Add Linux support via a TaskLocalContextManager (#546)

* Basic linux support via a concurrency based wrapper library

* Fix/don't run some tests when they can't pass on the current platform. Remove some unnecessary 'Base' protocols in favor of wrapper types in OpenTelemetryConcurrency

* Remove swift-atomics from the direct dependencies on Darwin platforms

* Remove unnecessary protocol functions, and add some documentation comments

* Update some more doc comments

* Rename OpenTelemetryTestCase to OpenTelemetryContextTestCase

* Remove an unnecessary import and assertion

* Remove debugging code

* Add linux test github action

* Add comments and clean up some issues in the tests

* Add a concurrency example, and allow SpanBuilderBase to startSpans

* Apply extensions to SpanBuilderBase instead of SpanBuilder

* Split building and running the tests into separate steps

* Avoid using docker

* Force noninteractive swiftly installation

* Try removing complex test case overrides

* Revert "Try removing complex test case overrides"

This reverts commit c982b2e.

* Revert "Force noninteractive swiftly installation"

This reverts commit a8bc0ac.

* Revert "Avoid using docker"

This reverts commit 387b99f.

* Allow batch worker threads to exit once they are cancelled, and increase scheduleDelay on batch workers to avoid keeping the condition variables locked

* Also check for cancellation on the inner loop in BatchWorker

* Update Package.swift

* Update [email protected]

* Update [email protected]

* fixed additional package issues

* added additional test skip

---------

Co-authored-by: Bryce Buchanan <[email protected]>
Co-authored-by: Bryce Buchanan <[email protected]>

Author: semicoleon

.github/workflows/BuildAndTest.yml

@@ -45,3 +45,12 @@ jobs:
       run: make build-for-testing-watchos
     - name: Test for watchOS
       run: make test-without-building-watchos
+  linux:
+    runs-on: ubuntu-latest
+    container: swift:5.10
+    steps:
+      - uses: actions/checkout@v2
+      - name: Build tests for Linux
+        run: swift build --build-tests
+      - name: Run tests for Linux
+        run: swift test

Examples/ConcurrencyContext/main.swift

@@ -0,0 +1,66 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#if canImport(_Concurrency)
+import OpenTelemetrySdk
+import OpenTelemetryConcurrency
+import StdoutExporter
+
+let sampleKey = "sampleKey"
+let sampleValue = "sampleValue"
+
+// On Apple platforms, the default is the activity based context manager. We want to opt-in to the structured concurrency based context manager instead.
+OpenTelemetry.registerDefaultConcurrencyContextManager()
+
+let stdout = StdoutExporter()
+OpenTelemetry.registerTracerProvider(
+    tracerProvider: TracerProviderBuilder().add(
+        spanProcessor: SimpleSpanProcessor(spanExporter: stdout)
+    ).build()
+)
+
+let tracer = OpenTelemetry.instance.tracerProvider.get(instrumentationName: "ConcurrencyContext", instrumentationVersion: "semver:0.1.0")
+
+extension Task where Failure == Never, Success == Never {
+    static func sleep(seconds: Double) async throws {
+        try await self.sleep(nanoseconds: UInt64(seconds * 1_000_000_000))
+    }
+}
+
+func simpleSpan() async throws {
+    let span = tracer.spanBuilder(spanName: "SimpleSpan").setSpanKind(spanKind: .client).startSpan()
+    span.setAttribute(key: sampleKey, value: sampleValue)
+    try await Task.sleep(seconds: 0.5)
+    span.end()
+}
+
+func childSpan() async throws {
+    // SpanBuilder's `setActive` method is not available here, since it isn't compatible with structured concurrency based context management
+    try await tracer.spanBuilder(spanName: "parentSpan").setSpanKind(spanKind: .client).withActiveSpan { span in
+        span.setAttribute(key: sampleKey, value: sampleValue)
+        await Task.detached {
+            // A detached task doesn't inherit the task local context, so this span won't have a parent.
+            let notAChildSpan = tracer.spanBuilder(spanName: "notAChild").setSpanKind(spanKind: .client).startSpan()
+            notAChildSpan.setAttribute(key: sampleKey, value: sampleValue)
+            notAChildSpan.end()
+        }.value
+
+        try await Task {
+            // Normal tasks should still inherit the context.
+            try await Task.sleep(seconds: 0.2)
+            let childSpan = tracer.spanBuilder(spanName: "childSpan").setSpanKind(spanKind: .client).startSpan()
+            childSpan.setAttribute(key: sampleKey, value: sampleValue)
+            try await Task.sleep(seconds: 0.5)
+            childSpan.end()
+        }.value
+    }
+}
+
+try await simpleSpan()
+try await Task.sleep(seconds: 1)
+try await childSpan()
+try await Task.sleep(seconds: 1)
+
+#endif

Examples/Logging Tracer/LoggingTracer.swift

@@ -69,5 +69,23 @@ class LoggingTracer: Tracer {
         func setActive(_ active: Bool) -> Self {
             return self
         }
+
+        func withActiveSpan<T>(_ operation: (any SpanBase) throws -> T) rethrows -> T {
+            let span = self.startSpan()
+            defer {
+                span.end()
+            }
+            return try operation(span)
+        }
+
+    #if canImport(_Concurrency)
+        func withActiveSpan<T>(_ operation: (any SpanBase) async throws -> T) async rethrows -> T {
+            let span = self.startSpan()
+            defer {
+                span.end()
+            }
+            return try await operation(span)
+        }
+    #endif
     }
 }

Package.resolved

@@ -7,8 +7,8 @@ let package = Package(
     name: "opentelemetry-swift",
     platforms: [
         .macOS(.v10_13),
-        .iOS(.v11),
-        .tvOS(.v11)
+        .iOS(.v12),
+        .tvOS(.v12)
     ],
     products: [
         .library(name: "OpenTelemetryApi", type: .static, targets: ["OpenTelemetryApi"]),
@@ -28,29 +28,31 @@ let package = Package(
         .library(name: "InMemoryExporter", type: .static, targets: ["InMemoryExporter"]),
         .library(name: "DatadogExporter", type: .static, targets: ["DatadogExporter"]),
         .library(name: "NetworkStatus", type: .static, targets: ["NetworkStatus"]),
-        .library(name: "OTelSwiftLog" type: .static, targets: ["OTelSwiftLog"])
+        .library(name: "OTelSwiftLog", type: .static, targets: ["OTelSwiftLog"]),
         .executable(name: "simpleExporter", targets: ["SimpleExporter"]),
         .executable(name: "OTLPExporter", targets: ["OTLPExporter"]),
         .executable(name: "OTLPHTTPExporter", targets: ["OTLPHTTPExporter"]),
         .executable(name: "loggingTracer", targets: ["LoggingTracer"]),
     ],
     dependencies: [
-        .package(name: "Opentracing", url: "https://github.com/undefinedlabs/opentracing-objc", exact: "0.5.2"),
-        .package(name: "Thrift", url: "https://github.com/undefinedlabs/Thrift-Swift", exact: "1.1.1"),
-        .package(name: "swift-nio", url: "https://github.com/apple/swift-nio.git", exact: "2.0.0"),
-        .package(name: "grpc-swift", url: "https://github.com/grpc/grpc-swift.git", exact: "1.0.0"),
-        .package(name: "swift-protobuf", url: "https://github.com/apple/swift-protobuf.git", exact: "1.20.2"),
-        .package(name: "swift-log", url: "https://github.com/apple/swift-log.git", exact: "1.4.4"),
-        .package(name: "swift-metrics", url: "https://github.com/apple/swift-metrics.git", exact: "2.1.1"),
-        .package(name: "Reachability.swift", url: "https://github.com/ashleymills/Reachability.swift", exact: "5.1.0")
+        .package(url: "https://github.com/undefinedlabs/opentracing-objc", exact: "0.5.2"),
+        .package(url: "https://github.com/undefinedlabs/Thrift-Swift", exact: "1.1.1"),
+        .package(url: "https://github.com/apple/swift-nio.git", exact: "2.0.0"),
+        .package(url: "https://github.com/grpc/grpc-swift.git", exact: "1.0.0"),
+        .package(url: "https://github.com/apple/swift-protobuf.git", exact: "1.20.2"),
+        .package(url: "https://github.com/apple/swift-log.git", exact: "1.4.4"),
+        .package(url: "https://github.com/apple/swift-metrics.git", exact: "2.1.1"),
+        .package(url: "https://github.com/ashleymills/Reachability.swift", exact: "5.1.0")
     ],
     targets: [
         .target(name: "OpenTelemetryApi",
                 dependencies: []),
         .target(name: "OpenTelemetrySdk",
                 dependencies: ["OpenTelemetryApi"]),
+        .target(name: "OpenTelemetryTestUtils",
+               dependencies: ["OpenTelemetryApi", "OpenTelemetrySdk"]),
         .target(name: "OTelSwiftLog",
-                dependencies: ["OpenTelemetryApigi",
+                dependencies: ["OpenTelemetryApi",
                               .product(name: "Logging", package: "swift-log")],
                 path: "Sources/Bridges/OTelSwiftLog"),
         .target(name: "ResourceExtension",
@@ -67,7 +69,7 @@ let package = Package(
                     .product(name: "Reachability", package: "Reachability.swift")
                 ],
                 path: "Sources/Instrumentation/NetworkStatus",
-                linkerSettings: [.linkedFramework("CoreTelephony", .when(platforms: [.iOS], configuration: nil))]),
+                linkerSettings: [.linkedFramework("CoreTelephony", .when(platforms: [.iOS]))]),
         .target(name: "SignPostIntegration",
                 dependencies: ["OpenTelemetrySdk"],
                 path: "Sources/Instrumentation/SignPostIntegration",
@@ -128,7 +130,7 @@ let package = Package(
                     dependencies: ["NetworkStatus", .product(name: "Reachability", package: "Reachability.swift")],
                     path: "Tests/InstrumentationTests/NetworkStatusTests"),
         .testTarget(name: "OpenTelemetryApiTests",
-                    dependencies: ["OpenTelemetryApi"],
+                    dependencies: ["OpenTelemetryApi", "OpenTelemetryTestUtils"],
                     path: "Tests/OpenTelemetryApiTests"),
         .testTarget(name: "OpenTelemetrySdkTests",
                     dependencies: ["OpenTelemetrySdk"],

Package.swift

@@ -50,6 +50,8 @@ let package = Package(
                 dependencies: []),
         .target(name: "OpenTelemetrySdk",
                 dependencies: ["OpenTelemetryApi"]),
+        .target(name: "OpenTelemetryTestUtils",
+               dependencies: ["OpenTelemetryApi", "OpenTelemetrySdk"]),
         .target(name: "ResourceExtension",
                 dependencies: ["OpenTelemetrySdk"],
                 path: "Sources/Instrumentation/SDKResourceExtension",
@@ -136,11 +138,12 @@ let package = Package(
                     ],
                     path: "Tests/InstrumentationTests/NetworkStatusTests"),
         .testTarget(name: "OpenTelemetryApiTests",
-                    dependencies: ["OpenTelemetryApi"],
+                    dependencies: ["OpenTelemetryApi", "OpenTelemetryTestUtils"],
                     path: "Tests/OpenTelemetryApiTests"),
         .testTarget(name: "OpenTelemetrySdkTests",
                     dependencies: ["OpenTelemetryApi",
-                                   "OpenTelemetrySdk"],
+                                   "OpenTelemetrySdk",
+                                  "OpenTelemetryTestUtils"],
                     path: "Tests/OpenTelemetrySdkTests"),
         .testTarget(name: "ResourceExtensionTests",
                     dependencies: ["ResourceExtension", "OpenTelemetrySdk"],