[PATCH RFC 37/59] libxl.go: Provide a single global context by default

[Ronald Rojas <ronladred@gmail.com>]

From: George Dunlap <george.dunlap@citrix.com>

Provide a single global context by default, Ctx.  Allow this to be
called with Ctx.Open() multiple times (but Close() only once).

Move xenworker.go to use this global context instead; and open it when
starting the benchmark (rather than opening and closing it for every
run, which is effectively what happens now).

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
---
 libxl.go     | 12 +++++-------
 run.go       |  7 +++++++
 xenworker.go | 25 +++++--------------------
 3 files changed, 17 insertions(+), 27 deletions(-)

diff --git a/libxl.go b/libxl.go
index 5bdabb1..9477bca 100644
--- a/libxl.go
+++ b/libxl.go
@@ -16,19 +16,17 @@ type Context struct {
 	ctx *C.libxl_ctx
 }
 
-func NewContext() (Ctx *Context, err error) {
-	Ctx = &Context{}
-	
-	err = Ctx.Open()
-
-	return
-}
+var Ctx Context
 
 func (Ctx *Context) IsOpen() bool {
 	return Ctx.ctx != nil
 }
 
 func (Ctx *Context) Open() (err error) {
+	if Ctx.ctx != nil {
+		return
+	}
+	
 	ret := C.libxl_ctx_alloc(unsafe.Pointer(&Ctx.ctx), C.LIBXL_VERSION, 0, nil)
 
 	if ret != 0 {
diff --git a/run.go b/run.go
index 1b39730..08a43ff 100644
--- a/run.go
+++ b/run.go
@@ -228,6 +228,13 @@ func (plan *BenchmarkPlan) Run() (err error) {
 	if err != nil {
 		return
 	}
+
+	if plan.WorkerType == WorkerXen {
+		err = Ctx.Open()
+		if err != nil {
+			return
+		}
+	}
 	
 	for i := range plan.Runs {
 		r := &plan.Runs[i];
diff --git a/xenworker.go b/xenworker.go
index 45e0876..2649392 100644
--- a/xenworker.go
+++ b/xenworker.go
@@ -27,13 +27,6 @@ import (
 	"io"
 )
 
-type xenGlobal struct {
-	Ctx Context
-	count int
-}
-
-var xg xenGlobal
-
 type XenWorker struct {
 	id WorkerId
 	Ctx Context
@@ -68,13 +61,9 @@ func (w *XenWorker) SetId(i WorkerId) {
 }
 
 func (w *XenWorker) Init(p WorkerParams, g WorkerConfig) (err error) {
-	if xg.count == 0 {
-		err = xg.Ctx.Open()
-		if err != nil {
-			return
-		}
+	if err != nil {
+		return
 	}
-	xg.count++
 	
 	mock := false
 	
@@ -220,11 +209,6 @@ func (w *XenWorker) Shutdown() {
 	e.Stdout = os.Stdout
 	e.Stderr = os.Stderr
 
-	xg.count--
-	if xg.count == 0 {
-		defer xg.Ctx.Close()
-	}
-
 	err := e.Run()
 	if err != nil {
 		fmt.Printf("Error destroying domain: %v\n", err)
@@ -249,7 +233,8 @@ func (w *XenWorker) DumpLog(f io.Writer) (err error) {
 // FIXME: Return an error
 func (w *XenWorker) Process(report chan WorkerReport, done chan WorkerId) {
 	// // xl unpause [vmname]
-	err := xg.Ctx.DomainUnpause(Domid(w.domid))
+	//err := xg.Ctx.DomainUnpause(Domid(w.domid))
+	err := Ctx.DomainUnpause(Domid(w.domid))
 	if err != nil {
 		fmt.Printf("Error unpausing domain: %v\n", err)
 		return
@@ -268,7 +253,7 @@ func (w *XenWorker) Process(report chan WorkerReport, done chan WorkerId) {
 			var r WorkerReport
 			json.Unmarshal([]byte(s), &r)
 			r.Id = w.id
-			di, err := xg.Ctx.DomainInfo(Domid(w.domid))
+			di, err := Ctx.DomainInfo(Domid(w.domid))
 			// Ignore errors for now
 			if err == nil {
 				r.Cputime = di.Cpu_time
-- 
2.7.4


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel