Activity啟動流程

0x01

public
void
startactivity(intent intent)

最終走到

public
void startactivityforresult(@requirespermission intent intent, int requestcode,
@nullable bundle options)

分兩種情況

１mparent

２mparent!=null

mparent = null 的情況最後分析

public activityresult execstartactivity(
context who, ibinder contextthread, ibinder token, activity target,
intent intent, int requestcode, bundle options)

uri referrer = target != null ? target.onprovidereferrer() : null;

if (referrer != null)

if (mactivitymonitors != null)

break;}}

}}

try catch (remoteexception e)

return

null;

這段**主要用途是為啟動乙個activity準備引數，下面說說所準備的引數

２　呼叫這packagname

3 intent

4 type （provider.gettype返回的資訊）

５　token

該activityrecord的客戶端

６requestcode

接下來就呼叫到ams裡面了

public final int intent intent, string resolvedtype, ibinder resultto, string resultwho, int requestcode,

int startflags, profilerinfo profilerinfo, bundle boptions, int userid) {

這個函式會先檢查呼叫者uid是否可以執行啟動activity．如果該uid＞99000&&uid<99999 則不允許啟動activity,具體為什麼這麼劃分還不清楚，應該和多使用者有關

檢查多使用者的userid是否可以啟動這個activity，比如有些多使用者不能啟動瀏覽器等

string callingpackage, intent intent, string resolvedtype,

ivoiceinteractionsession voicesession, ivoiceinteractor voiceinteractor,

ibinder resultto, string resultwho, int requestcode, int startflags,

profilerinfo profilerinfo, iactivitymanager.waitresult outresult, configuration config,

bundle boptions, boolean ignoretargetsecurity, int userid,

iactivitycontainer icontainer, taskrecord intask) {

檢查intent中包含檔案描述符，丟擲異常

通過pms解析intent，返回resolveinfo資訊

通過resolveinfo解析activityinfo

activitystarter->final string resolvedtype, activityinfo ainfo, resolveinfo rinfo, ivoiceinteractionsession voicesession, ivoiceinteractor voiceinteractor, ibinder resultto, string resultwho, int requestcode, int callingpid, int callinguid, string callingpackage, int realcallingpid, int realcallinguid, int startflags, activityoptions options, boolean ignoretargetsecurity, boolean componentspecified, activityrecord outactivity, activitystacksupervisor.activitycontainer container,

taskrecord intask) {

找到接受結果的activity的activityrecord(如果有)

這裡建立兩個變數sourcerecord 和resultrecord分別代呼叫這activityrecord和接受結果的　一般這二者為同乙個，如果不接收結果ｒｅｓｕｌｔ可能為空，如果設定了flag_activity_forward_result，則二者不同

檢查許可權

permissions_review_required　相關的邏輯　彈出中間介面

ephemeralresolveinfo狀態的任務，（可能是正在安裝的程式，被替換後要重新啟動該介面）

activitystarter->private intstartactivityunchecked(final activityrecord r, activityrecord sourcerecord, ivoiceinteractionsession voicesession, ivoiceinteractor voiceinteractor,

int startflags, boolean doresume, activityoptions options, taskrecord intask) {

計算啟動flags

private
void
computelaunchingtaskflags() {

計算stack

private
void
computesourcestack() {

如果掉啟的activity　finish了，則新增new_task

Activity啟動流程

Activity啟動流程

activity啟動流程

activity啟動流程

Activity啟動流程

Activity啟動流程

activity啟動流程

activity啟動流程

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