Add new SignPostIntegration instrumentation, it allow to integrate spans created in opentelemetry with os_signpost functionality, allowing the spans to appear automatically in Instruments when profiling the app.

Author: Ignacio Bonafonte

Examples/Simple Exporter/README.md

@@ -1,6 +1,6 @@
 ### Simple Exporter
 
-This example shows the Jaeger an Stdout exporters in action using a MultiSpanExporter
+This example shows the Jaeger an Stdout exporters in action using a MultiSpanExporter. It also adds support for SignPostIntegration, so running this app in `Instruments` will show the span creation and duration
 
 The sample expects a local Jaeger installation as explained in [Jaeger docs](https://www.jaegertracing.io/docs/1.16/getting-started/#all-in-one):
 

Examples/Simple Exporter/main.swift

@@ -20,6 +20,7 @@ import OpenTelemetrySdk
 import ResourceExtension
 import StdoutExporter
 import ZipkinExporter
+import SignPostIntegration
 
 let sampleKey = "sampleKey"
 let sampleValue = "sampleValue"
@@ -36,15 +37,18 @@ tracer = OpenTelemetrySDK.instance.tracerProvider.get(instrumentationName: instr
 func simpleSpan() {
     let span = tracer.spanBuilder(spanName: "SimpleSpan").setSpanKind(spanKind: .client).startSpan()
     span.setAttribute(key: sampleKey, value: sampleValue)
+    Thread.sleep(forTimeInterval: 0.5)
     span.end()
 }
 
 func childSpan() {
     let span = tracer.spanBuilder(spanName: "parentSpan").setSpanKind(spanKind: .client).startSpan()
     span.setAttribute(key: sampleKey, value: sampleValue)
+    Thread.sleep(forTimeInterval: 0.2)
     OpenTelemetry.instance.contextProvider.setActiveSpan(span)
     let childSpan = tracer.spanBuilder(spanName: "childSpan").setSpanKind(spanKind: .client).startSpan()
     childSpan.setAttribute(key: sampleKey, value: sampleValue)
+    Thread.sleep(forTimeInterval: 0.5)
     childSpan.end()
     span.end()
 }
@@ -61,6 +65,11 @@ let spanExporter = MultiSpanExporter(spanExporters: [jaegerExporter, stdoutExpor
 let spanProcessor = SimpleSpanProcessor(spanExporter: spanExporter)
 OpenTelemetrySDK.instance.tracerProvider.addSpanProcessor(spanProcessor)
 
+if #available(macOS 10.14, *) {
+    OpenTelemetrySDK.instance.tracerProvider.addSpanProcessor(SignPostIntegration())
+}
+
+
 simpleSpan()
 sleep(1)
 childSpan()

Package.swift

@@ -18,6 +18,8 @@ let package = Package(
         .library(name: "libResourceExtension", type: .static, targets: ["ResourceExtension"]),
         .library(name: "URLSessionInstrumentation", type: .dynamic, targets: ["URLSessionInstrumentation"]),
         .library(name: "libURLSessionInstrumentation", type: .static, targets: ["URLSessionInstrumentation"]),
+        .library(name: "SignPostIntegration", type: .dynamic, targets: ["SignPostIntegration"]),
+        .library(name: "libSignPostIntegration", type: .static, targets: ["SignPostIntegration"]),
         .library(name: "OpenTracingShim-experimental", type: .dynamic, targets: ["OpenTracingShim"]),
         .library(name: "libOpenTracingShim-experimental", type: .static, targets: ["OpenTracingShim"]),
         .library(name: "SwiftMetricsShim-experimental", type: .dynamic, targets: ["SwiftMetricsShim"]),
@@ -61,6 +63,10 @@ let package = Package(
                 dependencies: ["OpenTelemetrySdk"],
                 path: "Sources/Instrumentation/URLSession",
                 exclude: ["README.md"]),
+        .target(name: "SignPostIntegration",
+                dependencies: ["OpenTelemetrySdk"],
+                path: "Sources/Instrumentation/SignPostIntegration",
+                exclude: ["README.md"]),
         .target(name: "OpenTracingShim",
                 dependencies: ["OpenTelemetrySdk",
                                "Opentracing"],
@@ -145,7 +151,7 @@ let package = Package(
                 dependencies: ["OpenTelemetryApi"],
                 path: "Examples/Logging Tracer"),
         .target(name: "SimpleExporter",
-                dependencies: ["OpenTelemetrySdk", "JaegerExporter", "StdoutExporter", "ZipkinExporter", "ResourceExtension"],
+                dependencies: ["OpenTelemetrySdk", "JaegerExporter", "StdoutExporter", "ZipkinExporter", "ResourceExtension", "SignPostIntegration"],
                 path: "Examples/Simple Exporter",
                 exclude: ["README.md"]),
         .target(name: "PrometheusSample",

Sources/Instrumentation/SignPostIntegration/README.md

@@ -0,0 +1,15 @@
+# SignPost Integration
+
+This package creates `os_signpost` `begin` and `end` calls when spans are started or ended. It allows automatic integration of applications
+instrumented with opentelemetry to show their spans in a profiling app like `Instruments`. It also exports the `OSLog` it uses for posting so the user can add extra signpost events. This functionality is shown in `Simple Exporter` example
+
+
+## Usage 
+
+Just add SignpostIntegration as any other Span Processor:
+
+```
+OpenTelemetry.instance.tracerProvider.addSpanProcessor(SignPostIntegration())`
+```
+
+

Sources/Instrumentation/SignPostIntegration/SignPostIntegration.swift

@@ -0,0 +1,43 @@
+// Copyright 2020, OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+
+import Foundation
+import os
+import OpenTelemetryApi
+import OpenTelemetrySdk
+
+/// A span processor that decorates spans with the origin attribute
+@available(macOS 10.14, *)
+public class SignPostIntegration: SpanProcessor {
+    public let isStartRequired = true
+    public let isEndRequired = true
+    public let osLog = OSLog(subsystem: "OpenTelemetry", category: .pointsOfInterest)
+
+    public init() {}
+
+    public func onStart(parentContext: SpanContext?, span: ReadableSpan) {
+        let signpostID = OSSignpostID(log: osLog, object: self)
+        os_signpost(.begin, log: osLog, name: "Span", signpostID: signpostID, "%{public}@", span.name)
+    }
+
+    public func onEnd(span: ReadableSpan) {
+        let signpostID = OSSignpostID(log: osLog, object: self)
+        os_signpost(.end, log: osLog, name: "Span", signpostID: signpostID)
+    }
+
+    public func shutdown() {}
+    public func forceFlush() {}
+}