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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 Received: from nue.mailmanlists.eu (nue.mailmanlists.eu [94.130.110.93]) (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 E58FA1F44D for ; Mon, 19 Feb 2024 18:44:57 +0000 (UTC) Received: from nue.mailmanlists.eu (localhost [127.0.0.1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 661BA82A50; Mon, 19 Feb 2024 18:44:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1708368289; bh=iOH1OGXfHhbgeH6+XPxYTcLiHiDGieNuNRgIC+I3K+k=; 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=NO59v28hT8vEvHTaoco5zUdBNNRaSq1QuzSKqutS3iyCBaDjFh9JB+Gu8Vv34eIEw 8PiuHShjesrjz7+k2u9Br8mfo6WVsCXSEavi7zzlNOFW2IxpzLPG4SAZ8doQFcTf6J qz178DjzcHKeK53iOGMSi5PCHZZT+ToXkzVHPX74= Received: from wrqvtvvn.outbound-mail.sendgrid.net (wrqvtvvn.outbound-mail.sendgrid.net [149.72.120.130]) by nue.mailmanlists.eu (Postfix) with ESMTPS id D72097F57F for ; Mon, 19 Feb 2024 18:44:45 +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=Qf/VzInR; 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=B4DhJCj2xT0DQiZ6XonJfzwPtizGSf/x4f5fOoxvElA=; b=Qf/VzInRfJHmpH/uQ6fi+VHuuFfrXyj/mZYc6IpsthS5AjRU/JcqnilRq4gSBtHlVDhW PuDyUM5xzsfTm6pkRLFjXvKIKf/mXF2S793zKkKm4yEyUO25g9OJginVKDdBZ0SCbGiv1k mAb5Zl+bmknZfoe/Af7BRmhUZweZhBrgaH8CDH70AE8MeDKHw50Hu1rfc17j9iCfZlRkLG OM/DrZQvLze7XI7Um/dNU34RGK4ezCzg3IRa56ngM2ykAsBvugetvwp4PStKDeMTqp9w92 0ecNbtbLjCdQzIQ1Xi70dcrzjecHjdhszVQnoylEGOGIgA94nd5vlb2wgv/rUlXg== Received: by filterdrecv-674cc56c7b-5m6n4 with SMTP id filterdrecv-674cc56c7b-5m6n4-1-65D3A19C-25 2024-02-19 18:44:44.636706643 +0000 UTC m=+472066.376152737 Received: from herokuapp.com (unknown) by geopod-ismtpd-13 (SG) with ESMTP id kpXHmo5TQsaz6tz5SPyf3A for ; Mon, 19 Feb 2024 18:44:44.576 +0000 (UTC) Date: Mon, 19 Feb 2024 18:44:44 +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-Sender: forthoney 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: 93407 X-SG-EID: =?us-ascii?Q?jBUhz5dHVsRmglvuc9n+7tg6xgYgtRGNSl8oA=2Fe3uRMXEjL8PqBCCRh+GSV5o2?= =?us-ascii?Q?QGUu46Tn6qPlXdH1BIf1zY4aAj=2FeT7dBD8vCBA2?= =?us-ascii?Q?NgcM=2FYGVgyYJXOHxseiVW3xQrxZVhfVnMcZB7Ep?= =?us-ascii?Q?hgoWYqK5f+sxpdnihPdvoewSEh1cmdacJ1OtFL9?= =?us-ascii?Q?n3WfioztGopMv5wnyxZpJQp2pZ7JgKiFcsvHPsm?= =?us-ascii?Q?iwReVjBMrtAslRZt8K3WhXCi+aJiyGRKmMKBjpK?= =?us-ascii?Q?1uQI9JACu=2FSu7pygjScKg=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: b/2+PoftWZ6GuOu3b0IycA== Message-ID-Hash: YFK7ODZG7V5MRCRQXQ3G7BOUGY65ZS4B X-Message-ID-Hash: YFK7ODZG7V5MRCRQXQ3G7BOUGY65ZS4B 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:116851] [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: "forthoney (Seong-Heon Jung) via ruby-core" Cc: "forthoney (Seong-Heon Jung)" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Issue #20215 has been updated by forthoney (Seong-Heon Jung). I think the name is potentially confusing. Consider the following: ```ruby if client.readable? client.read # this may block end ``` I personally would be a bit surprised if `client.read` blocked despite `client.readable?` returning true. `readable` is ambiguous between "there is something to read right now" and "there will eventually be something to read". ---------------------------------------- Feature #20215: Introduce `IO#readable?` https://bugs.ruby-lang.org/issues/20215#change-106883 * Author: ioquatix (Samuel Williams) * Status: Open * Priority: Normal ---------------------------------------- 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/