公司部门职责及配置,福州网站的优化,百度网站的结构,北京怎样建设公司网站1 重点知识
1.1 Alarm
当手机重启或者应用被杀死的时候#xff0c;Alarm会被删除#xff0c;因此#xff0c;如果想通过Alarm来完成长久定时任务是不可靠的#xff0c;如果非要完成长久定时任务#xff0c;可以这样#xff1a;将应用的所有Alarm信息存到数据库中#xf…1 重点知识
1.1 Alarm
当手机重启或者应用被杀死的时候Alarm会被删除因此如果想通过Alarm来完成长久定时任务是不可靠的如果非要完成长久定时任务可以这样将应用的所有Alarm信息存到数据库中每次应用启动的时候都重新注册Alarm并更新Alarm的触发时间通过这种方式就不存在Alarm丢失的情况了。1.2 Android-N app seinfo设置流程
frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java
startProcessLocked() {[…]Process.ProcessStartResult startResult Process.start(entryPoint,app.processName,uid, uid, gids,debugFlags, mountExternal,app.info.targetSdkVersion,app.info.seinfo,requiredAbi, instructionSet,app.info.dataDir, entryPointArgs);[…]
}frameworks/base/core/java/android/os/Process.java
start() {try {return startViaZygote(processClass,niceName,uid, gid, gids,debugFlags, mountExternal,targetSdkVersion, seInfo,abi, instructionSet,appDataDir, zygoteArgs);} catch (ZygoteStartFailedEx ex) {[…]
}frameworks/base/core/jni/com_android_internal_os_Zygote.cpp
ForkAndSpecializeCommon() {[…]rc selinux_android_setcontext(uid, is_system_server,se_info_c_str, se_name_c_str);[…]
}external/libselinux/src/android.c
int selinux_android_setcontext(uid_t uid,bool isSystemServer,const char *seinfo,const char *pkgname)
{[…]
}1.3 Launcher的启动
/* ActivityThread.java */
SystemServer.java
private void startOtherServices() {[...]mActivityManagerService.systemReady(new Runnable() {});
}1.4 屏幕永不超时
frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
frameworks/base/packages/SettingsProvider/res/values/defaults.xml
将def_screen_off_timeout的值改成21474836470x7fffffff。/data/system/users/0/settings_system.xml
adb shell settings put system screen_off_timeout 3600000 #一小时超时1.5 禁止锁屏
frameworks/policies/base/phone/com/android/internal/policy/impl/KeyguardViewMediator.java
将mExternallyEnabled的值改成false。1.6 tmpfs文件系统
mkdir /data/tmp
mount -t tmpfs -o size100M tmpfs /data/tmp1.7 apk signer
apk: private key signer
keystore: 密钥库2 Android异常分析汇总
2.1 Android卡在开机动画
1AudioFlinger反复重启
2systemui ANR2.2 framework反复重启
1boot_progress|low-level shutdown|am_crash|checkScreenEnabled|ILL_ILLOPN2.3 no window focus
ViewRootImpl.java
mAttachInfo.mHasWindowFocus trueActivity中在dispatchKeyEvent()或者dispatchTouchEvent()方法里面通过反射把mAttachInfo.mHasWindowFocus重置为true可以解决no window focus。Override
public boolean dispatchTouchEvent(NonNull KeyEvent event) {try {ViewParent viewRootImpl getWindow().getDecorView().getParent();Class viewRootImplClass viewRootImpl.getClass();
Field mAttachInfoField viewRootImplClass.getDeclaredField(mAttachInfo);mAttachInfoField.setAccessible(true);Object mAttachInfo mAttachInfoField.get(viewRootImpl);Class mAttachInfoClass mAttachInfo.getClass();
Field mHasWindowFocusField mAttachInfoClass.getDeclaredField(mHasWindowFocus);mHasWindowFocusField.setAccessible(true);mHasWindowFocusField.set(mAttachInfo,true);boolean mHasWindowFocus (boolean) mHasWindowFocusField.get(mAttachInfo);
} catch (Exception e) {e.printStackTrace();}
return super.dispatchKeyEvent(event);
}2.4 dumpsys gfxinfo
使用dumpsys gfxinfo命令可获取128帧的绘制信息详细包括每一帧绘制的Draw、Process、Execute三个过程的耗时如果这三个时间总和超过16.6ms即认为发生了卡顿。2.5 Linux disk usage
查看当前目录下面所有文件夹所占的空间。
du -h -d 1显示目录和目录下子目录和文件占用磁盘空间的大小。
du -h /data/data2.6 提取log
import io
import re
import sys,os
import shutilarg0_proc_name
def print_usage():print(\nUsage: python arg0_proc_name DIR file_prefix match_string)print(refer to the below showcases regarding match_string\n)list [boot_progress|shutdown,boot_progress|low-level shutdown|am_crash,boot_progress|shutdown|am_crash|bootinfo,checkScreenEnabled|ILL_ILLOPN,UIWDT,]
for item in list:print( \ item \)print()def remove_dir(dir_path):if os.path.isdir(dir_path):for file in os.listdir(dir_path):if (os.path.isdir(dir_path os.path.sep file)):remove_dir(dir_path os.path.sep file)else:os.remove(dir_path os.path.sep file)os.removedirs(dir_path)def write_file_string(file, line_string):h open(file, a)h.writelines(line_string)h.close()def write_line_string_to_log(src_file,dst_file, match_string):line_cnt 1fp io.open(src_file, r, encodingutf-8,errorsignore)for line_string in fp:if re.findall(match_string, line_string.lower()):#if re.findall(match_string, line_string.lower(),#re.I):write_file_string(dst_file, str(line_cnt) line_string)line_cnt 1def find_string(dir_path, file_prefix, match_string):remove_dir(dir_path os.path.sep my_out)os.makedirs(dir_path os.path.sep my_out)
try:for file in os.listdir(dir_path):if (os.path.isfile(dir_path os.path.sep file) and \file.startswith(file_prefix)):write_line_string_to_log(dir_path os.path.sep file,dir_path os.path.sep my_out os.path.sep file,match_string)except KeyboardInterrupt:print(Got ^C exit signal)def main():global arg0_proc_namearg0_proc_name sys.argv[0]if sys.argv[0].rfind(os.path.sep) 0 :index sys.argv[0].rfind(os.path.sep)arg0_proc_name sys.argv[0][index1:]
if len(sys.argv) 4:print_usage()sys.exit(0)
print(to be found: sys.argv[2])find_string(sys.argv[1], sys.argv[2],sys.argv[3])if __name__ __main__:main()3 USB异步API
development/samples/USB/AdbTest
import static java.lang.Integer.toHexString;
Integer.toHexString(USB_VID)USB gadget state is not attachedMTP/mass_storage
Maybe the USB cable|idVendor1d6b|idVendor12d1|usb disconnect|over-current|nearby|wwan0, isUp is:1) Choose xxx-Domain, then click Create to create a new page BBB under xxx-Domain.
2) Add Link to xxx-Domain, Edit - copy other line to get prefix format - Insert Link - Search BBB.4 ART
adb shell oatdump --oat-file/data/dalvik-cache/xxx/xxx.dexLinux
readelf -a xxx.dex5 Abbreviations
Android PMS LI、LIF、LPw、LPr要想弄明白方法名中的LI、LIF、LPw、LPr的含义需要先了解PackageManagerService内部使用的两个锁。因为LI、LIF、LPw、LPr中的L指的是Lock而后面跟的I和P指的是两个锁I表示mInstallLock同步锁P表示mPackages同步锁。LPw、LPr中的w表示writingr表示reading。LIF中的F表示Freeze。
ILL_ILLOPNillegal operand
scanDirLI()scanDir Lock mInstallLock
