Is there a way to load a pre-built dynamic library along with flutter-tizen app?

[srix55]

I have built a specific library for linux_ia32, that samsung tv emulators use. I have that lib.so file. No matter where I put it in the tizen folder, my app says it's nowhere to be found. Is there a specific location I need to put the .so file, or is that simply not possible?

[swift-kim]

Hi. You can create a directory named lib or res under tizen and any file in that directory will be included in your TPK (reference). There are several ways to get a path to the directory at runtime (e.g. using tizen_interop's app_get_resource_path) but the simplest one would be (informal way):

print('${Platform.environment['AUL_ROOT_PATH']}/res');

Then you can use DynamicLibrary.open with the path to open the library.

[swift-kim]

Ah, I think you can just pass the lib name only (DynamicLibrary.open('libabc.so')) if you place the library in lib.

[srix55]

@swift-kim Thanks a lot. '${Platform.environment['AUL_ROOT_PATH']}lib/mylib.so' - this did it for me. With just the lib name, DynamicLibrary.open isn't finding it for me.

[srix55]

With that, isar works on Tizen 🎈 🥳 Some specific rust steps needed to build the dynamic library. But it works great.

[swift-kim]

Glad to hear that! I just looked into https://github.com/isar/isar-core/releases and the binary for Android x86 (libisar_android_x86.so) might be used on Tizen emulator as well because it depends on only libc and libdl. I'm not very sure though.

[srix55]

Tried using the android x86 binary. Tizen emulator throws up some liblog.so not found on it. Included liblog.so into lib and still it throws the same error.

[E] [ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: IsarError: Could not initialize IsarCore library. If you create a Flutter app, make sure to add isar_flutter_libs to your dependencies: Invalid argument(s): Failed to load dynamic library '/opt/usr/apps/signage.player.player/lib/libisar_android_x86.so': liblog.so: cannot open shared object file: No such file or directory

[srix55]

Overall, it's awesome that isar works with Tizen. That's huge... Would be awesome if it is in the list of supported tizen plugins. For that, I tried including that prebuilt libisar.so the way isar does - via the isar_flutter_libs package. However my c/c++ skills are non-existent... so tinkering with some cpp code went dud.

For now, it's about including the custom linux_ia32 libisar32.so into tizen build's lib folder and loading it up with '${Platform.environment['AUL_ROOT_PATH']}lib/libisar32.so' for isar. Requires a line of change at isar's end to support linux_ia32 abi.

[swift-kim]

Hmm, if you don't mind, could you share the binary here? I'd like to do some testing.

[swift-kim]

It should be possible to let my app load libisar.so before isar loads it if I use isar <= 2.4.0, but the current version of isar (2.5.x and 3.x) doesn't seem to allow it:

https://github.com/isar/isar/blob/2.4.0/packages/isar/lib/src/native/isar_core.dart#L44-L45

https://github.com/isar/isar/blob/3.0.0-dev.12/packages/isar/lib/src/native/isar_core.dart#L210-L213

Which version of isar are you using?

[srix55]

I am using isar 2.5.0
Here's the linux_ia32 binary for 2.5.0 -
libisar_linux_ia32.zip

And here, i added a case for linuxIA32

      case Abi.linuxIA32:
        library = 'libisar_linux_ia32.so';
        break;
        
// and later at line 71
if (library == "libisar_linux_ia32.so") 
        _IC ??= IsarCoreBindings(DynamicLibrary.open('${Platform.environment['AUL_ROOT_PATH']}lib/$library'));

[swift-kim]

I thought the following would work for isar <= 2.4.0 but it didn't.

// Load from path.
DynamicLibrary.open('${Platform.environment['AUL_ROOT_PATH']}/lib/libisar.so');

// Load the same library again by name.
// expected: not throws exception
// actual: throws exception
DynamicLibrary.open('libisar.so');

There doesn't seem to be a way to make things work without modifying the isar code itself. Things will become easier if isar provides something similar to sqlite3's open.overrideFor or open.overrideForAll.

[srix55]

The main problem for isar to support 32 bit seems to be that binaries for both x86 & arm64 cannot be shipped in a flutter library as stated by the author here.

Sorry, I don't think it is possible to ship both, x86 and arm64 linux binaries in a Flutter library. You would need to compile Isar core yourself for x86 linux.

[swift-kim]

The above example code worked by explicitly setting the library's soname to libisar.so by running:

$ patchelf --set-soname libisar.so tizen/lib/libisar.so

but now I see a different error when I click the "Load" button in the quotes sample app. Maybe it's due to a version mismatch or something because I'm using isar 2.4.0 and your binary was built for isar 2.5.0.

Thread 26 "io.flutter.ui" received signal SIGABRT, Aborted.
0xb7784a51 in __kernel_vsyscall ()
(gdb) bt
#0  0xb7784a51 in __kernel_vsyscall ()
#1  0xb75ca246 in __libc_signal_restore_set (set=0x9dafb200) at ../sysdeps/unix/sysv/linux/internal-signals.h:84
#2  __GI_raise (sig=6) at ../sysdeps/unix/sysv/linux/raise.c:48
#3  0xb75b13ce in __GI_abort () at abort.c:79
#4  0xb75b129e in __assert_fail_base (fmt=0xb772c044 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x9e1e4c16 "limit >= 3 - 1", file=0x9e1e415f "mdbx", line=6482,
    function=0x9e1f029c "mdbx_pnl_check") at assert.c:92
#5  0xb75c1de6 in __GI___assert_fail (assertion=0x9e1e4c16 "limit >= 3 - 1", file=0x9e1e415f "mdbx", line=6482, function=0x9e1f029c "mdbx_pnl_check") at assert.c:101
#6  0x9e0bc4f6 in ?? () from target:/opt/usr/globalapps/dev.isar.quotes/lib/libisar.so
#7  0x9e1a641c in ?? () from target:/opt/usr/globalapps/dev.isar.quotes/lib/libisar.so

Anyway we can now make this into a simple Tizen plugin as shown here. lib/isar_flutter_libs_tizen.dart contains code that invokes DynamicLibrary.open and the native part (tizen) only contains the lib/libisar.so binary without actual implementation. You can simply depend on the plugin from your app (it doesn't work in the way isar_flutter_libs does).

But still it will be a problem if I upgrade isar to 2.5.0. You may ask the isar author if we can add just three lines to the package:

      case Abi.linuxArm:
      case Abi.linuxArm64:
      case Abi.linuxIA32:

even though the official libisar.so binary is not available for the architectures.

[swift-kim]

Hmm, it seems you don't even need to call DynamicLibrary.open('${Platform.environment['AUL_ROOT_PATH']}/lib/libisar.so') if the library soname has been set to libisar.so as I mentioned above.

[srix55]

That SigAbrt definitely looks like a version mismatch issue. Let me confirm. I'll open a discussion with isar author and see if it can be made possible. Would be awesome to see isar among the list of flutter-tizen supported packages. Will recheck the AUL_ROOT_PATH necessity on my machine. Last time i checked, it couldn't find the binary without it.

[srix55]

You are right. There's no need to have AUL_ROOT_PATH when flutter_isar_libs_tizen is included. Some things I verified:

1. isar_flutter_libs and isar_flutter_libs_tizen can be included in pubspec together for a project and it works fine for web, linux and tizen 6.5 emulator.
2. Those SigAbrt errors seem to be because of version mismatch. I used 2.5.0 isar version everywhere and did not encounter any errors.
3. No need for AUL_ROOT_PATH or anything when using the correct libisar.so with isar_flutter_libs_tizen