* mempool: Keep cache hashmap and linked list in sync
This removes bugs with the linked list being full, but hashmap empty
* address PR comments
* switch clist back to list
* #1920 try to fix race condition on proposal height for published txs
- related to create_empty_blocks=false
- published height for accepted tx can be wrong (too low)
- use the actual mempool height + 1 for the proposal
- expose Height() on mempool
* #1920 add initial test for mempool.Height()
- not sure how to test the lock
- can the mutex reference be of type Locker?
-- this way, we can use a "mock" of the mutex to test triggering
* #1920 use the ConsensusState height in favor of mempool
- gets rid of indirections
- doesn't need any "+1" magic
* #1920 cosmetic
- if we use cs.Height, it's enough to evaluate right before propose
* #1920 cleanup TODO and non-needed code
* #1920 add changelog entry
* updateToState exits early if the state isn't new, which happens after
* fast syncing. This results in not sending a NewRoundStep message. The mempool
* reactor depends on PeerState, which is updated by NewRoundStep
* messages. If the peer never sends a NewRoundStep, the mempool reactor
* will think they're behind, and never forward transactions. Note this
* only happens when `create_empty_blocks = false`, because otherwise
* peers will move through the consensus state and send a NewRoundStep
* for a new step soon anyways. Simple fix is just to send the
* NewRoundStep message during updateToState even if exit early
https://play.golang.org/p/gN21yO9IRs3
```
func waitWithCancel(f func() *clist.CElement, ctx context.Context) *clist.CElement {
el := make(chan *clist.CElement, 1)
select {
case el <- f():
```
will just run f() blockingly, so this doesn't change much in terms of behavior.
if we call it after, we might receive a "fresh" transaction from
`broadcast_tx_sync` before old transactions (which were not
committed).
Refs #1091
```
Commit is called with a lock on the mempool, meaning no calls to CheckTx
can start. However, since CheckTx is called async in the mempool
connection, some CheckTx might have already "sailed", when the lock is
released in the mempool and Commit proceeds.
Then, that spurious CheckTx has not yet "begun" in the ABCI app (stuck
in transport?). Instead, ABCI app manages to start to process the
Commit. Next, the spurious, "sailed" CheckTx happens in the wrong place.
```
Dev Ojha
Jun Kimura
Ethan Buchman
srmo
Anton Kaliaev
Alexander Simmerl
Emmanuel Odeke
Zach Ramsay
Adrian Brink
spring1843