android 开发中 __monitor_enter 是什么意思？

Question

    package com.alibaba.wireless.security.securitybody;
    
    import android.content.Context;
    import android.location.Location;
    import android.location.LocationListener;
    import android.location.LocationManager;
    import android.os.Bundle;
    import android.os.HandlerThread;
    import android.os.Looper;
    import android.util.Log;
    
    public class SGLocation {
        final class com.alibaba.wireless.security.securitybody.SGLocation$2 implements LocationListener {
            com.alibaba.wireless.security.securitybody.SGLocation$2() {
                super();
            }
    
            public void onLocationChanged(Location arg5) {
                if(SGLocation.a()) {
                    Log.i("SGLocation", "loaction changed");
                }
    
                if(arg5 != null) {
                    if(SGLocation.a()) {
                        Log.i("SGLocation", "catch loc " + arg5.getLongitude());
                    }
    
                    Object v0 = SGLocation.b();
                    __monitor_enter(v0);
                    try {
                        SGLocation.a(arg5);
                        SGLocation.b().notify();
                        __monitor_exit(v0);
                        return;
                    label_25:
                        __monitor_exit(v0);
                    }
                    catch(Throwable v5) {
                        goto label_25;
                    }
    
                    throw v5;
                }
            }
    
            public void onProviderDisabled(String arg5) {
                Object v0 = SGLocation.b();
                __monitor_enter(v0);
                try {
                    if(SGLocation.a()) {
                        Log.i("SGLocation", "loaction disabled " + arg5);
                    }
    
                    SGLocation.b().notify();
                    __monitor_exit(v0);
                    return;
                label_17:
                    __monitor_exit(v0);
                }
                catch(Throwable v5) {
                    goto label_17;
                }
    
                throw v5;
            }
    
            public void onProviderEnabled(String arg4) {
                if(SGLocation.a()) {
                    Log.i("SGLocation", "loaction enabled " + arg4);
                }
            }
    
            public void onStatusChanged(String arg1, int arg2, Bundle arg3) {
            }
        }
    
        private static Looper a = null;
        private static final String b = "SGLocation";
        private static Context c = null;
        private static Location d = null;
        private static Object e = null;
        private static LocationManager f = null;
        private static boolean g = false;
        private static LocationListener h;
    
        static {
            SGLocation.e = new Object();
            SGLocation.h = new com.alibaba.wireless.security.securitybody.SGLocation$2();
        }
    
        public SGLocation() {
            super();
        }
    
        public static Location SGRequestLocationUpdates(Context arg8, String arg9, long arg10, float arg12) {
            Location v0 = null;
            if(SGLocation.a != null) {
                if(SGLocation.f == null) {
                    return v0;
                }
    
                try {
                    SGLocation.f.requestLocationUpdates(arg9, arg10, arg12, SGLocation.h, SGLocation.a);
                    return SGLocation.a(0);
                }
                catch(Throwable ) {
                    return v0;
                }
            }
    
            return v0;
        }
    
        private static Location a(int arg5) {
            Object v0 = SGLocation.e;
            __monitor_enter(v0);
            try {
                if(SGLocation.g) {
                    Log.i("SGLocation", "xxxx wait begin");
                }
    
                if(SGLocation.f != null) {
                    goto label_13;
                }
            }
            catch(Throwable v5) {
                goto label_28;
            }
            catch(InterruptedException ) {
                goto label_29;
            }
    
            Location v5_1 = null;
            try {
                __monitor_exit(v0);
                return v5_1;
                try {
                label_13:
                    SGLocation.e.wait(2000);
                    if(arg5 == 1) {
                    }
                    else {
                        SGLocation.f.removeUpdates(SGLocation.h);
                    }
    
                    if(!SGLocation.g) {
                        goto label_34;
                    }
    
                    Log.i("SGLocation", "xxxx wait end");
                    goto label_34;
                }
                catch(InterruptedException ) {
                label_29:
                    if(arg5 == 1) {
                        goto label_34;
                    }
    
                    try {
                        SGLocation.f.removeUpdates(SGLocation.h);
                    label_34:
                        __monitor_exit(v0);
                        return SGLocation.d;
                    }
                    catch(Throwable v5) {
                    label_28:
                        try {
                            __monitor_exit(v0);
                        }
                        catch(Throwable v5) {
                            goto label_28;
                        }
    
                        throw v5;
                    }
                }
            }
            catch(Throwable v5) {
                goto label_28;
            }
        }
    
        static Location a(Location arg0) {
            SGLocation.d = arg0;
            return arg0;
        }
    
        static Looper a(Looper arg0) {
            SGLocation.a = arg0;
            return arg0;
        }
    
        public static void a(Context arg1) {
            SGLocation.c();
            SGLocation.c = arg1;
            try {
                SGLocation.f = arg1.getSystemService("location");
                return;
            }
            catch(Throwable ) {
                return;
            }
        }
    
        static boolean a() {
            return SGLocation.g;
        }
    
        static Object b() {
            return SGLocation.e;
        }
    
        private static void c() {
            new Thread(new Runnable() {
                public void run() {
                    HandlerThread v0 = new HandlerThread("SGL");
                    v0.start();
                    SGLocation.a(v0.getLooper());
                }
            }).start();
        }
    
        public static void cancel() {
            Object v0 = SGLocation.e;
            __monitor_enter(v0);
            try {
                if(SGLocation.g) {
                    Log.i("SGLocation", "loaction canceled");
                }
    
                SGLocation.e.notify();
                __monitor_exit(v0);
                return;
            label_12:
                __monitor_exit(v0);
            }
            catch(Throwable v1) {
                goto label_12;
            }
    
            throw v1;
        }
    
        public static Location getLocation(Context arg2, String arg3) {
            Location v3;
            Location v2 = null;
            try {
                if(SGLocation.f == null) {
                    return v2;
                }
    
                v3 = SGLocation.f.getLastKnownLocation(arg3);
            }
            catch(Throwable ) {
                return v2;
            }
    
            try {
                if(!SGLocation.g) {
                    return v3;
                }
    
                Log.i("SGLocation", "lastknown loaction " + v3 + ";");
                return v3;
            }
            catch(Throwable ) {
                return v3;
            }
        }
    }

__monitor_enter 在这里什么意思?

Answer 1

建议查看源码，而不是通过反编译