From cdcd3745830492a08685f380c2691a26efb429e9 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Mon, 5 Apr 2021 15:56:38 -0400
Subject: [PATCH 01/17] Migrate processor + sampler to TracerContext to ensure
 changes in TracerProvider reflect to all tracers.

---
 .../sdk/common/atomic_unique_ptr.h            |  2 +
 sdk/include/opentelemetry/sdk/trace/tracer.h  | 44 +++------
 .../opentelemetry/sdk/trace/tracer_context.h  | 79 +++++++++++++++
 .../opentelemetry/sdk/trace/tracer_provider.h | 39 ++++----
 sdk/src/trace/span.cc                         | 12 +--
 sdk/src/trace/span.h                          |  5 +-
 sdk/src/trace/tracer.cc                       | 26 +----
 sdk/src/trace/tracer_context.cc               | 40 ++++++++
 sdk/src/trace/tracer_provider.cc              | 39 +++-----
 sdk/test/trace/sampler_benchmark.cc           |  6 +-
 sdk/test/trace/tracer_provider_test.cc        | 50 +++-------
 sdk/test/trace/tracer_test.cc                 | 99 +++++--------------
 12 files changed, 215 insertions(+), 226 deletions(-)
 create mode 100644 sdk/include/opentelemetry/sdk/trace/tracer_context.h
 create mode 100644 sdk/src/trace/tracer_context.cc

diff --git a/sdk/include/opentelemetry/sdk/common/atomic_unique_ptr.h b/sdk/include/opentelemetry/sdk/common/atomic_unique_ptr.h
index d93d9b72b2..32217da220 100644
--- a/sdk/include/opentelemetry/sdk/common/atomic_unique_ptr.h
+++ b/sdk/include/opentelemetry/sdk/common/atomic_unique_ptr.h
@@ -20,6 +20,8 @@ class AtomicUniquePtr
 public:
   AtomicUniquePtr() noexcept {}
 
+  explicit AtomicUniquePtr(std::unique_ptr<T> &&other) noexcept : ptr_(other.release()) {}
+
   ~AtomicUniquePtr() noexcept { Reset(); }
 
   T &operator*() const noexcept { return *Get(); }
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer.h b/sdk/include/opentelemetry/sdk/trace/tracer.h
index 1e52b0e377..4e31c2c204 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer.h
@@ -4,6 +4,7 @@
 #include "opentelemetry/sdk/resource/resource.h"
 #include "opentelemetry/sdk/trace/processor.h"
 #include "opentelemetry/sdk/trace/samplers/always_on.h"
+#include "opentelemetry/sdk/trace/tracer_context.h"
 #include "opentelemetry/trace/noop.h"
 #include "opentelemetry/trace/tracer.h"
 #include "opentelemetry/version.h"
@@ -18,33 +19,8 @@ namespace trace
 class Tracer final : public trace_api::Tracer, public std::enable_shared_from_this<Tracer>
 {
 public:
-  /**
-   * Initialize a new tracer.
-   * @param processor The span processor for this tracer. This must not be a
-   * nullptr.
-   */
-  explicit Tracer(std::shared_ptr<SpanProcessor> processor,
-                  const opentelemetry::sdk::resource::Resource &resource,
-                  std::shared_ptr<Sampler> sampler = std::make_shared<AlwaysOnSampler>()) noexcept;
-
-  /**
-   * Set the span processor associated with this tracer.
-   * @param processor The new span processor for this tracer. This must not be
-   * a nullptr.
-   */
-  void SetProcessor(std::shared_ptr<SpanProcessor> processor) noexcept;
-
-  /**
-   * Obtain the span processor associated with this tracer.
-   * @return The span processor for this tracer.
-   */
-  std::shared_ptr<SpanProcessor> GetProcessor() const noexcept;
-
-  /**
-   * Obtain the sampler associated with this tracer.
-   * @return The sampler for this tracer.
-   */
-  std::shared_ptr<Sampler> GetSampler() const noexcept;
+  /** Construct a new Tracer with the given context pipeline. */
+  explicit Tracer(std::shared_ptr<sdk::trace::TracerContext> context) noexcept;
 
   nostd::shared_ptr<trace_api::Span> StartSpan(
       nostd::string_view name,
@@ -56,10 +32,18 @@ class Tracer final : public trace_api::Tracer, public std::enable_shared_from_th
 
   void CloseWithMicroseconds(uint64_t timeout) noexcept override;
 
+
+  /** Returns the currently active span processor. */
+  SpanProcessor& GetActiveProcessor() noexcept {
+    return context_->GetActiveProcessor();
+  }
+
+
+  // Note: Test only
+  Sampler& GetSampler() { return context_->GetSampler(); }
+
 private:
-  opentelemetry::sdk::common::AtomicSharedPtr<SpanProcessor> processor_;
-  const std::shared_ptr<Sampler> sampler_;
-  const opentelemetry::sdk::resource::Resource &resource_;
+  std::shared_ptr<sdk::trace::TracerContext> context_;
 };
 }  // namespace trace
 }  // namespace sdk
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_context.h b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
new file mode 100644
index 0000000000..a25bbdc056
--- /dev/null
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
@@ -0,0 +1,79 @@
+#pragma once
+
+#include "opentelemetry/sdk/common/atomic_unique_ptr.h"
+#include "opentelemetry/sdk/resource/resource.h"
+#include "opentelemetry/sdk/trace/processor.h"
+#include "opentelemetry/sdk/trace/samplers/always_on.h"
+#include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace trace
+{
+
+/**
+ * A class which stores the TracerProvider context.
+ *
+ * This class meets the following design criteria:
+ * - A shared reference between TracerProvider and Tracers instantiated.
+ * - A thread-safe class that allows updating/altering processor/exporter pipelines
+ *   and sampling config.
+ * - The owner/destroyer of Processors/Exporters.  These will remain active until
+ *   this class is destroyed.  I.e. Sampling, Exporting, flushing etc. are all ok if this
+ *   object is alive, and they willl work together.   If this object is destroyed, then
+ *   no shared references to Processor, Exporter, Recordable etc. should exist, and all
+ *   associated pipelines will have been flushed.
+ */
+class TracerContext
+{
+public:
+  explicit TracerContext(std::unique_ptr<SpanProcessor> processor,
+                         opentelemetry::sdk::resource::Resource resource =
+                             opentelemetry::sdk::resource::Resource::Create({}),
+                         std::unique_ptr<Sampler> sampler =
+                             std::unique_ptr<AlwaysOnSampler>(new AlwaysOnSampler)) noexcept;
+  /**
+   * Attaches a span processor to this tracer context.
+   * 
+   * @param processor The new span processor for this tracer. This must not be
+   * a nullptr.  Ownership is given to the `TracerContext`.
+   */
+  void RegisterPipeline(std::unique_ptr<SpanProcessor> processor) noexcept;
+
+  /**
+   * Obtain the sampler associated with this tracer.
+   * @return The sampler for this tracer.
+   */
+  Sampler &GetSampler() const noexcept;
+
+  /**
+   * Obtain the (conceptual) active processor.
+   * 
+   * Note: When more than one processor is active, this will
+   * return an "aggregate" processor
+   */
+  SpanProcessor& GetActiveProcessor() const noexcept;
+
+  /**
+   * Obtain the resource associated with this tracer context.
+   * @return The resource for this tracer context.
+   */
+  const opentelemetry::sdk::resource::Resource &GetResource() const noexcept;
+
+  /**
+   * Force all active SpanProcessors to flush any buffered spans
+   * within the given timeout.
+   */
+  void ForceFlushWithMicroseconds(uint64_t timeout) noexcept;
+
+private:
+  // This is an atomic pointer so we can adapt the processor pipeline dynamically.
+  opentelemetry::sdk::common::AtomicUniquePtr<SpanProcessor> processor_;
+  opentelemetry::sdk::resource::Resource resource_;
+  std::unique_ptr<Sampler> sampler_;
+};
+
+}  // namespace trace
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_provider.h b/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
index f56a0fdab6..978ed0a7dc 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
@@ -10,6 +10,7 @@
 #include "opentelemetry/sdk/trace/samplers/always_on.h"
 #include "opentelemetry/sdk/trace/tracer.h"
 #include "opentelemetry/trace/tracer_provider.h"
+#include "opentelemetry/sdk/trace/tracer_context.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace sdk
@@ -26,34 +27,30 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
    * @param sampler The sampler for this tracer provider. This must
    * not be a nullptr.
    */
-  explicit TracerProvider(
-      std::shared_ptr<SpanProcessor> processor,
-      opentelemetry::sdk::resource::Resource &&resource =
-          opentelemetry::sdk::resource::Resource::Create({}),
-      std::shared_ptr<Sampler> sampler = std::make_shared<AlwaysOnSampler>()) noexcept;
+  explicit TracerProvider(std::unique_ptr<SpanProcessor> processor,
+                          opentelemetry::sdk::resource::Resource resource =
+                              opentelemetry::sdk::resource::Resource::Create({}),
+                          std::unique_ptr<Sampler> sampler =
+                              std::unique_ptr<AlwaysOnSampler>(new AlwaysOnSampler)) noexcept;
+
+  /**
+   * Initialize a new tracer provider with a specified context
+   * @param context The shared tracer configuration/pipeline for this provider.
+   */
+  explicit TracerProvider(std::shared_ptr<sdk::trace::TracerContext> context) noexcept;
 
   opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer> GetTracer(
       nostd::string_view library_name,
       nostd::string_view library_version = "") noexcept override;
 
   /**
-   * Set the span processor associated with this tracer provider.
+   * Attaches a span processor to this tracer provider.
    * @param processor The new span processor for this tracer provider. This
    * must not be a nullptr.
+   * 
+   * Note: This process may not receive any in-flight spans, but will get newly created spans.
    */
-  void SetProcessor(std::shared_ptr<SpanProcessor> processor) noexcept;
-
-  /**
-   * Obtain the span processor associated with this tracer provider.
-   * @return The span processor for this tracer provider.
-   */
-  std::shared_ptr<SpanProcessor> GetProcessor() const noexcept;
-
-  /**
-   * Obtain the sampler associated with this tracer provider.
-   * @return The sampler for this tracer provider.
-   */
-  std::shared_ptr<Sampler> GetSampler() const noexcept;
+  void RegisterProcessor(std::unique_ptr<SpanProcessor> processor) noexcept;
 
   /**
    * Obtain the resource associated with this tracer provider.
@@ -72,10 +69,8 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
   bool ForceFlush(std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept;
 
 private:
-  opentelemetry::sdk::common::AtomicSharedPtr<SpanProcessor> processor_;
+  std::shared_ptr<sdk::trace::TracerContext> context_;
   std::shared_ptr<opentelemetry::trace::Tracer> tracer_;
-  const std::shared_ptr<Sampler> sampler_;
-  const opentelemetry::sdk::resource::Resource resource_;
 };
 }  // namespace trace
 }  // namespace sdk
diff --git a/sdk/src/trace/span.cc b/sdk/src/trace/span.cc
index 576d54f38c..00c73378cb 100644
--- a/sdk/src/trace/span.cc
+++ b/sdk/src/trace/span.cc
@@ -58,18 +58,15 @@ trace_api::SpanId GenerateRandomSpanId()
 }
 
 Span::Span(std::shared_ptr<Tracer> &&tracer,
-           std::shared_ptr<SpanProcessor> processor,
            nostd::string_view name,
            const opentelemetry::common::KeyValueIterable &attributes,
            const trace_api::SpanContextKeyValueIterable &links,
            const trace_api::StartSpanOptions &options,
            const trace_api::SpanContext &parent_span_context,
-           const opentelemetry::sdk::resource::Resource &resource,
            const nostd::shared_ptr<opentelemetry::trace::TraceState> trace_state,
            const bool sampled) noexcept
     : tracer_{std::move(tracer)},
-      processor_{processor},
-      recordable_{processor_->MakeRecordable()},
+      recordable_{tracer_->GetActiveProcessor().MakeRecordable()},
       start_steady_time{options.start_steady_time},
       has_ended_{false}
 {
@@ -118,8 +115,9 @@ Span::Span(std::shared_ptr<Tracer> &&tracer,
   recordable_->SetSpanKind(options.kind);
   recordable_->SetStartTime(NowOr(options.start_system_time));
   start_steady_time = NowOr(options.start_steady_time);
-  // recordable_->SetResource(resource_); TODO
-  processor_->OnStart(*recordable_, parent_span_context);
+  // recordable_->SetResource(tracer_->GetResoource()); TODO
+  // recordable_->SetResource(tracer_->GetInstrumentationLibrary()); TODO
+  tracer_->GetActiveProcessor().OnStart(*recordable_, parent_span_context);
 }
 
 Span::~Span()
@@ -206,7 +204,7 @@ void Span::End(const trace_api::EndSpanOptions &options) noexcept
   recordable_->SetDuration(std::chrono::steady_clock::time_point(end_steady_time) -
                            std::chrono::steady_clock::time_point(start_steady_time));
 
-  processor_->OnEnd(std::move(recordable_));
+  tracer_->GetActiveProcessor().OnEnd(std::move(recordable_));
   recordable_.reset();
 }
 
diff --git a/sdk/src/trace/span.h b/sdk/src/trace/span.h
index 01fb995517..efc16d6c59 100644
--- a/sdk/src/trace/span.h
+++ b/sdk/src/trace/span.h
@@ -16,13 +16,11 @@ class Span final : public trace_api::Span
 {
 public:
   Span(std::shared_ptr<Tracer> &&tracer,
-       std::shared_ptr<SpanProcessor> processor,
        nostd::string_view name,
        const opentelemetry::common::KeyValueIterable &attributes,
        const trace_api::SpanContextKeyValueIterable &links,
        const trace_api::StartSpanOptions &options,
        const trace_api::SpanContext &parent_span_context,
-       const opentelemetry::sdk::resource::Resource &resource,
        const nostd::shared_ptr<opentelemetry::trace::TraceState> trace_state =
            trace_api::TraceState::GetDefault(),
        const bool sampled = false) noexcept;
@@ -52,8 +50,7 @@ class Span final : public trace_api::Span
   trace_api::SpanContext GetContext() const noexcept override { return *span_context_.get(); }
 
 private:
-  std::shared_ptr<trace_api::Tracer> tracer_;
-  std::shared_ptr<SpanProcessor> processor_;
+  std::shared_ptr<Tracer> tracer_;
   mutable std::mutex mu_;
   std::unique_ptr<Recordable> recordable_;
   opentelemetry::core::SteadyTimestamp start_steady_time;
diff --git a/sdk/src/trace/tracer.cc b/sdk/src/trace/tracer.cc
index 93fdc6f680..c7214a803c 100644
--- a/sdk/src/trace/tracer.cc
+++ b/sdk/src/trace/tracer.cc
@@ -10,26 +10,8 @@ namespace sdk
 {
 namespace trace
 {
-Tracer::Tracer(std::shared_ptr<SpanProcessor> processor,
-               const opentelemetry::sdk::resource::Resource &resource,
-               std::shared_ptr<Sampler> sampler) noexcept
-    : processor_{processor}, sampler_{sampler}, resource_{resource}
-{}
 
-void Tracer::SetProcessor(std::shared_ptr<SpanProcessor> processor) noexcept
-{
-  processor_.store(processor);
-}
-
-std::shared_ptr<SpanProcessor> Tracer::GetProcessor() const noexcept
-{
-  return processor_.load();
-}
-
-std::shared_ptr<Sampler> Tracer::GetSampler() const noexcept
-{
-  return sampler_;
-}
+Tracer::Tracer(std::shared_ptr<sdk::trace::TracerContext> context) noexcept : context_{context} {}
 
 trace_api::SpanContext GetCurrentSpanContext(const trace_api::SpanContext &explicit_parent)
 {
@@ -61,7 +43,7 @@ nostd::shared_ptr<trace_api::Span> Tracer::StartSpan(
   trace_api::SpanContext parent = GetCurrentSpanContext(options.parent);
 
   auto sampling_result =
-      sampler_->ShouldSample(parent, parent.trace_id(), name, options.kind, attributes, links);
+      context_->GetSampler().ShouldSample(parent, parent.trace_id(), name, options.kind, attributes, links);
   if (sampling_result.decision == Decision::DROP)
   {
     // Don't allocate a no-op span for every DROP decision, but use a static
@@ -74,8 +56,8 @@ nostd::shared_ptr<trace_api::Span> Tracer::StartSpan(
   else
   {
     auto span = nostd::shared_ptr<trace_api::Span>{new (std::nothrow) Span{
-        this->shared_from_this(), processor_.load(), name, attributes, links, options, parent,
-        resource_, sampling_result.trace_state, true}};
+        this->shared_from_this(), name, attributes, links, options, parent,
+        sampling_result.trace_state, true}};
 
     // if the attributes is not nullptr, add attributes to the span.
     if (sampling_result.attributes)
diff --git a/sdk/src/trace/tracer_context.cc b/sdk/src/trace/tracer_context.cc
new file mode 100644
index 0000000000..8384d4d2a5
--- /dev/null
+++ b/sdk/src/trace/tracer_context.cc
@@ -0,0 +1,40 @@
+#include "opentelemetry/sdk/trace/tracer_context.h"
+#include "opentelemetry/sdk/trace/processor.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace trace
+{
+
+TracerContext::TracerContext(std::unique_ptr<SpanProcessor> processor,
+                             opentelemetry::sdk::resource::Resource resource,
+                             std::unique_ptr<Sampler> sampler) noexcept
+    : processor_(std::move(processor)), resource_(resource), sampler_(std::move(sampler))
+{}
+
+Sampler &TracerContext::GetSampler() const noexcept
+{
+  return *sampler_.get();
+}
+
+const opentelemetry::sdk::resource::Resource &TracerContext::GetResource() const noexcept
+{
+  return resource_;
+}
+
+void TracerContext::RegisterPipeline(std::unique_ptr<SpanProcessor> processor) noexcept
+{
+  // TODO(jsuereth): Implement
+  // 1. If existing processor is an "AggregateProcessor" append the new processor to it.
+  // 2. If the existing processor is NOT an "AggregateProcessor", create a new Aggregate of this and the other,
+  //    then replace our atomic ptr with the new aggregate.
+}
+
+SpanProcessor& TracerContext::GetActiveProcessor() const noexcept {
+  return *processor_;
+}
+
+}  // namespace trace
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE
diff --git a/sdk/src/trace/tracer_provider.cc b/sdk/src/trace/tracer_provider.cc
index cc236292a2..cb1fd0327a 100644
--- a/sdk/src/trace/tracer_provider.cc
+++ b/sdk/src/trace/tracer_provider.cc
@@ -5,13 +5,14 @@ namespace sdk
 {
 namespace trace
 {
-TracerProvider::TracerProvider(std::shared_ptr<SpanProcessor> processor,
-                               opentelemetry::sdk::resource::Resource &&resource,
-                               std::shared_ptr<Sampler> sampler) noexcept
-    : processor_{processor},
-      tracer_(new Tracer(std::move(processor), resource, sampler)),
-      sampler_(sampler),
-      resource_(resource)
+TracerProvider::TracerProvider(std::shared_ptr<sdk::trace::TracerContext> context) noexcept
+    : context_{context}, tracer_(new Tracer(context))
+{}
+
+TracerProvider::TracerProvider(std::unique_ptr<SpanProcessor> processor,
+                               opentelemetry::sdk::resource::Resource resource,
+                               std::unique_ptr<Sampler> sampler) noexcept
+    : TracerProvider(std::make_shared<TracerContext>(std::move(processor), resource, std::move(sampler)))
 {}
 
 opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer> TracerProvider::GetTracer(
@@ -21,38 +22,26 @@ opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer> TracerProvider::G
   return opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer>(tracer_);
 }
 
-void TracerProvider::SetProcessor(std::shared_ptr<SpanProcessor> processor) noexcept
-{
-  processor_.store(processor);
-
-  auto sdkTracer = static_cast<Tracer *>(tracer_.get());
-  sdkTracer->SetProcessor(processor);
-}
-
-std::shared_ptr<SpanProcessor> TracerProvider::GetProcessor() const noexcept
+void TracerProvider::RegisterProcessor(std::unique_ptr<SpanProcessor> processor) noexcept
 {
-  return processor_.load();
-}
-
-std::shared_ptr<Sampler> TracerProvider::GetSampler() const noexcept
-{
-  return sampler_;
+  return context_->RegisterPipeline(std::move(processor));
 }
 
 const opentelemetry::sdk::resource::Resource &TracerProvider::GetResource() const noexcept
 {
-  return resource_;
+  return context_->GetResource();
 }
 
 bool TracerProvider::Shutdown() noexcept
 {
-  return GetProcessor()->Shutdown();
+  return context_->GetActiveProcessor().Shutdown();
 }
 
 bool TracerProvider::ForceFlush(std::chrono::microseconds timeout) noexcept
 {
-  return GetProcessor()->ForceFlush(timeout);
+  return context_->GetActiveProcessor().ForceFlush(timeout);
 }
+
 }  // namespace trace
 }  // namespace sdk
 OPENTELEMETRY_END_NAMESPACE
diff --git a/sdk/test/trace/sampler_benchmark.cc b/sdk/test/trace/sampler_benchmark.cc
index 5606206ce6..90a07adc77 100644
--- a/sdk/test/trace/sampler_benchmark.cc
+++ b/sdk/test/trace/sampler_benchmark.cc
@@ -118,10 +118,10 @@ BENCHMARK(BM_TraceIdRatioBasedSamplerShouldSample);
 void BenchmarkSpanCreation(std::shared_ptr<Sampler> sampler, benchmark::State &state)
 {
   std::unique_ptr<SpanExporter> exporter(new InMemorySpanExporter());
-  auto processor = std::make_shared<SimpleSpanProcessor>(std::move(exporter));
+  auto processor = std::unique_ptr<SpanProcessor>(new SimpleSpanProcessor(std::move(exporter)));
+  auto context   = std::make_shared<TracerContext>(std::move(processor));
   auto resource  = opentelemetry::sdk::resource::Resource::Create({});
-  auto tracer =
-      std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, resource, sampler));
+  auto tracer    = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
 
   while (state.KeepRunning())
   {
diff --git a/sdk/test/trace/tracer_provider_test.cc b/sdk/test/trace/tracer_provider_test.cc
index 7cfe306278..55a5a9be44 100644
--- a/sdk/test/trace/tracer_provider_test.cc
+++ b/sdk/test/trace/tracer_provider_test.cc
@@ -12,9 +12,9 @@ using namespace opentelemetry::sdk::resource;
 
 TEST(TracerProvider, GetTracer)
 {
-  std::shared_ptr<SpanProcessor> processor(new SimpleSpanProcessor(nullptr));
+  std::unique_ptr<SpanProcessor> processor(new SimpleSpanProcessor(nullptr));
 
-  TracerProvider tp1(processor, Resource::Create({}));
+  TracerProvider tp1(std::make_shared<TracerContext>(std::move(processor), Resource::Create({})));
   auto t1 = tp1.GetTracer("test");
   auto t2 = tp1.GetTracer("test");
   auto t3 = tp1.GetTracer("different", "1.0.0");
@@ -24,58 +24,34 @@ TEST(TracerProvider, GetTracer)
 
   // Should return the same instance each time.
   ASSERT_EQ(t1, t2);
+  // TODO: t3 should be a different instance.
   ASSERT_EQ(t1, t3);
 
   // Should be an sdk::trace::Tracer with the processor attached.
   auto sdkTracer1 = dynamic_cast<Tracer *>(t1.get());
   ASSERT_NE(nullptr, sdkTracer1);
-  ASSERT_EQ(processor, sdkTracer1->GetProcessor());
-  ASSERT_EQ("AlwaysOnSampler", sdkTracer1->GetSampler()->GetDescription());
-
-  TracerProvider tp2(processor, Resource::Create({}), std::make_shared<AlwaysOffSampler>());
+  ASSERT_EQ("AlwaysOnSampler", sdkTracer1->GetSampler().GetDescription());
+  TracerProvider tp2(std::make_shared<TracerContext>(
+      std::unique_ptr<SpanProcessor>(new SimpleSpanProcessor(nullptr)), Resource::Create({}),
+      std::unique_ptr<Sampler>(new AlwaysOffSampler())));
   auto sdkTracer2 = dynamic_cast<Tracer *>(tp2.GetTracer("test").get());
-  ASSERT_EQ("AlwaysOffSampler", sdkTracer2->GetSampler()->GetDescription());
-}
-
-TEST(TracerProvider, GetSampler)
-{
-  std::shared_ptr<SpanProcessor> processor1(new SimpleSpanProcessor(nullptr));
-
-  // Create a TracerProvicer with a default AlwaysOnSampler.
-  TracerProvider tp1(processor1);
-  auto t1 = tp1.GetSampler();
-  auto t2 = tp1.GetSampler();
-  ASSERT_NE(nullptr, t1);
-  ASSERT_NE(nullptr, t2);
-
-  // Should return the same sampler each time.
-  ASSERT_EQ(t1, t2);
-
-  // Should be AlwaysOnSampler
-  ASSERT_EQ("AlwaysOnSampler", t2->GetDescription());
-
-  // Create a TracerProvicer with a custom AlwaysOffSampler.
-  std::shared_ptr<SpanProcessor> processor2(new SimpleSpanProcessor(nullptr));
-  TracerProvider tp2(processor2, Resource::Create({}), std::make_shared<AlwaysOffSampler>());
-  auto t3 = tp2.GetSampler();
-
-  ASSERT_EQ("AlwaysOffSampler", t3->GetDescription());
+  ASSERT_EQ("AlwaysOffSampler", sdkTracer2->GetSampler().GetDescription());
 }
 
 TEST(TracerProvider, Shutdown)
 {
-  std::shared_ptr<SpanProcessor> processor1(new SimpleSpanProcessor(nullptr));
+  std::unique_ptr<SpanProcessor> processor1(new SimpleSpanProcessor(nullptr));
 
-  TracerProvider tp1(processor1);
+  TracerProvider tp1(std::make_shared<TracerContext>(std::move(processor1)));
 
   EXPECT_TRUE(tp1.Shutdown());
 }
 
 TEST(TracerProvider, ForceFlush)
 {
-  std::shared_ptr<SpanProcessor> processor1(new SimpleSpanProcessor(nullptr));
+  std::unique_ptr<SpanProcessor> processor1(new SimpleSpanProcessor(nullptr));
 
-  TracerProvider tp1(processor1);
+  TracerProvider tp1(std::move(processor1));
 
   EXPECT_TRUE(tp1.ForceFlush());
-}
+}
\ No newline at end of file
diff --git a/sdk/test/trace/tracer_test.cc b/sdk/test/trace/tracer_test.cc
index 60544f6fdc..176a949670 100644
--- a/sdk/test/trace/tracer_test.cc
+++ b/sdk/test/trace/tracer_test.cc
@@ -19,7 +19,6 @@ using opentelemetry::common::KeyValueIterableView;
 using opentelemetry::exporter::memory::InMemorySpanData;
 using opentelemetry::exporter::memory::InMemorySpanExporter;
 using opentelemetry::trace::SpanContext;
-using opentelemetry::trace::TraceFlags;
 
 /**
  * A mock sampler that returns non-empty sampling results attributes.
@@ -48,22 +47,23 @@ class MockSampler final : public Sampler
 
 namespace
 {
-std::shared_ptr<opentelemetry::trace::Tracer> initTracer(
-    std::unique_ptr<InMemorySpanExporter> &&exporter)
+std::shared_ptr<opentelemetry::trace::Tracer> initTracer(std::unique_ptr<SpanExporter> &&exporter)
 {
-  auto processor = std::make_shared<SimpleSpanProcessor>(std::move(exporter));
-  auto resource  = Resource::Create({});
-  return std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, resource));
+  auto processor = std::unique_ptr<SpanProcessor>(new SimpleSpanProcessor(std::move(exporter)));
+  auto context   = std::make_shared<TracerContext>(std::move(processor));
+  return std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
 }
 
 std::shared_ptr<opentelemetry::trace::Tracer> initTracer(
-    std::unique_ptr<InMemorySpanExporter> &&exporter,
-    std::shared_ptr<Sampler> sampler)
+    std::unique_ptr<SpanExporter> &&exporter,
+    // For testing, just shove a pointer over, we'll take it over.
+    Sampler *sampler)
 {
-  auto processor = std::make_shared<SimpleSpanProcessor>(std::move(exporter));
+  auto processor = std::unique_ptr<SpanProcessor>(new SimpleSpanProcessor(std::move(exporter)));
   auto resource  = Resource::Create({});
-
-  return std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, resource, sampler));
+  auto context   = std::make_shared<TracerContext>(std::move(processor), resource,
+                                                 std::unique_ptr<Sampler>(sampler));
+  return std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
 }
 }  // namespace
 
@@ -122,7 +122,7 @@ TEST(Tracer, StartSpanSampleOff)
 {
   std::unique_ptr<InMemorySpanExporter> exporter(new InMemorySpanExporter());
   std::shared_ptr<InMemorySpanData> span_data = exporter->GetData();
-  auto tracer_off = initTracer(std::move(exporter), std::make_shared<AlwaysOffSampler>());
+  auto tracer_off = initTracer(std::move(exporter), new AlwaysOffSampler());
 
   // This span will not be recorded.
   tracer_off->StartSpan("span 2")->End();
@@ -283,19 +283,16 @@ TEST(Tracer, GetSampler)
 {
   auto resource = Resource::Create({});
   // Create a Tracer with a default AlwaysOnSampler
-  std::shared_ptr<SpanProcessor> processor_1(new SimpleSpanProcessor(nullptr));
-  std::shared_ptr<Tracer> tracer_on(new Tracer(std::move(processor_1), resource));
+  auto tracer_on = initTracer(nullptr);
 
-  auto t1 = tracer_on->GetSampler();
-  ASSERT_EQ("AlwaysOnSampler", t1->GetDescription());
+  auto &t1 = std::dynamic_pointer_cast<Tracer>(tracer_on)->GetSampler();
+  ASSERT_EQ("AlwaysOnSampler", t1.GetDescription());
 
   // Create a Tracer with a AlwaysOffSampler
-  std::shared_ptr<SpanProcessor> processor_2(new SimpleSpanProcessor(nullptr));
-  std::shared_ptr<Tracer> tracer_off(
-      new Tracer(std::move(processor_2), resource, std::make_shared<AlwaysOffSampler>()));
+  auto tracer_off = initTracer(nullptr, new AlwaysOffSampler());
 
-  auto t2 = tracer_off->GetSampler();
-  ASSERT_EQ("AlwaysOffSampler", t2->GetDescription());
+  auto &t2 = std::dynamic_pointer_cast<Tracer>(tracer_off)->GetSampler();
+  ASSERT_EQ("AlwaysOffSampler", t2.GetDescription());
 }
 
 TEST(Tracer, SpanSetAttribute)
@@ -441,7 +438,7 @@ TEST(Tracer, TestAlwaysOffSampler)
 {
   std::unique_ptr<InMemorySpanExporter> exporter(new InMemorySpanExporter());
   std::shared_ptr<InMemorySpanData> span_data = exporter->GetData();
-  auto tracer_off = initTracer(std::move(exporter), std::make_shared<AlwaysOffSampler>());
+  auto tracer_off = initTracer(std::move(exporter), new AlwaysOffSampler());
   auto span_off_1 = tracer_off->StartSpan("span 1");
   auto span_off_2 = tracer_off->StartSpan("span 2");
 
@@ -461,8 +458,7 @@ TEST(Tracer, TestParentBasedSampler)
   std::unique_ptr<InMemorySpanExporter> exporter(new InMemorySpanExporter());
   std::shared_ptr<InMemorySpanData> span_data_parent_on = exporter->GetData();
   auto tracer_parent_on =
-      initTracer(std::move(exporter),
-                 std::make_shared<ParentBasedSampler>(std::make_shared<AlwaysOnSampler>()));
+      initTracer(std::move(exporter), new ParentBasedSampler(std::make_shared<AlwaysOnSampler>()));
 
   auto span_parent_on_1 = tracer_parent_on->StartSpan("span 1");
   auto span_parent_on_2 = tracer_parent_on->StartSpan("span 2");
@@ -481,9 +477,8 @@ TEST(Tracer, TestParentBasedSampler)
   // so this sampler will work as an AlwaysOnSampler.
   std::unique_ptr<InMemorySpanExporter> exporter2(new InMemorySpanExporter());
   std::shared_ptr<InMemorySpanData> span_data_parent_off = exporter2->GetData();
-  auto tracer_parent_off =
-      initTracer(std::move(exporter2),
-                 std::make_shared<ParentBasedSampler>(std::make_shared<AlwaysOffSampler>()));
+  auto tracer_parent_off                                 = initTracer(std::move(exporter2),
+                                      new ParentBasedSampler(std::make_shared<AlwaysOffSampler>()));
 
   auto span_parent_off_1 = tracer_parent_off->StartSpan("span 1");
   auto span_parent_off_2 = tracer_parent_off->StartSpan("span 2");
@@ -563,52 +558,4 @@ TEST(Tracer, ExpectParent)
 
   EXPECT_EQ(spandata_first->GetSpanId(), spandata_second->GetParentSpanId());
   EXPECT_EQ(spandata_second->GetSpanId(), spandata_third->GetParentSpanId());
-}
-
-TEST(Tracer, ExpectParentWithValidSpanContext)
-{
-  std::unique_ptr<InMemorySpanExporter> exporter(new InMemorySpanExporter());
-  std::shared_ptr<InMemorySpanData> span_data = exporter->GetData();
-  auto tracer                                 = initTracer(std::move(exporter));
-  auto spans                                  = span_data.get()->GetSpans();
-
-  ASSERT_EQ(0, spans.size());
-
-  // produce valid SpanContext with pseudo span and trace Id.
-  uint8_t span_id_buf[trace_api::SpanId::kSize] = {
-      1,
-  };
-  trace_api::SpanId span_id{span_id_buf};
-  uint8_t trace_id_buf[trace_api::TraceId::kSize] = {
-      2,
-  };
-  trace_api::TraceId trace_id{trace_id_buf};
-
-  trace_api::StartSpanOptions options;
-  options.parent = SpanContext(trace_id, span_id, TraceFlags{TraceFlags::kIsSampled}, true);
-
-  auto span_first = tracer->StartSpan("span 1", options);
-
-  EXPECT_EQ(span_first->GetContext().trace_flags().IsSampled(), true);
-
-  options.parent   = span_first->GetContext();
-  auto span_second = tracer->StartSpan("span 2", options);
-  EXPECT_EQ(span_second->GetContext().trace_flags().IsSampled(), true);
-
-  options.parent  = span_second->GetContext();
-  auto span_third = tracer->StartSpan("span 3", options);
-  EXPECT_EQ(span_third->GetContext().trace_flags().IsSampled(), true);
-
-  span_third->End();
-  span_second->End();
-  span_first->End();
-
-  spans = span_data->GetSpans();
-  ASSERT_EQ(3, spans.size());
-  auto spandata_first  = std::move(spans.at(2));
-  auto spandata_second = std::move(spans.at(1));
-  auto spandata_third  = std::move(spans.at(0));
-
-  EXPECT_EQ(spandata_first->GetSpanId(), spandata_second->GetParentSpanId());
-  EXPECT_EQ(spandata_second->GetSpanId(), spandata_third->GetParentSpanId());
-}
+}
\ No newline at end of file

From 7a65e53508ff64365a95a4c5b427b0554f1d17e8 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Mon, 5 Apr 2021 16:12:54 -0400
Subject: [PATCH 02/17] Fix build for non-SDK directories.

---
 examples/batch/main.cc                         | 4 ++--
 examples/multithreaded/main.cc                 | 4 ++--
 examples/otlp/main.cc                          | 4 ++--
 examples/simple/main.cc                        | 5 ++---
 exporters/otlp/test/otlp_exporter_test.cc      | 4 ++--
 ext/include/opentelemetry/ext/zpages/zpages.h  | 4 +---
 ext/test/w3c_tracecontext_test/main.cc         | 5 +++--
 ext/test/zpages/tracez_data_aggregator_test.cc | 6 ++++--
 ext/test/zpages/tracez_processor_test.cc       | 7 ++++++-
 9 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/examples/batch/main.cc b/examples/batch/main.cc
index 36372d0eb3..32e285d344 100644
--- a/examples/batch/main.cc
+++ b/examples/batch/main.cc
@@ -28,11 +28,11 @@ void initTracer()
   // We export `kNumSpans` after every `schedule_delay_millis` milliseconds.
   options.max_export_batch_size = kNumSpans;
 
-  auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
+  auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::BatchSpanProcessor(std::move(exporter), options));
 
   auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(processor));
+      new sdktrace::TracerProvider(std::move(processor)));
   // Set the global trace provider.
   opentelemetry::trace::Provider::SetTracerProvider(provider);
 }
diff --git a/examples/multithreaded/main.cc b/examples/multithreaded/main.cc
index 1a756c973b..c4d20b2924 100644
--- a/examples/multithreaded/main.cc
+++ b/examples/multithreaded/main.cc
@@ -16,10 +16,10 @@ void initTracer()
 {
   auto exporter = std::unique_ptr<sdktrace::SpanExporter>(
       new opentelemetry::exporter::trace::OStreamSpanExporter);
-  auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
+  auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
   auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(processor, opentelemetry::sdk::resource::Resource::Create({})));
+      new sdktrace::TracerProvider(std::move(processor), opentelemetry::sdk::resource::Resource::Create({})));
   // Set the global trace provider
   opentelemetry::trace::Provider::SetTracerProvider(provider);
 }
diff --git a/examples/otlp/main.cc b/examples/otlp/main.cc
index 00a557c1ff..de43ad1be5 100644
--- a/examples/otlp/main.cc
+++ b/examples/otlp/main.cc
@@ -17,9 +17,9 @@ void InitTracer()
 {
   // Create OTLP exporter instance
   auto exporter  = std::unique_ptr<sdktrace::SpanExporter>(new otlp::OtlpExporter(opts));
-  auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
+  auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
-  auto provider = nostd::shared_ptr<trace::TracerProvider>(new sdktrace::TracerProvider(processor));
+  auto provider = nostd::shared_ptr<trace::TracerProvider>(new sdktrace::TracerProvider(std::move(processor)));
   // Set the global trace provider
   trace::Provider::SetTracerProvider(provider);
 }
diff --git a/examples/simple/main.cc b/examples/simple/main.cc
index 5d22c6b155..28d9196dd6 100644
--- a/examples/simple/main.cc
+++ b/examples/simple/main.cc
@@ -12,11 +12,10 @@ void initTracer()
 {
   auto exporter = std::unique_ptr<sdktrace::SpanExporter>(
       new opentelemetry::exporter::trace::OStreamSpanExporter);
-  auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
+  auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
   auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(processor, opentelemetry::sdk::resource::Resource::Create({}),
-                                   std::make_shared<opentelemetry::sdk::trace::AlwaysOnSampler>()));
+      new sdktrace::TracerProvider(std::move(processor)));
 
   // Set the global trace provider
   opentelemetry::trace::Provider::SetTracerProvider(provider);
diff --git a/exporters/otlp/test/otlp_exporter_test.cc b/exporters/otlp/test/otlp_exporter_test.cc
index f23696ddad..3d474c6d03 100644
--- a/exporters/otlp/test/otlp_exporter_test.cc
+++ b/exporters/otlp/test/otlp_exporter_test.cc
@@ -67,10 +67,10 @@ TEST_F(OtlpExporterTestPeer, ExportIntegrationTest)
 
   auto exporter = GetExporter(stub_interface);
 
-  auto processor = std::shared_ptr<sdk::trace::SpanProcessor>(
+  auto processor = std::unique_ptr<sdk::trace::SpanProcessor>(
       new sdk::trace::SimpleSpanProcessor(std::move(exporter)));
   auto provider =
-      nostd::shared_ptr<trace::TracerProvider>(new sdk::trace::TracerProvider(processor));
+      nostd::shared_ptr<trace::TracerProvider>(new sdk::trace::TracerProvider(std::move(processor)));
   auto tracer = provider->GetTracer("test");
 
   EXPECT_CALL(*mock_stub, Export(_, _, _))
diff --git a/ext/include/opentelemetry/ext/zpages/zpages.h b/ext/include/opentelemetry/ext/zpages/zpages.h
index a32b2bf161..49f5bb7f94 100644
--- a/ext/include/opentelemetry/ext/zpages/zpages.h
+++ b/ext/include/opentelemetry/ext/zpages/zpages.h
@@ -51,10 +51,8 @@ class ZPages
   /** Replaces the global tracer provider with an instance that exports to tracez. */
   void ReplaceGlobalProvider()
   {
-    std::shared_ptr<opentelemetry::sdk::trace::SpanProcessor> tracez_processor(
-        MakeSpanProcessor().release());
     auto tracez_provider_ = opentelemetry::nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-        new opentelemetry::sdk::trace::TracerProvider(tracez_processor));
+        new opentelemetry::sdk::trace::TracerProvider(MakeSpanProcessor()));
     opentelemetry::trace::Provider::SetTracerProvider(tracez_provider_);
   }
 
diff --git a/ext/test/w3c_tracecontext_test/main.cc b/ext/test/w3c_tracecontext_test/main.cc
index 7ec727957f..fc26801079 100644
--- a/ext/test/w3c_tracecontext_test/main.cc
+++ b/ext/test/w3c_tracecontext_test/main.cc
@@ -38,10 +38,11 @@ void initTracer()
 {
   auto exporter = std::unique_ptr<sdktrace::SpanExporter>(
       new opentelemetry::exporter::trace::OStreamSpanExporter);
-  auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
+  auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
+  auto context  = std::make_shared<sdktrace::TracerContext>(std::move(processor));
   auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(processor));
+      new sdktrace::TracerProvider(context));
   // Set the global trace provider
   opentelemetry::trace::Provider::SetTracerProvider(provider);
 }
diff --git a/ext/test/zpages/tracez_data_aggregator_test.cc b/ext/test/zpages/tracez_data_aggregator_test.cc
index 82af11a274..3cfd98b54a 100644
--- a/ext/test/zpages/tracez_data_aggregator_test.cc
+++ b/ext/test/zpages/tracez_data_aggregator_test.cc
@@ -35,9 +35,11 @@ class TracezDataAggregatorTest : public ::testing::Test
   void SetUp() override
   {
     std::shared_ptr<TracezSharedData> shared_data(new TracezSharedData());
-    std::shared_ptr<TracezSpanProcessor> processor(new TracezSpanProcessor(shared_data));
     auto resource = opentelemetry::sdk::resource::Resource::Create({});
-    tracer        = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, resource));
+    auto context  = std::make_shared<TracerContext>(
+      std::unique_ptr<SpanProcessor>(new TracezSpanProcessor(shared_data)),
+      resource);
+    tracer        = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
     tracez_data_aggregator = std::unique_ptr<TracezDataAggregator>(
         new TracezDataAggregator(shared_data, milliseconds(10)));
   }
diff --git a/ext/test/zpages/tracez_processor_test.cc b/ext/test/zpages/tracez_processor_test.cc
index c0ec2dde39..22c09efaf1 100644
--- a/ext/test/zpages/tracez_processor_test.cc
+++ b/ext/test/zpages/tracez_processor_test.cc
@@ -178,8 +178,13 @@ class TracezProcessor : public ::testing::Test
     shared_data   = std::shared_ptr<TracezSharedData>(new TracezSharedData());
     processor     = std::shared_ptr<TracezSpanProcessor>(new TracezSpanProcessor(shared_data));
     auto resource = opentelemetry::sdk::resource::Resource::Create({});
+    // Note: we make a *different* processor for the tracercontext. THis is because
+    // all the tests use shared data, and we want to make sure this works correctly.
+    auto context  = std::make_shared<TracerContext>(
+      std::unique_ptr<SpanProcessor>(new TracezSpanProcessor(shared_data)),
+      resource);
 
-    tracer     = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, resource));
+    tracer     = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
     auto spans = shared_data->GetSpanSnapshot();
     running    = spans.running;
     completed  = std::move(spans.completed);

From 0e69d1d17913f062f04f3ef04beb0efbb8ae458e Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Mon, 5 Apr 2021 16:17:27 -0400
Subject: [PATCH 03/17] Fix cmake.

---
 sdk/src/trace/CMakeLists.txt | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sdk/src/trace/CMakeLists.txt b/sdk/src/trace/CMakeLists.txt
index d4ff82f63e..e3d3e0afec 100644
--- a/sdk/src/trace/CMakeLists.txt
+++ b/sdk/src/trace/CMakeLists.txt
@@ -1,7 +1,12 @@
 add_library(
   opentelemetry_trace
-  tracer_provider.cc tracer.cc span.cc batch_span_processor.cc
-  samplers/parent.cc samplers/trace_id_ratio.cc)
+  tracer_context.cc
+  tracer_provider.cc
+  tracer.cc
+  span.cc
+  batch_span_processor.cc
+  samplers/parent.cc
+  samplers/trace_id_ratio.cc)
 
 set_target_properties(opentelemetry_trace PROPERTIES EXPORT_NAME trace)
 

From 7849f77443ea3d3e33fba518da0d070c352ac270 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Mon, 5 Apr 2021 16:26:34 -0400
Subject: [PATCH 04/17] Run formatter.

---
 examples/multithreaded/main.cc                        |  5 +++--
 examples/otlp/main.cc                                 |  3 ++-
 ext/test/zpages/tracez_data_aggregator_test.cc        |  5 ++---
 ext/test/zpages/tracez_processor_test.cc              |  5 ++---
 sdk/include/opentelemetry/sdk/trace/tracer.h          |  8 ++------
 sdk/include/opentelemetry/sdk/trace/tracer_context.h  |  6 +++---
 sdk/include/opentelemetry/sdk/trace/tracer_provider.h |  4 ++--
 sdk/src/trace/span.cc                                 |  6 +++---
 sdk/src/trace/tracer.cc                               | 10 +++++-----
 sdk/src/trace/tracer_context.cc                       |  6 ++++--
 sdk/src/trace/tracer_provider.cc                      |  3 ++-
 11 files changed, 30 insertions(+), 31 deletions(-)

diff --git a/examples/multithreaded/main.cc b/examples/multithreaded/main.cc
index c4d20b2924..309d7ff19a 100644
--- a/examples/multithreaded/main.cc
+++ b/examples/multithreaded/main.cc
@@ -18,8 +18,9 @@ void initTracer()
       new opentelemetry::exporter::trace::OStreamSpanExporter);
   auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
-  auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(std::move(processor), opentelemetry::sdk::resource::Resource::Create({})));
+  auto provider =
+      nostd::shared_ptr<opentelemetry::trace::TracerProvider>(new sdktrace::TracerProvider(
+          std::move(processor), opentelemetry::sdk::resource::Resource::Create({})));
   // Set the global trace provider
   opentelemetry::trace::Provider::SetTracerProvider(provider);
 }
diff --git a/examples/otlp/main.cc b/examples/otlp/main.cc
index de43ad1be5..f2ec3c3edd 100644
--- a/examples/otlp/main.cc
+++ b/examples/otlp/main.cc
@@ -19,7 +19,8 @@ void InitTracer()
   auto exporter  = std::unique_ptr<sdktrace::SpanExporter>(new otlp::OtlpExporter(opts));
   auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
-  auto provider = nostd::shared_ptr<trace::TracerProvider>(new sdktrace::TracerProvider(std::move(processor)));
+  auto provider =
+      nostd::shared_ptr<trace::TracerProvider>(new sdktrace::TracerProvider(std::move(processor)));
   // Set the global trace provider
   trace::Provider::SetTracerProvider(provider);
 }
diff --git a/ext/test/zpages/tracez_data_aggregator_test.cc b/ext/test/zpages/tracez_data_aggregator_test.cc
index 3cfd98b54a..324cf0c612 100644
--- a/ext/test/zpages/tracez_data_aggregator_test.cc
+++ b/ext/test/zpages/tracez_data_aggregator_test.cc
@@ -37,9 +37,8 @@ class TracezDataAggregatorTest : public ::testing::Test
     std::shared_ptr<TracezSharedData> shared_data(new TracezSharedData());
     auto resource = opentelemetry::sdk::resource::Resource::Create({});
     auto context  = std::make_shared<TracerContext>(
-      std::unique_ptr<SpanProcessor>(new TracezSpanProcessor(shared_data)),
-      resource);
-    tracer        = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
+        std::unique_ptr<SpanProcessor>(new TracezSpanProcessor(shared_data)), resource);
+    tracer                 = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
     tracez_data_aggregator = std::unique_ptr<TracezDataAggregator>(
         new TracezDataAggregator(shared_data, milliseconds(10)));
   }
diff --git a/ext/test/zpages/tracez_processor_test.cc b/ext/test/zpages/tracez_processor_test.cc
index 22c09efaf1..7ea4063d60 100644
--- a/ext/test/zpages/tracez_processor_test.cc
+++ b/ext/test/zpages/tracez_processor_test.cc
@@ -180,9 +180,8 @@ class TracezProcessor : public ::testing::Test
     auto resource = opentelemetry::sdk::resource::Resource::Create({});
     // Note: we make a *different* processor for the tracercontext. THis is because
     // all the tests use shared data, and we want to make sure this works correctly.
-    auto context  = std::make_shared<TracerContext>(
-      std::unique_ptr<SpanProcessor>(new TracezSpanProcessor(shared_data)),
-      resource);
+    auto context = std::make_shared<TracerContext>(
+        std::unique_ptr<SpanProcessor>(new TracezSpanProcessor(shared_data)), resource);
 
     tracer     = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(context));
     auto spans = shared_data->GetSpanSnapshot();
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer.h b/sdk/include/opentelemetry/sdk/trace/tracer.h
index 4e31c2c204..f764c48478 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer.h
@@ -32,15 +32,11 @@ class Tracer final : public trace_api::Tracer, public std::enable_shared_from_th
 
   void CloseWithMicroseconds(uint64_t timeout) noexcept override;
 
-
   /** Returns the currently active span processor. */
-  SpanProcessor& GetActiveProcessor() noexcept {
-    return context_->GetActiveProcessor();
-  }
-
+  SpanProcessor &GetActiveProcessor() noexcept { return context_->GetActiveProcessor(); }
 
   // Note: Test only
-  Sampler& GetSampler() { return context_->GetSampler(); }
+  Sampler &GetSampler() { return context_->GetSampler(); }
 
 private:
   std::shared_ptr<sdk::trace::TracerContext> context_;
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_context.h b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
index a25bbdc056..963d010316 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_context.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
@@ -35,7 +35,7 @@ class TracerContext
                              std::unique_ptr<AlwaysOnSampler>(new AlwaysOnSampler)) noexcept;
   /**
    * Attaches a span processor to this tracer context.
-   * 
+   *
    * @param processor The new span processor for this tracer. This must not be
    * a nullptr.  Ownership is given to the `TracerContext`.
    */
@@ -49,11 +49,11 @@ class TracerContext
 
   /**
    * Obtain the (conceptual) active processor.
-   * 
+   *
    * Note: When more than one processor is active, this will
    * return an "aggregate" processor
    */
-  SpanProcessor& GetActiveProcessor() const noexcept;
+  SpanProcessor &GetActiveProcessor() const noexcept;
 
   /**
    * Obtain the resource associated with this tracer context.
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_provider.h b/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
index 978ed0a7dc..2e56bf7019 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
@@ -9,8 +9,8 @@
 #include "opentelemetry/sdk/trace/processor.h"
 #include "opentelemetry/sdk/trace/samplers/always_on.h"
 #include "opentelemetry/sdk/trace/tracer.h"
-#include "opentelemetry/trace/tracer_provider.h"
 #include "opentelemetry/sdk/trace/tracer_context.h"
+#include "opentelemetry/trace/tracer_provider.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace sdk
@@ -47,7 +47,7 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
    * Attaches a span processor to this tracer provider.
    * @param processor The new span processor for this tracer provider. This
    * must not be a nullptr.
-   * 
+   *
    * Note: This process may not receive any in-flight spans, but will get newly created spans.
    */
   void RegisterProcessor(std::unique_ptr<SpanProcessor> processor) noexcept;
diff --git a/sdk/src/trace/span.cc b/sdk/src/trace/span.cc
index 00c73378cb..adcc858b6d 100644
--- a/sdk/src/trace/span.cc
+++ b/sdk/src/trace/span.cc
@@ -96,9 +96,9 @@ Span::Span(std::shared_ptr<Tracer> &&tracer,
       trace_id, span_id,
       sampled ? trace_api::TraceFlags{trace_api::TraceFlags::kIsSampled} : trace_api::TraceFlags{},
       false,
-      trace_state ? trace_state
-                  : is_parent_span_valid ? parent_span_context.trace_state()
-                                         : trace_api::TraceState::GetDefault()));
+      trace_state            ? trace_state
+      : is_parent_span_valid ? parent_span_context.trace_state()
+                             : trace_api::TraceState::GetDefault()));
 
   attributes.ForEachKeyValue(
       [&](nostd::string_view key, opentelemetry::common::AttributeValue value) noexcept {
diff --git a/sdk/src/trace/tracer.cc b/sdk/src/trace/tracer.cc
index c7214a803c..2d67321d83 100644
--- a/sdk/src/trace/tracer.cc
+++ b/sdk/src/trace/tracer.cc
@@ -42,8 +42,8 @@ nostd::shared_ptr<trace_api::Span> Tracer::StartSpan(
 {
   trace_api::SpanContext parent = GetCurrentSpanContext(options.parent);
 
-  auto sampling_result =
-      context_->GetSampler().ShouldSample(parent, parent.trace_id(), name, options.kind, attributes, links);
+  auto sampling_result = context_->GetSampler().ShouldSample(parent, parent.trace_id(), name,
+                                                             options.kind, attributes, links);
   if (sampling_result.decision == Decision::DROP)
   {
     // Don't allocate a no-op span for every DROP decision, but use a static
@@ -55,9 +55,9 @@ nostd::shared_ptr<trace_api::Span> Tracer::StartSpan(
   }
   else
   {
-    auto span = nostd::shared_ptr<trace_api::Span>{new (std::nothrow) Span{
-        this->shared_from_this(), name, attributes, links, options, parent,
-        sampling_result.trace_state, true}};
+    auto span = nostd::shared_ptr<trace_api::Span>{
+        new (std::nothrow) Span{this->shared_from_this(), name, attributes, links, options, parent,
+                                sampling_result.trace_state, true}};
 
     // if the attributes is not nullptr, add attributes to the span.
     if (sampling_result.attributes)
diff --git a/sdk/src/trace/tracer_context.cc b/sdk/src/trace/tracer_context.cc
index 8384d4d2a5..88afa8331a 100644
--- a/sdk/src/trace/tracer_context.cc
+++ b/sdk/src/trace/tracer_context.cc
@@ -27,11 +27,13 @@ void TracerContext::RegisterPipeline(std::unique_ptr<SpanProcessor> processor) n
 {
   // TODO(jsuereth): Implement
   // 1. If existing processor is an "AggregateProcessor" append the new processor to it.
-  // 2. If the existing processor is NOT an "AggregateProcessor", create a new Aggregate of this and the other,
+  // 2. If the existing processor is NOT an "AggregateProcessor", create a new Aggregate of this and
+  // the other,
   //    then replace our atomic ptr with the new aggregate.
 }
 
-SpanProcessor& TracerContext::GetActiveProcessor() const noexcept {
+SpanProcessor &TracerContext::GetActiveProcessor() const noexcept
+{
   return *processor_;
 }
 
diff --git a/sdk/src/trace/tracer_provider.cc b/sdk/src/trace/tracer_provider.cc
index cb1fd0327a..cc4822a724 100644
--- a/sdk/src/trace/tracer_provider.cc
+++ b/sdk/src/trace/tracer_provider.cc
@@ -12,7 +12,8 @@ TracerProvider::TracerProvider(std::shared_ptr<sdk::trace::TracerContext> contex
 TracerProvider::TracerProvider(std::unique_ptr<SpanProcessor> processor,
                                opentelemetry::sdk::resource::Resource resource,
                                std::unique_ptr<Sampler> sampler) noexcept
-    : TracerProvider(std::make_shared<TracerContext>(std::move(processor), resource, std::move(sampler)))
+    : TracerProvider(
+          std::make_shared<TracerContext>(std::move(processor), resource, std::move(sampler)))
 {}
 
 opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer> TracerProvider::GetTracer(

From 664299e9082429654b3e16a42d12fc7204c41000 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Mon, 5 Apr 2021 18:38:10 -0400
Subject: [PATCH 05/17] Fixes from latest clang format.

---
 sdk/src/trace/span.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sdk/src/trace/span.cc b/sdk/src/trace/span.cc
index adcc858b6d..439de4e704 100644
--- a/sdk/src/trace/span.cc
+++ b/sdk/src/trace/span.cc
@@ -97,8 +97,8 @@ Span::Span(std::shared_ptr<Tracer> &&tracer,
       sampled ? trace_api::TraceFlags{trace_api::TraceFlags::kIsSampled} : trace_api::TraceFlags{},
       false,
       trace_state            ? trace_state
-      : is_parent_span_valid ? parent_span_context.trace_state()
-                             : trace_api::TraceState::GetDefault()));
+                             : is_parent_span_valid ? parent_span_context.trace_state()
+                                                    : trace_api::TraceState::GetDefault()));
 
   attributes.ForEachKeyValue(
       [&](nostd::string_view key, opentelemetry::common::AttributeValue value) noexcept {

From 0dde5c46fb978f770404ea22a15d90ae11988dfc Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Mon, 5 Apr 2021 18:54:23 -0400
Subject: [PATCH 06/17] Add bazel build for http example and fix compilation.

---
 examples/http/BUILD             | 28 ++++++++++++++++++++++++++++
 examples/http/tracer_common.hpp |  9 +++++----
 2 files changed, 33 insertions(+), 4 deletions(-)
 create mode 100644 examples/http/BUILD

diff --git a/examples/http/BUILD b/examples/http/BUILD
new file mode 100644
index 0000000000..f06d1ee7c7
--- /dev/null
+++ b/examples/http/BUILD
@@ -0,0 +1,28 @@
+cc_binary(
+    name = "example_http_client",
+    srcs = [
+        "tracer_common.hpp",
+        "client.cc",
+    ],
+    deps = [
+        "//api",
+        "//ext/src/http/client/curl:http_client_curl",
+        "//exporters/ostream:ostream_span_exporter",
+        "//sdk/src/trace",
+    ],
+)
+
+cc_binary(
+    name = "example_http_server",
+    srcs = [
+        "server.cc",
+        "tracer_common.hpp",
+        "server.hpp",
+    ],
+    deps = [
+        "//api",
+        "//ext:headers",
+        "//exporters/ostream:ostream_span_exporter",
+        "//sdk/src/trace",
+    ],
+)
diff --git a/examples/http/tracer_common.hpp b/examples/http/tracer_common.hpp
index b45102ac9e..19239890c6 100644
--- a/examples/http/tracer_common.hpp
+++ b/examples/http/tracer_common.hpp
@@ -11,11 +11,12 @@ namespace {
 void initTracer() {
   auto exporter = std::unique_ptr<sdktrace::SpanExporter>(
       new opentelemetry::exporter::trace::OStreamSpanExporter);
-  auto processor = std::shared_ptr<sdktrace::SpanProcessor>(
+  auto processor = std::unique_ptr<sdktrace::SpanProcessor>(
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
-  auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-      new sdktrace::TracerProvider(processor, opentelemetry::sdk::resource::Resource::Create({}),
-                                   std::make_shared<opentelemetry::sdk::trace::AlwaysOnSampler>()));
+  // Default is an always-on sampler.
+  auto context = std::make_shared<sdktrace::TracerContext>(std::move(processor));
+  auto provider =  nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
+      new sdktrace::TracerProvider(context));
   // Set the global trace provider
   opentelemetry::trace::Provider::SetTracerProvider(provider);
 }

From 1e746e21945b96694bd374fb59aaeb9129fc3246 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Wed, 7 Apr 2021 11:19:18 -0400
Subject: [PATCH 07/17] Fixes from review and gcc 4.8

---
 ext/include/opentelemetry/ext/zpages/zpages.h        |  4 +++-
 sdk/include/opentelemetry/sdk/trace/tracer_context.h |  8 +++++++-
 sdk/src/trace/tracer_context.cc                      | 10 ++++++++++
 sdk/src/trace/tracer_provider.cc                     |  4 ++--
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/ext/include/opentelemetry/ext/zpages/zpages.h b/ext/include/opentelemetry/ext/zpages/zpages.h
index 49f5bb7f94..ca09ac65a6 100644
--- a/ext/include/opentelemetry/ext/zpages/zpages.h
+++ b/ext/include/opentelemetry/ext/zpages/zpages.h
@@ -51,8 +51,10 @@ class ZPages
   /** Replaces the global tracer provider with an instance that exports to tracez. */
   void ReplaceGlobalProvider()
   {
+    // GCC 4.8 can't infer the type coercion.
+    std::unique_ptr<opentelemetry::sdk::trace::SpanProcessor> processor(MakeSpanProcessor().release());
     auto tracez_provider_ = opentelemetry::nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-        new opentelemetry::sdk::trace::TracerProvider(MakeSpanProcessor()));
+        new opentelemetry::sdk::trace::TracerProvider(std::move(MakeSpanProcessor())));
     opentelemetry::trace::Provider::SetTracerProvider(tracez_provider_);
   }
 
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_context.h b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
index 963d010316..596ccc473c 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_context.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
@@ -65,7 +65,13 @@ class TracerContext
    * Force all active SpanProcessors to flush any buffered spans
    * within the given timeout.
    */
-  void ForceFlushWithMicroseconds(uint64_t timeout) noexcept;
+  bool ForceFlush(
+      std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept;
+
+  /**
+   * Shutdown the span processor associated with this tracer provider.
+   */
+  bool Shutdown() noexcept;
 
 private:
   // This is an atomic pointer so we can adapt the processor pipeline dynamically.
diff --git a/sdk/src/trace/tracer_context.cc b/sdk/src/trace/tracer_context.cc
index 88afa8331a..a463ec81d4 100644
--- a/sdk/src/trace/tracer_context.cc
+++ b/sdk/src/trace/tracer_context.cc
@@ -37,6 +37,16 @@ SpanProcessor &TracerContext::GetActiveProcessor() const noexcept
   return *processor_;
 }
 
+bool TracerContext::ForceFlush(std::chrono::microseconds timeout) noexcept
+{
+  return processor_->ForceFlush(timeout);
+}
+
+bool TracerContext::Shutdown() noexcept
+{
+  return processor_->Shutdown();
+}
+
 }  // namespace trace
 }  // namespace sdk
 OPENTELEMETRY_END_NAMESPACE
diff --git a/sdk/src/trace/tracer_provider.cc b/sdk/src/trace/tracer_provider.cc
index cc4822a724..39018653b7 100644
--- a/sdk/src/trace/tracer_provider.cc
+++ b/sdk/src/trace/tracer_provider.cc
@@ -35,12 +35,12 @@ const opentelemetry::sdk::resource::Resource &TracerProvider::GetResource() cons
 
 bool TracerProvider::Shutdown() noexcept
 {
-  return context_->GetActiveProcessor().Shutdown();
+  return context_->Shutdown();
 }
 
 bool TracerProvider::ForceFlush(std::chrono::microseconds timeout) noexcept
 {
-  return context_->GetActiveProcessor().ForceFlush(timeout);
+  return context_->ForceFlush(timeout);
 }
 
 }  // namespace trace

From d0ea2969c5f341d063e3ef308c1c8fb8bc3a5a83 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Wed, 7 Apr 2021 11:21:03 -0400
Subject: [PATCH 08/17] Fix typo.

---
 sdk/include/opentelemetry/sdk/trace/tracer_context.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_context.h b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
index 596ccc473c..42a067d20f 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_context.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
@@ -21,7 +21,7 @@ namespace trace
  *   and sampling config.
  * - The owner/destroyer of Processors/Exporters.  These will remain active until
  *   this class is destroyed.  I.e. Sampling, Exporting, flushing etc. are all ok if this
- *   object is alive, and they willl work together.   If this object is destroyed, then
+ *   object is alive, and they will work together. If this object is destroyed, then
  *   no shared references to Processor, Exporter, Recordable etc. should exist, and all
  *   associated pipelines will have been flushed.
  */

From 576cf7c7c76e02c8a0a8d7ebb5eea97fd90df534 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Wed, 7 Apr 2021 11:27:39 -0400
Subject: [PATCH 09/17] Fix bazel build for http-client windows.

---
 examples/http/BUILD | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/examples/http/BUILD b/examples/http/BUILD
index f06d1ee7c7..9c05b08d7d 100644
--- a/examples/http/BUILD
+++ b/examples/http/BUILD
@@ -10,6 +10,19 @@ cc_binary(
         "//exporters/ostream:ostream_span_exporter",
         "//sdk/src/trace",
     ],
+    # TODO: Move copts/linkopts for static CURL usage into shared bzl file.
+    copts = [
+        "-DCURL_STATICLIB",
+        "-DWITH_CURL",
+    ],
+    linkopts = select({
+        "//bazel:windows": [
+            "-DEFAULTLIB:advapi32.lib",
+            "-DEFAULTLIB:crypt32.lib",
+            "-DEFAULTLIB:Normaliz.lib",
+        ],
+        "//conditions:default": [],
+    }),
 )
 
 cc_binary(

From cb5dfdb851a7dde115c4573b16d66ece0e70793d Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Wed, 7 Apr 2021 12:41:38 -0400
Subject: [PATCH 10/17] Take 2 at fixing the builds.

---
 examples/http/BUILD                           | 1 +
 ext/include/opentelemetry/ext/zpages/zpages.h | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/examples/http/BUILD b/examples/http/BUILD
index 9c05b08d7d..758a6af069 100644
--- a/examples/http/BUILD
+++ b/examples/http/BUILD
@@ -6,6 +6,7 @@ cc_binary(
     ],
     deps = [
         "//api",
+        "//ext:headers",
         "//ext/src/http/client/curl:http_client_curl",
         "//exporters/ostream:ostream_span_exporter",
         "//sdk/src/trace",
diff --git a/ext/include/opentelemetry/ext/zpages/zpages.h b/ext/include/opentelemetry/ext/zpages/zpages.h
index ca09ac65a6..12b0fdb5ec 100644
--- a/ext/include/opentelemetry/ext/zpages/zpages.h
+++ b/ext/include/opentelemetry/ext/zpages/zpages.h
@@ -54,7 +54,7 @@ class ZPages
     // GCC 4.8 can't infer the type coercion.
     std::unique_ptr<opentelemetry::sdk::trace::SpanProcessor> processor(MakeSpanProcessor().release());
     auto tracez_provider_ = opentelemetry::nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
-        new opentelemetry::sdk::trace::TracerProvider(std::move(MakeSpanProcessor())));
+        new opentelemetry::sdk::trace::TracerProvider(std::move(processor)));
     opentelemetry::trace::Provider::SetTracerProvider(tracez_provider_);
   }
 

From 2620a96a61a66be1dbe2c91064a26073831b9d11 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Wed, 7 Apr 2021 13:03:51 -0400
Subject: [PATCH 11/17] Another attempt to get windows to build (define curl
 things prior to building client lib.

---
 ext/src/http/client/curl/BUILD | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ext/src/http/client/curl/BUILD b/ext/src/http/client/curl/BUILD
index e01988a388..e01a087762 100644
--- a/ext/src/http/client/curl/BUILD
+++ b/ext/src/http/client/curl/BUILD
@@ -7,6 +7,11 @@ cc_library(
         "http_client_factory_curl.cc",
     ],
     include_prefix = "src/http/client/curl",
+    # TODO: Move copts/linkopts for static CURL usage into shared bzl file.
+    copts = [
+        "-DCURL_STATICLIB",
+        "-DWITH_CURL",
+    ],
     deps = [
         "//api",
         "//ext:headers",

From 9d506f18f26c4bb8bacbd77efa953e0163bf5d33 Mon Sep 17 00:00:00 2001
From: Josh Suereth <Joshua.Suereth@gmail.com>
Date: Wed, 7 Apr 2021 17:29:50 -0400
Subject: [PATCH 12/17] Fix windows build

Migrate needed windows staitc libs to the curl client library and do minor cleanup to builds.
---
 ext/src/http/client/curl/BUILD |  9 +++++++++
 ext/test/http/BUILD            | 13 -------------
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/ext/src/http/client/curl/BUILD b/ext/src/http/client/curl/BUILD
index e01a087762..40cd547595 100644
--- a/ext/src/http/client/curl/BUILD
+++ b/ext/src/http/client/curl/BUILD
@@ -12,6 +12,15 @@ cc_library(
         "-DCURL_STATICLIB",
         "-DWITH_CURL",
     ],
+    linkopts = select({
+        "//bazel:windows": [
+            "-DEFAULTLIB:advapi32.lib",
+            "-DEFAULTLIB:crypt32.lib",
+            "-DEFAULTLIB:Normaliz.lib",
+            "-DEFAULTLIB:Ws2_32.lib",
+        ],
+        "//conditions:default": [],
+    }),
     deps = [
         "//api",
         "//ext:headers",
diff --git a/ext/test/http/BUILD b/ext/test/http/BUILD
index 7251c0fde6..c2d24c6e77 100644
--- a/ext/test/http/BUILD
+++ b/ext/test/http/BUILD
@@ -3,19 +3,6 @@ cc_test(
     srcs = [
         "curl_http_test.cc",
     ],
-    # TODO: Move copts/linkopts for static CURL usage into shared bzl file.
-    copts = [
-        "-DCURL_STATICLIB",
-        "-DWITH_CURL",
-    ],
-    linkopts = select({
-        "//bazel:windows": [
-            "-DEFAULTLIB:advapi32.lib",
-            "-DEFAULTLIB:crypt32.lib",
-            "-DEFAULTLIB:Normaliz.lib",
-        ],
-        "//conditions:default": [],
-    }),
     deps = [
         "//ext:headers",
         "//ext/src/http/client/curl:http_client_curl",

From 6bc5f2a43efa4f56bd9a2b5d63ac2466546d172b Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Fri, 16 Apr 2021 10:12:20 -0400
Subject: [PATCH 13/17] Fixes from review.

---
 sdk/include/opentelemetry/sdk/trace/tracer_context.h  | 2 +-
 sdk/include/opentelemetry/sdk/trace/tracer_provider.h | 4 ++--
 sdk/src/trace/tracer_provider.cc                      | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_context.h b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
index 42a067d20f..c613fd37e4 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_context.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
@@ -37,7 +37,7 @@ class TracerContext
    * Attaches a span processor to this tracer context.
    *
    * @param processor The new span processor for this tracer. This must not be
-   * a nullptr.  Ownership is given to the `TracerContext`.
+   * a nullptr. Ownership is given to the `TracerContext`.
    */
   void RegisterPipeline(std::unique_ptr<SpanProcessor> processor) noexcept;
 
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_provider.h b/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
index 2e56bf7019..0301aa7e44 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_provider.h
@@ -44,13 +44,13 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
       nostd::string_view library_version = "") noexcept override;
 
   /**
-   * Attaches a span processor to this tracer provider.
+   * Attaches a span processor pipeline to this tracer provider.
    * @param processor The new span processor for this tracer provider. This
    * must not be a nullptr.
    *
    * Note: This process may not receive any in-flight spans, but will get newly created spans.
    */
-  void RegisterProcessor(std::unique_ptr<SpanProcessor> processor) noexcept;
+  void RegisterPipeline(std::unique_ptr<SpanProcessor> processor) noexcept;
 
   /**
    * Obtain the resource associated with this tracer provider.
diff --git a/sdk/src/trace/tracer_provider.cc b/sdk/src/trace/tracer_provider.cc
index 39018653b7..0eaf6782f2 100644
--- a/sdk/src/trace/tracer_provider.cc
+++ b/sdk/src/trace/tracer_provider.cc
@@ -23,7 +23,7 @@ opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer> TracerProvider::G
   return opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer>(tracer_);
 }
 
-void TracerProvider::RegisterProcessor(std::unique_ptr<SpanProcessor> processor) noexcept
+void TracerProvider::RegisterPipeline(std::unique_ptr<SpanProcessor> processor) noexcept
 {
   return context_->RegisterPipeline(std::move(processor));
 }

From 50339431b6c5e548efbe3bbe063bc6ec425cd3cc Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Fri, 16 Apr 2021 10:16:42 -0400
Subject: [PATCH 14/17] Ran local code format.

---
 exporters/otlp/test/otlp_exporter_test.cc            | 4 ++--
 ext/include/opentelemetry/ext/zpages/zpages.h        | 3 ++-
 sdk/include/opentelemetry/sdk/trace/tracer_context.h | 3 +--
 sdk/src/trace/span.cc                                | 4 ++--
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/exporters/otlp/test/otlp_exporter_test.cc b/exporters/otlp/test/otlp_exporter_test.cc
index 28aacbd72c..c5a6098a02 100644
--- a/exporters/otlp/test/otlp_exporter_test.cc
+++ b/exporters/otlp/test/otlp_exporter_test.cc
@@ -75,8 +75,8 @@ TEST_F(OtlpExporterTestPeer, ExportIntegrationTest)
 
   auto processor = std::unique_ptr<sdk::trace::SpanProcessor>(
       new sdk::trace::SimpleSpanProcessor(std::move(exporter)));
-  auto provider =
-      nostd::shared_ptr<trace::TracerProvider>(new sdk::trace::TracerProvider(std::move(processor)));
+  auto provider = nostd::shared_ptr<trace::TracerProvider>(
+      new sdk::trace::TracerProvider(std::move(processor)));
   auto tracer = provider->GetTracer("test");
 
   EXPECT_CALL(*mock_stub, Export(_, _, _))
diff --git a/ext/include/opentelemetry/ext/zpages/zpages.h b/ext/include/opentelemetry/ext/zpages/zpages.h
index 12b0fdb5ec..b1e3606277 100644
--- a/ext/include/opentelemetry/ext/zpages/zpages.h
+++ b/ext/include/opentelemetry/ext/zpages/zpages.h
@@ -52,7 +52,8 @@ class ZPages
   void ReplaceGlobalProvider()
   {
     // GCC 4.8 can't infer the type coercion.
-    std::unique_ptr<opentelemetry::sdk::trace::SpanProcessor> processor(MakeSpanProcessor().release());
+    std::unique_ptr<opentelemetry::sdk::trace::SpanProcessor> processor(
+        MakeSpanProcessor().release());
     auto tracez_provider_ = opentelemetry::nostd::shared_ptr<opentelemetry::trace::TracerProvider>(
         new opentelemetry::sdk::trace::TracerProvider(std::move(processor)));
     opentelemetry::trace::Provider::SetTracerProvider(tracez_provider_);
diff --git a/sdk/include/opentelemetry/sdk/trace/tracer_context.h b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
index c613fd37e4..e5af3a87ba 100644
--- a/sdk/include/opentelemetry/sdk/trace/tracer_context.h
+++ b/sdk/include/opentelemetry/sdk/trace/tracer_context.h
@@ -65,8 +65,7 @@ class TracerContext
    * Force all active SpanProcessors to flush any buffered spans
    * within the given timeout.
    */
-  bool ForceFlush(
-      std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept;
+  bool ForceFlush(std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept;
 
   /**
    * Shutdown the span processor associated with this tracer provider.
diff --git a/sdk/src/trace/span.cc b/sdk/src/trace/span.cc
index 338d8c4b36..7d0896b1ec 100644
--- a/sdk/src/trace/span.cc
+++ b/sdk/src/trace/span.cc
@@ -97,8 +97,8 @@ Span::Span(std::shared_ptr<Tracer> &&tracer,
       sampled ? trace_api::TraceFlags{trace_api::TraceFlags::kIsSampled} : trace_api::TraceFlags{},
       false,
       trace_state            ? trace_state
-                             : is_parent_span_valid ? parent_span_context.trace_state()
-                                                    : trace_api::TraceState::GetDefault()));
+      : is_parent_span_valid ? parent_span_context.trace_state()
+                             : trace_api::TraceState::GetDefault()));
 
   recordable_->SetIdentity(*span_context_, parent_span_id);
 

From 01bc7c7ef271572a7b4440bb0ef60fa1ae24e218 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Fri, 16 Apr 2021 10:22:23 -0400
Subject: [PATCH 15/17] Manually fix style from remote tool.

---
 examples/http/BUILD            | 8 ++++----
 ext/src/http/client/curl/BUILD | 2 +-
 sdk/src/trace/span.cc          | 6 +++---
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/examples/http/BUILD b/examples/http/BUILD
index 758a6af069..29cde19b30 100644
--- a/examples/http/BUILD
+++ b/examples/http/BUILD
@@ -1,14 +1,14 @@
 cc_binary(
     name = "example_http_client",
     srcs = [
-        "tracer_common.hpp",
         "client.cc",
+        "tracer_common.hpp",
     ],
     deps = [
         "//api",
+        "//exporters/ostream:ostream_span_exporter",
         "//ext:headers",
         "//ext/src/http/client/curl:http_client_curl",
-        "//exporters/ostream:ostream_span_exporter",
         "//sdk/src/trace",
     ],
     # TODO: Move copts/linkopts for static CURL usage into shared bzl file.
@@ -30,13 +30,13 @@ cc_binary(
     name = "example_http_server",
     srcs = [
         "server.cc",
-        "tracer_common.hpp",
         "server.hpp",
+        "tracer_common.hpp",
     ],
     deps = [
         "//api",
-        "//ext:headers",
         "//exporters/ostream:ostream_span_exporter",
+        "//ext:headers",
         "//sdk/src/trace",
     ],
 )
diff --git a/ext/src/http/client/curl/BUILD b/ext/src/http/client/curl/BUILD
index 40cd547595..6d484d3770 100644
--- a/ext/src/http/client/curl/BUILD
+++ b/ext/src/http/client/curl/BUILD
@@ -6,12 +6,12 @@ cc_library(
         "http_client_curl.cc",
         "http_client_factory_curl.cc",
     ],
-    include_prefix = "src/http/client/curl",
     # TODO: Move copts/linkopts for static CURL usage into shared bzl file.
     copts = [
         "-DCURL_STATICLIB",
         "-DWITH_CURL",
     ],
+    include_prefix = "src/http/client/curl",
     linkopts = select({
         "//bazel:windows": [
             "-DEFAULTLIB:advapi32.lib",
diff --git a/sdk/src/trace/span.cc b/sdk/src/trace/span.cc
index 7d0896b1ec..388d0ab923 100644
--- a/sdk/src/trace/span.cc
+++ b/sdk/src/trace/span.cc
@@ -96,9 +96,9 @@ Span::Span(std::shared_ptr<Tracer> &&tracer,
       trace_id, span_id,
       sampled ? trace_api::TraceFlags{trace_api::TraceFlags::kIsSampled} : trace_api::TraceFlags{},
       false,
-      trace_state            ? trace_state
-      : is_parent_span_valid ? parent_span_context.trace_state()
-                             : trace_api::TraceState::GetDefault()));
+      trace_state ? trace_state
+                  : is_parent_span_valid ? parent_span_context.trace_state()
+                                         : trace_api::TraceState::GetDefault()));
 
   recordable_->SetIdentity(*span_context_, parent_span_id);
 

From ec4c83de6d1c9093877eee1f49a1851a3fe07fe8 Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Fri, 16 Apr 2021 10:26:00 -0400
Subject: [PATCH 16/17] Last manual style fix.

---
 examples/http/BUILD | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/examples/http/BUILD b/examples/http/BUILD
index 29cde19b30..89fffa2676 100644
--- a/examples/http/BUILD
+++ b/examples/http/BUILD
@@ -4,6 +4,11 @@ cc_binary(
         "client.cc",
         "tracer_common.hpp",
     ],
+    # TODO: Move copts/linkopts for static CURL usage into shared bzl file.
+    copts = [
+        "-DCURL_STATICLIB",
+        "-DWITH_CURL",
+    ],
     deps = [
         "//api",
         "//exporters/ostream:ostream_span_exporter",
@@ -11,11 +16,6 @@ cc_binary(
         "//ext/src/http/client/curl:http_client_curl",
         "//sdk/src/trace",
     ],
-    # TODO: Move copts/linkopts for static CURL usage into shared bzl file.
-    copts = [
-        "-DCURL_STATICLIB",
-        "-DWITH_CURL",
-    ],
     linkopts = select({
         "//bazel:windows": [
             "-DEFAULTLIB:advapi32.lib",

From a0999fcb1f9448b0a5beb6303b4199adace4b36f Mon Sep 17 00:00:00 2001
From: Josh Suereth <joshuasuereth@google.com>
Date: Fri, 16 Apr 2021 10:32:14 -0400
Subject: [PATCH 17/17] one last fix...

---
 examples/http/BUILD | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/examples/http/BUILD b/examples/http/BUILD
index 89fffa2676..4fce0a2e27 100644
--- a/examples/http/BUILD
+++ b/examples/http/BUILD
@@ -9,13 +9,6 @@ cc_binary(
         "-DCURL_STATICLIB",
         "-DWITH_CURL",
     ],
-    deps = [
-        "//api",
-        "//exporters/ostream:ostream_span_exporter",
-        "//ext:headers",
-        "//ext/src/http/client/curl:http_client_curl",
-        "//sdk/src/trace",
-    ],
     linkopts = select({
         "//bazel:windows": [
             "-DEFAULTLIB:advapi32.lib",
@@ -24,6 +17,13 @@ cc_binary(
         ],
         "//conditions:default": [],
     }),
+    deps = [
+        "//api",
+        "//exporters/ostream:ostream_span_exporter",
+        "//ext:headers",
+        "//ext/src/http/client/curl:http_client_curl",
+        "//sdk/src/trace",
+    ],
 )
 
 cc_binary(