old-cross-binutils/gdb/testsuite/gdb.threads/manythreads.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

184 lines
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Text

# manythreads.exp -- Expect script to test stopping many threads
# Copyright (C) 2004-2016 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 Jeff Johnston. (jjohnstn@redhat.com)
# This test requires sending ^C to interrupt the running target.
if [target_info exists gdb,nointerrupts] {
verbose "Skipping manythreads.exp because of nointerrupts."
return
}
standard_testfile
set opts { debug }
if [info exists DEBUG] {
# make check RUNTESTFLAGS='gdb.threads/manythreads.exp DEBUG=1'
lappend opts "additional_flags=-DDEBUG"
}
if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable $opts] != "" } {
return -1
}
clean_restart ${binfile}
gdb_test_no_output "set print sevenbit-strings"
runto_main
# We'll need this when we send_gdb a ^C to GDB. Need to do it before we
# run the program and gdb starts saving and restoring tty states.
gdb_test "shell stty intr '^C'" ".*"
set message "first continue"
gdb_test_multiple "continue" "first continue" {
-re "error:.*$gdb_prompt $" {
fail "$message"
}
-re "Continuing" {
pass "$message"
}
}
# Wait one second. This is better than the TCL "after" command, because
# we don't lose GDB's output while we do it.
remote_expect host 1 { timeout { } }
# Send a Ctrl-C and wait for the SIGINT.
proc interrupt_and_wait { message } {
global gdb_prompt
send_gdb "\003"
gdb_test_multiple "" $message {
-re "\\\[New \[^\]\]*\\\]\r\n" {
exp_continue
}
-re "\\\[\[^\]\]* exited\\\]\r\n" {
exp_continue
}
-re " received signal SIGINT.*$gdb_prompt $" {
pass "$message"
}
-re "$gdb_prompt $" {
# Note that with this regex order, if GDB emits [New
# Thread ...] output between "Program received signal" and
# the prompt, the "received signal" regex won't match.
# That's good, as if we see that happening, it's a
# regression.
#
# GDB makes sure to notify about signal stops, end of
# stepping ranges, etc., only after updating the thread
# list, otherwise that stop info would be easy to miss.
#
# A BROKEN example would be:
#
# ... pages of new threads output ...
# [New Thread NNN]
# ^C
# ... more new threads output ...
# [New Thread NNN]
# [New Thread NNN]
# Thread NNN received signal SIGINT, Interrupt.
# [New Thread NNN]
# [New Thread NNN]
# ... pages of new threads output ...
# [Switching to Thread NNN]
# foo () at foo.c:31
# 31 bar ();
#
fail $message
}
}
}
# Send a Ctrl-C and verify that we can do info threads and continue
interrupt_and_wait "stop threads 1"
set cmd "info threads"
set ok 0
gdb_test_multiple $cmd $cmd {
-re " 1 *Thread " {
set ok 1
exp_continue
}
-re ".*\r\n" {
# Eat this line and continue, to prevent the buffer overflowing.
exp_continue
}
-re "$gdb_prompt $" {
if { $ok } {
pass $cmd
} else {
fail $cmd
}
}
}
gdb_test_no_output "thread name zardoz" "give a name to the thread"
gdb_test "info threads" ".*zardoz.*" "check thread name"
set message "second continue"
gdb_test_multiple "continue" "second continue" {
-re "error:.*$gdb_prompt $" {
fail "$message"
}
-re "Continuing" {
pass "$message"
}
}
# Wait another second. If the program stops on its own, GDB has failed
# to handle duplicate SIGINTs sent to multiple threads.
set failed 0
remote_expect host 1 {
-re "\\\[New \[^\]\]*\\\]\r\n" {
exp_continue -continue_timer
}
-re "\\\[\[^\]\]* exited\\\]\r\n" {
exp_continue -continue_timer
}
-re "Program received signal SIGINT.*$gdb_prompt $" {
if { $failed == 0 } {
fail "check for duplicate SIGINT"
}
send_gdb "continue\n"
set failed 1
exp_continue
}
timeout {
if { $failed == 0 } {
pass "check for duplicate SIGINT"
}
}
}
# Send another Ctrl-C and verify that we can do info threads and quit
interrupt_and_wait "stop threads 2"
gdb_test_multiple "quit" "GDB exits after stopping multithreaded program" {
-re "Quit anyway\\? \\(y or n\\) $" {
send_gdb "y\n"
exp_continue
}
eof {
pass "GDB exits after stopping multithreaded program"
}
timeout {
fail "GDB exits after stopping multithreaded program (timeout)"
}
}