Add allocation counter tests. (#153)

Motivation:

To do proper performance work it's necessary to have insight into what
programs are actually doing. One of the two major axes the SwiftNIO
project uses to measure is heap allocations. Currently swift-nio-ssl has
no introspection of heap allocations, so doing informed performance work
is very hard.

Modifications:

- Added the allocation counter test framework.
- Added two allocation counter tests.

Result:

Better idea of what's going on in heap allocations.

IntegrationTests/tests_02_allocation_counters/defines.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftNIO open source project
+##
+## Copyright (c) 2019 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
+##
+##===----------------------------------------------------------------------===##

IntegrationTests/tests_02_allocation_counters/test_01_allocation_counts.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftNIO open source project
+##
+## Copyright (c) 2017-2019 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
+##
+##===----------------------------------------------------------------------===##
+
+source defines.sh
+
+set -eu
+here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+all_tests=()
+for file in "$here/test_01_resources/"test_*.swift; do
+    test_name=$(basename "$file")
+    test_name=${test_name#test_*}
+    test_name=${test_name%*.swift}
+    all_tests+=( "$test_name" )
+done
+
+"$here/test_01_resources/run-nio-ssl-alloc-counter-tests.sh" -t "$tmp" > "$tmp/output"
+
+for test in "${all_tests[@]}"; do
+    cat "$tmp/output"  # helps debugging
+    total_allocations=$(grep "^test_$test.total_allocations:" "$tmp/output" | cut -d: -f2 | sed 's/ //g')
+    not_freed_allocations=$(grep "^test_$test.remaining_allocations:" "$tmp/output" | cut -d: -f2 | sed 's/ //g')
+    max_allowed_env_name="MAX_ALLOCS_ALLOWED_$test"
+
+    info "$test: allocations not freed: $not_freed_allocations"
+    info "$test: total number of mallocs: $total_allocations"
+
+    assert_less_than "$not_freed_allocations" 5     # allow some slack
+    assert_greater_than "$not_freed_allocations" -5 # allow some slack
+    assert_greater_than "$total_allocations" 1000
+    if [[ -z "${!max_allowed_env_name+x}" ]]; then
+        if [[ -z "${!max_allowed_env_name+x}" ]]; then
+            warn "no reference number of allocations set (set to \$$max_allowed_env_name)"
+            warn "to set current number:"
+            warn "    export $max_allowed_env_name=$total_allocations"
+        fi
+    else
+        assert_less_than_or_equal "$total_allocations" "${!max_allowed_env_name}"
+    fi
+done

IntegrationTests/tests_02_allocation_counters/test_01_resources/run-nio-ssl-alloc-counter-tests.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftNIO open source project
+##
+## Copyright (c) 2019 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
+##
+##===----------------------------------------------------------------------===##
+
+set -eu
+here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+tmp_dir="/tmp"
+
+while getopts "t:" opt; do
+    case "$opt" in
+        t)
+            tmp_dir="$OPTARG"
+            ;;
+        *)
+            exit 1
+            ;;
+    esac
+done
+
+nio_checkout=$(mktemp -d "$tmp_dir/.swift-nio_XXXXXX")
+(
+cd "$nio_checkout"
+git clone --depth 1 https://github.com/apple/swift-nio
+)
+
+shift $((OPTIND-1))
+
+tests_to_run=("$here"/test_*.swift)
+
+if [[ $# -gt 0 ]]; then
+    tests_to_run=("$@")
+fi
+
+"$nio_checkout/swift-nio/IntegrationTests/allocation-counter-tests-framework/run-allocation-counter.sh" \
+    -p "$here/../../.." \
+    -m NIO \
+    -m NIOSSL \
+    -s "$here/shared.swift" \
+    -t "$tmp_dir" \
+    -d <( echo '.package(url: "https://github.com/apple/swift-nio.git", from: "2.0.0"),' ) \
+    "${tests_to_run[@]}"

IntegrationTests/tests_02_allocation_counters/test_01_resources/shared.swift

@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2019 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 Foundation
+import NIO
+import NIOSSL
+
+class BackToBackEmbeddedChannel {
+    private(set) var client: EmbeddedChannel
+    private(set) var server: EmbeddedChannel
+    private var loop: EmbeddedEventLoop
+
+
+    init() {
+        self.loop = EmbeddedEventLoop()
+        self.client = EmbeddedChannel(loop: self.loop)
+        self.server = EmbeddedChannel(loop: self.loop)
+    }
+
+    func run() {
+        self.loop.run()
+    }
+
+    func interactInMemory() throws {
+        var workToDo = true
+
+        while workToDo {
+            workToDo = false
+
+            self.loop.run()
+            let clientDatum = try self.client.readOutbound(as: IOData.self)
+            let serverDatum = try self.server.readOutbound(as: IOData.self)
+
+            if let clientMsg = clientDatum {
+                try self.server.writeInbound(clientMsg)
+                workToDo = true
+            }
+
+            if let serverMsg = serverDatum {
+                try self.client.writeInbound(serverMsg)
+                workToDo = true
+            }
+        }
+    }
+}
+
+
+extension BackToBackEmbeddedChannel {
+    enum Error: Swift.Error {
+        case nonCleanExit
+    }
+}
+
+
+extension NIOSSLCertificate {
+    static func forTesting() throws -> NIOSSLCertificate {
+        return try .init(bytes: certificatePemBytes, format: .pem)
+    }
+}
+
+
+extension NIOSSLPrivateKey {
+    static func forTesting() throws -> NIOSSLPrivateKey {
+        return try .init(bytes: keyPemBytes, format: .pem)
+    }
+}
+
+
+fileprivate let certificatePemBytes = Array("""
+-----BEGIN CERTIFICATE-----
+MIIBTzCB9qADAgECAhQkvv72Je/v+B/cgJ53f84O82z6WTAKBggqhkjOPQQDAjAU
+MRIwEAYDVQQDDAlsb2NhbGhvc3QwHhcNMTkxMTI3MTAxMjMwWhcNMjkxMTI0MTAx
+MjMwWjAUMRIwEAYDVQQDDAlsb2NhbGhvc3QwWTATBgcqhkjOPQIBBggqhkjOPQMB
+BwNCAAShtZ9TRt7I+7Y0o99XUkrgSYmUmpr4K8CB0IkTCX6b1tXp3Xqs1V5BckTd
+qrls+zsm3AfeiNBb9EDdxiX9DdzuoyYwJDAUBgNVHREEDTALgglsb2NhbGhvc3Qw
+DAYDVR0TAQH/BAIwADAKBggqhkjOPQQDAgNIADBFAiAKxYON+YTnIHNR0R6SLP8R
+R7hjsjV5NDs18XLoeRnA1gIhANwyggmE6NQW/r9l59fexj/ZrjaS3jYOTNCfC1Lo
+5NgJ
+-----END CERTIFICATE-----
+""".utf8)
+
+
+fileprivate let keyPemBytes = Array("""
+-----BEGIN PRIVATE KEY-----
+MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgCn182hBmYVMAiNPO
++7w05F40SlAqqxgBEYJZOeK47aihRANCAAShtZ9TRt7I+7Y0o99XUkrgSYmUmpr4
+K8CB0IkTCX6b1tXp3Xqs1V5BckTdqrls+zsm3AfeiNBb9EDdxiX9Ddzu
+-----END PRIVATE KEY-----
+""".utf8)

IntegrationTests/tests_02_allocation_counters/test_01_resources/test_many_writes.swift

@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2019 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 NIO
+import NIOSSL
+
+func run(identifier: String) {
+    let serverContext = try! NIOSSLContext(configuration: .forServer(certificateChain: [.certificate(.forTesting())], privateKey: .privateKey(.forTesting())))
+    let clientContext = try! NIOSSLContext(configuration: .forClient(trustRoots: .certificates([.forTesting()])))
+
+    let dummyAddress = try! SocketAddress(ipAddress: "1.2.3.4", port: 5678)
+    let backToBack = BackToBackEmbeddedChannel()
+    let serverHandler = try! NIOSSLServerHandler(context: serverContext)
+    let clientHandler = try! NIOSSLClientHandler(context: clientContext, serverHostname: "localhost")
+    try! backToBack.client.pipeline.addHandler(clientHandler).wait()
+    try! backToBack.server.pipeline.addHandler(serverHandler).wait()
+
+    // To trigger activation of both channels we use connect().
+    try! backToBack.client.connect(to: dummyAddress).wait()
+    try! backToBack.server.connect(to: dummyAddress).wait()
+
+    try! backToBack.interactInMemory()
+
+    // Let's try 512 bytes.
+    var buffer = backToBack.client.allocator.buffer(capacity: 512)
+    buffer.writeBytes(repeatElement(0, count: 512))
+
+    measure(identifier: identifier) {
+        for _ in 0..<1000 {
+            // A vector of 100 writes.
+            for _ in 0..<100 {
+                backToBack.client.write(buffer, promise: nil)
+            }
+            backToBack.client.flush()
+
+            try! backToBack.interactInMemory()
+
+            // Pull any data out of the server to avoid ballooning in memory.
+            while let _ = try! backToBack.server.readInbound(as: ByteBuffer.self) { }
+        }
+
+        return 1000
+    }
+}

IntegrationTests/tests_02_allocation_counters/test_01_resources/test_simple_handshake.swift

@@ -0,0 +1,47 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2019 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 NIO
+import NIOSSL
+
+func run(identifier: String) {
+    let serverContext = try! NIOSSLContext(configuration: .forServer(certificateChain: [.certificate(.forTesting())], privateKey: .privateKey(.forTesting())))
+    let clientContext = try! NIOSSLContext(configuration: .forClient(trustRoots: .certificates([.forTesting()])))
+
+    let dummyAddress = try! SocketAddress(ipAddress: "1.2.3.4", port: 5678)
+
+    measure(identifier: identifier) {
+        for _ in 0..<1000 {
+            let backToBack = BackToBackEmbeddedChannel()
+            let serverHandler = try! NIOSSLServerHandler(context: serverContext)
+            let clientHandler = try! NIOSSLClientHandler(context: clientContext, serverHostname: "localhost")
+            try! backToBack.client.pipeline.addHandler(clientHandler).wait()
+            try! backToBack.server.pipeline.addHandler(serverHandler).wait()
+
+            // To trigger activation of both channels we use connect().
+            try! backToBack.client.connect(to: dummyAddress).wait()
+            try! backToBack.server.connect(to: dummyAddress).wait()
+
+            try! backToBack.interactInMemory()
+
+            // Ok, now do shutdown.
+            backToBack.client.close(promise: nil)
+            try! backToBack.interactInMemory()
+            try! backToBack.client.closeFuture.wait()
+            try! backToBack.server.closeFuture.wait()
+        }
+
+        return 1000
+    }
+}