Cannot cast Android Java API in plugin

[zwyuan]

The below demo code will lead to crash if saved as a plugin (main.mi2app):

#!/usr/bin/python

import os
import sys
import kivy
import jnius
from jnius import autoclass, cast

print "Start"

activity = cast("android.app.Activity", autoclass("org.kivy.android.PythonActivity").mActivity)
print activity.getFilesDir().getAbsolutePath()

print "End"

The crash log is attached here:

10-23 16:10:00.769 24857 24872 I python2.7: Phone model: Nexus 6P
10-23 16:10:00.769 24857 24872 I python2.7: Running app: /storage/emulated/0/mobileinsight/plugins/WiFi/main.mi2app
10-23 16:10:00.791 24857 24872 I python2.7: Start
10-23 16:10:00.877   646  1206 I slim_daemon: [QMILOC] requestTimeData: Sending Time Data to LocApi
10-23 16:10:00.916 24857 24872 F libc    : Fatal signal 11 (SIGSEGV), code 2, fault addr 0xd61e7d00 in tid 24872 (Thread-2)
10-23 16:10:00.916   361   361 W         : debuggerd: handling request: pid=24857 uid=10226 gid=10226 tid=24872
10-23 16:10:00.919 24875 24875 I debuggerd: type=1400 audit(0.0:426): avc: denied { read } for name="libpymodules.so" dev="dm-0" ino=426736 scontext=u:r:debuggerd:s0 tcontext=u:object_r:app_data_file:s0:c512,c768 tclass=file permissive=1
10-23 16:10:00.919 24875 24875 I debuggerd: type=1400 audit(0.0:427): avc: denied { open } for path="/data/data/net.mobileinsight.app/files/app/libpymodules.so" dev="dm-0" ino=426736 scontext=u:r:debuggerd:s0 tcontext=u:object_r:app_data_file:s0:c512,c768 tclass=file permissive=1
10-23 16:10:00.919 24875 24875 I debuggerd: type=1400 audit(0.0:428): avc: denied { getattr } for path="/data/data/net.mobileinsight.app/files/app/libpymodules.so" dev="dm-0" ino=426736 scontext=u:r:debuggerd:s0 tcontext=u:object_r:app_data_file:s0:c512,c768 tclass=file permissive=1
10-23 16:10:00.988 24875 24875 F DEBUG   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
10-23 16:10:00.988 24875 24875 F DEBUG   : Build fingerprint: 'google/angler/angler:7.1.2/N2G47H/3783593:user/release-keys'
10-23 16:10:00.989 24875 24875 F DEBUG   : Revision: '0'
10-23 16:10:00.989 24875 24875 F DEBUG   : ABI: 'arm'
10-23 16:10:00.989 24875 24875 F DEBUG   : pid: 24857, tid: 24872, name: Thread-2  >>> net.mobileinsight.app:pythonservice <<<
10-23 16:10:00.989 24875 24875 F DEBUG   : signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0xd61e7d00
10-23 16:10:00.989 24875 24875 F DEBUG   :     r0 d5425d50  r1 d61e7d00  r2 d5be5145  r3 656e6f4f
10-23 16:10:00.989 24875 24875 F DEBUG   :     r4 d5db1ef0  r5 d5425d50  r6 d5d7c4b0  r7 d61e7d00
10-23 16:10:00.989 24875 24875 F DEBUG   :     r8 d5d44b04  r9 d621f90c  sl d55904b8  fp d6254fe4
10-23 16:10:00.989 24875 24875 F DEBUG   :     ip d5d44bb4  sp ee3eca80  lr d5bf3d23  pc d5c04fd6  cpsr 00010030
10-23 16:10:00.990 24875 24875 F DEBUG   :
10-23 16:10:00.990 24875 24875 F DEBUG   : backtrace:
10-23 16:10:00.990 24875 24875 F DEBUG   :     #00 pc 00224fd6  /data/data/net.mobileinsight.app/files/app/libpymodules.so
10-23 16:10:00.990 24875 24875 F DEBUG   :     #01 pc 00213d1f  /data/data/net.mobileinsight.app/files/app/libpymodules.so
10-23 16:10:01.804   361   361 W         : debuggerd: resuming target 24857
10-23 16:10:01.805  1001  1023 I BootReceiver: Copying /data/tombstones/tombstone_02 to DropBox (SYSTEM_TOMBSTONE)
10-23 16:10:01.833  1001  4160 I ActivityManager: Process net.mobileinsight.app:pythonservice (pid 24857) has died
10-23 16:10:01.834  1001  4160 D ActivityManager: cleanUpApplicationRecord -- 24857
10-23 16:10:01.834  1001  4160 W ActivityManager: Scheduling restart of crashed service net.mobileinsight.app/org.kivy.android.PythonService in 1000ms
10-23 16:10:01.837   610   610 I Zygote  : Process 24857 exited due to signal (11)

[zwyuan]

The bug is cause by using PythonActivity to cast an Android class. In fact, the plugins are run as PythonService in MobileInsight, therefore the type of pyActivity will be <type 'NoneType'> and cause error. Users should use PythonService to cast classes, see below an example:

#!/usr/bin/python

import os
import sys
from jnius import autoclass, cast

'''
Don't use the following block in a plugin:

    PythonActivity = autoclass('org.kivy.android.PythonActivity')
    pyActivity = PythonActivity.mActivity

The plugins are run as PythonService in MobileInsight, therefore
the type of pyActivity will be <type 'NoneType'> and cause error
'''

PythonService  = autoclass('org.kivy.android.PythonService')
pyService = PythonService.mService

Context = autoclass('android.content.Context')

mWifiManager = pyService.getSystemService(Context.WIFI_SERVICE)
mWifiInfo = mWifiManager.getConnectionInfo()

print mWifiInfo.getBSSID()
print mWifiInfo.getFrequency()

I will commit an example plugin for this.

[zwyuan]

See commit 222861d