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 [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)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 25CA11F44D for ; Mon, 22 Apr 2024 04:08:14 +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=tx5Es+Z5; 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=dny8TBbR; dkim-atps=neutral Received: from nue.mailmanlists.eu (localhost [127.0.0.1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 63AEE84402; Mon, 22 Apr 2024 04:08:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1713758886; bh=J57RGTDEVoreBFcdBNQh9dSJuGD7FdRUGOKFvOsgKlc=; 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=tx5Es+Z5pbpdhVGye47R4l5ZHcKEk2yqNs4fhrjvw26T9tuYjdxQWSt2KbkqcZzaO 4UgW7HMNbSoVs5oerlhy1FX250nvj+T1+nV5Sz+soaxExcOvY3fkaXWix4E7V5CW3o I7LyMLfJeN9jM3QJrK45n4AFwp8pSvRDUQXYl4iE= 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 8E3A78134E for ; Mon, 22 Apr 2024 04:08:02 +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=dny8TBbR; 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=A+Y5b76OTpUCQoYloKXR705pz07qPjpJN8DX/e4BV24=; b=dny8TBbRYFIkfjDBAUjnccUkHeg8HOsCS2MstflSzubRYxfREXzUOboFA8Qx88sQGkys zkoe6ziU73LKfgwz8+VKAvZLXUNNy6BlvDoMurh7gs6ejcBWHLF5S5EXlB7GnpayUzyQZq lJyU9VvzLIm7Uyut5ALJ50ljVi0lKIQwU0OywOvCr/1pdKHiNsVU9vIikDK0sBeaBVITTe N/mPDwP3rSQb62Z+HV+AXmHDSnezchpygMi3RofIP3/chYY/jBzTddGgbiEeCaP2/9j/ZH A+vH/A+VWxQOKO6UwnJotulPZ4D6Piiy352XDE+uq8/KwJ43ruBudKHagbdaTuyw== Received: by recvd-bb7996b79-55b88 with SMTP id recvd-bb7996b79-55b88-1-6625E2A1-B 2024-04-22 04:08:01.602401618 +0000 UTC m=+799682.998231443 Received: from herokuapp.com (unknown) by geopod-ismtpd-12 (SG) with ESMTP id rTmfplhHSo2cupkJD_a32g for ; Mon, 22 Apr 2024 04:08:01.557 +0000 (UTC) Date: Mon, 22 Apr 2024 04:08:01 +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: 94233 X-SG-EID: =?us-ascii?Q?u001=2E3QFJPY5gaRwyNXkncYONHM3OeFnb=2FgeOrLDgg3PYIKrq5rvk81iAipQ1q?= =?us-ascii?Q?cdmuT9o5PIWGjXtTDstodNmslT=2F6xfCuIofWR2K?= =?us-ascii?Q?w8msDgVaVLzfX6uOIfpTWi8gaxZBcqsPYByALJy?= =?us-ascii?Q?QANUl5B=2F9JYVLg3EgJPGowQXOhUlyFyKks0fhSE?= =?us-ascii?Q?9ioLqr3M6JxUnV8HLiWZGynCRi0QevV=2FM4Z8dbP?= =?us-ascii?Q?DP0jwyj1hVuJNOoTdm8RGL9TasSKoPb18Xd8UJX?= =?us-ascii?Q?59CZRHeK4lVgMMWmjBjQFRMBSg=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: u001.I8uzylDtAfgbeCOeLBYDww== Message-ID-Hash: TSQPEOVVSHE5BFHAOMWRMUEA5ETHYTBA X-Message-ID-Hash: TSQPEOVVSHE5BFHAOMWRMUEA5ETHYTBA 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:117637] [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). > I'm not quite sure why you say this method is like eof? rather than closed? We work with the interface and taxonomy given to us by POSIX. `close(fd)` causes the file descriptor to become invalid. It's different from what happens if the **remote end** closes or shuts down the connection. In that case, the file descriptor is still valid, but operations like `read` and `write` will fail. ---------------------------------------- Feature #20215: Introduce `IO#readable?` https://bugs.ruby-lang.org/issues/20215#change-108045 * 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/