prometheus/util/netconnlimit/netconnlimit_test.go
Julien Pivotto 9b5e7623f4 Add support for multiple listening addresses
Fixes #9105

Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>
Signed-off-by: Julien <roidelapluie@o11y.eu>
2024-08-20 13:09:16 +02:00

125 lines
3.1 KiB
Go

// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package netconnlimit
import (
"io"
"net"
"sync"
"testing"
"time"
"github.com/stretchr/testify/require"
)
func TestSharedLimitListenerConcurrency(t *testing.T) {
testCases := []struct {
name string
semCapacity int
connCount int
expected int // Expected number of connections processed simultaneously.
}{
{
name: "Single connection allowed",
semCapacity: 1,
connCount: 3,
expected: 1,
},
{
name: "Two connections allowed",
semCapacity: 2,
connCount: 3,
expected: 2,
},
{
name: "Three connections allowed",
semCapacity: 3,
connCount: 3,
expected: 3,
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
sem := NewSharedSemaphore(tc.semCapacity)
listener, err := net.Listen("tcp", "127.0.0.1:0")
require.NoError(t, err, "failed to create listener")
defer listener.Close()
limitedListener := SharedLimitListener(listener, sem)
var wg sync.WaitGroup
var activeConnCount int64
var mu sync.Mutex
wg.Add(tc.connCount)
// Accept connections.
for i := 0; i < tc.connCount; i++ {
go func() {
defer wg.Done()
conn, err := limitedListener.Accept()
require.NoError(t, err, "failed to accept connection")
defer conn.Close()
// Simulate work and track the active connection count.
mu.Lock()
activeConnCount++
require.LessOrEqual(t, activeConnCount, int64(tc.expected), "too many simultaneous connections")
mu.Unlock()
time.Sleep(100 * time.Millisecond)
mu.Lock()
activeConnCount--
mu.Unlock()
}()
}
// Create clients that attempt to connect to the listener.
for i := 0; i < tc.connCount; i++ {
go func() {
conn, err := net.Dial("tcp", listener.Addr().String())
require.NoError(t, err, "failed to connect to listener")
defer conn.Close()
_, _ = io.WriteString(conn, "hello")
}()
}
wg.Wait()
// Ensure all connections are released and semaphore is empty.
require.Empty(t, sem)
})
}
}
func TestSharedLimitListenerClose(t *testing.T) {
sem := NewSharedSemaphore(2)
listener, err := net.Listen("tcp", "127.0.0.1:0")
require.NoError(t, err, "failed to create listener")
limitedListener := SharedLimitListener(listener, sem)
// Close the listener and ensure it does not accept new connections.
err = limitedListener.Close()
require.NoError(t, err, "failed to close listener")
conn, err := limitedListener.Accept()
require.Error(t, err, "expected error on accept after listener closed")
if conn != nil {
conn.Close()
}
}