Reduce error allocations (#446)

Motivation: Existential errors are unconditionally boxed. We typically create and use errors to fail promises when performing cleanup work. One example of this is failing pending writes when a stream channel is closed, however this is done unconditionally which means every stream channel incurs an allocation when it closes. Modifications: - Statically create some existential errors ahead of time Result: Fewer allocations
apple · Jul 5, 2024 · ed8a315 · ed8a315
1 parent d629013
commit ed8a315
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Showing 5 changed files with 62 additions and 40 deletions.
diff --git a/Sources/NIOHTTP2/Error+Any.swift b/Sources/NIOHTTP2/Error+Any.swift
@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2024 Apple Inc. and the SwiftNIO project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import NIOCore
+
+// 'any Error' is unconditionally boxed, avoid allocating per use by statically boxing them.
+extension ChannelError {
+    static let _alreadyClosed: any Error = ChannelError.alreadyClosed
+    static let _eof: any Error = ChannelError.eof
+    static let _ioOnClosedChannel: any Error = ChannelError.ioOnClosedChannel
+}
diff --git a/Sources/NIOHTTP2/HTTP2StreamChannel.swift b/Sources/NIOHTTP2/HTTP2StreamChannel.swift
@@ -513,7 +513,7 @@ final class HTTP2StreamChannel: Channel, ChannelCore, @unchecked Sendable {
 
     public func write0(_ data: NIOAny, promise userPromise: EventLoopPromise<Void>?) {
         guard self.state != .closed else {
-            userPromise?.fail(ChannelError.ioOnClosedChannel)
+            userPromise?.fail(ChannelError._ioOnClosedChannel)
             return
         }
 
@@ -584,7 +584,7 @@ final class HTTP2StreamChannel: Channel, ChannelCore, @unchecked Sendable {
         // If the stream is already closed, we can fail this early and abort processing. If it's not, we need to emit a
         // RST_STREAM frame.
         guard self.state != .closed else {
-            promise?.fail(ChannelError.alreadyClosed)
+            promise?.fail(ChannelError._alreadyClosed)
             return
         }
 
@@ -643,7 +643,7 @@ final class HTTP2StreamChannel: Channel, ChannelCore, @unchecked Sendable {
         }
         self.modifyingState { $0.completeClosing() }
         self.dropPendingReads()
-        self.failPendingWrites(error: ChannelError.eof)
+        self.failPendingWrites(error: ChannelError._eof)
         if let promise = self.pendingClosePromise {
             self.pendingClosePromise = nil
             promise.succeed(())
@@ -842,7 +842,7 @@ internal extension HTTP2StreamChannel {
     ///   - promise: The promise associated with the frame write.
     private func receiveOutboundFrame(_ frame: HTTP2Frame, promise: EventLoopPromise<Void>?) {
         guard self.state != .closed else {
-            let error = ChannelError.alreadyClosed
+            let error = ChannelError._alreadyClosed
             promise?.fail(error)
             self.errorEncountered(error: error)
             return

diff --git a/docker/docker-compose.2204.510.yaml b/docker/docker-compose.2204.510.yaml
@@ -28,18 +28,18 @@ services:
   test:
     image: swift-nio-http2:22.04-5.10
     environment:
-      - MAX_ALLOCS_ALLOWED_1k_requests_inline_interleaved=35150
-      - MAX_ALLOCS_ALLOWED_1k_requests_inline_noninterleaved=34100
-      - MAX_ALLOCS_ALLOWED_1k_requests_interleaved=41150
-      - MAX_ALLOCS_ALLOWED_1k_requests_noninterleaved=40100
-      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response=288050
-      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response_inline=273050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response=257050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_inline=248050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_many=1202050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_many_inline=893050
-      - MAX_ALLOCS_ALLOWED_create_client_stream_channel=39050
-      - MAX_ALLOCS_ALLOWED_create_client_stream_channel_inline=39050
+      - MAX_ALLOCS_ALLOWED_1k_requests_inline_interleaved=34150
+      - MAX_ALLOCS_ALLOWED_1k_requests_inline_noninterleaved=33100
+      - MAX_ALLOCS_ALLOWED_1k_requests_interleaved=40150
+      - MAX_ALLOCS_ALLOWED_1k_requests_noninterleaved=39100
+      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response=286050
+      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response_inline=271050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response=255050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_inline=246050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_many=1200050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_many_inline=891050
+      - MAX_ALLOCS_ALLOWED_create_client_stream_channel=38050
+      - MAX_ALLOCS_ALLOWED_create_client_stream_channel_inline=38050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form=200050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace=200050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace_from_long_string=300050

diff --git a/docker/docker-compose.2204.58.yaml b/docker/docker-compose.2204.58.yaml
@@ -28,18 +28,18 @@ services:
   test:
     image: swift-nio-http2:22.04-5.8
     environment:
-      - MAX_ALLOCS_ALLOWED_1k_requests_inline_interleaved=35150
-      - MAX_ALLOCS_ALLOWED_1k_requests_inline_noninterleaved=34100
-      - MAX_ALLOCS_ALLOWED_1k_requests_interleaved=41150
-      - MAX_ALLOCS_ALLOWED_1k_requests_noninterleaved=40100
-      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response=288050
-      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response_inline=273050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response=257050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_inline=248050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_many=1202050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_many_inline=893050
-      - MAX_ALLOCS_ALLOWED_create_client_stream_channel=39050
-      - MAX_ALLOCS_ALLOWED_create_client_stream_channel_inline=39050
+      - MAX_ALLOCS_ALLOWED_1k_requests_inline_interleaved=34150
+      - MAX_ALLOCS_ALLOWED_1k_requests_inline_noninterleaved=33100
+      - MAX_ALLOCS_ALLOWED_1k_requests_interleaved=40150
+      - MAX_ALLOCS_ALLOWED_1k_requests_noninterleaved=39100
+      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response=286050
+      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response_inline=271050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response=255050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_inline=246050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_many=1200050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_many_inline=891050
+      - MAX_ALLOCS_ALLOWED_create_client_stream_channel=38050
+      - MAX_ALLOCS_ALLOWED_create_client_stream_channel_inline=38050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form=200050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace=200050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace_from_long_string=300050

diff --git a/docker/docker-compose.2204.59.yaml b/docker/docker-compose.2204.59.yaml
@@ -28,18 +28,18 @@ services:
   test:
     image: swift-nio-http2:22.04-5.9
     environment:
-      - MAX_ALLOCS_ALLOWED_1k_requests_inline_interleaved=35150
-      - MAX_ALLOCS_ALLOWED_1k_requests_inline_noninterleaved=34100
-      - MAX_ALLOCS_ALLOWED_1k_requests_interleaved=41150
-      - MAX_ALLOCS_ALLOWED_1k_requests_noninterleaved=40100
-      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response=288050
-      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response_inline=273050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response=257050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_inline=248050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_many=1202050
-      - MAX_ALLOCS_ALLOWED_client_server_request_response_many_inline=893050
-      - MAX_ALLOCS_ALLOWED_create_client_stream_channel=39050
-      - MAX_ALLOCS_ALLOWED_create_client_stream_channel_inline=39050
+      - MAX_ALLOCS_ALLOWED_1k_requests_inline_interleaved=34150
+      - MAX_ALLOCS_ALLOWED_1k_requests_inline_noninterleaved=33100
+      - MAX_ALLOCS_ALLOWED_1k_requests_interleaved=40150
+      - MAX_ALLOCS_ALLOWED_1k_requests_noninterleaved=39100
+      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response=286050
+      - MAX_ALLOCS_ALLOWED_client_server_h1_request_response_inline=271050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response=255050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_inline=246050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_many=1200050
+      - MAX_ALLOCS_ALLOWED_client_server_request_response_many_inline=891050
+      - MAX_ALLOCS_ALLOWED_create_client_stream_channel=38050
+      - MAX_ALLOCS_ALLOWED_create_client_stream_channel_inline=38050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form=200050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace=200050
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace_from_long_string=300050