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lock.go
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lock.go
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// Package test contains utilities to test topo.Impl
// implementations. If you are testing your implementation, you will
// want to call CheckAll in your test method. For an example, look at
// the tests in github.com/youtube/vitess/go/vt/zktopo.
package test
import (
"testing"
"time"
"github.com/youtube/vitess/go/vt/topo"
"golang.org/x/net/context"
topodatapb "github.com/youtube/vitess/go/vt/proto/topodata"
)
// timeUntilLockIsTaken is the time to wait until a lock is taken.
// We haven't found a better simpler way to guarantee a routine is stuck
// waiting for a topo lock than sleeping that amount.
var timeUntilLockIsTaken = 10 * time.Millisecond
// CheckKeyspaceLock checks we can take a keyspace lock as expected.
func CheckKeyspaceLock(ctx context.Context, t *testing.T, ts topo.Impl) {
if err := ts.CreateKeyspace(ctx, "test_keyspace", &topodatapb.Keyspace{}); err != nil {
t.Fatalf("CreateKeyspace: %v", err)
}
checkKeyspaceLockTimeout(ctx, t, ts)
checkKeyspaceLockMissing(ctx, t, ts)
checkKeyspaceLockUnblocks(ctx, t, ts)
}
func checkKeyspaceLockTimeout(ctx context.Context, t *testing.T, ts topo.Impl) {
lockPath, err := ts.LockKeyspaceForAction(ctx, "test_keyspace", "fake-content")
if err != nil {
t.Fatalf("LockKeyspaceForAction: %v", err)
}
// test we can't take the lock again
fastCtx, cancel := context.WithTimeout(ctx, timeUntilLockIsTaken)
if _, err := ts.LockKeyspaceForAction(fastCtx, "test_keyspace", "unused-fake-content"); err != topo.ErrTimeout {
t.Fatalf("LockKeyspaceForAction(again): %v", err)
}
cancel()
// test we can interrupt taking the lock
interruptCtx, cancel := context.WithCancel(ctx)
go func() {
time.Sleep(timeUntilLockIsTaken)
cancel()
}()
if _, err := ts.LockKeyspaceForAction(interruptCtx, "test_keyspace", "unused-fake-content"); err != topo.ErrInterrupted {
t.Fatalf("LockKeyspaceForAction(interrupted): %v", err)
}
if err := ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath, "fake-results"); err != nil {
t.Fatalf("UnlockKeyspaceForAction(): %v", err)
}
// test we can't unlock again
if err := ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath, "fake-results"); err == nil {
t.Fatalf("UnlockKeyspaceForAction(again) worked")
}
}
// checkKeyspaceLockMissing makes sure we can't lock a non-existing keyspace
func checkKeyspaceLockMissing(ctx context.Context, t *testing.T, ts topo.Impl) {
if _, err := ts.LockKeyspaceForAction(ctx, "test_keyspace_666", "fake-content"); err == nil {
t.Fatalf("LockKeyspaceForAction(test_keyspace_666) worked for non-existing keyspace")
}
}
// checkKeyspaceLockUnblocks makes sure that a routine waiting on a lock
// is unblocked when another routine frees the lock
func checkKeyspaceLockUnblocks(ctx context.Context, t *testing.T, ts topo.Impl) {
unblock := make(chan struct{})
finished := make(chan struct{})
// as soon as we're unblocked, we try to lock the keyspace
go func() {
<-unblock
lockPath, err := ts.LockKeyspaceForAction(ctx, "test_keyspace", "fake-content")
if err != nil {
t.Fatalf("LockKeyspaceForAction(test_keyspace) failed: %v", err)
}
if err = ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath, "fake-results"); err != nil {
t.Fatalf("UnlockKeyspaceForAction(test_keyspace): %v", err)
}
close(finished)
}()
// lock the keyspace
lockPath2, err := ts.LockKeyspaceForAction(ctx, "test_keyspace", "fake-content")
if err != nil {
t.Fatalf("LockKeyspaceForAction(test_keyspace) failed: %v", err)
}
// unblock the go routine so it starts waiting
close(unblock)
// sleep for a while so we're sure the go routine is blocking
time.Sleep(timeUntilLockIsTaken)
if err = ts.UnlockKeyspaceForAction(ctx, "test_keyspace", lockPath2, "fake-results"); err != nil {
t.Fatalf("UnlockKeyspaceForAction(test_keyspace): %v", err)
}
timeout := time.After(10 * time.Second)
select {
case <-finished:
case <-timeout:
t.Fatalf("unlocking timed out")
}
}
// CheckShardLock checks we can take a shard lock
func CheckShardLock(ctx context.Context, t *testing.T, ts topo.Impl) {
if err := ts.CreateKeyspace(ctx, "test_keyspace", &topodatapb.Keyspace{}); err != nil {
t.Fatalf("CreateKeyspace: %v", err)
}
if err := ts.CreateShard(ctx, "test_keyspace", "10-20", &topodatapb.Shard{
KeyRange: newKeyRange("10-20"),
}); err != nil {
t.Fatalf("CreateShard: %v", err)
}
checkShardLockTimeout(ctx, t, ts)
checkShardLockMissing(ctx, t, ts)
checkShardLockUnblocks(ctx, t, ts)
}
func checkShardLockTimeout(ctx context.Context, t *testing.T, ts topo.Impl) {
lockPath, err := ts.LockShardForAction(ctx, "test_keyspace", "10-20", "fake-content")
if err != nil {
t.Fatalf("LockShardForAction: %v", err)
}
// test we can't take the lock again
fastCtx, cancel := context.WithTimeout(ctx, timeUntilLockIsTaken)
if _, err := ts.LockShardForAction(fastCtx, "test_keyspace", "10-20", "unused-fake-content"); err != topo.ErrTimeout {
t.Fatalf("LockShardForAction(again): %v", err)
}
cancel()
// test we can interrupt taking the lock
interruptCtx, cancel := context.WithCancel(ctx)
go func() {
time.Sleep(timeUntilLockIsTaken)
cancel()
}()
if _, err := ts.LockShardForAction(interruptCtx, "test_keyspace", "10-20", "unused-fake-content"); err != topo.ErrInterrupted {
t.Fatalf("LockShardForAction(interrupted): %v", err)
}
if err := ts.UnlockShardForAction(ctx, "test_keyspace", "10-20", lockPath, "fake-results"); err != nil {
t.Fatalf("UnlockShardForAction(): %v", err)
}
// test we can't unlock again
if err := ts.UnlockShardForAction(ctx, "test_keyspace", "10-20", lockPath, "fake-results"); err == nil {
t.Error("UnlockShardForAction(again) worked")
}
}
func checkShardLockMissing(ctx context.Context, t *testing.T, ts topo.Impl) {
// test we can't lock a non-existing shard
if _, err := ts.LockShardForAction(ctx, "test_keyspace", "20-30", "fake-content"); err == nil {
t.Fatalf("LockShardForAction(test_keyspace/20-30) worked for non-existing shard")
}
}
// checkShardLockUnblocks makes sure that a routine waiting on a lock
// is unblocked when another routine frees the lock
func checkShardLockUnblocks(ctx context.Context, t *testing.T, ts topo.Impl) {
unblock := make(chan struct{})
finished := make(chan struct{})
// as soon as we're unblocked, we try to lock the shard
go func() {
<-unblock
lockPath, err := ts.LockShardForAction(ctx, "test_keyspace", "10-20", "fake-content")
if err != nil {
t.Fatalf("LockShardForAction(test_keyspace, 10-20) failed: %v", err)
}
if err = ts.UnlockShardForAction(ctx, "test_keyspace", "10-20", lockPath, "fake-results"); err != nil {
t.Fatalf("UnlockShardForAction(test_keyspace, 10-20): %v", err)
}
close(finished)
}()
// lock the shard
lockPath2, err := ts.LockShardForAction(ctx, "test_keyspace", "10-20", "fake-content")
if err != nil {
t.Fatalf("LockShardForAction(test_keyspace, 10-20) failed: %v", err)
}
// unblock the go routine so it starts waiting
close(unblock)
// sleep for a while so we're sure the go routine is blocking
time.Sleep(timeUntilLockIsTaken)
if err = ts.UnlockShardForAction(ctx, "test_keyspace", "10-20", lockPath2, "fake-results"); err != nil {
t.Fatalf("UnlockShardForAction(test_keyspace, 10-20): %v", err)
}
timeout := time.After(10 * time.Second)
select {
case <-finished:
case <-timeout:
t.Fatalf("unlocking timed out")
}
}
// CheckSrvShardLock tests we can take a SrvShard lock
func CheckSrvShardLock(ctx context.Context, t *testing.T, ts topo.Impl) {
checkSrvShardLockGeneral(ctx, t, ts)
checkSrvShardLockUnblocks(ctx, t, ts)
}
func checkSrvShardLockGeneral(ctx context.Context, t *testing.T, ts topo.Impl) {
cell := getLocalCell(ctx, t, ts)
// make sure we can create the lock even if no directory exists
lockPath, err := ts.LockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", "fake-content")
if err != nil {
t.Fatalf("LockSrvShardForAction: %v", err)
}
if err := ts.UnlockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", lockPath, "fake-results"); err != nil {
t.Fatalf("UnlockShardForAction: %v", err)
}
// now take the lock again after the root exists
lockPath, err = ts.LockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", "fake-content")
if err != nil {
t.Fatalf("LockSrvShardForAction: %v", err)
}
// test we can't take the lock again
fastCtx, cancel := context.WithTimeout(ctx, timeUntilLockIsTaken)
if _, err := ts.LockSrvShardForAction(fastCtx, cell, "test_keyspace", "10-20", "unused-fake-content"); err != topo.ErrTimeout {
t.Fatalf("LockSrvShardForAction(again): %v", err)
}
cancel()
// test we can interrupt taking the lock
interruptCtx, cancel := context.WithCancel(ctx)
go func() {
time.Sleep(timeUntilLockIsTaken)
cancel()
}()
if _, err := ts.LockSrvShardForAction(interruptCtx, cell, "test_keyspace", "10-20", "unused-fake-content"); err != topo.ErrInterrupted {
t.Fatalf("LockSrvShardForAction(interrupted): %v", err)
}
// unlock now
if err := ts.UnlockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", lockPath, "fake-results"); err != nil {
t.Fatalf("UnlockSrvShardForAction(): %v", err)
}
// test we can't unlock again
if err := ts.UnlockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", lockPath, "fake-results"); err == nil {
t.Error("UnlockSrvShardForAction(again) worked")
}
}
// checkSrvShardLockUnblocks makes sure that a routine waiting on a lock
// is unblocked when another routine frees the lock
func checkSrvShardLockUnblocks(ctx context.Context, t *testing.T, ts topo.Impl) {
cell := getLocalCell(ctx, t, ts)
unblock := make(chan struct{})
finished := make(chan struct{})
// as soon as we're unblocked, we try to lock the shard
go func() {
<-unblock
lockPath, err := ts.LockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", "fake-content")
if err != nil {
t.Fatalf("LockSrvShardForAction(test, test_keyspace, 10-20) failed: %v", err)
}
if err = ts.UnlockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", lockPath, "fake-results"); err != nil {
t.Fatalf("UnlockSrvShardForAction(test, test_keyspace, 10-20): %v", err)
}
close(finished)
}()
// lock the shard
lockPath2, err := ts.LockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", "fake-content")
if err != nil {
t.Fatalf("LockSrvShardForAction(test, test_keyspace, 10-20) failed: %v", err)
}
// unblock the go routine so it starts waiting
close(unblock)
// sleep for a while so we're sure the go routine is blocking
time.Sleep(timeUntilLockIsTaken)
if err = ts.UnlockSrvShardForAction(ctx, cell, "test_keyspace", "10-20", lockPath2, "fake-results"); err != nil {
t.Fatalf("UnlockSrvShardForAction(test, test_keyspace, 10-20): %v", err)
}
timeout := time.After(10 * time.Second)
select {
case <-finished:
case <-timeout:
t.Fatalf("unlocking timed out")
}
}