lab4

src/shardctrler/client.go

@@ -7,11 +7,17 @@ package shardctrler
 import "6.5840/labrpc"
 import "time"
 import "crypto/rand"
+import rand2 "math/rand"
 import "math/big"
 
 type Clerk struct {
 	servers []*labrpc.ClientEnd
-	// Your data here.
+	cid     int32
+	leader  int32
+}
+
+func (ck *Clerk) args() Args {
+	return Args{ClientId: ck.cid, RequestId: nrand()}
 }
 
 func nrand() int64 {
@@ -24,20 +30,18 @@ func nrand() int64 {
 func MakeClerk(servers []*labrpc.ClientEnd) *Clerk {
 	ck := new(Clerk)
 	ck.servers = servers
-	// Your code here.
+	ck.cid = rand2.Int31()
 	return ck
 }
 
 func (ck *Clerk) Query(num int) Config {
-	args := &QueryArgs{}
-	// Your code here.
-	args.Num = num
+	args := &QueryArgs{Num: num}
 	for {
 		// try each known server.
 		for _, srv := range ck.servers {
 			var reply QueryReply
 			ok := srv.Call("ShardCtrler.Query", args, &reply)
-			if ok && reply.WrongLeader == false {
+			if ok && reply.WrongLeader == false && reply.Err == OK {
 				return reply.Config
 			}
 		}
@@ -46,16 +50,13 @@ func (ck *Clerk) Query(num int) Config {
 }
 
 func (ck *Clerk) Join(servers map[int][]string) {
-	args := &JoinArgs{}
-	// Your code here.
-	args.Servers = servers
-
+	args := &JoinArgs{Servers: servers, Args: ck.args()}
 	for {
 		// try each known server.
 		for _, srv := range ck.servers {
 			var reply JoinReply
 			ok := srv.Call("ShardCtrler.Join", args, &reply)
-			if ok && reply.WrongLeader == false {
+			if ok && reply.WrongLeader == false && reply.Err == OK {
 				return
 			}
 		}
@@ -64,16 +65,13 @@ func (ck *Clerk) Join(servers map[int][]string) {
 }
 
 func (ck *Clerk) Leave(gids []int) {
-	args := &LeaveArgs{}
-	// Your code here.
-	args.GIDs = gids
-
+	args := &LeaveArgs{GIDs: gids, Args: ck.args()}
 	for {
 		// try each known server.
 		for _, srv := range ck.servers {
 			var reply LeaveReply
 			ok := srv.Call("ShardCtrler.Leave", args, &reply)
-			if ok && reply.WrongLeader == false {
+			if ok && reply.WrongLeader == false && reply.Err == OK {
 				return
 			}
 		}
@@ -82,20 +80,16 @@ func (ck *Clerk) Leave(gids []int) {
 }
 
 func (ck *Clerk) Move(shard int, gid int) {
-	args := &MoveArgs{}
-	// Your code here.
-	args.Shard = shard
-	args.GID = gid
-
+	args := &MoveArgs{Shard: shard, GID: gid, Args: ck.args()}
 	for {
 		// try each known server.
 		for _, srv := range ck.servers {
 			var reply MoveReply
 			ok := srv.Call("ShardCtrler.Move", args, &reply)
-			if ok && reply.WrongLeader == false {
+			if ok && reply.WrongLeader == false && reply.Err == OK {
 				return
 			}
 		}
 		time.Sleep(100 * time.Millisecond)
 	}
-}
+}

src/shardctrler/common.go

@@ -29,13 +29,20 @@ type Config struct {
 }
 
 const (
-	OK = "OK"
+	OK         = "OK"
+	ErrTimeout = "ErrTimeout"
 )
 
 type Err string
 
+type Args struct {
+	ClientId  int32
+	RequestId int64
+}
+
 type JoinArgs struct {
 	Servers map[int][]string // new GID -> servers mappings
+	Args
 }
 
 type JoinReply struct {
@@ -45,6 +52,7 @@ type JoinReply struct {
 
 type LeaveArgs struct {
 	GIDs []int
+	Args
 }
 
 type LeaveReply struct {
@@ -55,6 +63,7 @@ type LeaveReply struct {
 type MoveArgs struct {
 	Shard int
 	GID   int
+	Args
 }
 
 type MoveReply struct {
@@ -70,4 +79,4 @@ type QueryReply struct {
 	WrongLeader bool
 	Err         Err
 	Config      Config
-}
+}