threadJoin: WaitForSingleObject unexpected error %d

Error message

threadJoin: WaitForSingleObject unexpected error %d

What it means

Windows threadJoin: WaitForSingleObject returned a value that is neither WAIT_OBJECT_0 nor WAIT_FAILED. With an INFINITE timeout on a thread handle this should be unreachable (WAIT_TIMEOUT and friends require a timeout), so it indicates handle-type confusion (waiting on a non-thread object) or corrupted handle data. The raw value is printed and returned as the join result.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/os/windows/thread.c:61

  } else {
    ret = GetLastError();
    fprintf(stderr, "threadCreate: CreateThread failed with error %d\n", ret);
  }
  return ret;
}

int threadJoin(const thread *t) {
  DWORD ret = WaitForSingleObject(t->id, INFINITE);
  switch (ret) {
  case WAIT_OBJECT_0:
    break;
  case WAIT_FAILED:
    ret = GetLastError();
    fprintf(stderr, "threadJoin: WaitForSingleObject failed with error %d\n",
      ret);
    break;
  default:
    fprintf(stderr, "threadJoin: WaitForSingleObject unexpected error %d\n",
      ret);
    break;
  }
  return ret;
}

View on GitHub (pinned to 2add963021)

Solutions

Capture the raw value and confirm the HANDLE originated from threadCreate on the same struct
Run with Application Verifier (handles) or a debugger to detect handle misuse
Audit for writes past the end of the thread struct

Defensive patterns

Strategy: validation

Try / catch

DWORD rc = WaitForSingleObject(t.id, INFINITE);
if (rc != WAIT_OBJECT_0) {
    /* unexpected: verify the handle is a thread and not corrupted */
    assert(rc == WAIT_FAILED); /* else treat as corruption smoke */
}

Prevention

Only pass handles returned by threadCreate into threadJoin
Run Application Verifier handle checks when this appears
Treat as a memory-corruption smoke signal and investigate surrounding writes

When it happens

Trigger: Passing a HANDLE that is not a thread (event/mutex/file) into threadJoin; memory corruption of the thread struct's stored handle.

Common situations: Almost never seen; when it appears, treat it as a corruption or API-misuse smoke signal in the surrounding code.

Related errors

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/8f1bd87adb4ca078. Report an issue: GitHub.