adb shell下向应用发送GC命令

DDMS里有个Cause GC命令，用来要求虚拟机强制GC,如下图：

但是在有些环境下面，测试同学，或者用户机器上面没有安装Android Sdk，这个时候使用adb shell来执行GC命令是比较合适的，但是网上搜索了一下，发现adb shell下没有提供这个命令。

根据网上介绍，执行GC命令实际上是通过kill命令向进程发送了数字为10的自定义信号而已，代码如下：

private void gc() {
        String pid = String.valueOf(ProcessUtils
                .getProcessPID(AUTManager.pkn.toString()));

        if (!pid.equals("-1")) {
            boolean isSucess = true;
            ProcessBuilder pb = null;

            String cmd = "kill -10 " + pid;
            pb = new ProcessBuilder("su", "-c", cmd);

            Process exec = null;

            pb.redirectErrorStream(true);
            try {
                exec = pb.start();

                InputStream is = exec.getInputStream();
                BufferedReader reader = new BufferedReader(
                        new InputStreamReader(is));

                while ((reader.readLine()) != null) {
                    isSucess = false;
                }
            } catch (Exception e) {
                e.printStackTrace();
                isSucess = false;
            }
            // 至此命令算是执行成功
            if (isSucess)
            {
                handler.sendEmptyMessage(5);
            }

        } else {
            Log.d("gc error", "pid not found!");
        }
    }

    private void dumpHeap() {
        String pid = String.valueOf(ProcessUtils
                .getProcessPID(AUTManager.pkn.toString()));

        if (!pid.equals("-1")) {
            boolean isSucess = true;
            ProcessBuilder pb = null;

            String sFolder = Env.S_ROOT_DUMP_FOLDER + AUTManager.pkn.toString() + "/";
            File folder = new File(sFolder);
            if (!folder.exists())
            {
                folder.mkdirs();
            }

            String cmd = "am dumpheap " + pid + " "// 命令
                    + Env.S_ROOT_DUMP_FOLDER + AUTManager.pkn.toString() + "/"// 输出路径
                    + "dump_" + pid + "_" + GTUtils.getSaveDate() + ".hprof"; // 输出文件名
            pb = new ProcessBuilder("su", "-c", cmd);

            Process exec = null;

            pb.redirectErrorStream(true);
            try {
                exec = pb.start();

                InputStream is = exec.getInputStream();
                BufferedReader reader = new BufferedReader(
                        new InputStreamReader(is));

                while ((reader.readLine()) != null) {
                    isSucess = false;
                }
            } catch (Exception e) {
                e.printStackTrace();
                isSucess = false;
            }
            // 至此命令算是执行成功
            if (isSucess)
            {
                handler.sendEmptyMessage(6);
            }

        } else {
            Log.d("dump error", "pid not found!");
        }
    }

相同道理，我们只要直接在adb shell里面直接向进程发送数字为10的自定义信号就可以了。

参考链接

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关于使用 adb 命令触发 GC 操作的问题