From patchwork Sat Mar 9 17:22:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Tromey X-Patchwork-Id: 31800 Received: (qmail 29362 invoked by alias); 9 Mar 2019 17:23:08 -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 29341 invoked by uid 89); 9 Mar 2019 17:23:07 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-21.9 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_HELO_PASS autolearn=ham version=3.3.1 spammy=serial X-HELO: gateway32.websitewelcome.com Received: from gateway32.websitewelcome.com (HELO gateway32.websitewelcome.com) (192.185.145.170) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sat, 09 Mar 2019 17:23:06 +0000 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway32.websitewelcome.com (Postfix) with ESMTP id DED5315CF14 for ; Sat, 9 Mar 2019 11:23:03 -0600 (CST) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id 2fgdhUUE02qH72fgdhxqKS; Sat, 09 Mar 2019 11:23:03 -0600 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=wV3jiG+ApLQjkIOAj/AgwjmsWed5W0/YMZpJCiPXzRE=; b=WOeHFuepxpHdmTTCSDOo/i5Zxb XTjq6gy62ZtQrKuXI3oVFCkjs7AdqHwaPSmJUCrN+ApkTuPItZjwbPWhb4GCKhKLhu+qOkgVAv14A fBoh6KFZwVncZmbF5Au2ycoV7; Received: from 75-166-85-218.hlrn.qwest.net ([75.166.85.218]:56494 helo=bapiya.Home) by box5379.bluehost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1h2fgd-003et2-GW; Sat, 09 Mar 2019 11:23:03 -0600 From: Tom Tromey To: gdb-patches@sourceware.org Cc: Tom Tromey Subject: [RFC 4/6] Introduce run_on_main_thread Date: Sat, 9 Mar 2019 10:22:58 -0700 Message-Id: <20190309172300.2764-5-tom@tromey.com> In-Reply-To: <20190309172300.2764-1-tom@tromey.com> References: <20190309172300.2764-1-tom@tromey.com> This introduces a way for a callback to be run on the main thread. 2019-03-08 Tom Tromey * 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 | 8 +++++++ gdb/ser-event.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++ gdb/ser-event.h | 6 +++++ 3 files changed, 73 insertions(+) diff --git a/gdb/ser-event.c b/gdb/ser-event.c index d3956346246..821b2f169df 100644 --- a/gdb/ser-event.c +++ b/gdb/ser-event.c @@ -20,6 +20,8 @@ #include "ser-event.h" #include "serial.h" #include "common/filestuff.h" +#include +#include "event-loop.h" /* On POSIX hosts, a serial_event is basically an abstraction for the classical self-pipe trick. @@ -217,3 +219,60 @@ 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; + +/* Mutex to hold when handling runnable_event or runnables. */ + +static std::mutex runnable_mutex; + +/* 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. */ + { + std::lock_guard lock (runnable_mutex); + + /* 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. */ + std::swap (local, runnables); + } + + for (auto &item : local) + item (); +} + +/* See ser-event.h. */ + +void +run_on_main_thread (std::function &&func) +{ + std::lock_guard lock (runnable_mutex); + 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