Re: [PATCH v2] Add mi-threads-interrupt.exp test (PR 20039)

[Simon Marchi <simon.marchi@ericsson.com>]

On 16-05-05 02:19 PM, Simon Marchi wrote:
> Add a new test for PR 20039.  The test spawns new threads, then tries to
> interrupt, continue, and interrupt again.  This use case was fixed by
> commit 5fe966540d6b748f825774868463003700f0c878 in master, but gdb 7.11
> is affected (so if you try it on the gdb-7.11-branch right now, the test
> will fail).
> 
> New in v2, the test now handles mi-async on mode properly.  The failure
> was specific to mi-async off, but I don't think it's bad to test the
> same thing under async on mode.  I added a little hack when running in
> async mode to work around bug 20045.
> 
> I also removed one continue/interrupt pair, as a single one was enough to
> trigger the problem.
> 
> gdb/testsuite/ChangeLog:
> 
> 	* gdb.mi/mi-threads-interrupt.c: New file.
> 	* gdb.mi/mi-threads-interrupt.exp: New file.
> ---
>  gdb/testsuite/gdb.mi/mi-threads-interrupt.c   | 61 ++++++++++++++++++++++
>  gdb/testsuite/gdb.mi/mi-threads-interrupt.exp | 75 +++++++++++++++++++++++++++
>  2 files changed, 136 insertions(+)
>  create mode 100644 gdb/testsuite/gdb.mi/mi-threads-interrupt.c
>  create mode 100644 gdb/testsuite/gdb.mi/mi-threads-interrupt.exp
> 
> diff --git a/gdb/testsuite/gdb.mi/mi-threads-interrupt.c b/gdb/testsuite/gdb.mi/mi-threads-interrupt.c
> new file mode 100644
> index 0000000..8747806
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/mi-threads-interrupt.c
> @@ -0,0 +1,61 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> +   Copyright 2016 Free Software Foundation, Inc.
> +
> +   This program is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License as published by
> +   the Free Software Foundation; either version 3 of the License, or
> +   (at your option) any later version.
> +
> +   This program is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +
> +   You should have received a copy of the GNU General Public License
> +   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> +
> +#include <pthread.h>
> +#include <unistd.h>
> +
> +#define NUM_THREADS 2
> +
> +static pthread_barrier_t barrier;
> +
> +static void *
> +thread_func (void *v)
> +{
> +  int i;
> +
> +  pthread_barrier_wait (&barrier);
> +
> +  for (i = 0; i < 100; i++)
> +    sleep (1);
> +}
> +
> +static void
> +all_threads_created (void)
> +{
> +}
> +
> +int
> +main(void)
> +{
> +  int i;
> +  pthread_t threads[NUM_THREADS];
> +
> +  /* +1 to account for the main thread */
> +  pthread_barrier_init (&barrier, NULL, NUM_THREADS + 1);
> +
> +  for (i = 0; i < NUM_THREADS; i++)
> +    pthread_create (&threads[i], NULL, thread_func, NULL);
> +
> +  pthread_barrier_wait (&barrier);
> +
> +  all_threads_created ();
> +
> +  for (i = 0; i < 100; i++)
> +    sleep (1);
> +
> +  return 0;
> +}
> diff --git a/gdb/testsuite/gdb.mi/mi-threads-interrupt.exp b/gdb/testsuite/gdb.mi/mi-threads-interrupt.exp
> new file mode 100644
> index 0000000..af5d99b
> --- /dev/null
> +++ b/gdb/testsuite/gdb.mi/mi-threads-interrupt.exp
> @@ -0,0 +1,75 @@
> +# Copyright 2016 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +
> +load_lib mi-support.exp
> +set MIFLAGS "-i=mi"
> +
> +standard_testfile
> +
> +if {[gdb_compile_pthreads "$srcdir/$subdir/$srcfile" $binfile executable {debug}] != "" } {
> +    return -1
> +}
> +
> +# This tests the resolution of PR 20039.
> +#
> +# With a multi-threaded inferior and with MI/all-stop, it was not possible
> +# to interrupt it with ctrl-C after a continue.
> +
> +proc test_continue_interrupt { } {
> +  global binfile
> +  global async
> +
> +  gdb_exit
> +  if {[mi_gdb_start]} {
> +      continue
> +  }
> +
> +  # Load the binary in gdb...
> +  mi_gdb_load $binfile
> +
> +  # ... and run it.
> +  #
> +  # Note this test relies on mi_runto deleting the breakpoint.
> +  # A step-over here would mask the bug.
> +  mi_runto "all_threads_created"
> +
> +  # Consistency check.
> +  mi_check_thread_states {"stopped" "stopped" "stopped"} "check thread states"
> +
> +  # Continue.
> +  mi_gdb_test "565-exec-continue" "565\\^running\r\n\\*running,thread-id=\"all\"" "continue"

I was about to push this, but decided to run the test again.  For some reason, this line
gives me a FAIL, which I didn't see before:

  FAIL: gdb.mi/mi-threads-interrupt.exp: continue

and I can't see what's wrong with:

101 Expecting: ^(.*[^M
102 ]+)?(565\^running^M
103 \*running,thread-id="all"[^M
104 ]+[(]gdb[)] ^M
105 [ ]*)
106 565-exec-continue^M
107 565^running^M
108 *running,thread-id="all"^M
109 =thread-selected,id="3"^M
110 (gdb) ^M
111 FAIL: gdb.mi/mi-threads-interrupt.exp: continue

Changing this line to be

  mi_send_resuming_command "exec-continue" "continue"

makes it work, although I don't see why.  Does it sound like a good change?

> +  if { $async } {
> +    # Workaround for PR 20045, where -exec-continue will output two (gdb) prompts
> +    # when in "mi-async on" mode.  This mi_gdb_test will consume the extra (gdb).
> +    # Once that bug is fixed, this can be removed.
> +    mi_gdb_test
> +  }

I'll remove this, since I'll put the fix for 20045 before this patch.