| 1 | package bakeoff |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "net" |
| 6 | "net/http" |
| 7 | "os" |
| 8 | "os/exec" |
| 9 | "path/filepath" |
| 10 | "strconv" |
| 11 | "strings" |
| 12 | "syscall" |
| 13 | "time" |
| 14 | ) |
| 15 | |
| 16 | // Memory is an app's resident memory, from Linux's /proc, in kilobytes: |
| 17 | // just after start, the peak over a load run, and a few seconds after. |
| 18 | type Memory struct{ IdleKB, PeakKB, AfterKB int } |
| 19 | |
| 20 | // ParseProcStatus reads VmRSS (resident now) and VmHWM (peak resident) |
| 21 | // from /proc/<pid>/status. |
| 22 | func ParseProcStatus(status string) (rss, hwm int, err error) { |
| 23 | for _, line := range strings.Split(status, "\n") { |
| 24 | k, v, ok := strings.Cut(line, ":") |
| 25 | if !ok { |
| 26 | continue |
| 27 | } |
| 28 | f := strings.Fields(v) |
| 29 | if len(f) == 0 { |
| 30 | continue |
| 31 | } |
| 32 | n, _ := strconv.Atoi(f[0]) |
| 33 | switch k { |
| 34 | case "VmRSS": |
| 35 | rss = n |
| 36 | case "VmHWM": |
| 37 | hwm = n |
| 38 | } |
| 39 | } |
| 40 | if rss == 0 { |
| 41 | return 0, 0, fmt.Errorf("no VmRSS in status") |
| 42 | } |
| 43 | return rss, hwm, nil |
| 44 | } |
| 45 | |
| 46 | func procStatus(pid int) (int, int, error) { |
| 47 | b, err := os.ReadFile(fmt.Sprintf("/proc/%d/status", pid)) |
| 48 | if err != nil { |
| 49 | return 0, 0, err |
| 50 | } |
| 51 | return ParseProcStatus(string(b)) |
| 52 | } |
| 53 | |
| 54 | // MeasureMemory runs the app binary locally (on --listen, with a fresh |
| 55 | // database), reads its memory at rest, drives it with 64 concurrent reads |
| 56 | // and then 64 concurrent toggles for d each, and reads it again. The |
| 57 | // working directory is the app's own (the binary's parent's parent, since |
| 58 | // builds land in dist/). |
| 59 | func MeasureMemory(bin string, extra []string, d time.Duration) (Memory, error) { |
| 60 | ln, err := net.Listen("tcp", "127.0.0.1:0") |
| 61 | if err != nil { |
| 62 | return Memory{}, err |
| 63 | } |
| 64 | addr := ln.Addr().String() |
| 65 | ln.Close() |
| 66 | tmp, err := os.MkdirTemp(os.Getenv("TMPDIR"), "bakeoff-mem-") |
| 67 | if err != nil { |
| 68 | return Memory{}, err |
| 69 | } |
| 70 | defer os.RemoveAll(tmp) |
| 71 | cmd := exec.Command(bin, append(extra, "--listen", addr, "--db", filepath.Join(tmp, "app.db"))...) |
| 72 | cmd.Dir = filepath.Dir(filepath.Dir(bin)) |
| 73 | cmd.Stdout, cmd.Stderr = nil, nil |
| 74 | if err := cmd.Start(); err != nil { |
| 75 | return Memory{}, err |
| 76 | } |
| 77 | defer func() { |
| 78 | cmd.Process.Signal(syscall.SIGTERM) |
| 79 | done := make(chan error, 1) |
| 80 | go func() { done <- cmd.Wait() }() |
| 81 | select { |
| 82 | case <-done: |
| 83 | case <-time.After(10 * time.Second): |
| 84 | cmd.Process.Kill() |
| 85 | } |
| 86 | }() |
| 87 | base := "http://" + addr |
| 88 | up := false |
| 89 | for i := 0; i < 150 && !up; i++ { |
| 90 | if res, err := http.Get(base + "/healthz"); err == nil { |
| 91 | res.Body.Close() |
| 92 | up = res.StatusCode == 200 |
| 93 | } |
| 94 | if !up { |
| 95 | time.Sleep(200 * time.Millisecond) |
| 96 | } |
| 97 | } |
| 98 | if !up { |
| 99 | return Memory{}, fmt.Errorf("%s did not answer /healthz on %s", bin, addr) |
| 100 | } |
| 101 | time.Sleep(2 * time.Second) |
| 102 | var m Memory |
| 103 | if m.IdleKB, _, err = procStatus(cmd.Process.Pid); err != nil { |
| 104 | return m, err |
| 105 | } |
| 106 | s, err := NewSession(base) |
| 107 | if err != nil { |
| 108 | return m, err |
| 109 | } |
| 110 | if _, err := Seed(s, 50); err != nil { |
| 111 | return m, err |
| 112 | } |
| 113 | for _, sc := range []string{"read", "toggle"} { |
| 114 | if _, err := RunLoad(s, sc, 64, d); err != nil { |
| 115 | return m, err |
| 116 | } |
| 117 | } |
| 118 | if _, m.PeakKB, err = procStatus(cmd.Process.Pid); err != nil { |
| 119 | return m, err |
| 120 | } |
| 121 | time.Sleep(5 * time.Second) |
| 122 | m.AfterKB, _, err = procStatus(cmd.Process.Pid) |
| 123 | return m, err |
| 124 | } |
| 125 | |
amadan