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04296fa82e
The http2 random write scheduler should not queue RST_STREAM frames with the DATA frames, and instead treat them as control frames. There can be deadlock situations if data frames block the queue, because if the sender wants to close the stream it sends an RST frame, but if the client is not draining the queue, the RST frame is stuck and the sender is not able to finish. Fixes golang/go#49741 Change-Id: I0940a76d1aad95f1c4d3856e4d79cf5ce2a78ff2 Reviewed-on: https://go-review.googlesource.com/c/net/+/367154 Trust: Dave Cheney <dave@cheney.net> Reviewed-by: Damien Neil <dneil@google.com> Trust: Damien Neil <dneil@google.com> Run-TryBot: Damien Neil <dneil@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
78 lines
2.0 KiB
Go
78 lines
2.0 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package http2
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import "math"
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// NewRandomWriteScheduler constructs a WriteScheduler that ignores HTTP/2
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// priorities. Control frames like SETTINGS and PING are written before DATA
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// frames, but if no control frames are queued and multiple streams have queued
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// HEADERS or DATA frames, Pop selects a ready stream arbitrarily.
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func NewRandomWriteScheduler() WriteScheduler {
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return &randomWriteScheduler{sq: make(map[uint32]*writeQueue)}
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}
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type randomWriteScheduler struct {
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// zero are frames not associated with a specific stream.
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zero writeQueue
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// sq contains the stream-specific queues, keyed by stream ID.
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// When a stream is idle, closed, or emptied, it's deleted
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// from the map.
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sq map[uint32]*writeQueue
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// pool of empty queues for reuse.
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queuePool writeQueuePool
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}
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func (ws *randomWriteScheduler) OpenStream(streamID uint32, options OpenStreamOptions) {
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// no-op: idle streams are not tracked
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}
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func (ws *randomWriteScheduler) CloseStream(streamID uint32) {
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q, ok := ws.sq[streamID]
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if !ok {
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return
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}
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delete(ws.sq, streamID)
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ws.queuePool.put(q)
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}
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func (ws *randomWriteScheduler) AdjustStream(streamID uint32, priority PriorityParam) {
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// no-op: priorities are ignored
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}
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func (ws *randomWriteScheduler) Push(wr FrameWriteRequest) {
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if wr.isControl() {
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ws.zero.push(wr)
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return
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}
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id := wr.StreamID()
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q, ok := ws.sq[id]
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if !ok {
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q = ws.queuePool.get()
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ws.sq[id] = q
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}
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q.push(wr)
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}
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func (ws *randomWriteScheduler) Pop() (FrameWriteRequest, bool) {
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// Control and RST_STREAM frames first.
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if !ws.zero.empty() {
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return ws.zero.shift(), true
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}
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// Iterate over all non-idle streams until finding one that can be consumed.
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for streamID, q := range ws.sq {
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if wr, ok := q.consume(math.MaxInt32); ok {
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if q.empty() {
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delete(ws.sq, streamID)
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ws.queuePool.put(q)
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}
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return wr, true
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}
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}
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return FrameWriteRequest{}, false
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}
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