Re: [RFA/testsuite/threads] backtrace past pthread_cond_wait() (3rdversion)

Michael Snyder
2004-05-19T18:51:00Z

Joel Brobecker wrote:
Here a new version of the new testcase, with copyright dates updated,
and hopefully the correct changelog:
2004-05-18 J. Brobecker <brobecker@gnat.com>
Michael Snyder <msnyder@redhat.com>
* gdb.threads/pthread_cond_wait.c: New file.
* gdb.threads/pthread_cond_wait.exp: New testcase.
OK to apply?
Looks good to me -- Daniel?
[Joel, sorry for the flurry of nits. Good job. ;-)]
------------------------------------------------------------------------

/* A small multi-threaded test case.

Copyright 2004
Free Software Foundation, Inc.
This file is part of GDB.

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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <pthread.h>
#include <stdio.h>
#include <time.h>
void
cond_wait (pthread_cond_t *cond, pthread_mutex_t *mut)
{
pthread_mutex_lock(mut);
pthread_cond_wait (cond, mut);
pthread_mutex_unlock (mut);
}
void
noreturn (void)
{
pthread_mutex_t mut;
pthread_cond_t cond;
pthread_mutex_init (&mut, NULL);
pthread_cond_init (&cond, NULL);
/* Wait for a condition that will never be signaled, so we effectively
block the thread here. */
cond_wait (&cond, &mut);
}
void *
forever_pthread (void *unused)
{
noreturn ();
}
void
break_me (void)
{
/* Just an anchor to help putting a breakpoint. */
}
int
main (void)
{
pthread_t forever;
const struct timespec ts = { 0, 10000000 }; /* 0.01 sec */
pthread_create (&forever, NULL, forever_pthread, NULL);
for (;;)
{
nanosleep (&ts, NULL);
break_me();
}
return 0;
}

------------------------------------------------------------------------

# Copyright (C) 2004 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

# Please email any bugs, comments, and/or additions to this file to:
# bug-gdb@gnu.org
# This file verifies that GDB is able to compute a backtrace for a thread
# being blocked on a call to pthread_cond_wait().

if $tracelevel then {
strace $tracelevel
}
set testfile "pthread_cond_wait"
set srcfile ${testfile}.c
set binfile ${objdir}/${subdir}/${testfile}
if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug "incdir=${objdir}"]] != "" } {
return -1
}
gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
gdb_load ${binfile}
gdb_test "break break_me" \
"Breakpoint 1 at .*: file .*${srcfile}, line .*" \
"breakpoint on break_me"
gdb_test "run" \
".*Breakpoint 1, break_me ().*" \
"run to break_me"
#
# Backtrace all threads, find the one running noreturn, and
# verify that we are able to get a sensible backtrace, including
# the frame for the pthread_cond_wait() call.
#
# The string below will only match if the functions named
# occur in a single thread's backtrace, in the given order.
#

global hex
global decimal
#
# This is a "backtrace break" ("btb"):
#
set btb "\[^\r\n\]+\[\r\n\]+\#${decimal}\[ \t\]+${hex} in "
# One of the threads is blocked on a call to pthread_cond_wait, and
# we want to verify that we are able to get a sensible backtrace for
# that thread. Because we don't know its thread ID, we can't switch
# to it before doing the backtrace. So we get a backtrace for all
# threads, and verify that one them returns the expected backtrace.
gdb_test "thread apply all backtrace" \
"pthread_cond_wait${btb}cond_wait${btb}noreturn${btb}forever_pthread.*" \
"backtrace in blocked thread"