diff options
| -rw-r--r-- | gdb/ChangeLog | 10 | ||||
| -rw-r--r-- | gdb/linux-nat.c | 23 | ||||
| -rw-r--r-- | gdb/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.threads/continue-pending-after-query.c | 48 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.threads/continue-pending-after-query.exp | 90 |
5 files changed, 163 insertions, 13 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index b358c26..818eb7c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2015-01-23 Pedro Alves <palves@redhat.com> + + * linux-nat.c (linux_is_async_p): New macro. + (linux_nat_is_async_p): + (linux_nat_terminal_inferior): Check whether the target can async + instead of whether it is already async. + (linux_nat_terminal_ours): Don't check whether the target is + async. + (linux_async_pipe): Use linux_is_async_p. + 2015-01-22 Jan Kratochvil <jan.kratochvil@redhat.com> * NEWS (Changes since GDB 7.9): Add 'thread apply all' option diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index be52470..b49cd57 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -219,6 +219,9 @@ struct simple_pid_list *stopped_pids; event loop. */ static int linux_nat_event_pipe[2] = { -1, -1 }; +/* True if we're currently in async mode. */ +#define linux_is_async_p() (linux_nat_event_pipe[0] != -1) + /* Flush the event pipe. */ static void @@ -4302,10 +4305,7 @@ linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) static int linux_nat_is_async_p (struct target_ops *ops) { - /* NOTE: palves 2008-03-21: We're only async when the user requests - it explicitly with the "set target-async" command. - Someday, linux will always be async. */ - return target_async_permitted; + return linux_is_async_p (); } /* target_can_async_p implementation. */ @@ -4355,7 +4355,11 @@ static int async_terminal_is_ours = 1; static void linux_nat_terminal_inferior (struct target_ops *self) { - if (!target_is_async_p ()) + /* Like target_terminal_inferior, use target_can_async_p, not + target_is_async_p, since at this point the target is not async + yet. If it can async, then we know it will become async prior to + resume. */ + if (!target_can_async_p ()) { /* Async mode is disabled. */ child_terminal_inferior (self); @@ -4385,13 +4389,6 @@ linux_nat_terminal_inferior (struct target_ops *self) static void linux_nat_terminal_ours (struct target_ops *self) { - if (!target_is_async_p ()) - { - /* Async mode is disabled. */ - child_terminal_ours (self); - return; - } - /* GDB should never give the terminal to the inferior if the inferior is running in the background (run&, continue&, etc.), but claiming it sure should. */ @@ -4444,7 +4441,7 @@ handle_target_event (int error, gdb_client_data client_data) static int linux_async_pipe (int enable) { - int previous = (linux_nat_event_pipe[0] != -1); + int previous = linux_is_async_p (); if (previous != enable) { diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index faf8493..1a17ba4 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2015-01-23 Pedro Alves <palves@redhat.com> + + * gdb.threads/continue-pending-after-query.c: New file. + * gdb.threads/continue-pending-after-query.exp: New file. + 2015-01-22 Anders Granlund <anders.granlund@ericsson.com> Simon Marchi <simon.marchi@ericsson.com> diff --git a/gdb/testsuite/gdb.threads/continue-pending-after-query.c b/gdb/testsuite/gdb.threads/continue-pending-after-query.c new file mode 100644 index 0000000..9510ce8 --- /dev/null +++ b/gdb/testsuite/gdb.threads/continue-pending-after-query.c @@ -0,0 +1,48 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2013-2015 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/>. */ + +#include <pthread.h> + +static int global; + +static void +break_function (void) +{ + global = 42; /* set break here */ +} + +static void * +thread_function (void *arg) +{ + break_function (); + + return arg; +} + +int +main (void) +{ + pthread_t th; + + pthread_create (&th, NULL, thread_function, NULL); + + break_function (); + + pthread_join (th, NULL); + + return 0; +} diff --git a/gdb/testsuite/gdb.threads/continue-pending-after-query.exp b/gdb/testsuite/gdb.threads/continue-pending-after-query.exp new file mode 100644 index 0000000..d4d50c9 --- /dev/null +++ b/gdb/testsuite/gdb.threads/continue-pending-after-query.exp @@ -0,0 +1,90 @@ +# This testcase is part of GDB, the GNU debugger. +# +# Copyright 2013-2015 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/>. + +# Regression test for a bug that would go like this: +# +# - Run to a breakpoint that is hit by two threads (A and B) +# simultaneously. +# +# - One of the breakpoint hits is processed (e.g., thread A) and +# causes a user-visible stop. The other (thread B) is left pending. +# +# - The user deletes the breakpoint with "del", which causes a +# confirmation query. +# +# - By mistake, that would result in the target being left with async +# enabled, even though it wasn't to begin with. +# +# - GDB reacts to target async enablement by polling for target +# events. As no thread is resumed the target replies +# TARGET_WAITKIND_NO_RESUMED. +# +# - The user continues the program, expecting it to exit. The thread +# that has an event pending (thread B) is not really resumed. +# +# - But, nothing signals the event loop that there's a pending event +# waiting to be collected for thread B, so that event is never +# processed, thread B is never resumed and the program never exits. +# +# Ref: https://sourceware.org/ml/gdb-patches/2015-01/msg00592.html + +standard_testfile + +if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug pthreads}] == -1} { + return -1 +} + +proc test {} { + global srcfile gdb_prompt + + if ![runto_main] { + return -1 + } + + delete_breakpoints + + set bp_line [gdb_get_line_number "set break here" $srcfile] + + gdb_breakpoint "break_function" + gdb_continue_to_breakpoint "cont to break_function" ".*$srcfile:$bp_line\r\n.*" + + # Do something that causes a query/secondary prompt. + + set test "delete breakpoints, answer prompt" + set saw_prompt 0 + gdb_test_multiple "delete breakpoints" $test { + -re "Delete all breakpoints.*y or n.*$" { + set saw_prompt 1 + send_gdb "y\n" + exp_continue + } + -re "$gdb_prompt $" { + gdb_assert $saw_prompt $test + } + } + + gdb_continue_to_end "" "continue" 1 +} + +# Test a few times to make sure an event is left pending. At the time +# of writing, the bug always triggers, but that might naturally depend +# on machine. +for {set i 1} {$i <= 10} {incr i} { + with_test_prefix "iter $i" { + test + } +} |