# This testcase is part of GDB, the GNU debugger. # # Copyright 2013-2020 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 } } |