Re: [quicwg/base-drafts] Placeholder -1 (#2690)

Martin Thomson <> Sun, 12 May 2019 23:41 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id C310B12013C for <>; Sun, 12 May 2019 16:41:23 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -6.607
X-Spam-Status: No, score=-6.607 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_IMAGE_ONLY_28=1.404, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001, T_DKIMWL_WL_HIGH=-0.01] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id ZzaCH-147HSk for <>; Sun, 12 May 2019 16:41:22 -0700 (PDT)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 16EE212014F for <>; Sun, 12 May 2019 16:41:22 -0700 (PDT)
Date: Sun, 12 May 2019 16:41:21 -0700
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=pf2014; t=1557704481; bh=NaNtHVwrJX+Z3XrpB76TGIgdf6fiOqDJzIGom79+7lg=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=r09sXj84G8IHuFb5htd4uXCkQ+2O7LSE4Lc79BcpIZIpNA1eWCQ+O186k6nbvuaWX KfDz2IoQIgK+h0ENuYlgKiUqjIgUYftLkycB4Q0r933jtHYBoXZq3H/WjXRAgDndp2 crzWc6Xk/YlTcUlNDe9RavpTJingEXI2ExbgX8qg=
From: Martin Thomson <>
Reply-To: quicwg/base-drafts <>
To: quicwg/base-drafts <>
Cc: Subscribed <>
Message-ID: <quicwg/base-drafts/pull/2690/review/>
In-Reply-To: <quicwg/base-drafts/pull/>
References: <quicwg/base-drafts/pull/>
Subject: Re: [quicwg/base-drafts] Placeholder -1 (#2690)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5cd8af212dcaf_5f4d3ff216acd968252155"; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: martinthomson
X-GitHub-Recipient: quic-issues
X-GitHub-Reason: subscribed
X-Auto-Response-Suppress: All
Archived-At: <>
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sun, 12 May 2019 23:41:24 -0000

martinthomson commented on this pull request.

> @@ -1102,18 +1109,33 @@ that can be prioritized are:
 Taken together, the dependencies across all prioritized elements in a connection
 form a dependency tree. An element can depend on another element or on the root
-of the tree. A reference to an element which is no longer in the tree is treated
-as a reference to the root of the tree. The structure of the dependency tree
-changes as PRIORITY frames modify the dependency links between prioritized
-Due to reordering between streams, an element can also be prioritized which is
-not yet in the tree. Such elements are added to the tree with the requested
+of the tree.  The tree also contains a dedicated placeholder with index "-1"

I prefer Kazuho's idea here about "-1".  Though I disagree about weight 0.  HTTP/2 didn't have it, which makes this more complicated.  I don't even think that you need weight 0, that's a gratuitous change in this PR.  You can simply say that streams with an "orphaned" priority is not given resources until all prioritized streams are handled.

You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub: