31c21e2c13
When running test-case gdb.threads/access-mem-running-thread-exit.exp with
clang, we run into:
...
(gdb) print global_var = 555^M
No symbol "global_var" in current context.^M
(gdb) FAIL: gdb.threads/access-mem-running-thread-exit.exp: all-stop: \
access mem (write to global_var, inf=2, iter=1)
...
The problem is that clang removes the unused variable.
Fix this in the same way as done in commit b4f767131f
("Fix gdb.base/align-*.exp and Clang + LTO and AIX GCC"), by incrementing the
variable.
Tested on x86_64-linux with gcc and clang.
125 lines
3 KiB
C
125 lines
3 KiB
C
/* This testcase is part of GDB, the GNU debugger.
|
|
|
|
Copyright 2021-2024 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/>. */
|
|
|
|
#define _GNU_SOURCE
|
|
#include <assert.h>
|
|
#include <pthread.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <string.h>
|
|
|
|
#define THREADS 20
|
|
|
|
static volatile unsigned int global_var = 123;
|
|
|
|
/* Wrapper around pthread_create. */
|
|
|
|
static void
|
|
create_thread (pthread_t *child,
|
|
void *(*start_routine) (void *), void *arg)
|
|
{
|
|
int rc;
|
|
|
|
while ((rc = pthread_create (child, NULL, start_routine, arg)) != 0)
|
|
{
|
|
fprintf (stderr, "unexpected error from pthread_create: %s (%d)\n",
|
|
strerror (rc), rc);
|
|
sleep (1);
|
|
}
|
|
}
|
|
|
|
/* Data passed to threads on creation. This is allocated on the heap
|
|
and ownership transferred from parent to child. */
|
|
|
|
struct thread_arg
|
|
{
|
|
/* The thread's parent. */
|
|
pthread_t parent;
|
|
|
|
/* Whether to call pthread_join on the parent. */
|
|
int join_parent;
|
|
};
|
|
|
|
/* Entry point for threads. */
|
|
|
|
static void *
|
|
thread_fn (void *arg)
|
|
{
|
|
struct thread_arg *p = arg;
|
|
|
|
/* Passing no argument makes the thread exit immediately. */
|
|
if (p == NULL)
|
|
return NULL;
|
|
|
|
if (p->join_parent)
|
|
assert (pthread_join (p->parent, NULL) == 0);
|
|
|
|
/* Spawn a number of threads that exit immediately, and then join
|
|
them. The idea is to maximize the time window when we mostly
|
|
have threads exiting. */
|
|
{
|
|
pthread_t child[THREADS];
|
|
int i;
|
|
|
|
/* Passing no argument makes the thread exit immediately. */
|
|
for (i = 0; i < THREADS; i++)
|
|
create_thread (&child[i], thread_fn, NULL);
|
|
|
|
for (i = 0; i < THREADS; i++)
|
|
pthread_join (child[i], NULL);
|
|
}
|
|
|
|
/* Spawn a new thread that joins us, and exit. The idea here is to
|
|
not have any thread that stays around forever. */
|
|
{
|
|
pthread_t child;
|
|
|
|
p->parent = pthread_self ();
|
|
p->join_parent = 1;
|
|
create_thread (&child, thread_fn, p);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int
|
|
main (void)
|
|
{
|
|
int i;
|
|
|
|
global_var++;
|
|
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
struct thread_arg *p;
|
|
pthread_t child;
|
|
|
|
p = malloc (sizeof *p);
|
|
p->parent = pthread_self ();
|
|
/* Only join the parent once. */
|
|
if (i == 0)
|
|
p->join_parent = 1;
|
|
else
|
|
p->join_parent = 0;
|
|
create_thread (&child, thread_fn, p);
|
|
}
|
|
|
|
/* Exit the leader to make sure that we can access memory with the
|
|
leader gone. */
|
|
pthread_exit (NULL);
|
|
}
|