fix: data race issues with api.Server (#11724)

## Description

Closes: #11692

This PR adds a `sync.Mutex` to `api.Server` in order to prevent data race issues. In practice, these data races are unlikely to occur as you'd typically wait for Start to return. However, this does cause an issue with testing using the `-race` flag when using the `testutil/network` package. Currently races occur by default when running tests on projects generated using `ignite`. We should fix this for the sake of passing race detecting tests.

---

### Author Checklist

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please add links to any relevant follow up issues.*

I have...

- [X] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [X] added `!` to the type prefix if API or client breaking change
- [X] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [X] provided a link to the relevant issue or specification
- [X] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [X] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [x] added a changelog entry to `CHANGELOG.md`
- [X] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [X] updated the relevant documentation or specification
- [x] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

(cherry picked from commit 97d735f)

# Conflicts:
#	CHANGELOG.md

CHANGELOG.md

@@ -39,6 +39,44 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+<<<<<<< HEAD
+=======
+* [\#11696](https://github.com/cosmos/cosmos-sdk/pull/11696) Rename `helpers.GenTx` to `GenSignedMockTx` to avoid confusion with genutil's `GenTxCmd`.
+* (x/auth/vesting) [\#11652](https://github.com/cosmos/cosmos-sdk/pull/11652) Add util functions for `Period(s)`
+* [\#11630](https://github.com/cosmos/cosmos-sdk/pull/11630) Add SafeSub method to sdk.Coin.
+* [\#11511](https://github.com/cosmos/cosmos-sdk/pull/11511) Add api server flags to start command.
+* [\#11484](https://github.com/cosmos/cosmos-sdk/pull/11484) Implement getter for keyring backend option.
+* [\#11449](https://github.com/cosmos/cosmos-sdk/pull/11449) Improved error messages when node isn't synced.
+* [\#11349](https://github.com/cosmos/cosmos-sdk/pull/11349) Add `RegisterAminoMsg` function that checks that a msg name is <40 chars (else this would break ledger nano signing) then registers the concrete msg type with amino, it should be used for registering `sdk.Msg`s with amino instead of `cdc.RegisterConcrete`.
+* [\#11089](https://github.com/cosmos/cosmos-sdk/pull/11089]) Now cosmos-sdk consumers can upgrade gRPC to its newest versions.
+* [\#10439](https://github.com/cosmos/cosmos-sdk/pull/10439) Check error for `RegisterQueryHandlerClient` in all modules `RegisterGRPCGatewayRoutes`.
+* [\#9780](https://github.com/cosmos/cosmos-sdk/pull/9780) Remove gogoproto `moretags` YAML annotations and add `sigs.k8s.io/yaml` for YAML marshalling.
+* (x/bank) [\#10134](https://github.com/cosmos/cosmos-sdk/pull/10134) Add `HasDenomMetadata` function to bank `Keeper` to check if a client coin denom metadata exists in state.
+* (x/bank) [\#10022](https://github.com/cosmos/cosmos-sdk/pull/10022) `BankKeeper.SendCoins` now takes less execution time.
+* (deps) [\#9987](https://github.com/cosmos/cosmos-sdk/pull/9987) Bump Go version minimum requirement to `1.17`
+* (cli) [\#9856](https://github.com/cosmos/cosmos-sdk/pull/9856) Overwrite `--sequence` and `--account-number` flags with default flag values when used with `offline=false` in `sign-batch` command.
+* (rosetta) [\#10001](https://github.com/cosmos/cosmos-sdk/issues/10001) Add documentation for rosetta-cli dockerfile and rename folder for the rosetta-ci dockerfile
+* [\#9699](https://github.com/cosmos/cosmos-sdk/pull/9699) Add `:`, `.`, `-`, and `_` as allowed characters in the default denom regular expression.
+* (genesis) [\#9697](https://github.com/cosmos/cosmos-sdk/pull/9697) Ensure `InitGenesis` returns with non-empty validator set.
+* [\#10341](https://github.com/cosmos/cosmos-sdk/pull/10341) Move from `io/ioutil` to `io` and `os` packages.
+* [\#10468](https://github.com/cosmos/cosmos-sdk/pull/10468) Allow futureOps to queue additional operations in simulations
+* [\#10625](https://github.com/cosmos/cosmos-sdk/pull/10625) Add `--fee-payer` CLI flag
+* (cli) [\#10683](https://github.com/cosmos/cosmos-sdk/pull/10683) In CLI, allow 1 SIGN_MODE_DIRECT signer in transactions with multiple signers.
+* (deps) [\#10210](https://github.com/cosmos/cosmos-sdk/pull/10210) Bump Tendermint to [v0.35.0](https://github.com/tendermint/tendermint/releases/tag/v0.35.0).
+* (deps) [\#10706](https://github.com/cosmos/cosmos-sdk/issues/10706) Bump rosetta-sdk-go to v0.7.2 and rosetta-cli to v0.7.3
+* (types/errors) [\#10779](https://github.com/cosmos/cosmos-sdk/pull/10779) Move most functionality in `types/errors` to a standalone `errors` go module, except the `RootCodespace` errors and ABCI response helpers. All functions and types that used to live in `types/errors` are now aliased so this is not a breaking change.
+* (gov) [\#10854](https://github.com/cosmos/cosmos-sdk/pull/10854) v1beta2's vote doesn't include the deprecate `option VoteOption` anymore. Instead, it only uses `WeightedVoteOption`.
+* (types) [\#11004](https://github.com/cosmos/cosmos-sdk/pull/11004) Added mutable versions of many of the sdk.Dec types operations.  This improves performance when used by avoiding reallocating a new bigint for each operation.
+* (x/auth) [\#10880](https://github.com/cosmos/cosmos-sdk/pull/10880) Added a new query to the tx query service that returns a block with transactions fully decoded.
+* (types) [\#11200](https://github.com/cosmos/cosmos-sdk/pull/11200) Added `Min()` and `Max()` operations on sdk.Coins.
+* (gov) [\#11287](https://github.com/cosmos/cosmos-sdk/pull/11287) Fix error message when no flags are provided while executing `submit-legacy-proposal` transaction.
+* (x/auth) [\#11482](https://github.com/cosmos/cosmos-sdk/pull/11482) Improve panic message when attempting to register a method handler for a message that does not implement sdk.Msg
+* (x/staking) [\#11596](https://github.com/cosmos/cosmos-sdk/pull/11596) Add (re)delegation getters
+
+### Bug Fixes
+
+* [\#11724](https://github.com/cosmos/cosmos-sdk/pull/11724) Fix data race issues with api.Server
+>>>>>>> 97d735f15 (fix: data race issues with api.Server (#11724))
 * [\#11693](https://github.com/cosmos/cosmos-sdk/pull/11693) Add validation for gentx cmd.
 * [\#11686](https://github.com/cosmos/cosmos-sdk/pull/11686) Update the min required Golang version to `1.17`.
 * (x/auth/vesting) [\#11652](https://github.com/cosmos/cosmos-sdk/pull/11652) Add util functions for `Period(s)`

server/api/server.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"net/http"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/gogo/gateway"
@@ -30,8 +31,13 @@ type Server struct {
 	GRPCGatewayRouter *runtime.ServeMux
 	ClientCtx         client.Context
 
-	logger   log.Logger
-	metrics  *telemetry.Metrics
+	logger  log.Logger
+	metrics *telemetry.Metrics
+	// Start() is blocking and generally called from a separate goroutine.
+	// Close() can be called asynchronously and access shared memory
+	// via the listener. Therefore, we sync access to Start and Close with
+	// this mutex to avoid data races.
+	mtx      sync.Mutex
 	listener net.Listener
 }
 
@@ -83,9 +89,11 @@ func New(clientCtx client.Context, logger log.Logger) *Server {
 // and are delegated to the Tendermint JSON RPC server. The process is
 // non-blocking, so an external signal handler must be used.
 func (s *Server) Start(cfg config.Config) error {
+	s.mtx.Lock()
 	if cfg.Telemetry.Enabled {
 		m, err := telemetry.New(cfg.Telemetry)
 		if err != nil {
+			s.mtx.Unlock()
 			return err
 		}
 
@@ -101,6 +109,7 @@ func (s *Server) Start(cfg config.Config) error {
 
 	listener, err := tmrpcserver.Listen(cfg.API.Address, tmCfg)
 	if err != nil {
+		s.mtx.Unlock()
 		return err
 	}
 
@@ -111,15 +120,19 @@ func (s *Server) Start(cfg config.Config) error {
 
 	if cfg.API.EnableUnsafeCORS {
 		allowAllCORS := handlers.CORS(handlers.AllowedHeaders([]string{"Content-Type"}))
+		s.mtx.Unlock()
 		return tmrpcserver.Serve(s.listener, allowAllCORS(h), s.logger, tmCfg)
 	}
 
 	s.logger.Info("starting API server...")
+	s.mtx.Unlock()
 	return tmrpcserver.Serve(s.listener, s.Router, s.logger, tmCfg)
 }
 
 // Close closes the API server.
 func (s *Server) Close() error {
+	s.mtx.Lock()
+	defer s.mtx.Unlock()
 	return s.listener.Close()
 }