Getting : BUG: slow write timer already active

[bilal-psychplus]

This my storage.go file

package db

import (
	"context"
	"fmt"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
)

//Store provides all functions to execute db queries and transactions
type Store struct {
	*Queries
	db *pgx.Conn
}

type TransferTxParams struct {
	FromAccountID int64 					`json:"from_account_id"`
	ToAccountID 	int64 					`json:"to_account_id"`
	Amount 				pgtype.Numeric 	`json:"amount"`
}

type TransferTxResult struct {
	Transfer Transfer `json:"transfer"`
	FromAccount Account `json:"from_account"`
	ToAccount Account `json:"to_account"`
	FromEntry Entry `json:"from_entry"`
	ToEntry Entry `json:"to_entry"`
}

func NewStore(db *pgx.Conn) *Store {
		return &Store{
			db: db,
			Queries: New(db),
		}
}
//executeTranscation executres a function within a database transaction
func (store *Store) executeTransaction(ctx context.Context, fn func(*Queries) error) error {
	options := pgx.TxOptions {
		IsoLevel: pgx.TxIsoLevel(pgx.Deferrable),
		AccessMode: pgx.ReadWrite,
	}
	transaction, err := store.db.BeginTx(ctx, options)
	if err != nil {
		return err
	}
	query := New(transaction)
	err = fn(query)
	if err != nil {
		if rollbackError := transaction.Rollback(ctx); rollbackError != nil {
			return fmt.Errorf("transaction error: %v, rollback error: %v", err, rollbackError)
		}
		return err
	}
	return transaction.Commit(ctx)
}

func (store *Store) TransferTx(ctx context.Context, arg TransferTxParams) (TransferTxResult, error) {
	var result TransferTxResult
	err := store.executeTransaction(ctx, func(query *Queries) error {
		var err error

		transfer := CreateTransferParams(TransferTxParams {
			FromAccountID: 	arg.FromAccountID,
			ToAccountID: 		arg.ToAccountID,
			Amount: 				arg.Amount,
		})
		

		result.Transfer, err = query.CreateTransfer(ctx, transfer)
		if err != nil {
			return err
		}

		// result.FromEntry, err = query.CreateEntry(ctx, CreateEntryParams {
		// 	AccountID: arg.FromAccountID,
		// 	Amount: -arg.Amount.Int.Int64(),
		// })
		// if err != nil {
		// 	return err
		// }

		// result.ToEntry, err = query.CreateEntry(ctx, CreateEntryParams {
		// 	AccountID: arg.ToAccountID,
		// 	Amount: arg.Amount.Int.Int64(),
		// })
		// if err != nil {
		// 	return err
		// }

		// // TODO: update account's balance
		// account1, err := query.GetAccountForUpdate(ctx, arg.FromAccountID);
		// if err != nil {
		// 	return err
		// }

		// result.FromAccount, err = query.UpdateAccount(ctx, UpdateAccountParams {
		// 	ID: arg.FromAccountID,
		// 	Balance: util.FromIntToPgNumeric(account1.Balance.Int.Int64() - arg.Amount.Int.Int64()),
		// })
		// if err != nil {
		// 	return err
		// }

		// account2, err := query.GetAccountForUpdate(ctx, arg.ToAccountID);
		// if err != nil {
		// 	return err
		// }

		// result.ToAccount, err = query.UpdateAccount(ctx, UpdateAccountParams {
		// 	ID: arg.ToAccountID,
		// 	Balance: util.FromIntToPgNumeric(account2.Balance.Int.Int64() + arg.Amount.Int.Int64()),
		// })

		// if err != nil {
		// 	return err
		// }

		return nil
	})
	return result, err
}

And i am getting the following errors

>> before: 579 832
panic: BUG: slow write timer already active

goroutine 37 [running]:
github.com/jackc/pgx/v5/pgconn.(*PgConn).enterPotentialWriteReadDeadlock(...)
        /Users/bilalashraf/go/pkg/mod/github.com/jackc/pgx/[email protected]/pgconn/pgconn.go:1833
github.com/jackc/pgx/v5/pgconn.(*PgConn).flushWithPotentialWriteReadDeadlock(0x14000103680)
        /Users/bilalashraf/go/pkg/mod/github.com/jackc/pgx/[email protected]/pgconn/pgconn.go:1852 +0xb4
github.com/jackc/pgx/v5/pgconn.(*PgConn).Close(0x14000103680, {0x1009768a0?, 0x140000a8000})
        /Users/bilalashraf/go/pkg/mod/github.com/jackc/pgx/[email protected]/pgconn/pgconn.go:640 +0x160
github.com/jackc/pgx/v5.(*Conn).die(0x14000151c20, {0x1009767f8?, 0x100c9ef40?})
        /Users/bilalashraf/go/pkg/mod/github.com/jackc/pgx/[email protected]/conn.go:412 +0x74
github.com/jackc/pgx/v5.(*Conn).BeginTx(0x14000151c20, {0x1009767f8, 0x100c9ef40}, {{0x1007eca5c, 0xa}, {0x1007eca66, 0xa}, {0x0, 0x0}, {0x0, ...}})
        /Users/bilalashraf/go/pkg/mod/github.com/jackc/pgx/[email protected]/tx.go:104 +0x120
github.com/billalaashraf/simplebank/db/sqlc.(*Store).executeTransaction(0x0?, {0x1009767f8, 0x100c9ef40}, 0x140000b1960)
        /Users/bilalashraf/Work/Backend/simplebank/db/sqlc/storage.go:43 +0x80
github.com/billalaashraf/simplebank/db/sqlc.(*Store).TransferTx(_, {_, _}, {_, _, {_, _, _, _, _}})
        /Users/bilalashraf/Work/Backend/simplebank/db/sqlc/storage.go:60 +0xc8
github.com/billalaashraf/simplebank/db/sqlc.TestTransferTx.func1()
        /Users/bilalashraf/Work/Backend/simplebank/db/sqlc/storage_test.go:29 +0xa0
created by github.com/billalaashraf/simplebank/db/sqlc.TestTransferTx in goroutine 35
        /Users/bilalashraf/Work/Backend/simplebank/db/sqlc/storage_test.go:28 +0x2e0
FAIL    github.com/billalaashraf/simplebank/db/sqlc     0.698s
FAIL

What am i missing here.

[SaeedSkf]

you should change pgx.Conn to pgxpool.Pool, like below:

package db

import (
	"context"
	"log"
	"os"
	"testing"

	"github.com/jackc/pgx/v5/pgxpool"
	_ "github.com/lib/pq"
)

const (
	dbSource = "postgresql://root:secret@localhost:5432/simple_bank?sslmode=disable"
)

var testQueries *Queries
var testDB *pgxpool.Pool

func TestMain(m *testing.M) {
	ctx := context.Background()
	var err error

	testDB, err = pgxpool.New(ctx, dbSource)
	if err != nil {
		log.Fatal("Can not connect to the db: ", err)
	}
	defer testDB.Close()

	testQueries = New(testDB)

	os.Exit(m.Run())
}