add xsync

rewrite critical section with more safe code

Author: rekby

CHANGELOG.md

@@ -2,6 +2,7 @@
 * Added to query stats plan and AST
 * Changed behaviour of `result.Stats()` (if query result have no stats - returns `nil`) 
 * Added context cancel with specific error
+* Added mutex wrapper for mutex, rwmutex for guarantee unlock and better show critical section
 
 ## v3.26.10
 * Fixed syntax mistake in `trace.TablePooStateChangeInfo` to `trace.TablePoolStateChangeInfo` 

connection.go

@@ -8,6 +8,8 @@ import (
 
 	"google.golang.org/grpc"
 
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/xsync"
+
 	"github.com/ydb-platform/ydb-go-sdk/v3/config"
 	"github.com/ydb-platform/ydb-go-sdk/v3/coordination"
 	"github.com/ydb-platform/ydb-go-sdk/v3/discovery"
@@ -108,7 +110,7 @@ type connection struct {
 	balancer balancer.Connection
 
 	children    map[uint64]Connection
-	childrenMtx sync.Mutex
+	childrenMtx xsync.Mutex
 	onClose     []func(c *connection)
 
 	panicCallback func(e interface{})
@@ -124,13 +126,13 @@ func (c *connection) Close(ctx context.Context) error {
 		}
 	}()
 
-	c.childrenMtx.Lock()
 	closers := make([]func(context.Context) error, 0)
-	for _, child := range c.children {
-		closers = append(closers, child.Close)
-	}
-	c.children = nil
-	c.childrenMtx.Unlock()
+	c.childrenMtx.WithLock(func() {
+		for _, child := range c.children {
+			closers = append(closers, child.Close)
+		}
+		c.children = nil
+	})
 
 	closers = append(
 		closers,

internal/conn/pool.go

@@ -2,12 +2,13 @@ package conn
 
 import (
 	"context"
-	"sync"
 	"sync/atomic"
 	"time"
 
 	"google.golang.org/grpc"
 
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/xsync"
+
 	"github.com/ydb-platform/ydb-go-sdk/v3/internal/closer"
 	"github.com/ydb-platform/ydb-go-sdk/v3/internal/endpoint"
 	"github.com/ydb-platform/ydb-go-sdk/v3/internal/xerrors"
@@ -17,7 +18,7 @@ import (
 type Pool struct {
 	usages int64
 	config Config
-	mtx    sync.RWMutex
+	mtx    xsync.RWMutex
 	opts   []grpc.DialOption
 	conns  map[string]*conn
 	done   chan struct{}
@@ -100,12 +101,13 @@ func (p *Pool) Release(ctx context.Context) error {
 
 	close(p.done)
 
-	p.mtx.RLock()
-	conns := make([]closer.Closer, 0, len(p.conns))
-	for _, c := range p.conns {
-		conns = append(conns, c)
-	}
-	p.mtx.RUnlock()
+	var conns []closer.Closer
+	p.mtx.WithRLock(func() {
+		conns = make([]closer.Closer, 0, len(p.conns))
+		for _, c := range p.conns {
+			conns = append(conns, c)
+		}
+	})
 
 	var issues []error
 	for _, c := range conns {