[Bug testsuite/34425] [gdb/testsuite] FAIL: gdb.threads/leader-exit.exp: single thread has been left

https://sourceware.org/bugzilla/show_bug.cgi?id=34425

--- Comment #2 from Sourceware Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tom de Vries <[email protected]>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1fba9bb362c6ca7a0ae30f0fff7d8c1d68f8bdb4

commit 1fba9bb362c6ca7a0ae30f0fff7d8c1d68f8bdb4
Author: Tom de Vries <[email protected]>
Date:   Sat Jul 25 08:59:51 2026 +0200

    [gdb/testsuite] Fix race in gdb.threads/leader-exit.exp

    On aarch64-linux, when running test-case gdb.threads/leader-exit.exp with
    "taskset -c 0", 3 out of 10 times I run into:
    ...
    (gdb) continue
    Continuing.
    [New Thread 0xfffff7d1f160 (LWP 62010) (id 2)]
    [Switching to thread 2 (Thread 0xfffff7d1f160 (LWP 62010))]

    Thread 2 "leader-exit" hit Breakpoint 2, start (arg=0x0) at
leader-exit.c:32
    32        sleep (10);  /* break-here */
    (gdb) PASS: gdb.threads/leader-exit.exp: continue to breakpoint: break-here
    info threads
      Id   Target Id                                                 Frame
      1    Thread 0xfffff7fe8020 (LWP 62008) "leader-exit" (Exiting) \
             0x0000fffff7d46fa0 in __libc_start_call_main () from
/lib64/libc.so.6
    * 2    Thread 0xfffff7d1f160 (LWP 62010) "leader-exit" \
             start (arg=0x0) at leader-exit.c:32
    (gdb) FAIL: gdb.threads/leader-exit.exp: single thread has been left
    ...

    In a passing version, the continue produces a "Thread exited" message, but
    that's missing here.

    The problem is that after the pthread_join is executed:
    ...
      i = pthread_join (main_thread, NULL);
      ...

      sleep (10);  /* break-here */
    ...
    there's a race between:
    - the breakpoint at break-here triggering, and
    - the "Thread exited" message for the main thread being reported.

    Fix this by:
    - adding a loop before the break location
    - waiting in the loop until the "Thread exited" message is seen
    - sending ^C to get a prompt
    - setting a variable to exit the loop

    Likewise in gdb.threads/non-ldr-exc-2.exp.

    Reviewed-By: Keith Seitz <[email protected]>
    Approved-By: Kevin Buettner <[email protected]>

    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=34425

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