From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f47.google.com (mail-wm1-f47.google.com [209.85.128.47]) by sourceware.org (Postfix) with ESMTPS id 04F95388DF18 for ; Wed, 13 Jul 2022 22:25:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 04F95388DF18 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=palves.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wm1-f47.google.com with SMTP id v67-20020a1cac46000000b003a1888b9d36so2066467wme.0 for ; Wed, 13 Jul 2022 15:25:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9QJrAjglU0sZvHi3QDL6xPaTmbsTLq68JxCM5icum7k=; b=ErYn9b1nuSs2gWYj+C5y9bzgc5GvCxJMpaTzd0H/j1NTZbJGfuBOD3sxwNYZyXNe5O FA6WsFnxG8/FGulx68iEMxxwND0Wlb2VS3D6pt9l+tSLWQVQIvW5ay+hclV1CxmVEzJC u3vgHZwC0dD5RxYnwEt0eAD/AhXK5oXDnXAjp8k1d/YWNNdvuxA/7NzwZSztYZtHPaJ2 gZqmdtWqquSpDrSeyLjVtxOgZIbspk6rRC5PWeElLfc4fc3Ivc++7VfOT+R0Lb6nJCfN 9sR36WQOqmbY1Wc7Gmer4VEWT2hkV8DKLMegzzNxQdIeeBnRoAL9SlL8HOqQZP4hdi3w UCRQ== X-Gm-Message-State: AJIora9P6gEdbbGIRJ0AyZTNfADMb8Qg8zeK+O0w2KgLFXwgM+1HS+gG 306x5ROygdJl+tR5URc/6pvnWe5Culk= X-Google-Smtp-Source: AGRyM1uj9/kwlNCv6esasygzietCrWBgRbNqXIZ8yxCxaMaowiKXSUXPDhJQtFf3YD2FZhQQXLUI6Q== X-Received: by 2002:a7b:c31a:0:b0:39c:4783:385e with SMTP id k26-20020a7bc31a000000b0039c4783385emr11743896wmj.185.1657751140700; Wed, 13 Jul 2022 15:25:40 -0700 (PDT) Received: from localhost ([2001:8a0:f924:2600:209d:85e2:409e:8726]) by smtp.gmail.com with ESMTPSA id v8-20020a5d43c8000000b0021dc289b72fsm201329wrr.49.2022.07.13.15.25.39 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 13 Jul 2022 15:25:39 -0700 (PDT) From: Pedro Alves To: gdb-patches@sourceware.org Subject: [PATCH v2 29/29] Cancel execution command on thread exit, when stepping, nexting, etc. Date: Wed, 13 Jul 2022 23:24:33 +0100 Message-Id: <20220713222433.374898-30-pedro@palves.net> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220713222433.374898-1-pedro@palves.net> References: <20220713222433.374898-1-pedro@palves.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-9.9 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, GIT_PATCH_0, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Jul 2022 22:25:44 -0000 If your target has no support for TARGET_WAITKIND_NO_RESUMED events (and no way to support them, such as the yet-unsubmitted AMDGPU target), and you step over thread exit with scheduler-locking on, this is what you get: (gdb) n [Thread ... exited] *hang* Getting back the prompt by typing Ctrl-C may not even work, since no inferior thread is running to receive the SIGINT. Even if it works, it seems unnecessarily harsh. If you started an execution command for which there's a clear thread of interest (step, next, until, etc.), and that thread disappears, then I think it's more user friendly if GDB just detects the situation and aborts the command, giving back the prompt. That is what this commit implements. It does this by explicitly requesting the target to report thread exit events whenever the main resumed thread has a thread_fsm. Note that unlike stepping over a breakpoint, we don't need to enable clone events in this case. With this patch, we get: (gdb) n [Thread 0x7ffff7d89700 (LWP 3961883) exited] Command aborted, thread exited. (gdb) Change-Id: I901ab64c91d10830590b2dac217b5264635a2b95 --- gdb/infrun.c | 73 ++++++++++++++++--- .../gdb.threads/step-over-thread-exit.exp | 28 ++++--- 2 files changed, 81 insertions(+), 20 deletions(-) diff --git a/gdb/infrun.c b/gdb/infrun.c index c410dcdeb20..66a204a9a58 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -1818,6 +1818,22 @@ displaced_step_prepare (thread_info *thread) return status; } +/* True if any thread of TARGET that matches RESUME_PTID requires + target_thread_events enabled. This assumes TARGET does not support + target thread options. */ + +static bool +any_thread_needs_target_thread_events (process_stratum_target *target, + ptid_t resume_ptid) +{ + for (thread_info *tp : all_non_exited_threads (target, resume_ptid)) + if (displaced_step_in_progress_thread (tp) + || schedlock_applies (tp) + || tp->thread_fsm () != nullptr) + return true; + return false; +} + /* Maybe disable thread-{cloned,created,exited} event reporting after a step-over (either in-line or displaced) finishes. */ @@ -1841,9 +1857,10 @@ update_thread_events_after_step_over (thread_info *event_thread, else { /* We can only control the target-wide target_thread_events - setting. Disable it, but only if other threads don't need it - enabled. */ - if (!displaced_step_in_progress_any_thread ()) + setting. Disable it, but only if other threads in the target + don't need it enabled. */ + process_stratum_target *target = event_thread->inf->process_target (); + if (!any_thread_needs_target_thread_events (target, minus_one_ptid)) target_thread_events (false); } } @@ -2418,12 +2435,25 @@ do_target_resume (ptid_t resume_ptid, bool step, enum gdb_signal sig) else target_thread_events (true); } + else if (tp->thread_fsm () != nullptr) + { + gdb_thread_options options = GDB_TO_EXIT; + if (target_supports_set_thread_options (options)) + tp->set_thread_options (options); + else + target_thread_events (true); + } else { if (target_supports_set_thread_options (0)) tp->set_thread_options (0); - else if (!displaced_step_in_progress_any_thread ()) - target_thread_events (false); + else + { + process_stratum_target *resume_target = tp->inf->process_target (); + if (!any_thread_needs_target_thread_events (resume_target, + resume_ptid)) + target_thread_events (false); + } } /* If we're resuming more than one thread simultaneously, then any @@ -5581,6 +5611,13 @@ handle_thread_exited (execution_control_state *ecs) ecs->event_thread->stepping_over_breakpoint = 0; ecs->event_thread->stepping_over_watchpoint = 0; + /* If the thread had an FSM, then abort the command. But only after + finishing the step over, as in non-stop mode, aborting this + thread's command should not interfere with other threads. We + must check this before finish_step over, however, which may + update the thread list and delete the event thread. */ + bool abort_cmd = (ecs->event_thread->thread_fsm () != nullptr); + /* Maybe the thread was doing a step-over, if so release resources and start any further pending step-overs. @@ -5594,6 +5631,13 @@ handle_thread_exited (execution_control_state *ecs) the event thread has exited. */ gdb_assert (ret == 0); + if (abort_cmd) + { + delete_thread (ecs->event_thread); + ecs->event_thread = nullptr; + return false; + } + /* If finish_step_over started a new in-line step-over, don't try to restart anything else. */ if (step_over_info_valid_p ()) @@ -8978,7 +9022,8 @@ normal_stop (void) if (inferior_ptid != null_ptid) finish_ptid = ptid_t (inferior_ptid.pid ()); } - else if (last.kind () != TARGET_WAITKIND_NO_RESUMED) + else if (last.kind () != TARGET_WAITKIND_NO_RESUMED + && last.kind () != TARGET_WAITKIND_THREAD_EXITED) finish_ptid = inferior_ptid; gdb::optional maybe_finish_thread_state; @@ -9022,7 +9067,8 @@ normal_stop (void) && target_has_execution () && last.kind () != TARGET_WAITKIND_SIGNALLED && last.kind () != TARGET_WAITKIND_EXITED - && last.kind () != TARGET_WAITKIND_NO_RESUMED) + && last.kind () != TARGET_WAITKIND_NO_RESUMED + && last.kind () != TARGET_WAITKIND_THREAD_EXITED) { SWITCH_THRU_ALL_UIS () { @@ -9034,7 +9080,8 @@ normal_stop (void) previous_inferior_ptid = inferior_ptid; } - if (last.kind () == TARGET_WAITKIND_NO_RESUMED) + if (last.kind () == TARGET_WAITKIND_NO_RESUMED + || last.kind () == TARGET_WAITKIND_THREAD_EXITED) { stop_print_frame = false; @@ -9042,7 +9089,12 @@ normal_stop (void) if (current_ui->prompt_state == PROMPT_BLOCKED) { target_terminal::ours_for_output (); - gdb_printf (_("No unwaited-for children left.\n")); + if (last.kind () == TARGET_WAITKIND_NO_RESUMED) + gdb_printf (_("No unwaited-for children left.\n")); + else if (last.kind () == TARGET_WAITKIND_THREAD_EXITED) + gdb_printf (_("Command aborted, thread exited.\n")); + else + gdb_assert_not_reached ("unhandled"); } } @@ -9127,7 +9179,8 @@ normal_stop (void) { if (last.kind () != TARGET_WAITKIND_SIGNALLED && last.kind () != TARGET_WAITKIND_EXITED - && last.kind () != TARGET_WAITKIND_NO_RESUMED) + && last.kind () != TARGET_WAITKIND_NO_RESUMED + && last.kind () != TARGET_WAITKIND_THREAD_EXITED) /* Delete the breakpoint we stopped at, if it wants to be deleted. Delete any breakpoint that is to be deleted at the next stop. */ breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat); diff --git a/gdb/testsuite/gdb.threads/step-over-thread-exit.exp b/gdb/testsuite/gdb.threads/step-over-thread-exit.exp index 910577f5b9f..1b7341422fd 100644 --- a/gdb/testsuite/gdb.threads/step-over-thread-exit.exp +++ b/gdb/testsuite/gdb.threads/step-over-thread-exit.exp @@ -29,7 +29,7 @@ if { [build_executable "failed to prepare" $testfile \ # NS_STOP_ALL is only used if testing "set non-stop on", and indicates # whether to have GDB explicitly stop all threads before continuing to # thread exit. -proc test {displaced-stepping non-stop target-non-stop schedlock ns_stop_all} { +proc test {displaced-stepping non-stop target-non-stop schedlock cmd ns_stop_all} { if {${non-stop} == "off" && $ns_stop_all} { error "invalid arguments" } @@ -72,9 +72,15 @@ proc test {displaced-stepping non-stop target-non-stop schedlock ns_stop_all} { gdb_test_no_output "set scheduler-locking ${schedlock}" - gdb_test "continue" \ - "No unwaited-for children left." \ - "continue stops when thread exits" + if {$cmd == "continue"} { + gdb_test "continue" \ + "No unwaited-for children left." \ + "continue stops when thread exits" + } else { + gdb_test $cmd \ + "Command aborted, thread exited\\." \ + "command aborts when thread exits" + } } else { gdb_test_no_output "set scheduler-locking ${schedlock}" @@ -108,13 +114,15 @@ foreach_with_prefix displaced-stepping {off auto} { } foreach_with_prefix schedlock {off on} { - if {${non-stop} == "on"} { - foreach_with_prefix ns_stop_all {0 1} { - test ${displaced-stepping} ${non-stop} ${target-non-stop} \ - ${schedlock} ${ns_stop_all} + foreach_with_prefix cmd {"next" "continue"} { + if {${non-stop} == "on"} { + foreach_with_prefix ns_stop_all {0 1} { + test ${displaced-stepping} ${non-stop} ${target-non-stop} \ + ${schedlock} ${cmd} ${ns_stop_all} + } + } else { + test ${displaced-stepping} ${non-stop} ${target-non-stop} ${schedlock} ${cmd} 0 } - } else { - test ${displaced-stepping} ${non-stop} ${target-non-stop} ${schedlock} 0 } } } -- 2.36.0