os/exec: exec.command has memory leak #20989
Description
Please answer these questions before submitting your issue. Thanks!
What version of Go are you using (go version)?
1.8.3
What operating system and processor architecture are you using (go env)?
Linux
What did you do?
I am using exec.Command() in my code and observed that there is a memory leak in this call. Actually my requirement is my program will continuously runs on machine as a daemon, so memory used by program goes high after 2 to 3 days from initial 10MB to 200MB and increasing continuously unless i restart the daemon.
Below is the small test program which i can show you the memory leak in exec.Command. Here initially program taking 960-1000 KB, once it is executed some commands memory goes high to 1200KB+..
package main
import (
"fmt"
"os"
"os/exec"
"runtime"
"strings"
)
func main() {
//to get current executable PID
strPid := ExecuteCommand("pidof", os.Args[0])
//to get Memory used by executable
strMem := ExecuteCommand("ps", "-p", strings.TrimSpace(strPid), "-o", "rss")
fmt.Println(" Initial Memory in KB ", string(strMem[:]))
for i := 0; i < 10; i++ {
cmd := exec.Command("sleep", "1")
err := cmd.Start()
if err != nil {
fmt.Println(err)
}
err = cmd.Wait()
fmt.Printf("Command finished with error: %v\n", err)
}
strMem = ExecuteCommand("ps", "-p", strings.TrimSpace(strPid), "-o", "rss")
fmt.Println("\nAfter For loop, Memory in KB ", string(strMem[:]))
//running garbage collector
runtime.GC()
strMem = ExecuteCommand("ps", "-p", strings.TrimSpace(strPid), "-o", "rss")
fmt.Println("\nFinal Memory in KB ", string(strMem[:]))
}
func ExecuteCommand(str string, params ...string) string {
output, err := exec.Command(str, params...).Output()
if err != nil {
fmt.Println(err)
return ""
}
return string(output[:])
}