From 54b5584799a8206c53a4447449bc064eda3eeeae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Carlos=20Nieto?= <jose.carlos@menteslibres.net>
Date: Sun, 16 Oct 2016 08:48:48 -0500
Subject: [PATCH] Use a counter to get the number of prepared statements.
---
internal/sqladapter/statement.go | 21 +++----
internal/sqladapter/testing/adapter.go.tpl | 64 +++++++++++-----------
2 files changed, 39 insertions(+), 46 deletions(-)
diff --git a/internal/sqladapter/statement.go b/internal/sqladapter/statement.go
index b8c73938..0a8a4482 100644
--- a/internal/sqladapter/statement.go
+++ b/internal/sqladapter/statement.go
@@ -2,21 +2,17 @@ package sqladapter
import (
"database/sql"
- "sync"
"sync/atomic"
)
var (
- statements = make(map[*Stmt]bool)
- statementsMu sync.Mutex
+ activeStatements int64
)
// NumActiveStatements returns the number of prepared statements in use at any
// point.
-func NumActiveStatements() int {
- statementsMu.Lock()
- defer statementsMu.Unlock()
- return len(statements)
+func NumActiveStatements() int64 {
+ return atomic.LoadInt64(&activeStatements)
}
// Stmt represents a *sql.Stmt that is cached and provides the
@@ -37,9 +33,8 @@ func NewStatement(stmt *sql.Stmt, query string) *Stmt {
query: query,
count: 1,
}
- statementsMu.Lock()
- statements[s] = true
- statementsMu.Unlock()
+ // Increment active statements counter.
+ atomic.AddInt64(&activeStatements, 1)
return s
}
@@ -59,10 +54,8 @@ func (c *Stmt) Close() {
if atomic.LoadInt32(&c.dead) > 0 {
// Statement is dead and we can close it for real.
c.Stmt.Close()
-
- statementsMu.Lock()
- delete(statements, c)
- statementsMu.Unlock()
+ // Reduce active statements counter.
+ atomic.AddInt64(&activeStatements, -1)
}
}
diff --git a/internal/sqladapter/testing/adapter.go.tpl b/internal/sqladapter/testing/adapter.go.tpl
index eb539c50..7367a2d4 100644
--- a/internal/sqladapter/testing/adapter.go.tpl
+++ b/internal/sqladapter/testing/adapter.go.tpl
@@ -6,19 +6,19 @@ import (
"database/sql"
"flag"
"fmt"
+ "log"
"math/rand"
"os"
"strconv"
"strings"
"sync"
"testing"
- "log"
- "time"
+ "time"
"github.com/stretchr/testify/assert"
"upper.io/db.v2"
+ "upper.io/db.v2/internal/sqladapter"
"upper.io/db.v2/lib/sqlbuilder"
- "upper.io/db.v2/internal/sqladapter"
)
type customLogger struct {
@@ -81,41 +81,41 @@ func TestPreparedStatementsCache(t *testing.T) {
assert.NoError(t, err)
defer sess.Close()
- var tMu sync.Mutex
+ var tMu sync.Mutex
tFatal := func(err error) {
tMu.Lock()
defer tMu.Unlock()
t.Fatal(err)
}
- // The max number of elements we can have on our LRU is 128, if an statement
- // is evicted it will be marked as dead and will be closed only when no other
- // queries are using it.
- const maxPreparedStatements = 128*2
-
- var wg sync.WaitGroup
- for i := 0; i < 500; i++ {
- wg.Add(1)
- go func(i int) {
- defer wg.Done()
- // This query is different with each iteration and thus generates a new
- // prepared statement everytime it's called.
- res := sess.Collection("artist").Find().Select(db.Raw(fmt.Sprintf("COUNT(%d)", i)))
- var count map[string]uint64
- err := res.One(&count)
- if err != nil {
- tFatal(err)
- }
- if sqladapter.NumActiveStatements() > maxPreparedStatements {
- tFatal(fmt.Errorf("The number of active statements cannot exceed %d.", maxPreparedStatements))
- }
- }(i)
- if i%maxPreparedStatements == 0 {
- wg.Wait()
- }
- }
-
- wg.Wait()
+ // The max number of elements we can have on our LRU is 128, if an statement
+ // is evicted it will be marked as dead and will be closed only when no other
+ // queries are using it.
+ const maxPreparedStatements = 128 * 2
+
+ var wg sync.WaitGroup
+ for i := 0; i < 500; i++ {
+ wg.Add(1)
+ go func(i int) {
+ defer wg.Done()
+ // This query is different with each iteration and thus generates a new
+ // prepared statement everytime it's called.
+ res := sess.Collection("artist").Find().Select(db.Raw(fmt.Sprintf("COUNT(%d)", i)))
+ var count map[string]uint64
+ err := res.One(&count)
+ if err != nil {
+ tFatal(err)
+ }
+ if sqladapter.NumActiveStatements() > maxPreparedStatements {
+ tFatal(fmt.Errorf("The number of active statements cannot exceed %d.", maxPreparedStatements))
+ }
+ }(i)
+ if i%maxPreparedStatements == 0 {
+ wg.Wait()
+ }
+ }
+
+ wg.Wait()
}
func TestTruncateAllCollections(t *testing.T) {
--
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