Add concurrency safeguards to the current round timeout field on chain

[fabioDMFerreira]

Fixes

Add concurrency safeguards to the current round timeout field on chain (#629)
Also, add concurrency safeguards to the transaction cost as the processing of transactions may be done concurrently.

Changes

Need to be mentioned in CHANGELOG.md?

Tests

Tasks to complete before merging PR:

• Ensure system tests are passing. If not Run them manually to check for any regressions 📋
• Do any new system tests need added to test this change? do any existing system tests need updated? If so create a PR at 0chain/system_test
• Merge your system tests PR to master AFTER merging this PR

Associated PRs (Link as appropriate):

• blobber:
• gosdk:
• system_test:
• zboxcli:
• zwalletcli:
• Other: ...

[dabasov]

the problem here is that tii reference escapes from generate block and most likely is used concurrently in this closure. It is set to handler and

func txnIterHandlerFunc(mc *Chain,
	b *block.Block,
	lfb *block.Block,
	bState util.MerklePatriciaTrieI,
	txnProcessor txnProcessorHandler,
	tii *TxnIterInfo) func(context.Context, datastore.CollectionEntity) bool {
	return func(ctx context.Context, qe datastore.CollectionEntity) bool {

and handler lately is passed to iterate collection where it can be used concurrently

	err := transactionEntityMetadata.GetStore().IterateCollection(cctx, transactionEntityMetadata, collectionName, txnIterHandler)

please check all tii reference sharing between go routines

[fabioDMFerreira]

the problem here is that tii reference escapes from generate block and most likely is used concurrently in this closure. It is set to handler and

func txnIterHandlerFunc(mc *Chain,
	b *block.Block,
	lfb *block.Block,
	bState util.MerklePatriciaTrieI,
	txnProcessor txnProcessorHandler,
	tii *TxnIterInfo) func(context.Context, datastore.CollectionEntity) bool {
	return func(ctx context.Context, qe datastore.CollectionEntity) bool {

and handler lately is passed to iterate collection where it can be used concurrently

	err := transactionEntityMetadata.GetStore().IterateCollection(cctx, transactionEntityMetadata, collectionName, txnIterHandler)

please check all tii reference sharing between go routines

I got it. Only now, I realize tii escapes to txnProcessor which also updates fields. Thanks

[dabasov]

please fix lint error

[dabasov]

lgtm