<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/111583>111583</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Test flake in lldb concurrent break point tests
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            lldb
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          ilovepi
      </td>
    </tr>
</table>

<pre>
    We're seeing some LLDB tests flake in our CI. Given these are concurrent tests I assume there is some data race or lack of synchronization.

Flaky tests:
lldb-api :: functionalities/thread/concurrent_events/TestConcurrentSignalWatchBreak.py
lldb-api :: functionalities/thread/concurrent_events/TestConcurrentSignalNWatchNBreak.py

Bots: 
https://ci.chromium.org/ui/p/fuchsia/builders/toolchain.ci/lldb-linux-arm64/b8734630228996969777/infra
https://ci.chromium.org/ui/p/fuchsia/builders/toolchain.ci/lldb-linux-arm64/b8734618131611235377/overview


Error output:
```
******************** TEST 'lldb-api :: functionalities/thread/concurrent_events/TestConcurrentSignalWatchBreak.py' FAILED ********************
Script:
--
/b/s/w/ir/x/w/install-cpython-aarch64-linux-gnu/bin/python3 /b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/dotest.py -u CXXFLAGS -u CFLAGS --env ARCHIVER=/b/s/w/ir/x/w/cipd/clang/bin/llvm-ar --env OBJCOPY=/b/s/w/ir/x/w/cipd/clang/bin/llvm-objcopy --env LLVM_LIBS_DIR=/b/s/w/ir/x/w/llvm_build/./lib --env LLVM_INCLUDE_DIR=/b/s/w/ir/x/w/llvm_build/include --env LLVM_TOOLS_DIR=/b/s/w/ir/x/w/llvm_build/./bin --arch aarch64 --build-dir /b/s/w/ir/x/w/llvm_build/lldb-test-build.noindex --lldb-module-cache-dir /b/s/w/ir/x/w/llvm_build/lldb-test-build.noindex/module-cache-lldb/lldb-api --clang-module-cache-dir /b/s/w/ir/x/w/llvm_build/lldb-test-build.noindex/module-cache-clang/lldb-api --executable /b/s/w/ir/x/w/llvm_build/./bin/lldb --compiler /b/s/w/ir/x/w/cipd/clang/bin/clang --dsymutil /b/s/w/ir/x/w/llvm_build/./bin/dsymutil --llvm-tools-dir /b/s/w/ir/x/w/llvm_build/./bin --lldb-obj-root /b/s/w/ir/x/w/llvm_build/tools/lldb --lldb-libs-dir /b/s/w/ir/x/w/llvm_build/./lib --skip-category=pexpect /b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/functionalities/thread/concurrent_events -p TestConcurrentSignalWatchBreak.py
--
Exit Code: 1

Command Output (stdout):
--
lldb version 20.0.0git (https://llvm.googlesource.com/a/llvm-project revision 8ab77184dde2583950fc6e4886ff526e7e598f7e)
  clang revision 8ab77184dde2583950fc6e4886ff526e7e598f7e
  llvm revision 8ab77184dde2583950fc6e4886ff526e7e598f7e
Skipping the following test categories: ['pexpect', 'dsym', 'gmodules', 'debugserver', 'objc']

Watchpoint 1 hit:
old value: 0
new value: 1

--
Command Output (stderr):
--
FAIL: LLDB (/b/s/w/ir/x/w/cipd/clang/bin/clang-aarch64) :: test (TestConcurrentSignalWatchBreak.ConcurrentSignalWatchBreak.test)
======================================================================
FAIL: test (TestConcurrentSignalWatchBreak.ConcurrentSignalWatchBreak.test)
 Test a signal/watchpoint/breakpoint in multiple threads.
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/b/s/w/ir/x/w/llvm-llvm-project/lldb/packages/Python/lldbsuite/test/decorators.py", line 148, in wrapper
    return func(*args, **kwargs)
 ^^^^^^^^^^^^^^^^^^^^^
  File "/b/s/w/ir/x/w/llvm-llvm-project/lldb/test/API/functionalities/thread/concurrent_events/TestConcurrentSignalWatchBreak.py", line 15, in test
    self.do_thread_actions(
  File "/b/s/w/ir/x/w/llvm-llvm-project/lldb/packages/Python/lldbsuite/test/concurrent_base.py", line 333, in do_thread_actions
    self.assertEqual(
AssertionError: 1 != 2 : Expected 1 stops due to signal delivery, but got 2
Config=aarch64-/b/s/w/ir/x/w/cipd/clang/bin/clang
----------------------------------------------------------------------
Ran 1 test in 3.160s

FAILED (failures=1)

--

********************
```

https://github.com/llvm/llvm-project/issues/39394 seems to be a similar report. @JDevlieghere is this a known problem?

</pre>
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