From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: X-Spam-Status: No, score=-4.1 required=3.0 tests=ALL_TRUSTED,AWL,BAYES_00, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, T_SCC_BODY_TEXT_LINE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.6 Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id 451C51F406; Fri, 29 Dec 2023 17:44:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yhbt.net; s=selector1; t=1703871882; bh=a0mxN0OJd+VvLhpARDXKzCq1gT6RR8oxg6Fc/6DnThU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QL2JinyrUrGn0G7FlWsG78CT0PL7vnOoGU8dJHfhvwJpUaBXulN6KPcLdlkOHQ4Y4 UOn8qfNpMX42FexgLNvrCfU5khv0XX/ToTXULBTwtUi0f31gh4X7cxQ+P2D/S4SWVO g2qH88AZK9s7Mn+1bCTVe9fHcdRZ5Q1440Oti9b4= Date: Fri, 29 Dec 2023 17:44:18 +0000 From: Eric Wong To: Jean Boussier Cc: raindrops-public@yhbt.net Subject: [PATCH v3] middleware: reuse inet_diag netlink socket Message-ID: <20231229174418.M259631@dcvr> References: <6E0E349D-A7CE-4B88-8F89-66438BB775A1@gmail.com> <20230926214000.M564322@dcvr> <20230930231320.M781709@dcvr> <20230930233506.M141715@dcvr> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230930233506.M141715@dcvr> List-Id: Eric Wong wrote: > I'll squash this in for fork+preload safety. I forget there are multithreaded servers using this :x ------8<----- Subject: [PATCH v3] middleware: reuse inet_diag netlink socket No point in constantly allocating and deallocating FDs (and Ruby IO objects) when reusing them is supported. However, we must guard it against parallel callers since linux_inet_diag.c::diag releases the GVL while calling sendmsg(2) and recvmsg(2), so it's possible two Ruby threads can end up crossing streams if the middlware is used with a multi-threaded server. AFAIK, Raindrops::Middleware isn't a heavily-trafficked endpoint, so saving FDs and avoiding thread specific data is preferable for memory-constrained systems I use. --- lib/raindrops/middleware.rb | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/lib/raindrops/middleware.rb b/lib/raindrops/middleware.rb index d5e3927..20e573c 100644 --- a/lib/raindrops/middleware.rb +++ b/lib/raindrops/middleware.rb @@ -1,5 +1,6 @@ # -*- encoding: binary -*- require 'raindrops' +require 'thread' # Raindrops::Middleware is Rack middleware that allows snapshotting # current activity from an HTTP request. For all operating systems, @@ -93,11 +94,12 @@ def initialize(app, opts = {}) @app = app @stats = opts[:stats] || Stats.new @path = opts[:path] || "/_raindrops" + @mtx = Mutex.new tmp = opts[:listeners] if tmp.nil? && defined?(Unicorn) && Unicorn.respond_to?(:listener_names) tmp = Unicorn.listener_names end - @tcp = @unix = nil + @nl_sock = @tcp = @unix = nil if tmp @tcp = tmp.grep(/\A.+:\d+\z/) @@ -129,9 +131,12 @@ def stats_response # :nodoc: "writing: #{@stats.writing}\n" if defined?(Raindrops::Linux.tcp_listener_stats) - Raindrops::Linux.tcp_listener_stats(@tcp).each do |addr,stats| - body << "#{addr} active: #{stats.active}\n" \ - "#{addr} queued: #{stats.queued}\n" + @mtx.synchronize do + @nl_sock ||= Raindrops::InetDiagSocket.new + Raindrops::Linux.tcp_listener_stats(@tcp, @nl_sock).each do |addr,stats| + body << "#{addr} active: #{stats.active}\n" \ + "#{addr} queued: #{stats.queued}\n" + end end if @tcp Raindrops::Linux.unix_listener_stats(@unix).each do |addr,stats| body << "#{addr} active: #{stats.active}\n" \