Add android_run_app.go

platform_tools/android/bin/android_run_app.go

+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/*
+        Run a Skia app to completion, piping the log to stdout.
+*/
+
+package main
+
+import (
+        "flag"
+        "fmt"
+        "io"
+        "os"
+        "os/exec"
+        "os/signal"
+        "strconv"
+        "strings"
+        "time"
+
+        "github.com/skia-dev/glog"
+        "go.skia.org/infra/go/common"
+)
+
+const (
+        COM_SKIA = "com.skia"
+)
+
+var (
+        adb    = flag.String("adb", "", "Path to the ADB executable.")
+        app    = flag.String("app", "VisualBench", "Name of the app to run.")
+        serial = flag.String("s", "", "Serial number for the Android device to use.")
+)
+
+// ADB returns an os.Cmd for the given ADB command.
+func ADB(adb, serial string, log bool, args ...string) *exec.Cmd {

[stephana, 2015/07/30 13:37:42]

Nit: I think "adbCommand" or adbCmd would be more descriptive. Also, it doesn't
necessarily matter, but this and the other methods should be internal
(lowercase) methods. 

[borenet, 2015/07/30 17:37:49]

I took the suggestion of making ADB a struct. The analogous method is now
ADB.Cmd.

+        cmd := []string{}
+        if serial != "" {
+                cmd = append(cmd, "-s", serial)
+        }
+        cmd = append(cmd, args...)
+        if log {
+                glog.Infof("Exec `%s %s`", adb, strings.Join(cmd, " "))
+        }
+        return exec.Command(adb, cmd...)
+}
+
+// RunADB runs the given command through ADB.
+func RunADB(adb, serial string, log bool, args ...string) ([]byte, error) {
+        return ADB(adb, serial, log, args...).Output()

[stephana, 2015/07/30 13:37:42]

This is an unnecessary level of indirection. Instead one could just write:

  adbCmd(.....).Output() 


whenever RunADB(...) is called. 

[borenet, 2015/07/30 17:37:49]

Removed.

+}
+
+// KillSkia kills any running Skia process.
+func KillSkia(adb, serial string) error {
+        _, err := RunADB(adb, serial, false, "shell", "am", "force-stop", COM_SKIA)
+        return err
+}
+
+// PollSkia checks to see if any Skia process is running. If so, return the pid, otherwise return -1.
+func PollSkia(adb, serial string) (int64, error) {
+        output, err := RunADB(adb, serial, false, "shell", "ps")

[stephana, 2015/07/30 13:37:42]

It might make sense to create a type 'ADB' instead of passing the same arguments
around. 

[borenet, 2015/07/30 17:37:48]

I like this! Done.

+        if err != nil {
+                return -1, fmt.Errorf("Failed to check the running processes on the device: %v", err)
+        }
+        for _, line := range strings.Split(string(output), "\n") {
+                if strings.Contains(line, COM_SKIA) {
+                        fields := strings.Fields(line)
+                        pid, err := strconv.ParseInt(fields[1], 10, 32)
+                        if err != nil {
+                                return -1, fmt.Errorf("Failed to parse \"%s\" to an integer: %v", fields[1], err)
+                        }
+                        return pid, nil
+                }
+        }
+        return -1, nil
+}
+
+// ReadLinesFromPipe reads from the given pipe and logs its output.
+func ReadLinesFromPipe(pipe io.Reader, lines chan string) {
+        buf := []byte{}
+
+        // writeLine recovers from a panic when writing to the channel.
+        writeLine := func(s string) {
+                defer func() {
+                        if r := recover(); r != nil {
+                                glog.Warningf("Panic writing to channel... are we exiting?")
+                        }
+                }()
+                lines <- s
+        }
+
+        // readLines reads output lines from the buffer and pushes them into the channel.
+        readlines := func() {
+                readIdx := 0
+                // Read lines from buf.
+                for i, b := range buf {
+                        if b == '\n' {
+                                s := string(buf[readIdx:i])
+                                writeLine(s)
+                                readIdx = i + 1
+                        }
+                }
+                // Remove the lines we read.
+                buf = buf[readIdx:]
+        }
+
+        // Loop forever, reading bytes from the pipe.
+        readbuf := make([]byte, 4096)
+        for {
+                read, err := pipe.Read(readbuf)
+                if read > 0 {
+                        buf = append(buf, readbuf[:read]...)
+
+                        // Read lines from the buffers.
+                        readlines()
+                }
+                if err != nil {
+                        if err == io.EOF {
+                                break
+                        } else {
+                                glog.Error(err)
+                        }
+                } else if read == 0 {
+                        time.Sleep(20 * time.Millisecond)
+                }
+        }
+        // Read any remaining lines from the buffers.
+        readlines()
+        // "Flush" any incomplete lines from the buffers.
+        writeLine(string(buf))
+}
+
+// RunApp launches the given app on the device, pipes its log output to stdout,
+// and returns when the app finishes running, with an error if the app did not
+// complete successfully.
+func RunApp(adb, serial, appName string, args []string) error {
+        // Kill any running instances of the app.
+        if err := KillSkia(adb, serial); err != nil {
+                return fmt.Errorf("Failed to kill app: %v", err)
+        }
+
+        // Clear the ADB log.
+        if _, err := RunADB(adb, serial, false, "logcat", "-c"); err != nil {
+                return fmt.Errorf("Failed to clear ADB log: %v", err)
+        }
+
+        // Prepare to read the subprocess output.
+        logProc := ADB(adb, serial, false, "logcat")
+        defer func() {
+                // Cleanup.
+                if err := logProc.Process.Kill(); err != nil {
+                        glog.Errorf("Failed to kill logcat process: %v", err)
+                }
+        }()
+
+        stdout, err := logProc.StdoutPipe()
+        if err != nil {
+                return fmt.Errorf("Failed to obtain stdout pipe: %v", err)
+        }
+        stdoutLines := make(chan string)
+        stderr, err := logProc.StderrPipe()
+        if err != nil {
+                return fmt.Errorf("Failed to obtain stderr pipe: %v", err)
+        }
+        stderrLines := make(chan string)
+
+        go ReadLinesFromPipe(stdout, stdoutLines)
+        go ReadLinesFromPipe(stderr, stderrLines)
+        if err := logProc.Start(); err != nil {
+                return fmt.Errorf("Failed to start logcat process.")
+        }
+
+        // Launch the app.
+        stop := make(chan bool, 1)
+        activity := fmt.Sprintf("%s.%s/%s.%sActivity", COM_SKIA, strings.ToLower(appName), COM_SKIA, appName)
+        flags := strings.Join(args, " ")
+        cmd := []string{"shell", "am", "start", "-S", "-n", activity, "--es", "cmdLineFlags", flags}
+        output, err := RunADB(adb, serial, true, cmd...)
+        if err != nil {
+                return fmt.Errorf("Failed to launch app: %v", err)
+        }
+        glog.Info(string(output))
+        // Make a handler for SIGINT so that we can kill the app if this script is interrupted.
+        go func() {
+                interrupt := make(chan os.Signal, 1)
+                signal.Notify(interrupt, os.Interrupt)
+                for _ = range interrupt {
+                        glog.Infof("Received SIGINT; killing app.")
+                        stop <- true
+                        close(stdoutLines)
+                        close(stderrLines)
+                        if err := KillSkia(adb, serial); err != nil {
+                                glog.Errorf("Failed to kill app: %v", err)
+                        }
+                        if err := logProc.Process.Kill(); err != nil {
+                                glog.Errorf("Failed to kill logcat process: %v", err)
+                        }
+                }
+        }()
+
+        // Loop until the app finishes or we're interrupted, writing output as appropriate.
+        // TODO(borenet): VisualBench should print its exit code. This script should exit
+        // with that code, or a non-zero code if the process ended without printing any code.
+        second := time.Tick(time.Second)
+PollLoop:
+        for {
+                select {
+                case <-second:
+                        // Poll the Skia process every second to make sure it's still running.
+                        pid, err := PollSkia(adb, serial)
+                        if err != nil {
+                                glog.Errorf("Failed to poll Skia process: %v", err)
+                        } else if pid < 0 {
+                                glog.Infof("Skia process is no longer running!")
+                                break PollLoop
+                        }
+                case <-stop:
+                        break PollLoop
+                case line := <-stdoutLines:
+                        glog.Info(line)
+                case line := <-stderrLines:
+                        glog.Error(line)
+                }
+        }
+
+        return nil
+}
+
+func main() {
+        common.Init()
+        args := flag.Args()
+        adbPath := *adb
+        if adbPath == "" {
+                adbPath = "adb"
+        }
+        if err := RunApp(adbPath, *serial, *app, args); err != nil {
+                glog.Fatal(err)
+        }
+}