Have the clistate Lock use LockWithContext

- Have the ui Lock helper use state.LockWithContext.
- Rename the message package to clistate, since that's how it's imported
  everywhere.
- Use a more idiomatic placement of the Context in the LockWithContext
  args.

backend/local/backend_apply.go

@@ -9,7 +9,7 @@ import (
 	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/terraform/backend"
-	clistate "github.com/hashicorp/terraform/command/state"
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/config/module"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"

backend/local/backend_plan.go

@@ -10,8 +10,8 @@ import (
 	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/terraform/backend"
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/command/format"
-	clistate "github.com/hashicorp/terraform/command/state"
 	"github.com/hashicorp/terraform/config/module"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"

backend/local/backend_refresh.go

@@ -9,7 +9,7 @@ import (
 	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/terraform/backend"
-	clistate "github.com/hashicorp/terraform/command/state"
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/config/module"
 	"github.com/hashicorp/terraform/state"
 )

command/clistate/state.go

@@ -2,9 +2,10 @@
 //
 // This is a separate package so that backends can use this for consistent
 // messaging without creating a circular reference to the command package.
-package message
+package clistate
 
 import (
+	"context"
 	"fmt"
 	"strings"
 	"time"
@@ -48,12 +49,13 @@ that no one else is holding a lock.
 )
 
 // Lock locks the given state and outputs to the user if locking
-// is taking longer than the threshold.
-func Lock(s state.State, info *state.LockInfo, ui cli.Ui, color *colorstring.Colorize) (string, error) {
+// is taking longer than the threshold.  The lock is retried until the context
+// is cancelled.
+func Lock(ctx context.Context, s state.State, info *state.LockInfo, ui cli.Ui, color *colorstring.Colorize) (string, error) {
 	var lockID string
 
 	err := slowmessage.Do(LockThreshold, func() error {
-		id, err := s.Lock(info)
+		id, err := state.LockWithContext(ctx, s, info)
 		lockID = id
 		return err
 	}, func() {

command/env_delete.go

@@ -4,10 +4,9 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/state"
 	"github.com/mitchellh/cli"
-
-	clistate "github.com/hashicorp/terraform/command/state"
 )
 
 type EnvDeleteCommand struct {

command/env_new.go

@@ -5,11 +5,10 @@ import (
 	"os"
 	"strings"
 
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/cli"
-
-	clistate "github.com/hashicorp/terraform/command/state"
 )
 
 type EnvNewCommand struct {

command/meta_backend.go

@@ -16,13 +16,13 @@ import (
 	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/hcl"
 	"github.com/hashicorp/terraform/backend"
-	backendinit "github.com/hashicorp/terraform/backend/init"
-	clistate "github.com/hashicorp/terraform/command/state"
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/mapstructure"
 
+	backendinit "github.com/hashicorp/terraform/backend/init"
 	backendlocal "github.com/hashicorp/terraform/backend/local"
 )
 

command/meta_backend_migrate.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 
 	"github.com/hashicorp/terraform/backend"
-	clistate "github.com/hashicorp/terraform/command/state"
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
 )

command/taint.go

@@ -5,7 +5,7 @@ import (
 	"log"
 	"strings"
 
-	clistate "github.com/hashicorp/terraform/command/state"
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/state"
 	"github.com/hashicorp/terraform/terraform"
 )

command/untaint.go

@@ -5,7 +5,7 @@ import (
 	"log"
 	"strings"
 
-	clistate "github.com/hashicorp/terraform/command/state"
+	"github.com/hashicorp/terraform/command/clistate"
 	"github.com/hashicorp/terraform/state"
 )
 

state/state.go

@@ -74,9 +74,9 @@ type Locker interface {
 	Unlock(id string) error
 }
 
-// Lock the state, using the provided context for timeout and cancellation
+// Lock the state, using the provided context for timeout and cancellation.
 // TODO: this should probably backoff somewhat.
-func LockWithContext(s State, info *LockInfo, ctx context.Context) (string, error) {
+func LockWithContext(ctx context.Context, s State, info *LockInfo) (string, error) {
 	for {
 		id, err := s.Lock(info)
 		if err == nil {