As we all know , the java runtime in android framework is "REWRITE" by
google developers.
we can see many of method implementation in Android Java Runtime DO NOT same as Oracle JDK or Open JDK.
Recently , I found that Runtime#loadLibrary0 method is adapt with 「Synchronize」;
which will cause ANR in many Scene of Native library load.
For example:
//WIP flow chart here
BackGround Thread start → System.loadLibrary("")
MainThread → wait → System.loadLibrary("")
If BackGround Thread hold lock for a long time (such as load a huge library file); MainThread will block and wait until BackGround Thread load finish; which cause ANR.
many case online;
for deal this issue , we should find out why that Runtime#loadLibrary0 in Android platform implementation adapt with Synchronize.
In Open JDK the method implementation is :
the purpose of lock ”loadedLibraryNames“ is prevent cache fail or double-load of native library。
In Android platform ，implementation shows：
https://cs.android.com/android/platform/superproject/+/master:libcore/ojluni/src/main/java/java/lang/Runtime.java;drc=b0193ccac5b8399f9b5ef270d102b5a50f9446ab;bpv=1;bpt=1;l=1041?q=loadLibrary0&gsn=loadLibrary0&gs=kythe%3A%2F%2Fandroid.googlesource.com%2Fplatform%2Fsuperproject%3Flang%3Djava%3Fpath%3Djava.lang.Runtime%238f2e2901e98f19354082701a02fdce828b432d967e6845f6983c0fe061be5516&gs=kythe%3A%2F%2Fandroid.googlesource.com%2Fplatform%2Fsuperproject%3Flang%3Djava%3Fpath%3Djava.lang.Runtime%23d6a7908122c433e45aafe6d721fdec4ba2792519e8831d58e6937baff89f5d7e
