[binutils-gdb] Add test for continuing with some threads running

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=9a7189d061751693149d15f1bbcd78b532d78239

commit 9a7189d061751693149d15f1bbcd78b532d78239
Author: Pedro Alves <[email protected]>
Date:   Fri Jan 24 18:10:50 2025 +0000

    Add test for continuing with some threads running
    
    This testcase would have helped catch some issues I ran into while
    working on the Windows non-stop support.
    
    It tests continuing all threads in all-stop mode when at least one
    thread is already running.
    
    Approved-by: Kevin Buettner <[email protected]>
    Change-Id: Ie8cd5c67502aed3c3b159d5eb5eeedee2f84eeef
    commit-id:f4f07192

Diff:
---
 gdb/testsuite/gdb.threads/continue-some-running.c  | 77 ++++++++++++++++++++++
 .../gdb.threads/continue-some-running.exp          | 57 ++++++++++++++++
 2 files changed, 134 insertions(+)

diff --git a/gdb/testsuite/gdb.threads/continue-some-running.c b/gdb/testsuite/gdb.threads/continue-some-running.c
new file mode 100644
index 00000000000..fd77af3cefa
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/continue-some-running.c
@@ -0,0 +1,77 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2025-2026 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 <assert.h>
+#include <unistd.h>
+#include "gdb_watchdog.h"
+
+volatile int wait_for_gdb = 1;
+
+#define NUM_THREADS 3
+
+static pthread_barrier_t threads_started_barrier;
+
+static pthread_barrier_t may_exit_barrier;
+
+static void *
+thread_func (void *arg)
+{
+  /* Wait until all threads have started.  */
+  pthread_barrier_wait (&threads_started_barrier);
+
+  /* Wait until the main thread lets us exit.  */
+  pthread_barrier_wait (&may_exit_barrier);
+
+  return NULL;
+}
+
+static void
+threads_started (void)
+{
+}
+
+int
+main (void)
+{
+  pthread_t thread[NUM_THREADS];
+  int i;
+
+  gdb_watchdog (30);
+
+  pthread_barrier_init (&threads_started_barrier, NULL, NUM_THREADS + 1);
+  pthread_barrier_init (&may_exit_barrier, NULL, NUM_THREADS + 1);
+
+  for (i = 0; i < NUM_THREADS; i++)
+    {
+      int ret;
+
+      ret = pthread_create (&thread[i], NULL, thread_func, NULL);
+      assert (ret == 0);
+    }
+
+  pthread_barrier_wait (&threads_started_barrier);
+
+  threads_started ();
+
+  pthread_barrier_wait (&may_exit_barrier);
+
+  for (i = 0; i < NUM_THREADS; i++)
+    pthread_join (thread[i], NULL);
+
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.threads/continue-some-running.exp b/gdb/testsuite/gdb.threads/continue-some-running.exp
new file mode 100644
index 00000000000..d6716e8ff16
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/continue-some-running.exp
@@ -0,0 +1,57 @@
+# Copyright 2025-2026 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/>.
+
+# Test continuing in all-stop mode when one thread is already running.
+
+standard_testfile .c
+
+if { [build_executable "failed to prepare" $testfile $srcfile \
+	  {debug pthreads}] \
+	 == -1 } {
+    return
+}
+
+proc test {} {
+    # This test requires background execution, which relies on
+    # non-stop mode.
+    save_vars { ::GDBFLAGS } {
+	append ::GDBFLAGS " -ex \"maint set target-non-stop on\""
+	clean_restart $::testfile
+    }
+
+    if {![runto threads_started]} {
+	return
+    }
+
+    delete_breakpoints
+
+    # Set a non-main thread running, while everything else is left
+    # stopped.
+    gdb_test_no_output "set scheduler-locking on"
+
+    gdb_test "thread 2" ".*" "switch to secondary thread"
+
+    gdb_test -no-prompt-anchor "continue &" "Continuing\\."
+
+    # Now resume all threads, while there is already one thread
+    # running.
+    gdb_test "thread 1" ".*" "switch to main thread"
+
+    gdb_test_no_output "set scheduler-locking off"
+
+    gdb_continue_to_end "" continue 1
+}
+
+test