From patchwork Thu Jul 3 15:13:22 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 1884 Received: (qmail 13011 invoked by alias); 3 Jul 2014 15:13:57 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 12791 invoked by uid 89); 3 Jul 2014 15:13:54 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL, BAYES_00, SPF_HELO_PASS, SPF_PASS, T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 03 Jul 2014 15:13:45 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s63FDhd5022405 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 3 Jul 2014 11:13:43 -0400 Received: from brno.lan (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s63FDQOp021950 for ; Thu, 3 Jul 2014 11:13:42 -0400 From: Pedro Alves To: gdb-patches@sourceware.org Subject: [PATCH 7/9] Remove the target from the event loop while in secondary prompts Date: Thu, 3 Jul 2014 16:13:22 +0100 Message-Id: <1404400406-16708-15-git-send-email-palves@redhat.com> In-Reply-To: <1404400406-16708-1-git-send-email-palves@redhat.com> References: <1404400406-16708-1-git-send-email-palves@redhat.com> If a pagination prompt triggers while the target is running, and the target exits before the user responded to the pagination query, this happens: Starting program: foo ---Type to continue, or q to quit---No unwaited-for children left. Couldn't get registers: No such process. Couldn't get registers: No such process. Couldn't get registers: No such process. (gdb) Couldn't get registers: No such process. (gdb) To reiterate, the user hasn't replied to the pagination prompt above. A pagination query nests an event loop (in gdb_readline_wrapper). In async mode, in addition to stdin and signal handlers, we'll have the target also installed in the event loop still. So if the target stops, that wakes up the nested event loop, handles the event and generates further output, all while we should be waiting for pagination confirmation... I've played with a couple different approaches to fixing this, while at the same time trying to be not very invasive. Both revolve around not listening to target events while in a pagination prompt (doing anything else I think would be a much bigger change). The approach taken just removes the target from the event loop while within gdb_readline_wrapper. The other approach used gdb_select directly, with only input_fd installed, but that had the issue that it didn't handle the async signal handlers, and turned out to be a bit more code than the first version. gdb/ 2014-07-03 Pedro Alves PR gdb/17072 * top.c: Include "inf-loop.h". (struct gdb_readline_wrapper_cleanup) : New field. (gdb_readline_wrapper_cleanup): Make the target async again, if it was async before. (gdb_readline_wrapper): Store whether the target is async, and make it sync. gdb/testsuite/ 2014-07-03 Pedro Alves PR gdb/17072 * gdb.base/paginate-inferior-exit.c: New file. * gdb.base/paginate-inferior-exit.exp: New file. --- gdb/testsuite/gdb.base/paginate-inferior-exit.c | 30 +++++++++ gdb/testsuite/gdb.base/paginate-inferior-exit.exp | 82 +++++++++++++++++++++++ gdb/top.c | 12 ++++ 3 files changed, 124 insertions(+) create mode 100644 gdb/testsuite/gdb.base/paginate-inferior-exit.c create mode 100644 gdb/testsuite/gdb.base/paginate-inferior-exit.exp diff --git a/gdb/testsuite/gdb.base/paginate-inferior-exit.c b/gdb/testsuite/gdb.base/paginate-inferior-exit.c new file mode 100644 index 0000000..7457b18 --- /dev/null +++ b/gdb/testsuite/gdb.base/paginate-inferior-exit.c @@ -0,0 +1,30 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2014 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 . */ + +static void +after_sleep (void) +{ + return; /* after sleep */ +} + +int +main (void) +{ + sleep (3); + after_sleep (); + return 0; +} diff --git a/gdb/testsuite/gdb.base/paginate-inferior-exit.exp b/gdb/testsuite/gdb.base/paginate-inferior-exit.exp new file mode 100644 index 0000000..3418de8 --- /dev/null +++ b/gdb/testsuite/gdb.base/paginate-inferior-exit.exp @@ -0,0 +1,82 @@ +# Copyright (C) 2014 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 . + +# A collection of tests related to running execution commands directly +# from the command line, with "-ex". + +standard_testfile + +if {[build_executable "failed to prepare" $testfile $srcfile debug] == -1} { + return -1 +} + +# Test paginating while printing about the inferior having exited. +# +proc test_paginate_inferior_exited {} { + global binfile + global gdb_prompt pagination_prompt + global inferior_exited_re + + with_test_prefix "paginate" { + clean_restart $binfile + + if ![runto_main] then { + fail "Can't run to main" + return 0 + } + + # Force pagination. + gdb_test_no_output "set height 2" + + set test "continue to pagination" + + # Wait for the "Starting program" line, indicating the program + # is running. + set saw_starting 0 + gdb_test_multiple "continue" $test { + -re "$pagination_prompt" { + if {$saw_starting} { + pass $test + } else { + send_gdb "\n" + exp_continue + } + } + -re "Continuing" { + set saw_starting 1 + exp_continue + } + -notransfer -re "" { + # Otherwise gdb_test_multiple considers this an error. + exp_continue + } + } + + # We're now stopped in a pagination output while handling a + # target event, trying to print about the program exiting. + set test "inferior exits normally" + + send_gdb "\n" + gdb_test_multiple "" $test { + -re "$inferior_exited_re normally.*$gdb_prompt $" { + pass $test + } + } + + gdb_test "p 1" " = 1" "GDB accepts further input" + } +} + +test_paginate_inferior_exited diff --git a/gdb/top.c b/gdb/top.c index 93a4a16..19c88f9 100644 --- a/gdb/top.c +++ b/gdb/top.c @@ -68,6 +68,7 @@ #include "ui-out.h" #include "cli-out.h" #include "tracepoint.h" +#include "inf-loop.h" extern void initialize_all_files (void); @@ -766,6 +767,9 @@ struct gdb_readline_wrapper_cleanup { void (*handler_orig) (char *); int already_prompted_orig; + + /* Whether the target was async. */ + int target_is_async_orig; }; static void @@ -789,6 +793,9 @@ gdb_readline_wrapper_cleanup (void *arg) after_char_processing_hook = saved_after_char_processing_hook; saved_after_char_processing_hook = NULL; + if (cleanup->target_is_async_orig) + target_async (inferior_event_handler, 0); + xfree (cleanup); } @@ -805,8 +812,13 @@ gdb_readline_wrapper (char *prompt) cleanup->already_prompted_orig = rl_already_prompted; + cleanup->target_is_async_orig = target_is_async_p (); + back_to = make_cleanup (gdb_readline_wrapper_cleanup, cleanup); + if (cleanup->target_is_async_orig) + target_async (NULL, NULL); + /* Display our prompt and prevent double prompt display. */ display_gdb_prompt (prompt); rl_already_prompted = 1;