From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on starla X-Spam-Level: X-Spam-Status: No, score=0.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_BL_SPAMCOP_NET,SPF_HELO_PASS, SPF_PASS autolearn=no autolearn_force=no version=3.4.6 Received: from nue.mailmanlists.eu (nue.mailmanlists.eu [IPv6:2a01:4f8:1c0c:6b10::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id C38FC1F44D for ; Tue, 16 Apr 2024 09:54:31 +0000 (UTC) Authentication-Results: dcvr.yhbt.net; dkim=pass (1024-bit key; secure) header.d=ml.ruby-lang.org header.i=@ml.ruby-lang.org header.a=rsa-sha256 header.s=mail header.b=qTGrihEW; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ruby-lang.org header.i=@ruby-lang.org header.a=rsa-sha256 header.s=s1 header.b=KYfdOpjJ; dkim-atps=neutral Received: from nue.mailmanlists.eu (localhost [127.0.0.1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 8A00284357; Tue, 16 Apr 2024 09:54:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1713261263; bh=0mM6nq57SlQnZHEiMPcHXSwuuoyhP79OJhpSFQuUdfw=; h=Date:References:To:Reply-To:Subject:List-Id:List-Archive: List-Help:List-Owner:List-Post:List-Subscribe:List-Unsubscribe: From:Cc:From; b=qTGrihEWwhkfOEvCTS8eb+bNmnOXfhh9qO7Y3GzaOihYHYhoztAnd34TjxD+MoZSj yOFIBETMej/3oCxc2iYp1ecDRvkaQtBRxly+WYMhTRjCMEWxYth4JXWpKatCW7p8M5 d+27D6q90yGXJ49DamoeTAcye430zs6YanFc5JyI= Received: from s.wrqvtzvf.outbound-mail.sendgrid.net (s.wrqvtzvf.outbound-mail.sendgrid.net [149.72.126.143]) by nue.mailmanlists.eu (Postfix) with ESMTPS id 6D33484352 for ; Tue, 16 Apr 2024 09:54:20 +0000 (UTC) Authentication-Results: nue.mailmanlists.eu; dkim=pass (2048-bit key; unprotected) header.d=ruby-lang.org header.i=@ruby-lang.org header.a=rsa-sha256 header.s=s1 header.b=KYfdOpjJ; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ruby-lang.org; h=from:references:subject:mime-version:content-type: content-transfer-encoding:list-id:to:cc:content-type:from:subject:to; s=s1; bh=DbF/NeCbSMLzCsJ9X11yUR89jV5gRU3KMw60ADdH2p8=; b=KYfdOpjJZXqs7XccU4Oqe0IQPI6mO0wSeetPMhjv5AxM5Tm5sKqSAGkx7goJ4XJVbnYg 7/x5roa2/3VhKEgAVr+VJEgMAZVqy88r8i6KRrH0FeseTC0Bxq42snuLLn9yXkjr6QM9sQ DFEuXJOEvMWii4ZDWAbQ3EAfVj24HZdCBVYFLgCr59/orBBPiFqlqfgGJnOa1attfUl2o4 eSlUkJv0L1WJVjlWh3Qzy/c8vZetyFcV0X1BxA9uPMN86zsf/QPkUE7l9cIUEBkBHOFjQQ Bjs/qn//qUdnD+bpV/FQeDDzZWPl38XKf7EokeM+RoNARqeDUR4V/gfdJUCrcHbg== Received: by filterdrecv-6db7b8944d-x6lcf with SMTP id filterdrecv-6db7b8944d-x6lcf-1-661E4ACB-6 2024-04-16 09:54:19.245956169 +0000 UTC m=+302687.543585390 Received: from herokuapp.com (unknown) by geopod-ismtpd-3 (SG) with ESMTP id j11_IJt_T5ypb7tXxiZcjA for ; Tue, 16 Apr 2024 09:54:19.190 +0000 (UTC) Date: Tue, 16 Apr 2024 09:54:19 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Feature X-Redmine-Issue-Id: 20215 X-Redmine-Issue-Author: ioquatix X-Redmine-Issue-Priority: Normal X-Redmine-Sender: ioquatix X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-Redmine-MailingListIntegration-Message-Ids: 94123 X-SG-EID: =?us-ascii?Q?u001=2E3QFJPY5gaRwyNXkncYONHM3OeFnb=2FgeOrLDgg3PYIKrq5rvk81iAipQ1q?= =?us-ascii?Q?cdmuT9o5PIWGjXtTDstodNmslT=2F6xfCuIofWR2K?= =?us-ascii?Q?w8msDgVaVLwbBwJbEwvePQrqiMbuMTXBNPdWBqx?= =?us-ascii?Q?OGRrM594NHD52nzfQpyJIZVudVEMDLo6syYUZ2L?= =?us-ascii?Q?xMhpnX0nRcHo2xYQ5eOrAj+hfdueNiIcNLqEaZj?= =?us-ascii?Q?rmPtrKBTBbGycJ+L2gf+3TqgBfCkIP+oiw0rAAU?= =?us-ascii?Q?H0BfJ3XVY29s1OK+aZsx9SXoow=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: u001.I8uzylDtAfgbeCOeLBYDww== Message-ID-Hash: C3ESVVUNEHAFUAAFPHIJP6D5QZU3H47R X-Message-ID-Hash: C3ESVVUNEHAFUAAFPHIJP6D5QZU3H47R X-MailFrom: bounces+313651-b711-ruby-core=ml.ruby-lang.org@em5188.ruby-lang.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.3 Precedence: list Reply-To: Ruby developers Subject: [ruby-core:117528] [Ruby master Feature#20215] Introduce `IO#readable?` List-Id: Ruby developers Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: "ioquatix (Samuel Williams) via ruby-core" Cc: "ioquatix (Samuel Williams)" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Issue #20215 has been updated by ioquatix (Samuel Williams). After some discussion, I investigated libc's `feof`: 1. https://github.com/bminor/glibc/blob/14e56bd4ce15ac2d1cc43f762eb2e6b83fec1afe/libio/feof.c 2. https://github.com/bminor/glibc/blob/14e56bd4ce15ac2d1cc43f762eb2e6b83fec1afe/libio/bits/types/struct_FILE.h#L112 It looks like the expected behaviour of "eof?" should be non-blocking. ---------------------------------------- Feature #20215: Introduce `IO#readable?` https://bugs.ruby-lang.org/issues/20215#change-107918 * Author: ioquatix (Samuel Williams) * Status: Open ---------------------------------------- There are some cases where, as an optimisation, it's useful to know whether more data is potentially available. We already have `IO#eof?` but the problem with using `IO#eof?` is that it can block indefinitely for sockets. Therefore, code which uses `IO#eof?` to determine if there is potentially more data, may hang. ```ruby def make_request(path = "/") client = connect_remote_host # HTTP/1.0 request: client.write("GET #{path} HTTP/1.0\r\n\r\n") # Read response client.gets("\r\n") # => "HTTP/1.0 200 OK\r\n" # Assuming connection close, there are two things the server can do: # 1. peer.close # 2. peer.write(...); peer.close if client.eof? # <--- Can hang here! puts "Connection closed" # Avoid yielding as we know there definitely won't be any data. else puts "Connection open, data may be available..." # There might be data available, so yield. yield(client) end ensure client&.close end make_request do |client| puts client.read # <--- Prefer to wait here. end ``` The proposed `IO#readable?` is similar to `IO#eof?` but rather than blocking, would simply return false. The expectation is the user will subsequently call `read` which may then wait. The proposed implementation would look something like this: ```ruby class IO def readable? !self.closed? end end class BasicSocket # Is it likely that the socket is still connected? # May return false positive, but won't return false negative. def readable? return false unless super # If we can wait for the socket to become readable, we know that the socket may still be open. result = self.recv_nonblock(1, MSG_PEEK, exception: false) # No data was available - newer Ruby can return nil instead of empty string: return false if result.nil? # Either there was some data available, or we can wait to see if there is data avaialble. return !result.empty? || result == :wait_readable rescue Errno::ECONNRESET # This might be thrown by recv_nonblock. return false end end ``` For `IO` itself, when there is buffered data, `readable?` would also return true immediately, similar to `eof?`. This is not shown in the above implementation as I'm not sure if there is any Ruby method which exposes "there is buffered data". -- https://bugs.ruby-lang.org/ ______________________________________________ ruby-core mailing list -- ruby-core@ml.ruby-lang.org To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/