From 4d7bc49a23ab9416603390434a6c876df7ed6aae Mon Sep 17 00:00:00 2001
From: Ilja von Hoessle <ilja@perun.network>
Date: Tue, 16 Apr 2024 08:37:58 +0200
Subject: [PATCH] refactor(client): Remove shared mutex from client package, in
 favor of a mutex in the Client struct.

---
 client/client.go      | 4 +++-
 client/transaction.go | 7 ++-----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/client/client.go b/client/client.go
index a160855..06e7a2b 100644
--- a/client/client.go
+++ b/client/client.go
@@ -21,9 +21,9 @@ import (
 	"github.com/stellar/go/keypair"
 	"github.com/stellar/go/xdr"
 	"log"
-
 	pchannel "perun.network/go-perun/channel"
 	pwallet "perun.network/go-perun/wallet"
+	"sync"
 
 	"perun.network/perun-stellar-backend/event"
 	"perun.network/perun-stellar-backend/wire"
@@ -36,6 +36,7 @@ var ErrCouldNotDecodeTxMeta = errors.New("could not decode tx output")
 type Client struct {
 	hzClient  *horizonclient.Client
 	keyHolder keyHolder
+	mtx       sync.Mutex
 }
 type keyHolder struct {
 	kp *keypair.Full
@@ -45,6 +46,7 @@ func New(kp *keypair.Full) *Client {
 	return &Client{
 		hzClient:  NewHorizonClient(),
 		keyHolder: newKeyHolder(kp),
+		mtx:       sync.Mutex{},
 	}
 }
 
diff --git a/client/transaction.go b/client/transaction.go
index 2069501..eb1e27e 100644
--- a/client/transaction.go
+++ b/client/transaction.go
@@ -10,12 +10,9 @@ import (
 	"github.com/stellar/go/txnbuild"
 	"github.com/stellar/go/xdr"
 	"strconv"
-	"sync"
 	"time"
 )
 
-var sharedMtx sync.Mutex
-
 const sorobanRPCPort = 8000
 
 func (s *Client) CreateSignedTxFromParams(txParams txnbuild.TransactionParams) (*txnbuild.Transaction, error) {
@@ -50,8 +47,8 @@ func CreateSignedTransactionWithParams(signers []*keypair.Full, txParams txnbuil
 }
 
 func (c *Client) InvokeAndProcessHostFunction(fname string, callTxArgs xdr.ScVec, contractAddr xdr.ScAddress) (xdr.TransactionMeta, error) {
-	sharedMtx.Lock()
-	defer sharedMtx.Unlock()
+	c.mtx.Lock()
+	defer c.mtx.Unlock()
 	fnameXdr := xdr.ScSymbol(fname)
 	hzAcc, err := c.GetHorizonAccount()
 	if err != nil {