From cd532e08cbc188fc089a9e722b25c2a187fe9b12 Mon Sep 17 00:00:00 2001
From: Michael Baird <mbaird@umbel.com>
Date: Tue, 13 Jun 2017 16:14:45 -0500
Subject: [PATCH] Add -b option to lsof to avoid kernel blocks.

---
 docs/administration.md | 2 ++
 server.go              | 9 ++++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/docs/administration.md b/docs/administration.md
index 322b68e12..e562f94ce 100644
--- a/docs/administration.md
+++ b/docs/administration.md
@@ -157,3 +157,5 @@ We currently track the following events
 <strong id="garbage_collection">Garbage Collection:</strong> Event count when Garbage Collection occurs.
 
 <strong id="goroutines">Goroutines:</strong> Number of running Goroutines.
+
+<strong id="openfiles">OpenFiles:</strong> Number of open file handles associated with running Pilosa process ID.
\ No newline at end of file
diff --git a/server.go b/server.go
index 7f2027f10..57f3291eb 100644
--- a/server.go
+++ b/server.go
@@ -513,12 +513,15 @@ func CountOpenFiles() int {
 	case "unix":
 		fallthrough
 	case "freebsd":
-		out, err := exec.Command("/bin/sh", "-c", fmt.Sprintf("lsof -p %v", os.Getpid())).Output()
+		// -b option avoid kernel blocks
+		pid := os.Getpid()
+		out, err := exec.Command("/bin/sh", "-c", fmt.Sprintf("lsof -b -p %v", pid)).Output()
 		if err != nil {
 			log.Fatal(err)
 		}
-		lines := strings.Split(string(out), "\n")
-		count = len(lines) - 1
+		// only count lines with our pid, avoiding warning messages from -b
+		lines := strings.Split(string(out), strconv.Itoa(pid))
+		count = len(lines)
 	case "windows":
 		// TODO: count open file handles on windows
 	default: