minio/cmd/namespace-lock_test.go

105 lines
2.9 KiB
Go

/*
* MinIO Cloud Storage, (C) 2016 MinIO, Inc.
*
* 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 cmd
import (
"context"
"runtime"
"testing"
"time"
)
// WARNING:
//
// Expected source line number is hard coded, 31, in the
// following test. Adding new code before this test or changing its
// position will cause the line number to change and the test to FAIL
// Tests getSource().
func TestGetSource(t *testing.T) {
currentSource := func() string { return getSource(2) }
gotSource := currentSource()
// Hard coded line number, 34, in the "expectedSource" value
expectedSource := "[namespace-lock_test.go:34:TestGetSource()]"
if gotSource != expectedSource {
t.Errorf("expected : %s, got : %s", expectedSource, gotSource)
}
}
// Test lock race
func TestNSLockRace(t *testing.T) {
if testing.Short() {
t.Skip("skipping test in short mode.")
}
ctx := context.Background()
for i := 0; i < 10000; i++ {
nsLk := newNSLock(false)
// lk1; ref=1
if !nsLk.lock(ctx, "volume", "path", "source", "opsID", false, time.Second) {
t.Fatal("failed to acquire lock")
}
// lk2
lk2ch := make(chan struct{})
go func() {
defer close(lk2ch)
nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 1*time.Millisecond)
}()
time.Sleep(1 * time.Millisecond) // wait for goroutine to advance; ref=2
// Unlock the 1st lock; ref=1 after this line
nsLk.unlock("volume", "path", false)
// Taking another lockMapMutex here allows queuing up additional lockers. This should
// not be required but makes reproduction much easier.
nsLk.lockMapMutex.Lock()
// lk3 blocks.
lk3ch := make(chan bool)
go func() {
lk3ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)
}()
// lk4, blocks.
lk4ch := make(chan bool)
go func() {
lk4ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)
}()
runtime.Gosched()
// unlock the manual lock
nsLk.lockMapMutex.Unlock()
// To trigger the race:
// 1) lk3 or lk4 need to advance and increment the ref on the existing resource,
// successfully acquiring the lock.
// 2) lk2 then needs to advance and remove the resource from lockMap.
// 3) lk3 or lk4 (whichever didn't execute in step 1) then executes and creates
// a new entry in lockMap and acquires a lock for the same resource.
<-lk2ch
lk3ok := <-lk3ch
lk4ok := <-lk4ch
if lk3ok && lk4ok {
t.Fatalf("multiple locks acquired; iteration=%d, lk3=%t, lk4=%t", i, lk3ok, lk4ok)
}
}
}