Verifying and Troubleshooting the libp2j.so Build¶

• Verifying and Troubleshooting the libp2j.so Build
  • Using Linux Utilities
    • ldd
    • nm on statically linked ncurses
    • nm on dynamically linked ncurses
  • Using Java and FWD
  • Detailed Prerequisites for Dedicated Build Steps
  • Example listings of the Linux utilities
    • ldd
    • nm

Using Linux Utilities¶

The .so library is built on Linux, so you can use the following two utilities for testing and troubleshooting.

1. ldd
2. nm

ldd¶

If you run ldd libp2j.so , the availability of dynamic 'dependent' *.so files will be determined.
For statically linked ncurses , you must NOT see the reference to ncurses in the output of ldd, because it is "built in".
For dynamically linked ncurses , you MUST see the reference to ncurses in the output of ldd

nm on statically linked ncurses¶

If you run nm -g libp2j.so , you will see the external symbols listed.

Check if auto_getch_refresh is present in the listing, where:

• the reported line must be starting with a memory address string, followed by the letter T, followed by auto_getch_refresh, space delimited.

Here is an example for a proper nm test:

nm -g libp2j.so | grep -Ew '[0-9A-Fa-f]+ +T +auto_getch_refresh' && echo 'Test libp2j.so for auto_getch_refresh is OK' || echo 'Test libp2jso for auto_getch_refresh FAILED'

Which should output:

Test libp2j.so for auto_getch_refresh is OK

For reference, here is a correct output line of nm -g:

0000000000011fa0 T auto_getch_refresh

The reported type T means: Global text symbol. A memory address is shown.

And here is an incorrect output line of nm -g:

                 U auto_getch_refresh

This incorrect output (detected at a customer) was caused by a symbol is declared but not defined situation.
The reported type U means: Undefined symbol.
Recent versions of FWD use the -z defs linker flag, which guards against these situations.

nm on dynamically linked ncurses¶

When you have the dynamically linked ncurses setup for libp2j.so , the proper check on the system-wide patched ncurses shared object would be:

nm -g libncurses.so | grep -Ew '[0-9A-Fa-f]+ +T +auto_getch_refresh' && echo 'Test libncurses.so for auto_getch_refresh is OK' || echo 'Test libncurses.so for auto_getch_refresh FAILED'

The p2j.so will have auto_getch_refresh as well, so also do the check in the previous paragraph.

Using Java and FWD¶

To run a quick check by java/FWD: Start a 'dummy' ChUI session, using the command below.

Note 1:

Be aware that processes defined in your directory.xml currently run in ChUI mode, as of 2024Q2.
So even if you only run WebClient sessions, and do not have any ChUI programs to convert, you need the ChUI mode to work if you have processes defined.

Note 2:

Building libp2j.so does not require the TERMINFO patch, but running this ChUI test does require it.
Instructions are at Patching TERMINFO .

Here is the command for the ChUI test. Adjust paths where needed.

TERM=xterm LANG=en_US.UTF-8 $JAVA_HOME/bin/java -Djava.library.path=/my-converted-app-path/deploy/lib -classpath /my-converted-app-path/deploy/lib/p2j.jar com.goldencode.p2j.main.ClientDriver net:server:host=localhost net:connection:secure=false net:server:secure_port=41001 net:server:insecure_port=41000

If this gives errors (in the FWD server log, or in the stdout / stderr) on auto_getch_refresh , the build of libp2j.so is invalid, and/or the runtime settings are incorrect.

Other errors, not related to libp2j.so, can be ignored. Since nothing is configured, errors related to configuration are expected.

Detailed Prerequisites for Dedicated Build Steps¶

If your company uses dedicated build steps, these are the common ones, and they can all run at different machines (or have dedicated Docker images):

1. Build : Build FWD, including libp2j.so
2. Convert : Convert your application
3. Runtime : Run the converted application in FWD

For statically linked ncurses , the TERMINFO patch is only needed at the Runtime step. The NCURSES patch is NOT required to be applied system wide, on all three build steps. It IS applied in a separate temporary folder, by the build script for statically linked ncurses.

For dynamically linked ncurses, the NCURSES patch is required to be applied system wide, for all three build steps. The TERMINFO patch is only needed at the Runtime step, but the TERMINFO patch is a part of the NCURSES patch build script, so it will be present, system wide, in all build steps.

Example listings of the Linux utilities¶

ldd¶

This listing shows dynamically linked ncurses.

ldd ./server/lib/libp2j.so

./server/lib/libp2j.so: /lib/x86_64-linux-gnu/libncurses.so.6: no version information available (required by ./server/lib/libp2j.so)
        linux-vdso.so.1 (0x00007fff01dfc000)
        libffi.so.8 => /lib/x86_64-linux-gnu/libffi.so.8 (0x00007f6a16939000)
        libncurses.so.6 => /lib/x86_64-linux-gnu/libncurses.so.6 (0x00007f6a168d5000)
        libtinfo.so.6 => /lib/x86_64-linux-gnu/libtinfo.so.6 (0x00007f6a168a3000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f6a1667a000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f6a1695a000)

nm¶

The output is stripped.

nm ./server/lib/libp2j.so

000000000000d520 B acs_result
0000000000008ba8 T addchNative
0000000000009f20 t atexit
000000000000d4c0 D attribute_result
0000000000011fa0 T auto_getch_refresh
...
00000000000076e8 T Java_com_goldencode_p2j_library_LibraryManager_dispatch
0000000000007600 T Java_com_goldencode_p2j_library_LibraryManager_findByName
...
0000000000007172 T Java_com_goldencode_p2j_ui_client_chui_driver_console_ConsoleHelper_beep
0000000000007193 T Java_com_goldencode_p2j_ui_client_chui_driver_console_ConsoleHelper_clear

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