old-cross-binutils/gdb/testsuite/gdb.threads/schedlock.exp
Pedro Alves f303dbd60d Fix PR threads/19422 - show which thread caused stop
This commit changes GDB like this:

 - Program received signal SIGINT, Interrupt.
 + Thread 1 "main" received signal SIGINT, Interrupt.

 - Breakpoint 1 at 0x40087a: file threads.c, line 87.
 + Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file threads.c, line 87.

 ... once the program goes multi-threaded.  Until GDB sees a second
thread spawn, the output is still the same as before, per the
discussion back in 2012:

  https://www.sourceware.org/ml/gdb/2012-11/msg00010.html

This helps non-stop mode, where you can't easily tell which thread hit
a breakpoint or received a signal:

 (gdb) info threads
   Id   Target Id         Frame
 * 1    Thread 0x7ffff7fc1740 (LWP 19362) "main" (running)
   2    Thread 0x7ffff7fc0700 (LWP 19366) "foo" (running)
   3    Thread 0x7ffff77bf700 (LWP 19367) "bar" (running)
 (gdb)
 Program received signal SIGUSR1, User defined signal 1.
 0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
 92          lll_wait_tid (pd->tid);
 (gdb) b threads.c:87
 Breakpoint 1 at 0x40087a: file threads.c, line 87.
 (gdb)
 Breakpoint 1, thread_function1 (arg=0x1) at threads.c:87
 87              usleep (1);  /* Loop increment.  */

The best the user can do is run "info threads" and try to figure
things out.

It actually also affects all-stop mode, in case of "handle SIG print
nostop":

...
  Program received signal SIGUSR1, User defined signal 1.

  Program received signal SIGUSR1, User defined signal 1.

  Program received signal SIGUSR1, User defined signal 1.

  Program received signal SIGUSR1, User defined signal 1.
...

The above doesn't give any clue that these were different threads
getting the SIGUSR1 signal.

I initially thought of lowercasing "breakpoint" in

  "Thread 3 hit Breakpoint 1"

but then after trying it I realized that leaving "Breakpoint"
uppercase helps the eye quickly find the relevant information.  It's
also easier to implement not showing anything about threads until the
program goes multi-threaded this way.

Here's a larger example session in non-stop mode:

  (gdb) c -a&
  Continuing.
  (gdb) interrupt -a
  (gdb)
  Thread 1 "main" stopped.
  0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
  92          lll_wait_tid (pd->tid);

  Thread 2 "foo" stopped.
  0x0000003615ebc6ed in nanosleep () at ../sysdeps/unix/syscall-template.S:81
  81      T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)

  Thread 3 "bar" stopped.
  0x0000003615ebc6ed in nanosleep () at ../sysdeps/unix/syscall-template.S:81
  81      T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
  b threads.c:87
  Breakpoint 4 at 0x40087a: file threads.c, line 87.
  (gdb) b threads.c:67
  Breakpoint 5 at 0x400811: file threads.c, line 67.
  (gdb) c -a&
  Continuing.
  (gdb)
  Thread 3 "bar" hit Breakpoint 4, thread_function1 (arg=0x1) at threads.c:87
  87              usleep (1);  /* Loop increment.  */

  Thread 2 "foo" hit Breakpoint 5, thread_function0 (arg=0x0) at threads.c:68
  68              (*myp) ++;
  info threads
    Id   Target Id         Frame
  * 1  Thread 0x7ffff7fc1740 (LWP 31957) "main" (running)
    2  Thread 0x7ffff7fc0700 (LWP 31961) "foo" thread_function0 (arg=0x0) at threads.c:68
    3  Thread 0x7ffff77bf700 (LWP 31962) "bar" thread_function1 (arg=0x1) at threads.c:87
  (gdb) shell kill -SIGINT 31957
  (gdb)
  Thread 1 "main" received signal SIGINT, Interrupt.
  0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
  92          lll_wait_tid (pd->tid);
  info threads
    Id   Target Id         Frame
  * 1  Thread 0x7ffff7fc1740 (LWP 31957) "main" 0x0000003616a09237 in pthread_join (threadid=140737353877248, thread_return=0x7fffffffd5b8) at pthread_join.c:92
    2  Thread 0x7ffff7fc0700 (LWP 31961) "foo" thread_function0 (arg=0x0) at threads.c:68
    3  Thread 0x7ffff77bf700 (LWP 31962) "bar" thread_function1 (arg=0x1) at threads.c:87
  (gdb) t 2
  [Switching to thread 2, Thread 0x7ffff7fc0700 (LWP 31961)]
  #0  thread_function0 (arg=0x0) at threads.c:68
  68              (*myp) ++;
  (gdb) catch syscall
  Catchpoint 6 (any syscall)
  (gdb) c&
  Continuing.
  (gdb)
  Thread 2 "foo" hit Catchpoint 6 (call to syscall nanosleep), 0x0000003615ebc6ed in nanosleep () at ../sysdeps/unix/syscall-template.S:81
  81      T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)

I'll work on documentation next if this looks agreeable.

This patch applies on top of the star wildcards thread IDs series:

  https://sourceware.org/ml/gdb-patches/2016-01/msg00291.html

For convenience, I've pushed this to the
users/palves/show-which-thread-caused-stop branch.

gdb/doc/ChangeLog:
2016-01-18  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Threads): Mention that GDB displays the ID and name
	of the thread that hit a breakpoint or received a signal.

gdb/ChangeLog:
2016-01-18  Pedro Alves  <palves@redhat.com>

	* NEWS: Mention that GDB now displays the ID and name of the
	thread that hit a breakpoint or received a signal.
	* break-catch-sig.c (signal_catchpoint_print_it): Use
	maybe_print_thread_hit_breakpoint.
	* break-catch-syscall.c (print_it_catch_syscall): Likewise.
	* break-catch-throw.c (print_it_exception_catchpoint): Likewise.
	* breakpoint.c (maybe_print_thread_hit_breakpoint): New function.
	(print_it_catch_fork, print_it_catch_vfork, print_it_catch_solib)
	(print_it_catch_exec, print_it_ranged_breakpoint)
	(print_it_watchpoint, print_it_masked_watchpoint, bkpt_print_it):
	Use maybe_print_thread_hit_breakpoint.
	* breakpoint.h (maybe_print_thread_hit_breakpoint): Declare.
	* gdbthread.h (show_thread_that_caused_stop): Declare.
	* infrun.c (print_signal_received_reason): Print which thread
	received signal.
	* thread.c (show_thread_that_caused_stop): New function.

gdb/testsuite/ChangeLog:
2016-01-18  Pedro Alves  <palves@redhat.com>

	* gdb.base/async-shell.exp: Adjust expected output.
	* gdb.base/dprintf-non-stop.exp: Adjust expected output.
	* gdb.base/siginfo-thread.exp: Adjust expected output.
	* gdb.base/watchpoint-hw-hit-once.exp: Adjust expected output.
	* gdb.java/jnpe.exp: Adjust expected output.
	* gdb.threads/clone-new-thread-event.exp: Adjust expected output.
	* gdb.threads/continue-pending-status.exp: Adjust expected output.
	* gdb.threads/leader-exit.exp: Adjust expected output.
	* gdb.threads/manythreads.exp: Adjust expected output.
	* gdb.threads/pthreads.exp: Adjust expected output.
	* gdb.threads/schedlock.exp: Adjust expected output.
	* gdb.threads/siginfo-threads.exp: Adjust expected output.
	* gdb.threads/signal-command-multiple-signals-pending.exp: Adjust
	expected output.
	* gdb.threads/signal-delivered-right-thread.exp: Adjust expected
	output.
	* gdb.threads/sigthread.exp: Adjust expected output.
	* gdb.threads/watchpoint-fork.exp: Adjust expected output.
2016-01-18 15:15:18 +00:00

321 lines
8.1 KiB
Text

# Copyright (C) 1996-2016 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/>.
# This file was written by Daniel Jacobowitz <drow@mvista.com>
# (parts based on pthreads.exp by Fred Fish (fnf@cygnus.com).
#
# This test covers the various forms of "set scheduler-locking".
# This test requires sending ^C to interrupt the running target.
if [target_info exists gdb,nointerrupts] {
verbose "Skipping schedlock.exp because of nointerrupts."
return
}
standard_testfile
# The number of threads, including the main thread.
set NUM 2
if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable debug] != "" } {
return -1
}
# Now we can proceed with the real testing.
# Get the current contents of the `args` array in the test program.
# Description is appended to the test message.
proc get_args { description } {
global gdb_prompt
global NUM
set pattern "(\[0-9\]+)"
for {set i 1} {[expr $i < $NUM]} {incr i} {
append pattern ", (\[0-9\]+)"
}
set test "listed args ($description)"
gdb_test_multiple "print args" $test {
-re "\\\$\[0-9\]+ = {$pattern}.*$gdb_prompt $" {
pass $test
set result ""
for {set i 1} {[expr $i <= $NUM]} {incr i} {
lappend result $expect_out($i,string)
}
return $result
}
}
}
proc stop_process { description } {
global gdb_prompt
# For this to work we must be sure to consume the "Continuing."
# message first, or GDB's signal handler may not be in place.
after 1000 {send_gdb "\003"}
gdb_expect {
-re "Thread .* received signal SIGINT.*$gdb_prompt $"
{
pass $description
}
timeout
{
fail "$description (timeout)"
}
}
}
proc get_current_thread { description } {
global gdb_prompt
set test "find current thread ($description)"
gdb_test_multiple "bt" $test {
-re "thread_function \\(arg=0x(\[0-9\])\\).*$gdb_prompt $" {
pass $test
return $expect_out(1,string)
}
}
return ""
}
# Make sure we're stopped in the loop, in one of the non-main threads.
proc goto_loop { msg } {
gdb_breakpoint [concat [gdb_get_line_number "schedlock.exp: main loop"] " if arg != 0"]
set test "return to loop"
if {$msg != ""} {
set test "$test ($msg)"
}
gdb_continue_to_breakpoint $test
delete_breakpoints
}
proc my_continue { msg } {
set test "continue ($msg)"
gdb_test_multiple "continue" $test {
-re "Continuing" {
pass $test
}
}
stop_process "stop all threads ($msg)"
goto_loop $msg
}
# Use CMD to step the loop 10 times. CMD may be "step" or "next".
proc step_ten_loops { cmd } {
global gdb_prompt
for {set i 0} {[expr $i < 10]} {set i [expr $i + 1]} {
set other_step 0
set test "$cmd to increment ($i)"
gdb_test_multiple $cmd $test {
-re ".*myp\\) \\+\\+;\[\r\n\]+$gdb_prompt $" {
pass $test
}
-re "$gdb_prompt $" {
if {$other_step == 0} {
set other_step 1
send_gdb "$cmd\n"
exp_continue
} else {
fail $test
# FIXME cascade?
}
}
}
}
}
# Start with a fresh gdb.
gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir
# We'll need this when we send_gdb a ^C to GDB. Need to do it before we
# run the program and gdb starts saving and restoring tty states.
gdb_test "shell stty intr '^C'" ".*"
gdb_load ${binfile}
gdb_test_no_output "set print sevenbit-strings"
gdb_test_no_output "set width 0"
runto_main
# See if scheduler locking is available on this target.
global gdb_prompt
gdb_test_multiple "set scheduler-locking off" "scheduler locking set to none" {
-re "Target .* cannot support this command" {
unsupported "target does not support scheduler locking"
return
}
-re "$gdb_prompt $" {
pass "scheduler locking set to none"
}
timeout {
unsupported "target does not support scheduler locking (timeout)"
return
}
}
gdb_breakpoint [gdb_get_line_number "schedlock.exp: last thread start"]
gdb_continue_to_breakpoint "all threads started"
set start_args [get_args "before initial"]
# First make sure that all threads are alive.
my_continue "initial"
set cont_args [get_args "after initial"]
set bad 0
for {set i 0} {[expr $i < $NUM]} {set i [expr $i + 1]} {
if {[lindex $start_args $i] == [lindex $cont_args $i]} {
incr bad
}
}
if { $bad == 0 } {
pass "all threads alive"
} else {
fail "all threads alive ($bad/$NUM did not run)"
}
# Compare the previous thread and args with the current thread and
# args. Check that we didn't switch threads, and that the threads
# incremented their args counter the amounts expected. CMD is the
# command being tested. BEFORE_THREAD is the thread that was selected
# before the command was run. BEFORE_ARGS is the value of the
# thread's args before the command was run. LOCKED indicates whether
# we expect threads other than the selected thread remained locked.
proc check_result { cmd before_thread before_args locked } {
global NUM
# Make sure we're still in the same thread.
set newthread [get_current_thread "after"]
set test "$cmd does not change thread"
if {$before_thread == $newthread} {
pass "$test"
} else {
fail "$test (switched to thread $newthread)"
}
set after_args [get_args "after"]
set test "current thread advanced"
if { $locked } {
set test "$test - locked"
} else {
set test "$test - unlocked"
}
set num_other_threads 0
for {set i 0} {$i < $NUM} {incr i} {
if {[lindex $before_args $i] == [lindex $after_args $i]} {
if {$i == $before_thread} {
fail "$test (didn't run)"
}
} else {
if {$i == $before_thread} {
if {$cmd == "continue"
|| [lindex $before_args $i] == [expr [lindex $after_args $i] - 10]} {
pass "$test"
} else {
fail "$test (wrong amount)"
}
} else {
incr num_other_threads
}
}
}
if { $locked } {
gdb_assert {$num_other_threads == 0} "other threads didn't run - locked"
} else {
gdb_assert {$num_other_threads > 0} "other threads ran - unlocked"
}
}
with_test_prefix "schedlock=on: cmd=continue" {
# Use whichever we stopped in.
set curthread [get_current_thread "before"]
# Test continue with scheduler locking.
gdb_test "set scheduler-locking on" ""
my_continue "with lock"
check_result "continue" $curthread $cont_args 1
}
# Test stepping/nexting with different modes of scheduler locking.
proc test_step { schedlock cmd call_function } {
global NUM
gdb_test_no_output "set scheduler-locking off"
goto_loop ""
set curthread [get_current_thread "before"]
# No need to set to off again. This avoids a duplicate message.
if {$schedlock != "off"} {
gdb_test_no_output "set scheduler-locking $schedlock"
}
gdb_test "print call_function = $call_function" \
" = $call_function"
set before_args [get_args "before"]
step_ten_loops $cmd
if { $schedlock == "on" || $schedlock == "step" } {
set locked 1
} else {
set locked 0
}
check_result $cmd $curthread $before_args $locked
}
# Test stepping/nexting with different modes of scheduler locking.
foreach schedlock {"off" "step" "on"} {
with_test_prefix "schedlock=$schedlock" {
with_test_prefix "cmd=step" {
test_step $schedlock "step" 0
}
with_test_prefix "cmd=next" {
# In GDB <= 7.9, with schedlock "step", "next" would
# unlock threads when stepping over a function call. This
# exercises "next" with and without a function call. WRT
# "schedlock step", "next" should behave just like "step".
foreach call_function {0 1} {
with_test_prefix "call_function=$call_function" {
test_step $schedlock "next" $call_function
}
}
}
}
}