vendorize new dsync with new changes of logging.

vendor/github.com/minio/dsync/drwmutex.go

@@ -17,27 +17,36 @@
 package dsync
 
 import (
+	"log"
 	"math"
 	"math/rand"
 	"net"
+	"os"
 	"sync"
 	"time"
 )
 
-const DRWMutexAcquireTimeout = 25 * time.Millisecond
+// Indicator if logging is enabled.
+var dsyncLog bool
+
+func init() {
+	// Check for DSYNC_LOG env variable, if set logging will be enabled for failed RPC operations.
+	dsyncLog = os.Getenv("DSYNC_LOG") == "1"
+}
+
+// DRWMutexAcquireTimeout - tolerance limit to wait for lock acquisition before.
+const DRWMutexAcquireTimeout = 25 * time.Millisecond // 25ms.
 
 // A DRWMutex is a distributed mutual exclusion lock.
 type DRWMutex struct {
 	Name  string
 	locks []bool     // Array of nodes that granted a lock
-	uids  []string   // Array of uids for verification of sending correct release messages
 	m     sync.Mutex // Mutex to prevent multiple simultaneous locks from this node
 }
 
 type Granted struct {
 	index  int
 	locked bool
-	uid    string
 }
 
 type LockArgs struct {
@@ -58,7 +67,6 @@ func NewDRWMutex(name string) *DRWMutex {
 	return &DRWMutex{
 		Name:  name,
 		locks: make([]bool, dnodeCount),
-		uids:  make([]string, dnodeCount),
 	}
 }
 
@@ -78,15 +86,13 @@ func (dm *DRWMutex) RLock() {
 
 		// create temp arrays on stack
 		locks := make([]bool, dnodeCount)
-		ids := make([]string, dnodeCount)
 
 		// try to acquire the lock
 		isReadLock := true
-		success := lock(clnts, &locks, &ids, dm.Name, isReadLock)
+		success := lock(clnts, &locks, dm.Name, isReadLock)
 		if success {
 			// if success, copy array to object
 			copy(dm.locks, locks[:])
-			copy(dm.uids, ids[:])
 			return
 		}
 
@@ -121,15 +127,13 @@ func (dm *DRWMutex) Lock() {
 	for {
 		// create temp arrays on stack
 		locks := make([]bool, dnodeCount)
-		ids := make([]string, dnodeCount)
 
 		// try to acquire the lock
 		isReadLock := false
-		success := lock(clnts, &locks, &ids, dm.Name, isReadLock)
+		success := lock(clnts, &locks, dm.Name, isReadLock)
 		if success {
 			// if success, copy array to object
 			copy(dm.locks, locks[:])
-			copy(dm.uids, ids[:])
 			return
 		}
 
@@ -150,10 +154,10 @@ func (dm *DRWMutex) Lock() {
 
 // lock tries to acquire the distributed lock, returning true or false
 //
-func lock(clnts []RPC, locks *[]bool, uids *[]string, lockName string, isReadLock bool) bool {
+func lock(clnts []RPC, locks *[]bool, lockName string, isReadLock bool) bool {
 
 	// Create buffered channel of quorum size
-	ch := make(chan Granted, dquorum)
+	ch := make(chan Granted, dnodeCount)
 
 	for index, c := range clnts {
 
@@ -161,51 +165,52 @@ func lock(clnts []RPC, locks *[]bool, uids *[]string, lockName string, isReadLoc
 		go func(index int, isReadLock bool, c RPC) {
 			// All client methods issuing RPCs are thread-safe and goroutine-safe,
 			// i.e. it is safe to call them from multiple concurrently running go routines.
-			var status bool
+			var locked bool
-			var err error
 			if isReadLock {
-				err = c.Call("Dsync.RLock", &LockArgs{Name: lockName}, &status)
+				if err := c.Call("Dsync.RLock", &LockArgs{Name: lockName}, &locked); err != nil {
+					if dsyncLog {
+						log.Println("Unable to call Dsync.RLock", err)
+					}
+				}
 			} else {
-				err = c.Call("Dsync.Lock", &LockArgs{Name: lockName}, &status)
+				if err := c.Call("Dsync.Lock", &LockArgs{Name: lockName}, &locked); err != nil {
+					if dsyncLog {
+						log.Println("Unable to call Dsync.Lock", err)
+					}
+				}
 			}
 
-			locked, uid := false, ""
+			ch <- Granted{index: index, locked: locked}
-			if err == nil {
-				locked = status
-				// TODO: Get UIOD again
-				uid = ""
-			}
-			// silently ignore error, retry later
-
-			ch <- Granted{index: index, locked: locked, uid: uid}
 
 		}(index, isReadLock, c)
 	}
 
-	var wg sync.WaitGroup
-	wg.Add(1)
-
 	quorum := false
 
+	var wg sync.WaitGroup
+	wg.Add(1)
 	go func(isReadLock bool) {
 
-		// Wait until we have received (minimally) quorum number of responses or timeout
+		// Wait until we have either a) received all lock responses, b) received too many 'non-'locks for quorum to be or c) time out
-		i := 0
+		i, locksFailed := 0, 0
 		done := false
 		timeout := time.After(DRWMutexAcquireTimeout)
 
-		for ; i < dnodeCount; i++ {
+		for ; i < dnodeCount; i++ {	// Loop until we acquired all locks
 
 			select {
 			case grant := <-ch:
 				if grant.locked {
 					// Mark that this node has acquired the lock
 					(*locks)[grant.index] = true
-					(*uids)[grant.index] = grant.uid
 				} else {
-					done = true
+					locksFailed++
-					//fmt.Println("one lock failed before quorum -- release locks acquired")
+					if locksFailed > dnodeCount - dquorum {
-					releaseAll(clnts, locks, uids, lockName, isReadLock)
+						// We know that we are not going to get the lock anymore, so exit out
+						// and release any locks that did get acquired
+						done = true
+						releaseAll(clnts, locks, lockName, isReadLock)
+					}
 				}
 
 			case <-timeout:
@@ -213,8 +218,7 @@ func lock(clnts []RPC, locks *[]bool, uids *[]string, lockName string, isReadLoc
 				// timeout happened, maybe one of the nodes is slow, count
 				// number of locks to check whether we have quorum or not
 				if !quorumMet(locks) {
-					//fmt.Println("timed out -- release locks acquired")
+					releaseAll(clnts, locks, lockName, isReadLock)
-					releaseAll(clnts, locks, uids, lockName, isReadLock)
 				}
 			}
 
@@ -236,7 +240,7 @@ func lock(clnts []RPC, locks *[]bool, uids *[]string, lockName string, isReadLoc
 			grantToBeReleased := <-ch
 			if grantToBeReleased.locked {
 				// release lock
-				sendRelease(clnts[grantToBeReleased.index], lockName, grantToBeReleased.uid, isReadLock)
+				sendRelease(clnts[grantToBeReleased.index], lockName, isReadLock)
 			}
 		}
 	}(isReadLock)
@@ -260,13 +264,11 @@ func quorumMet(locks *[]bool) bool {
 }
 
 // releaseAll releases all locks that are marked as locked
-func releaseAll(clnts []RPC, locks *[]bool, ids *[]string, lockName string, isReadLock bool) {
+func releaseAll(clnts []RPC, locks *[]bool, lockName string, isReadLock bool) {
-
 	for lock := 0; lock < dnodeCount; lock++ {
 		if (*locks)[lock] {
-			sendRelease(clnts[lock], lockName, (*ids)[lock], isReadLock)
+			sendRelease(clnts[lock], lockName, isReadLock)
 			(*locks)[lock] = false
-			(*ids)[lock] = ""
 		}
 	}
 
@@ -288,7 +290,7 @@ func (dm *DRWMutex) RUnlock() {
 		if dm.locks[index] {
 			// broadcast lock release to all nodes the granted the lock
 			isReadLock := true
-			sendRelease(c, dm.Name, dm.uids[index], isReadLock)
+			sendRelease(c, dm.Name, isReadLock)
 
 			dm.locks[index] = false
 		}
@@ -312,7 +314,7 @@ func (dm *DRWMutex) Unlock() {
 		if dm.locks[index] {
 			// broadcast lock release to all nodes the granted the lock
 			isReadLock := false
-			sendRelease(c, dm.Name, dm.uids[index], isReadLock)
+			sendRelease(c, dm.Name, isReadLock)
 
 			dm.locks[index] = false
 		}
@@ -320,34 +322,46 @@ func (dm *DRWMutex) Unlock() {
 }
 
 // sendRelease sends a release message to a node that previously granted a lock
-func sendRelease(c RPC, name, uid string, isReadLock bool) {
+func sendRelease(c RPC, name string, isReadLock bool) {
 
-	backOffArray := []time.Duration{30 * time.Second, 1 * time.Minute, 3 * time.Minute, 10 * time.Minute, 30 * time.Minute, 1 * time.Hour}
+	backOffArray := []time.Duration{
+		30 * time.Second, // 30secs.
+		1 * time.Minute,  // 1min.
+		3 * time.Minute,  // 3min.
+		10 * time.Minute, // 10min.
+		30 * time.Minute, // 30min.
+		1 * time.Hour,    // 1hr.
+	}
 
-	go func(c RPC, name, uid string) {
+	go func(c RPC, name string) {
 
 		for _, backOff := range backOffArray {
 
 			// All client methods issuing RPCs are thread-safe and goroutine-safe,
 			// i.e. it is safe to call them from multiple concurrently running goroutines.
-			var status bool
+			var unlocked bool
-			var err error
+
-			// TODO: Send UID to server
 			if isReadLock {
-				if err = c.Call("Dsync.RUnlock", &LockArgs{Name: name}, &status); err == nil {
+				if err := c.Call("Dsync.RUnlock", &LockArgs{Name: name}, &unlocked); err == nil {
 					// RUnlock delivered, exit out
 					return
 				} else if err != nil {
+					if dsyncLog {
+						log.Println("Unable to call Dsync.RUnlock", err)
+					}
 					if nErr, ok := err.(net.Error); ok && nErr.Timeout() {
 						// RUnlock possibly failed with server timestamp mismatch, server may have restarted.
 						return
 					}
 				}
 			} else {
-				if err = c.Call("Dsync.Unlock", &LockArgs{Name: name}, &status); err == nil {
+				if err := c.Call("Dsync.Unlock", &LockArgs{Name: name}, &unlocked); err == nil {
 					// Unlock delivered, exit out
 					return
 				} else if err != nil {
+					if dsyncLog {
+						log.Println("Unable to call Dsync.Unlock", err)
+					}
 					if nErr, ok := err.(net.Error); ok && nErr.Timeout() {
 						// Unlock possibly failed with server timestamp mismatch, server may have restarted.
 						return
@@ -355,8 +369,8 @@ func sendRelease(c RPC, name, uid string, isReadLock bool) {
 				}
 			}
 
-			// wait
+			// Wait..
 			time.Sleep(backOff)
 		}
-	}(c, name, uid)
+	}(c, name)
 }

vendor/vendor.json

@@ -98,10 +98,10 @@
 			"revisionTime": "2015-11-18T20:00:48-08:00"
 		},
 		{
-			"checksumSHA1": "OOADbvXPHaDRzp8WEvNw6esmfu0=",
+			"checksumSHA1": "0raNaLP/AhxXhEeB5CdSnbED3O4=",
 			"path": "github.com/minio/dsync",
-			"revision": "a2d8949cd8284e6cfa5b2ff9b617e4edb87f513f",
+			"revision": "1f615ccd013d35489becfe710e0ba7dce98b59e5",
-			"revisionTime": "2016-08-24T09:12:34Z"
+			"revisionTime": "2016-08-29T17:06:27Z"
 		},
 		{
 			"path": "github.com/minio/go-homedir",