[VOL-3187]Pass Context down the execution call hierarchy across ofagent codebase

Change-Id: Ia5f2fa1509beefe0ddc427b83e39d2702782db8f
diff --git a/vendor/github.com/opentracing/opentracing-go/globaltracer.go b/vendor/github.com/opentracing/opentracing-go/globaltracer.go
new file mode 100644
index 0000000..4f7066a
--- /dev/null
+++ b/vendor/github.com/opentracing/opentracing-go/globaltracer.go
@@ -0,0 +1,42 @@
+package opentracing
+
+type registeredTracer struct {
+	tracer       Tracer
+	isRegistered bool
+}
+
+var (
+	globalTracer = registeredTracer{NoopTracer{}, false}
+)
+
+// SetGlobalTracer sets the [singleton] opentracing.Tracer returned by
+// GlobalTracer(). Those who use GlobalTracer (rather than directly manage an
+// opentracing.Tracer instance) should call SetGlobalTracer as early as
+// possible in main(), prior to calling the `StartSpan` global func below.
+// Prior to calling `SetGlobalTracer`, any Spans started via the `StartSpan`
+// (etc) globals are noops.
+func SetGlobalTracer(tracer Tracer) {
+	globalTracer = registeredTracer{tracer, true}
+}
+
+// GlobalTracer returns the global singleton `Tracer` implementation.
+// Before `SetGlobalTracer()` is called, the `GlobalTracer()` is a noop
+// implementation that drops all data handed to it.
+func GlobalTracer() Tracer {
+	return globalTracer.tracer
+}
+
+// StartSpan defers to `Tracer.StartSpan`. See `GlobalTracer()`.
+func StartSpan(operationName string, opts ...StartSpanOption) Span {
+	return globalTracer.tracer.StartSpan(operationName, opts...)
+}
+
+// InitGlobalTracer is deprecated. Please use SetGlobalTracer.
+func InitGlobalTracer(tracer Tracer) {
+	SetGlobalTracer(tracer)
+}
+
+// IsGlobalTracerRegistered returns a `bool` to indicate if a tracer has been globally registered
+func IsGlobalTracerRegistered() bool {
+	return globalTracer.isRegistered
+}