 
       let blocks = peer.network.chain.getBlockBodies(blocks)
       await peer.blockBodies(reqId, updateBV(), blocks)