From 2c5233814a30825abfd731ef2e39a802b68b11aa Mon Sep 17 00:00:00 2001
From: Diptanu Choudhury <diptanuc@gmail.com>
Date: Wed, 25 May 2016 17:46:24 -0700
Subject: [PATCH] simplified the stats method in basic executor

---
 client/driver/executor/executor.go       | 48 +-----------------------
 client/driver/executor/executor_basic.go | 42 ++++++++++++++++++++-
 2 files changed, 42 insertions(+), 48 deletions(-)

diff --git a/client/driver/executor/executor.go b/client/driver/executor/executor.go
index d0ffff68b..5beaa9514 100644
--- a/client/driver/executor/executor.go
+++ b/client/driver/executor/executor.go
@@ -717,11 +717,10 @@ func (e *UniversalExecutor) scanPids(parentPid int, allPids []ps.Process) ([]*no
 		foundNewPid := false
 
 		for _, pid := range allPids {
-			_, parentPid := processFamily[pid.Pid()]
 			_, childPid := processFamily[pid.PPid()]
 
 			// checking if the pid is a child of any of the parents
-			if parentPid || childPid {
+			if childPid {
 				processFamily[pid.Pid()] = struct{}{}
 				foundNewPid = true
 			} else {
@@ -743,48 +742,3 @@ func (e *UniversalExecutor) scanPids(parentPid int, allPids []ps.Process) ([]*no
 	}
 	return res, nil
 }
-
-// resourceUsagePids aggregates the resources used by all the pids that are
-// spawned by the executor and the user process.
-func (e *UniversalExecutor) resourceUsagePids() (*cstructs.TaskResourceUsage, error) {
-	ts := time.Now()
-	pidStats, err := e.pidStats()
-	if err != nil {
-		return nil, err
-	}
-	var (
-		systemModeCPU, userModeCPU, percent float64
-		totalRSS, totalSwap                 uint64
-	)
-
-	for _, pidStat := range pidStats {
-		systemModeCPU += pidStat.CpuStats.SystemMode
-		userModeCPU += pidStat.CpuStats.UserMode
-		percent += pidStat.CpuStats.Percent
-
-		totalRSS += pidStat.MemoryStats.RSS
-		totalSwap += pidStat.MemoryStats.Swap
-	}
-
-	totalCPU := &cstructs.CpuStats{
-		SystemMode: systemModeCPU,
-		UserMode:   userModeCPU,
-		Percent:    percent,
-	}
-
-	totalMemory := &cstructs.MemoryStats{
-		RSS:  totalRSS,
-		Swap: totalSwap,
-	}
-
-	resourceUsage := cstructs.ResourceUsage{
-		MemoryStats: totalMemory,
-		CpuStats:    totalCPU,
-		Timestamp:   ts,
-	}
-	return &cstructs.TaskResourceUsage{
-		ResourceUsage: &resourceUsage,
-		Timestamp:     ts,
-		Pids:          pidStats,
-	}, nil
-}
diff --git a/client/driver/executor/executor_basic.go b/client/driver/executor/executor_basic.go
index eb07a406d..a21bb9c64 100644
--- a/client/driver/executor/executor_basic.go
+++ b/client/driver/executor/executor_basic.go
@@ -4,6 +4,7 @@ package executor
 
 import (
 	"os"
+	"time"
 
 	cstructs "github.com/hashicorp/nomad/client/driver/structs"
 
@@ -36,7 +37,46 @@ func (e *UniversalExecutor) configureIsolation() error {
 }
 
 func (e *UniversalExecutor) Stats() (*cstructs.TaskResourceUsage, error) {
-	return e.resourceUsagePids()
+	ts := time.Now()
+	pidStats, err := e.pidStats()
+	if err != nil {
+		return nil, err
+	}
+	var (
+		systemModeCPU, userModeCPU, percent float64
+		totalRSS, totalSwap                 uint64
+	)
+
+	for _, pidStat := range pidStats {
+		systemModeCPU += pidStat.CpuStats.SystemMode
+		userModeCPU += pidStat.CpuStats.UserMode
+		percent += pidStat.CpuStats.Percent
+
+		totalRSS += pidStat.MemoryStats.RSS
+		totalSwap += pidStat.MemoryStats.Swap
+	}
+
+	totalCPU := &cstructs.CpuStats{
+		SystemMode: systemModeCPU,
+		UserMode:   userModeCPU,
+		Percent:    percent,
+	}
+
+	totalMemory := &cstructs.MemoryStats{
+		RSS:  totalRSS,
+		Swap: totalSwap,
+	}
+
+	resourceUsage := cstructs.ResourceUsage{
+		MemoryStats: totalMemory,
+		CpuStats:    totalCPU,
+		Timestamp:   ts,
+	}
+	return &cstructs.TaskResourceUsage{
+		ResourceUsage: &resourceUsage,
+		Timestamp:     ts,
+		Pids:          pidStats,
+	}, nil
 }
 
 func (e *UniversalExecutor) getAllPids() ([]*nomadPid, error) {