platform_build_soong/ui/metrics/proc/status_linux.go
Patrice Arruda 04157e186f Read the proc status file when PID is given for metrics purpose.
To measure the MaxRSS memory correctly, read the proc status file
under /proc/<pid>/status and extract the MaxRSS value from it. The
implementation is only available for Linux based distributions.

Bug: b/169453825
Test: go test
Change-Id: I32e3068fee7447f9ef5dfb5a8d8dcb6934e0af23
2020-12-17 14:52:14 -08:00

46 lines
1.2 KiB
Go

package proc
import (
"io/ioutil"
"path/filepath"
"strconv"
"strings"
"android/soong/finder/fs"
)
// NewProcStatus returns an instance of the ProcStatus that contains memory
// information of the process. The memory information is extracted from the
// "/proc/<pid>/status" text file. This is only available for Linux
// distribution that supports /proc.
func NewProcStatus(pid int, fileSystem fs.FileSystem) (*ProcStatus, error) {
statusFname := filepath.Join("/proc", strconv.Itoa(pid), "status")
r, err := fileSystem.Open(statusFname)
if err != nil {
return &ProcStatus{}, err
}
defer r.Close()
data, err := ioutil.ReadAll(r)
if err != nil {
return &ProcStatus{}, err
}
s := &ProcStatus{
pid: pid,
}
for _, l := range strings.Split(string(data), "\n") {
// If the status file does not contain "key: values", just skip the line
// as the information we are looking for is not needed.
if !strings.Contains(l, ":") {
continue
}
// At this point, we're only considering entries that has key, single value pairs.
kv := strings.SplitN(l, ":", 2)
fillProcStatus(s, strings.TrimSpace(kv[0]), strings.TrimSpace(kv[1]))
}
return s, nil
}