From dd9c654291f8686a614add8514b8a37fe37056ed Mon Sep 17 00:00:00 2001
From: Wang Xu <gnawux@gmail.com>
Date: Tue, 27 Feb 2018 15:37:12 +0800
Subject: [PATCH] tests for shrink the socks pool

Signed-off-by: Wang Xu <gnawux@gmail.com>
---
 session_test.go | 83 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/session_test.go b/session_test.go
index eb2c812b3..359b7455e 100644
--- a/session_test.go
+++ b/session_test.go
@@ -30,11 +30,13 @@ import (
 	"flag"
 	"fmt"
 	"math"
+	"math/rand"
 	"os"
 	"runtime"
 	"sort"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -166,6 +168,87 @@ func (s *S) TestURLInvalidReadPreference(c *C) {
 	}
 }
 
+func (s *S) TestMinPoolSize(c *C) {
+	tests := []struct {
+		url  string
+		size int
+		fail bool
+	}{
+		{"localhost:40001?minPoolSize=0", 0, false},
+		{"localhost:40001?minPoolSize=1", 1, false},
+		{"localhost:40001?minPoolSize=-1", -1, true},
+		{"localhost:40001?minPoolSize=-.", 0, true},
+	}
+	for _, test := range tests {
+		info, err := mgo.ParseURL(test.url)
+		if test.fail {
+			c.Assert(err, NotNil)
+		} else {
+			c.Assert(err, IsNil)
+			c.Assert(info.MinPoolSize, Equals, test.size)
+		}
+	}
+}
+
+func (s *S) TestMaxIdleTimeMS(c *C) {
+	tests := []struct {
+		url  string
+		size int
+		fail bool
+	}{
+		{"localhost:40001?maxIdleTimeMS=0", 0, false},
+		{"localhost:40001?maxIdleTimeMS=1", 1, false},
+		{"localhost:40001?maxIdleTimeMS=-1", -1, true},
+		{"localhost:40001?maxIdleTimeMS=-.", 0, true},
+	}
+	for _, test := range tests {
+		info, err := mgo.ParseURL(test.url)
+		if test.fail {
+			c.Assert(err, NotNil)
+		} else {
+			c.Assert(err, IsNil)
+			c.Assert(info.MaxIdleTimeMS, Equals, test.size)
+		}
+	}
+}
+
+func (s *S) TestPoolShrink(c *C) {
+	oldSocket := mgo.GetStats().SocketsAlive
+
+	session, err := mgo.Dial("localhost:40001?minPoolSize=1&maxIdleTimeMS=1000")
+	c.Assert(err, IsNil)
+	defer session.Close()
+
+	parallel := 10
+	res := make(chan error, parallel+1)
+	wg := &sync.WaitGroup{}
+	for i := 1; i < parallel; i++ {
+		wg.Add(1)
+		go func() {
+			s := session.Copy()
+			defer s.Close()
+			result := struct{}{}
+			err := s.Run("ping", &result)
+
+			//sleep random time to make the allocate and release in different sequence
+			time.Sleep(time.Duration(rand.Intn(parallel)*100) * time.Millisecond)
+			res <- err
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+	stats := mgo.GetStats()
+	c.Logf("living socket: After queries: %d, before queris: %d", stats.SocketsAlive, oldSocket)
+
+	// give some time for shrink the pool, the tick is set to 1 minute
+	c.Log("Sleeping... 1 minutes to for pool shrinking")
+	time.Sleep(61 * time.Second)
+
+	stats = mgo.GetStats()
+	c.Logf("living socket: After shrinking: %d, at the beginning of the test: %d", stats.SocketsAlive, oldSocket)
+	c.Assert(stats.SocketsAlive-oldSocket > 1, Equals, false)
+}
+
 func (s *S) TestURLReadPreferenceTags(c *C) {
 	type test struct {
 		url     string