From patchwork Tue Oct 1 20:12:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Tromey X-Patchwork-Id: 34776 Received: (qmail 41889 invoked by alias); 1 Oct 2019 20:12:42 -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 41830 invoked by uid 89); 1 Oct 2019 20:12:42 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-21.3 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_PASS autolearn=ham version=3.3.1 spammy=queued X-HELO: gateway20.websitewelcome.com Received: from gateway20.websitewelcome.com (HELO gateway20.websitewelcome.com) (192.185.64.36) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 01 Oct 2019 20:12:38 +0000 Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway20.websitewelcome.com (Postfix) with ESMTP id D7E7A400F2221 for ; Tue, 1 Oct 2019 14:05:50 -0500 (CDT) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id FOVfi2dFBPUvSFOVgighMy; Tue, 01 Oct 2019 15:12:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=s8VJ17QFlq9NU1BXv5jrZ2wSOFAkdQc5w+HPMf0yg7o=; b=GsZBCTIIb2HaBp+4UizaHJxZWR YlVK8Hp4WViwjvdHpmbur8heSOV/m2TkrRnLOtBVcxX1uQS3yYIy8ENW1Rj18N7C+nXb5+FepRFxx RlJIdOPoM1PlYEwayotrMXmyE; Received: from 75-166-72-156.hlrn.qwest.net ([75.166.72.156]:47310 helo=bapiya.Home) by box5379.bluehost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92) (envelope-from ) id 1iFOVf-0023p5-FW; Tue, 01 Oct 2019 14:12:35 -0600 From: Tom Tromey To: gdb-patches@sourceware.org Cc: Tom Tromey Subject: [PATCH v4 07/11] Introduce run_on_main_thread Date: Tue, 1 Oct 2019 14:12:23 -0600 Message-Id: <20191001201227.8519-8-tom@tromey.com> In-Reply-To: <20191001201227.8519-1-tom@tromey.com> References: <20191001201227.8519-1-tom@tromey.com> This introduces a way for a callback to be run on the main thread. gdb/ChangeLog 2019-10-01 Tom Tromey * unittests/main-thread-selftests.c: New file. * Makefile.in (SUBDIR_UNITTESTS_SRCS): Add main-thread-selftests.c. * ser-event.h (run_on_main_thread): Declare. * ser-event.c (runnable_event, runnables, runnable_mutex): New globals. (run_events, run_on_main_thread, _initialize_ser_event): New functions. --- gdb/ChangeLog | 11 ++++ gdb/Makefile.in | 1 + gdb/ser-event.c | 78 ++++++++++++++++++++++++++ gdb/ser-event.h | 6 ++ gdb/unittests/main-thread-selftests.c | 80 +++++++++++++++++++++++++++ 5 files changed, 176 insertions(+) create mode 100644 gdb/unittests/main-thread-selftests.c diff --git a/gdb/Makefile.in b/gdb/Makefile.in index c4c858b5594..d4eca61d06e 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -426,6 +426,7 @@ SUBDIR_UNITTESTS_SRCS = \ unittests/optional-selftests.c \ unittests/parse-connection-spec-selftests.c \ unittests/ptid-selftests.c \ + unittests/main-thread-selftests.c \ unittests/mkdir-recursive-selftests.c \ unittests/rsp-low-selftests.c \ unittests/scoped_fd-selftests.c \ diff --git a/gdb/ser-event.c b/gdb/ser-event.c index a65a186526f..029ced7619c 100644 --- a/gdb/ser-event.c +++ b/gdb/ser-event.c @@ -20,6 +20,10 @@ #include "ser-event.h" #include "serial.h" #include "gdbsupport/filestuff.h" +#if CXX_STD_THREAD +#include +#endif +#include "event-loop.h" /* On POSIX hosts, a serial_event is basically an abstraction for the classical self-pipe trick. @@ -217,3 +221,77 @@ serial_event_clear (struct serial_event *event) ResetEvent (state->event); #endif } + + + +/* The serial event used when posting runnables. */ + +static struct serial_event *runnable_event; + +/* Runnables that have been posted. */ + +static std::vector> runnables; + +#if CXX_STD_THREAD + +/* Mutex to hold when handling runnable_event or runnables. */ + +static std::mutex runnable_mutex; + +#endif + +/* Run all the queued runnables. */ + +static void +run_events (int error, gdb_client_data client_data) +{ + std::vector> local; + + /* Hold the lock while changing the globals, but not while running + the runnables. */ + { +#if CXX_STD_THREAD + std::lock_guard lock (runnable_mutex); +#endif + + /* Clear the event fd. Do this before flushing the events list, + so that any new event post afterwards is sure to re-awaken the + event loop. */ + serial_event_clear (runnable_event); + + /* Move the vector in case running a runnable pushes a new + runnable. */ + local = std::move (runnables); + } + + for (auto &item : local) + { + try + { + item (); + } + catch (...) + { + /* Ignore exceptions in the callback. */ + } + } +} + +/* See ser-event.h. */ + +void +run_on_main_thread (std::function &&func) +{ +#if CXX_STD_THREAD + std::lock_guard lock (runnable_mutex); +#endif + runnables.emplace_back (std::move (func)); + serial_event_set (runnable_event); +} + +void +_initialize_ser_event () +{ + runnable_event = make_serial_event (); + add_file_handler (serial_event_fd (runnable_event), run_events, nullptr); +} diff --git a/gdb/ser-event.h b/gdb/ser-event.h index 137348557f9..61a84f9cc79 100644 --- a/gdb/ser-event.h +++ b/gdb/ser-event.h @@ -19,6 +19,8 @@ #ifndef SER_EVENT_H #define SER_EVENT_H +#include + /* This is used to be able to signal the event loop (or any other select/poll) of events, in a race-free manner. @@ -48,4 +50,8 @@ extern void serial_event_set (struct serial_event *event); call is made. */ extern void serial_event_clear (struct serial_event *event); +/* Send a runnable to the main thread. */ + +extern void run_on_main_thread (std::function &&); + #endif diff --git a/gdb/unittests/main-thread-selftests.c b/gdb/unittests/main-thread-selftests.c new file mode 100644 index 00000000000..e5bd2d36cea --- /dev/null +++ b/gdb/unittests/main-thread-selftests.c @@ -0,0 +1,80 @@ +/* Self tests for run_on_main_thread + + Copyright (C) 2019 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 . */ + +#include "defs.h" +#include "gdbsupport/selftest.h" +#include "gdbsupport/block-signals.h" +#include "ser-event.h" +#include "event-loop.h" +#if CXX_STD_THREAD +#include +#endif + +namespace selftests { +namespace main_thread_tests { + +#if CXX_STD_THREAD + +static bool done; + +static void +set_done () +{ + run_on_main_thread ([] () + { + done = true; + }); +} + +static void +run_tests () +{ + std::thread thread; + + done = false; + + { + gdb::block_signals blocker; + + thread = std::thread (set_done); + } + + while (!done && gdb_do_one_event () >= 0) + ; + + /* Actually the test will just hang, but we want to test + something. */ + SELF_CHECK (done); + + thread.join (); +} + +#endif + +} +} + +void +_initialize_main_thread_selftests () +{ +#if CXX_STD_THREAD + selftests::register_test ("main_thread", + selftests::main_thread_tests::run_tests); +#endif +}