updated goprocess to deal with memory leak

Godeps/Godeps.json

@@ -199,7 +199,7 @@
 		},
 		{
 			"ImportPath": "github.com/jbenet/goprocess",
-			"Rev": "c877297c00ffe09f8213ceec3bbb0ab40871f8d4"
+			"Rev": "ea63e9540cd19cb39e0e4c4442b9c27664287bb8"
 		},
 		{
 			"ImportPath": "github.com/kardianos/osext",

Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess_test.go

@@ -71,10 +71,6 @@ func TestChildFunc(t *testing.T) {
 	wait2 := make(chan struct{})
 	wait3 := make(chan struct{})
 	wait4 := make(chan struct{})
-	go func() {
-		a.Close()
-		wait4 <- struct{}{}
-	}()
 
 	a.Go(func(process Process) {
 		wait1 <- struct{}{}
@@ -82,6 +78,11 @@ func TestChildFunc(t *testing.T) {
 		wait3 <- struct{}{}
 	})
 
+	go func() {
+		a.Close()
+		wait4 <- struct{}{}
+	}()
+
 	<-wait1
 	select {
 	case <-wait3:

Godeps/_workspace/src/github.com/jbenet/goprocess/impl-mutex.go

@@ -6,8 +6,10 @@ import (
 
 // process implements Process
 type process struct {
-	children []Process     // process to close with us
-	waitfors []Process     // process to only wait for
+	children []*processLink // process to close with us
+	waitfors []*processLink // process to only wait for
+	waiters  []*processLink // processes that wait for us. for gc.
+
 	teardown TeardownFunc  // called to run the teardown logic.
 	waiting  chan struct{} // closed when CloseAfterChildrenClosed is called.
 	closing  chan struct{} // closed once close starts.
@@ -47,8 +49,10 @@ func (p *process) WaitFor(q Process) {
 	default:
 	}
 
-	p.waitfors = append(p.waitfors, q)
+	pl := newProcessLink(p, q)
+	p.waitfors = append(p.waitfors, pl)
 	p.Unlock()
+	go pl.AddToChild()
 }
 
 func (p *process) AddChildNoWait(child Process) {
@@ -66,8 +70,10 @@ func (p *process) AddChildNoWait(child Process) {
 	default:
 	}
 
-	p.children = append(p.children, child)
+	pl := newProcessLink(p, child)
+	p.children = append(p.children, pl)
 	p.Unlock()
+	go pl.AddToChild()
 }
 
 func (p *process) AddChild(child Process) {
@@ -85,9 +91,11 @@ func (p *process) AddChild(child Process) {
 	default:
 	}
 
-	p.waitfors = append(p.waitfors, child)
-	p.children = append(p.children, child)
+	pl := newProcessLink(p, child)
+	p.waitfors = append(p.waitfors, pl)
+	p.children = append(p.children, pl)
 	p.Unlock()
+	go pl.AddToChild()
 }
 
 func (p *process) Go(f ProcessFunc) Process {
@@ -141,26 +149,38 @@ func (p *process) doClose() {
 	close(p.closing) // signal that we're shutting down (Closing)
 
 	for len(p.children) > 0 || len(p.waitfors) > 0 {
-		for _, c := range p.children {
-			go c.Close() // force all children to shut down
+		for _, plc := range p.children {
+			child := plc.Child()
+			if child != nil { // check because child may already have been removed.
+				go child.Close() // force all children to shut down
+			}
+			plc.ParentClear()
 		}
-		p.children = nil // clear them
+		p.children = nil // clear them. release memory.
 
 		// we must be careful not to iterate over waitfors directly, as it may
 		// change under our feet.
 		wf := p.waitfors
-		p.waitfors = nil // clear them
+		p.waitfors = nil // clear them. release memory.
 		for _, w := range wf {
 			// Here, we wait UNLOCKED, so that waitfors who are in the middle of
 			// adding a child to us can finish. we will immediately close the child.
 			p.Unlock()
-			<-w.Closed() // wait till all waitfors are fully closed (before teardown)
+			<-w.ChildClosed() // wait till all waitfors are fully closed (before teardown)
 			p.Lock()
+			w.ParentClear()
 		}
 	}
 
 	p.closeErr = p.teardown() // actually run the close logic (ok safe to teardown)
 	close(p.closed)           // signal that we're shut down (Closed)
+
+	// go remove all the parents from the process links. optimization.
+	go func(waiters []*processLink) {
+		for _, pl := range waiters {
+			pl.ClearChild()
+		}
+	}(p.waiters) // pass in so
 }
 
 // We will only wait on the children we have now.
@@ -186,10 +206,15 @@ func (p *process) CloseAfterChildren() error {
 		p.Lock()
 		defer p.Unlock()
 		for _, e := range p.waitfors {
+			c := e.Child()
+			if c == nil {
+				continue
+			}
+
 			select {
-			case <-e.Closed():
+			case <-c.Closed():
 			default:
-				return e
+				return c
 			}
 		}
 		return nil

Godeps/_workspace/src/github.com/jbenet/goprocess/link.go

+package goprocess
+
+import (
+	"sync"
+)
+
+// closedCh is an alread-closed channel. used to return
+// in cases where we already know a channel is closed.
+var closedCh chan struct{}
+
+func init() {
+	closedCh = make(chan struct{})
+	close(closedCh)
+}
+
+// a processLink is an internal bookkeeping datastructure.
+// it's used to form a relationship between two processes.
+// It is mostly for keeping memory usage down (letting
+// children close and be garbage-collected).
+type processLink struct {
+	// guards all fields.
+	// DO NOT HOLD while holding process locks.
+	// it may be slow, and could deadlock if not careful.
+	sync.Mutex
+	parent Process
+	child  Process
+}
+
+func newProcessLink(p, c Process) *processLink {
+	return &processLink{
+		parent: p,
+		child:  c,
+	}
+}
+
+// Closing returns whether the child is closing
+func (pl *processLink) ChildClosing() <-chan struct{} {
+	// grab a hold of it, and unlock, as .Closing may block.
+	pl.Lock()
+	child := pl.child
+	pl.Unlock()
+
+	if child == nil { // already closed? memory optimization.
+		return closedCh
+	}
+	return child.Closing()
+}
+
+func (pl *processLink) ChildClosed() <-chan struct{} {
+	// grab a hold of it, and unlock, as .Closed may block.
+	pl.Lock()
+	child := pl.child
+	pl.Unlock()
+
+	if child == nil { // already closed? memory optimization.
+		return closedCh
+	}
+	return child.Closed()
+}
+
+func (pl *processLink) ChildClose() {
+	// grab a hold of it, and unlock, as .Closed may block.
+	pl.Lock()
+	child := pl.child
+	pl.Unlock()
+
+	if child != nil { // already closed? memory optimization.
+		child.Close()
+	}
+}
+
+func (pl *processLink) ClearChild() {
+	pl.Lock()
+	pl.child = nil
+	pl.Unlock()
+}
+
+func (pl *processLink) ParentClear() {
+	pl.Lock()
+	pl.parent = nil
+	pl.Unlock()
+}
+
+func (pl *processLink) Child() Process {
+	pl.Lock()
+	defer pl.Unlock()
+	return pl.child
+}
+
+func (pl *processLink) Parent() Process {
+	pl.Lock()
+	defer pl.Unlock()
+	return pl.parent
+}
+
+func (pl *processLink) AddToChild() {
+	cp := pl.Child()
+
+	// is it a *process ? if not... panic.
+	c, ok := cp.(*process)
+	if !ok {
+		panic("goprocess does not yet support other process impls.")
+	}
+
+	// first, is it Closed?
+	c.Lock()
+	select {
+	case <-c.Closed():
+		c.Unlock()
+
+		// already closed. must not add.
+		// we must clear it, though. do so without the lock.
+		pl.ClearChild()
+		return
+
+	default:
+		// put the process link into q's waiters
+		c.waiters = append(c.waiters, pl)
+		c.Unlock()
+	}
+}

Godeps/_workspace/src/github.com/jbenet/goprocess/periodic/periodic_test.go

@@ -4,8 +4,8 @@ import (
 	"testing"
 	"time"
 
-	ci "github.com/jbenet/go-cienv"
 	gp "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/goprocess"
+	ci "github.com/jbenet/go-cienv"
 )
 
 var (