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# Copyright (C) 2021-2023 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 we can access memory while all the threads of the inferior
# are running, and even if:
#
# - the leader thread exits
# - the selected thread exits
#
# This test constantly spawns short lived threads to make sure that on
# systems with debug APIs that require passing down a specific thread
# to work with (e.g., GNU/Linux ptrace and /proc filesystem), GDB
# copes with accessing memory just while the thread it is accessing
# memory through exits.
#
# The test spawns two processes and alternates memory accesses between
# them to force flushing per-process caches. When the testcase was
# originally written, the Linux backend would access inferior memory
# via /proc/PID/mem, and kept one such file open, as a cache.
# Alternating inferiors would force re-opening such file for a
# different process, which would fail if GDB tried to open the file
# for a thread that exited. The test thus ensured those reopen/fail
# code paths were exercised. Nowadays, GDB keeps one /proc/PID/mem
# file open per inferior.
standard_testfile
if {[build_executable "failed to prepare" $testfile $srcfile {debug pthreads}] == -1} {
return -1
}
# The test proper. NON_STOP indicates whether we're testing in
# non-stop, or all-stop mode.
proc test { non_stop } {
global binfile
global gdb_prompt
global GDBFLAGS
save_vars { GDBFLAGS } {
append GDBFLAGS " -ex \"set non-stop $non_stop\""
clean_restart ${binfile}
}
if ![runto_main] {
return -1
}
# If debugging with target remote, check whether the all-stop variant
# of the RSP is being used. If so, we can't run the background tests.
if {!$non_stop
&& [target_info exists gdb_protocol]
&& ([target_info gdb_protocol] == "remote"
|| [target_info gdb_protocol] == "extended-remote")} {
gdb_test_multiple "maint show target-non-stop" "" {
-wrap -re "(is|currently) on.*" {
}
-wrap -re "(is|currently) off.*" {
unsupported "can't issue commands while target is running"
return 0
}
}
}
delete_breakpoints
# Start the second inferior.
with_test_prefix "second inferior" {
# With stub targets that do reload on run, if we let the new
# inferior share inferior 1's connection, runto_main would
# fail because GDB is already connected to something, like
# e.g. with --target_board=native-gdbserver:
#
# (gdb) kill
# ...
# (gdb) target remote localhost:2348
# Already connected to a remote target. Disconnect? (y or n)
#
# Instead, start the inferior with no connection, and let
# gdb_load/runto_main spawn a new remote connection/gdbserver.
#
# OTOH, with extended-remote, we must let the new inferior
# reuse the current connection, so that runto_main below can
# issue the "run" command, and have the inferior run on the
# remote target. If we forced no connection, then "run" would
# either fail if "set auto-connect-native-target" is on, like
# the native-extended-gdbserver board enforces, or it would
# run the inferior on the native target, which isn't what is
# being tested.
#
# Since it's reload_on_run targets that need special care, we
# default to reusing the connection on most targets.
if [target_info exists gdb,do_reload_on_run] {
gdb_test "add-inferior -no-connection" "New inferior 2.*"
} else {
gdb_test "add-inferior" "New inferior 2.*"
}
gdb_test "inferior 2" "Switching to inferior 2 .*"
gdb_load $binfile
if ![runto_main] {
return -1
}
}
delete_breakpoints
# These put too much noise in the logs.
gdb_test_no_output "set print thread-events off"
# Continue all threads of both processes.
gdb_test_no_output "set schedule-multiple on"
if {$non_stop == "off"} {
set cmd "continue &"
} else {
set cmd "continue -a &"
}
gdb_test_multiple $cmd "continuing" {
-re "Continuing\.\r\n$gdb_prompt " {
pass $gdb_test_name
}
}
# Like gdb_test, but:
# - don't issue a pass on success.
# - on failure, clear the ok variable in the calling context, and
# break it.
proc my_gdb_test {cmd pattern message} {
upvar inf inf
upvar iter iter
if {[gdb_test -nopass \
$cmd $pattern "access mem ($message, inf=$inf, iter=$iter)"] \
!= 0} {
uplevel 1 {set ok 0}
return -code break
}
}
# Hammer away for 5 seconds, alternating between inferiors.
set ::done 0
after 5000 { set ::done 1 }
set inf 1
set ok 1
set iter 0
while {!$::done && $ok} {
incr iter
verbose -log "xxxxx: iteration $iter"
gdb_test -nopass "info threads"
if {$inf == 1} {
set inf 2
} else {
set inf 1
}
my_gdb_test "inferior $inf" ".*" "inferior $inf"
my_gdb_test "print global_var = 555" " = 555" \
"write to global_var"
my_gdb_test "print global_var" " = 555" \
"print global_var after writing"
my_gdb_test "print global_var = 333" " = 333" \
"write to global_var again"
my_gdb_test "print global_var" " = 333" \
"print global_var after writing again"
}
if {$ok} {
pass "access mem"
}
}
foreach non_stop { "off" "on" } {
set stop_mode [expr ($non_stop=="off")?"all-stop":"non-stop"]
with_test_prefix "$stop_mode" {
test $non_stop
}
}
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