old-cross-binutils/gdb/testsuite/gdb.threads/step-over-lands-on-breakpoint.exp
Pedro Alves d4569d7bc5 Fix step-over-{trips-on-watchpoint|lands-on-breakpoint}.exp race
On a target that is both always in non-stop mode and can do displaced
stepping (such as native x86_64 GNU/Linux, with "maint set
target-non-stop on"), the step-over-trips-on-watchpoint.exp test
sometimes fails like this:

   (gdb) PASS: gdb.threads/step-over-trips-on-watchpoint.exp: no thread-specific bp: step: thread 1
   set scheduler-locking off
   (gdb) PASS: gdb.threads/step-over-trips-on-watchpoint.exp: no thread-specific bp: step: set scheduler-locking off
   step
  -[Switching to Thread 0x7ffff7fc0700 (LWP 11782)]
  -Hardware watchpoint 4: watch_me
  -
  -Old value = 0
  -New value = 1
  -child_function (arg=0x0) at /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.threads/step-over-trips-on-watchpoint.c:39
  -39           other = 1; /* set thread-specific breakpoint here */
  -(gdb) PASS: gdb.threads/step-over-trips-on-watchpoint.exp: no thread-specific bp: step: step
  +wait_threads () at /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.threads/step-over-trips-on-watchpoint.c:49
  +49       return 1; /* in wait_threads */
  +(gdb) FAIL: gdb.threads/step-over-trips-on-watchpoint.exp: no thread-specific bp: step: step

Note "scheduler-locking" was set off.  The problem is that on such
targets, the step-over of thread 2 and the "step" of thread 1 can be
set to run simultaneously (since with displaced stepping the
breakpoint isn't ever removed from the target), and sometimes, the
"step" of thread 1 finishes first, so it'd take another resume to see
the watchpoint trigger.  Fix this by replacing the wait_threads
function with a one-line infinite loop that doesn't call any function,
so that the "step" of thread 1 never finishes.

gdb/testsuite/ChangeLog:
2015-08-07  Pedro Alves  <palves@redhat.com>

	* gdb.threads/step-over-lands-on-breakpoint.c (wait_threads):
	Delete function.
	(main): Add alarm.  Run an infinite loop instead of calling
	wait_threads.
	* gdb.threads/step-over-lands-on-breakpoint.exp (do_test): Change
	comment.
	* gdb.threads/step-over-trips-on-watchpoint.c (wait_threads):
	Delete function.
	(main): Add alarm.  Run an infinite loop instead of calling
	wait_threads.
	* gdb.threads/step-over-trips-on-watchpoint.exp (do_test): Change
	comment.
2015-08-07 17:26:21 +01:00

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# Copyright (C) 2014-2015 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 that when a step-over lands on a breakpoint, that breakpoint
# hit is reported.
standard_testfile
set executable ${testfile}
if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
executable [list debug "incdir=${objdir}"]] != "" } {
return -1
}
# The test proper. DISPLACED is true if we should try with displaced
# stepping. COMMAND is the execution command to test.
proc do_test {displaced command} {
global executable
with_test_prefix "displaced=$displaced: $command" {
clean_restart $executable
if ![runto_main] {
continue
}
gdb_test_no_output "set displaced-stepping $displaced"
gdb_breakpoint [gdb_get_line_number "set wait-thread breakpoint here"]
gdb_continue_to_breakpoint "run to wait-thread breakpoint"
gdb_test "info threads" "2 .*\\\* 1.*" "info threads shows all threads"
gdb_test_no_output "set scheduler-locking on"
delete_breakpoints
gdb_breakpoint [gdb_get_line_number "set breakpoint child here"]
gdb_test "thread 2" "Switching to .*"
gdb_continue_to_breakpoint "run to breakpoint in thread 2"
gdb_test "p counter = 0" " = 0" "unbreak loop in thread 2"
# Set a breakpoint exactly where the step-over will land.
gdb_breakpoint [gdb_get_line_number "breakpoint after step-over here"]
# Switch back to thread 1 and disable scheduler locking.
gdb_test "thread 1" "Switching to .*"
gdb_test_no_output "set scheduler-locking off"
# Thread 2 is still stopped at a breakpoint that needs to be
# stepped over. However, right where the step-over lands
# there's another breakpoint installed, which should trap and
# be reported to the user.
gdb_test "$command" "step-over here.*"
}
}
foreach displaced { "off" "on" } {
if { $displaced != "off" && ![support_displaced_stepping] } {
continue
}
# Cover both stepping and non-stepping execution commands.
foreach command { "step" "next" "continue" } {
do_test $displaced $command
}
}