framework學(xué)習(xí)包括問(wèn)題分析的腳手架

打堆棧

打java堆棧

Exception e = new Exception("xxx");
e.printStackTrace();
或者
android.util.Log.d("xxx", e);

打native堆棧

對(duì)于c++
mk或者bp文件中引入libutils

#include <utils/CallStack.h>
android::CallStack cs("xxx");

對(duì)于c
mk或者bp文件中引入libutils敬鬓，再在項(xiàng)目里再加入一個(gè)c++的頭文件奈虾，比如callstack.h府瞄，里面是：
void dumping_callstack(void);

#include <utils/CallStack.h> 
extern "C" void dumping_callstack(void); 
void dumping_callstack(void) { 
    android::CallStack cs("xxx");

放開系統(tǒng)日志

一般對(duì)某個(gè)模塊不了解，可以全量開啟這塊的日志印蓖，再結(jié)合perfetto/systrace進(jìn)行分析辽慕。

一類是protolog
android R才啟用

 ProtoLog.v(WM_DEBUG_CONFIGURATION, "Starting activity when config "
                        + "will change = %b", globalConfigWillChange);

NX563J:/ # wm logging -h
Unknown command
Window manager logging options:
    //啟動(dòng)抓取proto logging
  start: Start proto logging 
  //停止抓取proto logging
  stop: Stop proto logging 
  //允許proto logging的輸出針對(duì)對(duì)應(yīng)group（
  enable [group...]: Enable proto logging for given groups 
  //禁止proto logging的輸出針對(duì)對(duì)應(yīng)group
  disable [group...]: Disable proto logging for given groups
  //允許locat的輸出針對(duì)對(duì)應(yīng)group
  enable-text [group...]: Enable logcat logging for given groups
  //禁止locat的輸出針對(duì)對(duì)應(yīng)group
  disable-text [group...]: Disable logcat logging for given groups
Not handled, please use `adb shell dumpsys activity service SystemUIService WMShell` if you are looking for ProtoLog in WMShell

enable對(duì)應(yīng)是proto logging這個(gè)就是像wms課程時(shí)候winscope抓取會(huì)把日志寫入到data/misc/wmtrace/路徑下wm_log.winscope
enable-text對(duì)應(yīng)就是logcat可以直接看到的，這個(gè)也就是我們經(jīng)常用的

一類是硬編碼的日志開關(guān)

public class WindowManagerDebugConfig {
    // All output logs in the window manager package use the {@link #TAG_WM} string for tagging
    // their log output. This makes it easy to identify the origin of the log message when sifting
    // through a large amount of log output from multiple sources. However, it also makes trying
    // to figure-out the origin of a log message while debugging the window manager a little
    // painful. By setting this constant to true, log messages from the window manager package
    // will be tagged with their class names instead fot the generic tag.
    static final boolean TAG_WITH_CLASS_NAME = false;

    // Default log tag for the window manager package.
    static final String TAG_WM = "WindowManager";

    static final boolean DEBUG = false;
    static final boolean DEBUG_LAYOUT = false;
    static final boolean DEBUG_LAYERS = false;
    static final boolean DEBUG_INPUT = false;
    static final boolean DEBUG_INPUT_METHOD = false;
    static final boolean DEBUG_VISIBILITY = false;
    static final boolean DEBUG_CONFIGURATION = false;
    static final boolean DEBUG_STARTING_WINDOW_VERBOSE = false;
    static final boolean DEBUG_WALLPAPER = false;
    static final boolean DEBUG_DRAG = true;
    static final boolean DEBUG_SCREENSHOT = false;
    static final boolean DEBUG_LAYOUT_REPEATS = false;
    static final boolean DEBUG_WINDOW_TRACE = false;
    static final boolean DEBUG_TASK_MOVEMENT = false;
    static final boolean DEBUG_TASK_POSITIONING = false;
    static final boolean DEBUG_ROOT_TASK = false;
    static final boolean DEBUG_DISPLAY = false;
    static final boolean DEBUG_POWER = false;
    static final boolean SHOW_VERBOSE_TRANSACTIONS = false;
    static final boolean SHOW_LIGHT_TRANSACTIONS = false;
    static final boolean SHOW_STACK_CRAWLS = false;
    static final boolean DEBUG_WINDOW_CROP = false;
    static final boolean DEBUG_UNKNOWN_APP_VISIBILITY = false;
}

    private final Predicate<WindowState> mComputeImeTargetPredicate = w -> {
        if (DEBUG_INPUT_METHOD && mUpdateImeTarget) Slog.i(TAG_WM, "Checking window @" + w
                + " fl=0x" + Integer.toHexString(w.mAttrs.flags));
        return w.canBeImeTarget();
    };

看日志

adb logcat只能查看包含main赦肃、system 和crash 緩沖區(qū)的log溅蛉。
要查看全部緩沖區(qū)日志adb logcat -b all

radio：查看包含無(wú)線裝置/電話相關(guān)消息的緩沖區(qū)。

events：查看已經(jīng)過(guò)解譯的二進(jìn)制系統(tǒng)事件緩沖區(qū)消息摆尝。 EventLog.writeEvent

main：查看主日志緩沖區(qū)（默認(rèn)）温艇，不包含系統(tǒng)和崩潰日志消息。Log.d

system：查看系統(tǒng)日志緩沖區(qū)（默認(rèn)）堕汞。Slog.d

crash：查看崩潰日志緩沖區(qū)（默認(rèn)）勺爱。

all：查看所有緩沖區(qū)。

default：包含main讯检、system 和crash 緩沖區(qū)

Image.png

查看kernel日志
常見場(chǎng)景如selinux相關(guān)dmesg

AS動(dòng)態(tài)調(diào)試

編譯userdebug鏡像或者嘗其他方式使得進(jìn)程可調(diào)試

image.png

預(yù)期這里會(huì)出現(xiàn)system_server等進(jìn)程琐鲁。

systrace/perfetto

非常強(qiáng)大的工具，可以用于模塊學(xué)習(xí)或者問(wèn)題分析人灼。
如何查看trace參考https://blog.csdn.net/learnframework/article/details/135020636
自己添加trace
可以添加的trace包括同步trace（方法围段、代碼塊）、異步trace投放、對(duì)于某個(gè)值的監(jiān)聽（局限了int和boolean類型奈泪，如vsync-sf等）,具體加trace方法參考https://blog.csdn.net/learnframework/article/details/133627031

dumpsys及system_server提供的一些adb命令

特定場(chǎng)景的分析工具

window、surfaceFlinger相關(guān)問(wèn)題

winscope參考https://blog.csdn.net/learnframework/article/details/129432374

anr灸芳、watchdog涝桅、lowmem

這三種場(chǎng)景下會(huì)生成/data/anr/traces.txt

dropbox:/data/system/dropbox有一些持久化的系統(tǒng)日志

system_app_anr：系統(tǒng)app無(wú)響應(yīng)

system_app_crash：系統(tǒng)app進(jìn)程崩潰

system_server_native_crash system進(jìn)程native出現(xiàn)崩潰

system_server_wtf：system進(jìn)程發(fā)生嚴(yán)重錯(cuò)誤

system_server_lowmem：system進(jìn)程內(nèi)存不足