[Lldb-commits] [lldb] [lldb-dap] Improving consistency of tests by removing concurrency. (PR #165496)

[David Spickett via lldb-commits]

DavidSpickett wrote:

This has actually reduced the consistency of tests on Arm 32-bit: https://lab.llvm.org/buildbot/#/builders/18/builds/22356

```
Unresolved Tests (10):
  lldb-api :: tools/lldb-dap/attach-commands/TestDAP_attachCommands.py
  lldb-api :: tools/lldb-dap/breakpoint-assembly/TestDAP_breakpointAssembly.py
  lldb-api :: tools/lldb-dap/breakpoint/TestDAP_logpoints.py
  lldb-api :: tools/lldb-dap/completions/TestDAP_completions.py
  lldb-api :: tools/lldb-dap/exception/TestDAP_exception.py
  lldb-api :: tools/lldb-dap/server/TestDAP_server.py
  lldb-api :: tools/lldb-dap/terminated-event/TestDAP_terminatedEvent.py
  lldb-api :: tools/lldb-dap/threads/TestDAP_threads.py
  lldb-api :: tools/lldb-dap/variables/TestDAP_variables.py
  lldb-api :: tools/lldb-dap/variables/children/TestDAP_variables_children.py
```
At least 9 of those are due to a truncated response:
```
$ cat stdio\ -\ 2025-10-30T100358.441 | grep JSONDecodeError
json.decoder.JSONDecodeError: Expecting property name enclosed in double quotes: line 1 column 8169 (char 8168)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 367 (char 366)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 5696 (char 5695)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 8136 (char 8135)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 8144 (char 8143)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 5696 (char 5695)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 8148 (char 8147)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 8160 (char 8159)
json.decoder.JSONDecodeError: Unterminated string starting at: line 1 column 8163 (char 8162)
```

However the inconsistency is...inconsistent :drum:  It failed again 2 builds later:
```
Unresolved Tests (19):
  lldb-api :: tools/lldb-dap/breakpoint/TestDAP_setBreakpoints.py
  lldb-api :: tools/lldb-dap/breakpoint/TestDAP_setFunctionBreakpoints.py
  lldb-api :: tools/lldb-dap/completions/TestDAP_completions.py
  lldb-api :: tools/lldb-dap/console/TestDAP_console.py
  lldb-api :: tools/lldb-dap/console/TestDAP_redirection_to_console.py
  lldb-api :: tools/lldb-dap/databreakpoint/TestDAP_setDataBreakpoints.py
  lldb-api :: tools/lldb-dap/disassemble/TestDAP_disassemble.py
  lldb-api :: tools/lldb-dap/disconnect/TestDAP_disconnect.py
  lldb-api :: tools/lldb-dap/evaluate/TestDAP_evaluate.py
  lldb-api :: tools/lldb-dap/exception/TestDAP_exception.py
  lldb-api :: tools/lldb-dap/exception/cpp/TestDAP_exception_cpp.py
  lldb-api :: tools/lldb-dap/instruction-breakpoint/TestDAP_instruction_breakpoint.py
  lldb-api :: tools/lldb-dap/invalidated-event/TestDAP_invalidatedEvent.py
  lldb-api :: tools/lldb-dap/launch/TestDAP_launch.py
  lldb-api :: tools/lldb-dap/locations/TestDAP_locations.py
  lldb-api :: tools/lldb-dap/memory/TestDAP_memory.py
  lldb-api :: tools/lldb-dap/optimized/TestDAP_optimized.py
  lldb-api :: tools/lldb-dap/output/TestDAP_output.py
  lldb-api :: tools/lldb-dap/restart/TestDAP_restart.py
```
https://lab.llvm.org/buildbot/#/builders/18/builds/22358

And has been doing so on and off since.

I'm going to revert this. I admit I haven't looked at the content of the PR and am very busy so I won't have time to test it on the machine soon. So please see if you can spot anything that could break due to scheduling or lack of synchronisation, and I'll find the time eventually to try to reproduce it.

I don't think this is to do with the host OS, it's just that the 32-bit container is generally lower performance. So running `stress -c` in the background might be enough to trigger the problem.

https://github.com/llvm/llvm-project/pull/165496