feat(telemetry): instrument inference duration and frame age

vendor/go.opentelemetry.io/otel/internal/baggage/baggage.go

@@ -0,0 +1,43 @@
+// Copyright The 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.
+
+/*
+Package baggage provides base types and functionality to store and retrieve
+baggage in Go context. This package exists because the OpenTracing bridge to
+OpenTelemetry needs to synchronize state whenever baggage for a context is
+modified and that context contains an OpenTracing span. If it were not for
+this need this package would not need to exist and the
+`go.opentelemetry.io/otel/baggage` package would be the singular place where
+W3C baggage is handled.
+*/
+package baggage // import "go.opentelemetry.io/otel/internal/baggage"
+
+// List is the collection of baggage members. The W3C allows for duplicates,
+// but OpenTelemetry does not, therefore, this is represented as a map.
+type List map[string]Item
+
+// Item is the value and metadata properties part of a list-member.
+type Item struct {
+	Value      string
+	Properties []Property
+}
+
+// Property is a metadata entry for a list-member.
+type Property struct {
+	Key, Value string
+
+	// HasValue indicates if a zero-value value means the property does not
+	// have a value or if it was the zero-value.
+	HasValue bool
+}

vendor/go.opentelemetry.io/otel/internal/baggage/context.go

@@ -0,0 +1,95 @@
+// Copyright The 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.
+
+package baggage // import "go.opentelemetry.io/otel/internal/baggage"
+
+import "context"
+
+type baggageContextKeyType int
+
+const baggageKey baggageContextKeyType = iota
+
+// SetHookFunc is a callback called when storing baggage in the context.
+type SetHookFunc func(context.Context, List) context.Context
+
+// GetHookFunc is a callback called when getting baggage from the context.
+type GetHookFunc func(context.Context, List) List
+
+type baggageState struct {
+	list List
+
+	setHook SetHookFunc
+	getHook GetHookFunc
+}
+
+// ContextWithSetHook returns a copy of parent with hook configured to be
+// invoked every time ContextWithBaggage is called.
+//
+// Passing nil SetHookFunc creates a context with no set hook to call.
+func ContextWithSetHook(parent context.Context, hook SetHookFunc) context.Context {
+	var s baggageState
+	switch v := parent.Value(baggageKey).(type) {
+	case baggageState:
+		s = v
+	}
+
+	s.setHook = hook
+	return context.WithValue(parent, baggageKey, s)
+}
+
+// ContextWithGetHook returns a copy of parent with hook configured to be
+// invoked every time FromContext is called.
+//
+// Passing nil GetHookFunc creates a context with no get hook to call.
+func ContextWithGetHook(parent context.Context, hook GetHookFunc) context.Context {
+	var s baggageState
+	switch v := parent.Value(baggageKey).(type) {
+	case baggageState:
+		s = v
+	}
+
+	s.getHook = hook
+	return context.WithValue(parent, baggageKey, s)
+}
+
+// ContextWithList returns a copy of parent with baggage. Passing nil list
+// returns a context without any baggage.
+func ContextWithList(parent context.Context, list List) context.Context {
+	var s baggageState
+	switch v := parent.Value(baggageKey).(type) {
+	case baggageState:
+		s = v
+	}
+
+	s.list = list
+	ctx := context.WithValue(parent, baggageKey, s)
+	if s.setHook != nil {
+		ctx = s.setHook(ctx, list)
+	}
+
+	return ctx
+}
+
+// ListFromContext returns the baggage contained in ctx.
+func ListFromContext(ctx context.Context) List {
+	switch v := ctx.Value(baggageKey).(type) {
+	case baggageState:
+		if v.getHook != nil {
+			return v.getHook(ctx, v.list)
+		}
+		return v.list
+	default:
+		return nil
+	}
+}

vendor/go.opentelemetry.io/otel/internal/global/propagator.go

@@ -0,0 +1,82 @@
+// Copyright The 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.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel/propagation"
+)
+
+// textMapPropagator is a default TextMapPropagator that delegates calls to a
+// registered delegate if one is set, otherwise it defaults to delegating the
+// calls to a the default no-op propagation.TextMapPropagator.
+type textMapPropagator struct {
+	mtx      sync.Mutex
+	once     sync.Once
+	delegate propagation.TextMapPropagator
+	noop     propagation.TextMapPropagator
+}
+
+// Compile-time guarantee that textMapPropagator implements the
+// propagation.TextMapPropagator interface.
+var _ propagation.TextMapPropagator = (*textMapPropagator)(nil)
+
+func newTextMapPropagator() *textMapPropagator {
+	return &textMapPropagator{
+		noop: propagation.NewCompositeTextMapPropagator(),
+	}
+}
+
+// SetDelegate sets a delegate propagation.TextMapPropagator that all calls are
+// forwarded to. Delegation can only be performed once, all subsequent calls
+// perform no delegation.
+func (p *textMapPropagator) SetDelegate(delegate propagation.TextMapPropagator) {
+	if delegate == nil {
+		return
+	}
+
+	p.mtx.Lock()
+	p.once.Do(func() { p.delegate = delegate })
+	p.mtx.Unlock()
+}
+
+// effectiveDelegate returns the current delegate of p if one is set,
+// otherwise the default noop TextMapPropagator is returned. This method
+// can be called concurrently.
+func (p *textMapPropagator) effectiveDelegate() propagation.TextMapPropagator {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+	if p.delegate != nil {
+		return p.delegate
+	}
+	return p.noop
+}
+
+// Inject set cross-cutting concerns from the Context into the carrier.
+func (p *textMapPropagator) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
+	p.effectiveDelegate().Inject(ctx, carrier)
+}
+
+// Extract reads cross-cutting concerns from the carrier into a Context.
+func (p *textMapPropagator) Extract(ctx context.Context, carrier propagation.TextMapCarrier) context.Context {
+	return p.effectiveDelegate().Extract(ctx, carrier)
+}
+
+// Fields returns the keys whose values are set with Inject.
+func (p *textMapPropagator) Fields() []string {
+	return p.effectiveDelegate().Fields()
+}

vendor/go.opentelemetry.io/otel/internal/global/state.go

@@ -0,0 +1,106 @@
+// Copyright The 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.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/trace"
+)
+
+type (
+	tracerProviderHolder struct {
+		tp trace.TracerProvider
+	}
+
+	propagatorsHolder struct {
+		tm propagation.TextMapPropagator
+	}
+)
+
+var (
+	globalTracer      = defaultTracerValue()
+	globalPropagators = defaultPropagatorsValue()
+
+	delegateTraceOnce             sync.Once
+	delegateTextMapPropagatorOnce sync.Once
+)
+
+// TracerProvider is the internal implementation for global.TracerProvider.
+func TracerProvider() trace.TracerProvider {
+	return globalTracer.Load().(tracerProviderHolder).tp
+}
+
+// SetTracerProvider is the internal implementation for global.SetTracerProvider.
+func SetTracerProvider(tp trace.TracerProvider) {
+	delegateTraceOnce.Do(func() {
+		current := TracerProvider()
+		if current == tp {
+			// Setting the provider to the prior default is nonsense, panic.
+			// Panic is acceptable because we are likely still early in the
+			// process lifetime.
+			panic("invalid TracerProvider, the global instance cannot be reinstalled")
+		} else if def, ok := current.(*tracerProvider); ok {
+			def.setDelegate(tp)
+		}
+
+	})
+	globalTracer.Store(tracerProviderHolder{tp: tp})
+}
+
+// TextMapPropagator is the internal implementation for global.TextMapPropagator.
+func TextMapPropagator() propagation.TextMapPropagator {
+	return globalPropagators.Load().(propagatorsHolder).tm
+}
+
+// SetTextMapPropagator is the internal implementation for global.SetTextMapPropagator.
+func SetTextMapPropagator(p propagation.TextMapPropagator) {
+	// For the textMapPropagator already returned by TextMapPropagator
+	// delegate to p.
+	delegateTextMapPropagatorOnce.Do(func() {
+		if current := TextMapPropagator(); current == p {
+			// Setting the provider to the prior default is nonsense, panic.
+			// Panic is acceptable because we are likely still early in the
+			// process lifetime.
+			panic("invalid TextMapPropagator, the global instance cannot be reinstalled")
+		} else if def, ok := current.(*textMapPropagator); ok {
+			def.SetDelegate(p)
+		}
+	})
+	// Return p when subsequent calls to TextMapPropagator are made.
+	globalPropagators.Store(propagatorsHolder{tm: p})
+}
+
+func defaultTracerValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(tracerProviderHolder{tp: &tracerProvider{}})
+	return v
+}
+
+func defaultPropagatorsValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(propagatorsHolder{tm: newTextMapPropagator()})
+	return v
+}
+
+// ResetForTest restores the initial global state, for testing purposes.
+func ResetForTest() {
+	globalTracer = defaultTracerValue()
+	globalPropagators = defaultPropagatorsValue()
+	delegateTraceOnce = sync.Once{}
+	delegateTextMapPropagatorOnce = sync.Once{}
+}

vendor/go.opentelemetry.io/otel/internal/global/trace.go

@@ -0,0 +1,192 @@
+// Copyright The 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.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+/*
+This file contains the forwarding implementation of the TracerProvider used as
+the default global instance. Prior to initialization of an SDK, Tracers
+returned by the global TracerProvider will provide no-op functionality. This
+means that all Span created prior to initialization are no-op Spans.
+
+Once an SDK has been initialized, all provided no-op Tracers are swapped for
+Tracers provided by the SDK defined TracerProvider. However, any Span started
+prior to this initialization does not change its behavior. Meaning, the Span
+remains a no-op Span.
+
+The implementation to track and swap Tracers locks all new Tracer creation
+until the swap is complete. This assumes that this operation is not
+performance-critical. If that assumption is incorrect, be sure to configure an
+SDK prior to any Tracer creation.
+*/
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// tracerProvider is a placeholder for a configured SDK TracerProvider.
+//
+// All TracerProvider functionality is forwarded to a delegate once
+// configured.
+type tracerProvider struct {
+	mtx      sync.Mutex
+	tracers  map[il]*tracer
+	delegate trace.TracerProvider
+}
+
+// Compile-time guarantee that tracerProvider implements the TracerProvider
+// interface.
+var _ trace.TracerProvider = &tracerProvider{}
+
+// setDelegate configures p to delegate all TracerProvider functionality to
+// provider.
+//
+// All Tracers provided prior to this function call are switched out to be
+// Tracers provided by provider.
+//
+// It is guaranteed by the caller that this happens only once.
+func (p *tracerProvider) setDelegate(provider trace.TracerProvider) {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	p.delegate = provider
+
+	if len(p.tracers) == 0 {
+		return
+	}
+
+	for _, t := range p.tracers {
+		t.setDelegate(provider)
+	}
+
+	p.tracers = nil
+}
+
+// Tracer implements TracerProvider.
+func (p *tracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.Tracer {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	if p.delegate != nil {
+		return p.delegate.Tracer(name, opts...)
+	}
+
+	// At this moment it is guaranteed that no sdk is installed, save the tracer in the tracers map.
+
+	c := trace.NewTracerConfig(opts...)
+	key := il{
+		name:    name,
+		version: c.InstrumentationVersion(),
+	}
+
+	if p.tracers == nil {
+		p.tracers = make(map[il]*tracer)
+	}
+
+	if val, ok := p.tracers[key]; ok {
+		return val
+	}
+
+	t := &tracer{name: name, opts: opts, provider: p}
+	p.tracers[key] = t
+	return t
+}
+
+type il struct {
+	name    string
+	version string
+}
+
+// tracer is a placeholder for a trace.Tracer.
+//
+// All Tracer functionality is forwarded to a delegate once configured.
+// Otherwise, all functionality is forwarded to a NoopTracer.
+type tracer struct {
+	name     string
+	opts     []trace.TracerOption
+	provider *tracerProvider
+
+	delegate atomic.Value
+}
+
+// Compile-time guarantee that tracer implements the trace.Tracer interface.
+var _ trace.Tracer = &tracer{}
+
+// setDelegate configures t to delegate all Tracer functionality to Tracers
+// created by provider.
+//
+// All subsequent calls to the Tracer methods will be passed to the delegate.
+//
+// It is guaranteed by the caller that this happens only once.
+func (t *tracer) setDelegate(provider trace.TracerProvider) {
+	t.delegate.Store(provider.Tracer(t.name, t.opts...))
+}
+
+// Start implements trace.Tracer by forwarding the call to t.delegate if
+// set, otherwise it forwards the call to a NoopTracer.
+func (t *tracer) Start(ctx context.Context, name string, opts ...trace.SpanStartOption) (context.Context, trace.Span) {
+	delegate := t.delegate.Load()
+	if delegate != nil {
+		return delegate.(trace.Tracer).Start(ctx, name, opts...)
+	}
+
+	s := nonRecordingSpan{sc: trace.SpanContextFromContext(ctx), tracer: t}
+	ctx = trace.ContextWithSpan(ctx, s)
+	return ctx, s
+}
+
+// nonRecordingSpan is a minimal implementation of a Span that wraps a
+// SpanContext. It performs no operations other than to return the wrapped
+// SpanContext.
+type nonRecordingSpan struct {
+	sc     trace.SpanContext
+	tracer *tracer
+}
+
+var _ trace.Span = nonRecordingSpan{}
+
+// SpanContext returns the wrapped SpanContext.
+func (s nonRecordingSpan) SpanContext() trace.SpanContext { return s.sc }
+
+// IsRecording always returns false.
+func (nonRecordingSpan) IsRecording() bool { return false }
+
+// SetStatus does nothing.
+func (nonRecordingSpan) SetStatus(codes.Code, string) {}
+
+// SetError does nothing.
+func (nonRecordingSpan) SetError(bool) {}
+
+// SetAttributes does nothing.
+func (nonRecordingSpan) SetAttributes(...attribute.KeyValue) {}
+
+// End does nothing.
+func (nonRecordingSpan) End(...trace.SpanEndOption) {}
+
+// RecordError does nothing.
+func (nonRecordingSpan) RecordError(error, ...trace.EventOption) {}
+
+// AddEvent does nothing.
+func (nonRecordingSpan) AddEvent(string, ...trace.EventOption) {}
+
+// SetName does nothing.
+func (nonRecordingSpan) SetName(string) {}
+
+func (s nonRecordingSpan) TracerProvider() trace.TracerProvider { return s.tracer.provider }

vendor/go.opentelemetry.io/otel/internal/metric/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
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+      the Work and Derivative Works thereof.
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+      the original version of the Work and any modifications or additions
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+      submitted to Licensor for inclusion in the Work by the copyright owner
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+      subsequently incorporated within the Work.
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
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+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
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+   6. Trademarks. This License does not grant permission to use the trade
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+
+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   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.

vendor/go.opentelemetry.io/otel/internal/metric/async.go

@@ -0,0 +1,149 @@
+// Copyright The 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.
+
+package metric // import "go.opentelemetry.io/otel/internal/metric"
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/sdkapi"
+)
+
+//nolint:revive // ignoring missing comments for exported error in an internal package
+var ErrInvalidAsyncRunner = errors.New("unknown async runner type")
+
+// AsyncCollector is an interface used between the MeterImpl and the
+// AsyncInstrumentState helper below.  This interface is implemented by
+// the SDK to provide support for running observer callbacks.
+type AsyncCollector interface {
+	// CollectAsync passes a batch of observations to the MeterImpl.
+	CollectAsync(labels []attribute.KeyValue, observation ...sdkapi.Observation)
+}
+
+// AsyncInstrumentState manages an ordered set of asynchronous
+// instruments and the distinct runners, taking into account batch
+// observer callbacks.
+type AsyncInstrumentState struct {
+	lock sync.Mutex
+
+	// errorOnce will use the otel.Handler to report an error
+	// once in case of an invalid runner attempting to run.
+	errorOnce sync.Once
+
+	// runnerMap keeps the set of runners that will run each
+	// collection interval.  Singletons are entered with a real
+	// instrument each, batch observers are entered with a nil
+	// instrument, ensuring that when a singleton callback is used
+	// repeatedly, it is executed repeatedly in the interval, while
+	// when a batch callback is used repeatedly, it only executes
+	// once per interval.
+	runnerMap map[asyncRunnerPair]struct{}
+
+	// runners maintains the set of runners in the order they were
+	// registered.
+	runners []asyncRunnerPair
+
+	// instruments maintains the set of instruments in the order
+	// they were registered.
+	instruments []sdkapi.AsyncImpl
+}
+
+// asyncRunnerPair is a map entry for Observer callback runners.
+type asyncRunnerPair struct {
+	// runner is used as a map key here.  The API ensures
+	// that all callbacks are pointers for this reason.
+	runner sdkapi.AsyncRunner
+
+	// inst refers to a non-nil instrument when `runner` is a
+	// AsyncSingleRunner.
+	inst sdkapi.AsyncImpl
+}
+
+// NewAsyncInstrumentState returns a new *AsyncInstrumentState, for
+// use by MeterImpl to manage running the set of observer callbacks in
+// the correct order.
+func NewAsyncInstrumentState() *AsyncInstrumentState {
+	return &AsyncInstrumentState{
+		runnerMap: map[asyncRunnerPair]struct{}{},
+	}
+}
+
+// Instruments returns the asynchronous instruments managed by this
+// object, the set that should be checkpointed after observers are
+// run.
+func (a *AsyncInstrumentState) Instruments() []sdkapi.AsyncImpl {
+	a.lock.Lock()
+	defer a.lock.Unlock()
+	return a.instruments
+}
+
+// Register adds a new asynchronous instrument to by managed by this
+// object.  This should be called during NewAsyncInstrument() and
+// assumes that errors (e.g., duplicate registration) have already
+// been checked.
+func (a *AsyncInstrumentState) Register(inst sdkapi.AsyncImpl, runner sdkapi.AsyncRunner) {
+	a.lock.Lock()
+	defer a.lock.Unlock()
+
+	a.instruments = append(a.instruments, inst)
+
+	// asyncRunnerPair reflects this callback in the asyncRunners
+	// list.  If this is a batch runner, the instrument is nil.
+	// If this is a single-Observer runner, the instrument is
+	// included.  This ensures that batch callbacks are called
+	// once and single callbacks are called once per instrument.
+	rp := asyncRunnerPair{
+		runner: runner,
+	}
+	if _, ok := runner.(sdkapi.AsyncSingleRunner); ok {
+		rp.inst = inst
+	}
+
+	if _, ok := a.runnerMap[rp]; !ok {
+		a.runnerMap[rp] = struct{}{}
+		a.runners = append(a.runners, rp)
+	}
+}
+
+// Run executes the complete set of observer callbacks.
+func (a *AsyncInstrumentState) Run(ctx context.Context, collector AsyncCollector) {
+	a.lock.Lock()
+	runners := a.runners
+	a.lock.Unlock()
+
+	for _, rp := range runners {
+		// The runner must be a single or batch runner, no
+		// other implementations are possible because the
+		// interface has un-exported methods.
+
+		if singleRunner, ok := rp.runner.(sdkapi.AsyncSingleRunner); ok {
+			singleRunner.Run(ctx, rp.inst, collector.CollectAsync)
+			continue
+		}
+
+		if multiRunner, ok := rp.runner.(sdkapi.AsyncBatchRunner); ok {
+			multiRunner.Run(ctx, collector.CollectAsync)
+			continue
+		}
+
+		a.errorOnce.Do(func() {
+			otel.Handle(fmt.Errorf("%w: type %T (reported once)", ErrInvalidAsyncRunner, rp))
+		})
+	}
+}

vendor/go.opentelemetry.io/otel/internal/metric/global/meter.go

@@ -0,0 +1,361 @@
+// Copyright The 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.
+
+package global // import "go.opentelemetry.io/otel/internal/metric/global"
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/internal/metric/registry"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/number"
+	"go.opentelemetry.io/otel/metric/sdkapi"
+)
+
+// This file contains the forwarding implementation of MeterProvider used as
+// the default global instance.  Metric events using instruments provided by
+// this implementation are no-ops until the first Meter implementation is set
+// as the global provider.
+//
+// The implementation here uses Mutexes to maintain a list of active Meters in
+// the MeterProvider and Instruments in each Meter, under the assumption that
+// these interfaces are not performance-critical.
+//
+// We have the invariant that setDelegate() will be called before a new
+// MeterProvider implementation is registered as the global provider.  Mutexes
+// in the MeterProvider and Meters ensure that each instrument has a delegate
+// before the global provider is set.
+//
+// Bound instrument operations are implemented by delegating to the
+// instrument after it is registered, with a sync.Once initializer to
+// protect against races with Release().
+//
+// Metric uniqueness checking is implemented by calling the exported
+// methods of the api/metric/registry package.
+
+type meterKey struct {
+	InstrumentationName    string
+	InstrumentationVersion string
+	SchemaURL              string
+}
+
+type meterProvider struct {
+	delegate metric.MeterProvider
+
+	// lock protects `delegate` and `meters`.
+	lock sync.Mutex
+
+	// meters maintains a unique entry for every named Meter
+	// that has been registered through the global instance.
+	meters map[meterKey]*meterEntry
+}
+
+type meterImpl struct {
+	delegate unsafe.Pointer // (*metric.MeterImpl)
+
+	lock       sync.Mutex
+	syncInsts  []*syncImpl
+	asyncInsts []*asyncImpl
+}
+
+type meterEntry struct {
+	unique sdkapi.MeterImpl
+	impl   meterImpl
+}
+
+type instrument struct {
+	descriptor sdkapi.Descriptor
+}
+
+type syncImpl struct {
+	delegate unsafe.Pointer // (*sdkapi.SyncImpl)
+
+	instrument
+}
+
+type asyncImpl struct {
+	delegate unsafe.Pointer // (*sdkapi.AsyncImpl)
+
+	instrument
+
+	runner sdkapi.AsyncRunner
+}
+
+// SyncImpler is implemented by all of the sync metric
+// instruments.
+type SyncImpler interface {
+	SyncImpl() sdkapi.SyncImpl
+}
+
+// AsyncImpler is implemented by all of the async
+// metric instruments.
+type AsyncImpler interface {
+	AsyncImpl() sdkapi.AsyncImpl
+}
+
+type syncHandle struct {
+	delegate unsafe.Pointer // (*sdkapi.BoundInstrumentImpl)
+
+	inst   *syncImpl
+	labels []attribute.KeyValue
+
+	initialize sync.Once
+}
+
+var _ metric.MeterProvider = &meterProvider{}
+var _ sdkapi.MeterImpl = &meterImpl{}
+var _ sdkapi.InstrumentImpl = &syncImpl{}
+var _ sdkapi.BoundSyncImpl = &syncHandle{}
+var _ sdkapi.AsyncImpl = &asyncImpl{}
+
+func (inst *instrument) Descriptor() sdkapi.Descriptor {
+	return inst.descriptor
+}
+
+// MeterProvider interface and delegation
+
+func newMeterProvider() *meterProvider {
+	return &meterProvider{
+		meters: map[meterKey]*meterEntry{},
+	}
+}
+
+func (p *meterProvider) setDelegate(provider metric.MeterProvider) {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	p.delegate = provider
+	for key, entry := range p.meters {
+		entry.impl.setDelegate(key, provider)
+	}
+	p.meters = nil
+}
+
+func (p *meterProvider) Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	if p.delegate != nil {
+		return p.delegate.Meter(instrumentationName, opts...)
+	}
+
+	cfg := metric.NewMeterConfig(opts...)
+	key := meterKey{
+		InstrumentationName:    instrumentationName,
+		InstrumentationVersion: cfg.InstrumentationVersion(),
+		SchemaURL:              cfg.SchemaURL(),
+	}
+	entry, ok := p.meters[key]
+	if !ok {
+		entry = &meterEntry{}
+		// Note: This code implements its own MeterProvider
+		// name-uniqueness logic because there is
+		// synchronization required at the moment of
+		// delegation.  We use the same instrument-uniqueness
+		// checking the real SDK uses here:
+		entry.unique = registry.NewUniqueInstrumentMeterImpl(&entry.impl)
+		p.meters[key] = entry
+	}
+	return metric.WrapMeterImpl(entry.unique)
+}
+
+// Meter interface and delegation
+
+func (m *meterImpl) setDelegate(key meterKey, provider metric.MeterProvider) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	d := new(sdkapi.MeterImpl)
+	*d = provider.Meter(
+		key.InstrumentationName,
+		metric.WithInstrumentationVersion(key.InstrumentationVersion),
+		metric.WithSchemaURL(key.SchemaURL),
+	).MeterImpl()
+	m.delegate = unsafe.Pointer(d)
+
+	for _, inst := range m.syncInsts {
+		inst.setDelegate(*d)
+	}
+	m.syncInsts = nil
+	for _, obs := range m.asyncInsts {
+		obs.setDelegate(*d)
+	}
+	m.asyncInsts = nil
+}
+
+func (m *meterImpl) NewSyncInstrument(desc sdkapi.Descriptor) (sdkapi.SyncImpl, error) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if meterPtr := (*sdkapi.MeterImpl)(atomic.LoadPointer(&m.delegate)); meterPtr != nil {
+		return (*meterPtr).NewSyncInstrument(desc)
+	}
+
+	inst := &syncImpl{
+		instrument: instrument{
+			descriptor: desc,
+		},
+	}
+	m.syncInsts = append(m.syncInsts, inst)
+	return inst, nil
+}
+
+// Synchronous delegation
+
+func (inst *syncImpl) setDelegate(d sdkapi.MeterImpl) {
+	implPtr := new(sdkapi.SyncImpl)
+
+	var err error
+	*implPtr, err = d.NewSyncInstrument(inst.descriptor)
+
+	if err != nil {
+		// TODO: There is no standard way to deliver this error to the user.
+		// See https://github.com/open-telemetry/opentelemetry-go/issues/514
+		// Note that the default SDK will not generate any errors yet, this is
+		// only for added safety.
+		panic(err)
+	}
+
+	atomic.StorePointer(&inst.delegate, unsafe.Pointer(implPtr))
+}
+
+func (inst *syncImpl) Implementation() interface{} {
+	if implPtr := (*sdkapi.SyncImpl)(atomic.LoadPointer(&inst.delegate)); implPtr != nil {
+		return (*implPtr).Implementation()
+	}
+	return inst
+}
+
+func (inst *syncImpl) Bind(labels []attribute.KeyValue) sdkapi.BoundSyncImpl {
+	if implPtr := (*sdkapi.SyncImpl)(atomic.LoadPointer(&inst.delegate)); implPtr != nil {
+		return (*implPtr).Bind(labels)
+	}
+	return &syncHandle{
+		inst:   inst,
+		labels: labels,
+	}
+}
+
+func (bound *syncHandle) Unbind() {
+	bound.initialize.Do(func() {})
+
+	implPtr := (*sdkapi.BoundSyncImpl)(atomic.LoadPointer(&bound.delegate))
+
+	if implPtr == nil {
+		return
+	}
+
+	(*implPtr).Unbind()
+}
+
+// Async delegation
+
+func (m *meterImpl) NewAsyncInstrument(
+	desc sdkapi.Descriptor,
+	runner sdkapi.AsyncRunner,
+) (sdkapi.AsyncImpl, error) {
+
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if meterPtr := (*sdkapi.MeterImpl)(atomic.LoadPointer(&m.delegate)); meterPtr != nil {
+		return (*meterPtr).NewAsyncInstrument(desc, runner)
+	}
+
+	inst := &asyncImpl{
+		instrument: instrument{
+			descriptor: desc,
+		},
+		runner: runner,
+	}
+	m.asyncInsts = append(m.asyncInsts, inst)
+	return inst, nil
+}
+
+func (obs *asyncImpl) Implementation() interface{} {
+	if implPtr := (*sdkapi.AsyncImpl)(atomic.LoadPointer(&obs.delegate)); implPtr != nil {
+		return (*implPtr).Implementation()
+	}
+	return obs
+}
+
+func (obs *asyncImpl) setDelegate(d sdkapi.MeterImpl) {
+	implPtr := new(sdkapi.AsyncImpl)
+
+	var err error
+	*implPtr, err = d.NewAsyncInstrument(obs.descriptor, obs.runner)
+
+	if err != nil {
+		// TODO: There is no standard way to deliver this error to the user.
+		// See https://github.com/open-telemetry/opentelemetry-go/issues/514
+		// Note that the default SDK will not generate any errors yet, this is
+		// only for added safety.
+		panic(err)
+	}
+
+	atomic.StorePointer(&obs.delegate, unsafe.Pointer(implPtr))
+}
+
+// Metric updates
+
+func (m *meterImpl) RecordBatch(ctx context.Context, labels []attribute.KeyValue, measurements ...sdkapi.Measurement) {
+	if delegatePtr := (*sdkapi.MeterImpl)(atomic.LoadPointer(&m.delegate)); delegatePtr != nil {
+		(*delegatePtr).RecordBatch(ctx, labels, measurements...)
+	}
+}
+
+func (inst *syncImpl) RecordOne(ctx context.Context, number number.Number, labels []attribute.KeyValue) {
+	if instPtr := (*sdkapi.SyncImpl)(atomic.LoadPointer(&inst.delegate)); instPtr != nil {
+		(*instPtr).RecordOne(ctx, number, labels)
+	}
+}
+
+// Bound instrument initialization
+
+func (bound *syncHandle) RecordOne(ctx context.Context, number number.Number) {
+	instPtr := (*sdkapi.SyncImpl)(atomic.LoadPointer(&bound.inst.delegate))
+	if instPtr == nil {
+		return
+	}
+	var implPtr *sdkapi.BoundSyncImpl
+	bound.initialize.Do(func() {
+		implPtr = new(sdkapi.BoundSyncImpl)
+		*implPtr = (*instPtr).Bind(bound.labels)
+		atomic.StorePointer(&bound.delegate, unsafe.Pointer(implPtr))
+	})
+	if implPtr == nil {
+		implPtr = (*sdkapi.BoundSyncImpl)(atomic.LoadPointer(&bound.delegate))
+	}
+	// This may still be nil if instrument was created and bound
+	// without a delegate, then the instrument was set to have a
+	// delegate and unbound.
+	if implPtr == nil {
+		return
+	}
+	(*implPtr).RecordOne(ctx, number)
+}
+
+func AtomicFieldOffsets() map[string]uintptr {
+	return map[string]uintptr{
+		"meterProvider.delegate": unsafe.Offsetof(meterProvider{}.delegate),
+		"meterImpl.delegate":     unsafe.Offsetof(meterImpl{}.delegate),
+		"syncImpl.delegate":      unsafe.Offsetof(syncImpl{}.delegate),
+		"asyncImpl.delegate":     unsafe.Offsetof(asyncImpl{}.delegate),
+		"syncHandle.delegate":    unsafe.Offsetof(syncHandle{}.delegate),
+	}
+}

vendor/go.opentelemetry.io/otel/internal/metric/global/metric.go

@@ -0,0 +1,66 @@
+// Copyright The 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.
+
+package global // import "go.opentelemetry.io/otel/internal/metric/global"
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/metric"
+)
+
+type meterProviderHolder struct {
+	mp metric.MeterProvider
+}
+
+var (
+	globalMeter = defaultMeterValue()
+
+	delegateMeterOnce sync.Once
+)
+
+// MeterProvider is the internal implementation for global.MeterProvider.
+func MeterProvider() metric.MeterProvider {
+	return globalMeter.Load().(meterProviderHolder).mp
+}
+
+// SetMeterProvider is the internal implementation for global.SetMeterProvider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	delegateMeterOnce.Do(func() {
+		current := MeterProvider()
+
+		if current == mp {
+			// Setting the provider to the prior default is nonsense, panic.
+			// Panic is acceptable because we are likely still early in the
+			// process lifetime.
+			panic("invalid MeterProvider, the global instance cannot be reinstalled")
+		} else if def, ok := current.(*meterProvider); ok {
+			def.setDelegate(mp)
+		}
+	})
+	globalMeter.Store(meterProviderHolder{mp: mp})
+}
+
+func defaultMeterValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(meterProviderHolder{mp: newMeterProvider()})
+	return v
+}
+
+// ResetForTest restores the initial global state, for testing purposes.
+func ResetForTest() {
+	globalMeter = defaultMeterValue()
+	delegateMeterOnce = sync.Once{}
+}

vendor/go.opentelemetry.io/otel/internal/metric/registry/doc.go

@@ -0,0 +1,24 @@
+// Copyright The 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.
+
+/*
+Package registry provides a non-standalone implementation of
+MeterProvider that adds uniqueness checking for instrument descriptors
+on top of other MeterProvider it wraps.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+*/
+package registry // import "go.opentelemetry.io/otel/internal/metric/registry"

vendor/go.opentelemetry.io/otel/internal/metric/registry/registry.go

@@ -0,0 +1,139 @@
+// Copyright The 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.
+
+package registry // import "go.opentelemetry.io/otel/internal/metric/registry"
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/sdkapi"
+)
+
+// UniqueInstrumentMeterImpl implements the metric.MeterImpl interface, adding
+// uniqueness checking for instrument descriptors.
+type UniqueInstrumentMeterImpl struct {
+	lock  sync.Mutex
+	impl  sdkapi.MeterImpl
+	state map[string]sdkapi.InstrumentImpl
+}
+
+var _ sdkapi.MeterImpl = (*UniqueInstrumentMeterImpl)(nil)
+
+// ErrMetricKindMismatch is the standard error for mismatched metric
+// instrument definitions.
+var ErrMetricKindMismatch = fmt.Errorf(
+	"a metric was already registered by this name with another kind or number type")
+
+// NewUniqueInstrumentMeterImpl returns a wrapped metric.MeterImpl
+// with the addition of instrument name uniqueness checking.
+func NewUniqueInstrumentMeterImpl(impl sdkapi.MeterImpl) *UniqueInstrumentMeterImpl {
+	return &UniqueInstrumentMeterImpl{
+		impl:  impl,
+		state: map[string]sdkapi.InstrumentImpl{},
+	}
+}
+
+// MeterImpl gives the caller access to the underlying MeterImpl
+// used by this UniqueInstrumentMeterImpl.
+func (u *UniqueInstrumentMeterImpl) MeterImpl() sdkapi.MeterImpl {
+	return u.impl
+}
+
+// RecordBatch implements sdkapi.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) RecordBatch(ctx context.Context, labels []attribute.KeyValue, ms ...sdkapi.Measurement) {
+	u.impl.RecordBatch(ctx, labels, ms...)
+}
+
+// NewMetricKindMismatchError formats an error that describes a
+// mismatched metric instrument definition.
+func NewMetricKindMismatchError(desc sdkapi.Descriptor) error {
+	return fmt.Errorf("metric %s registered as %s %s: %w",
+		desc.Name(),
+		desc.NumberKind(),
+		desc.InstrumentKind(),
+		ErrMetricKindMismatch)
+}
+
+// Compatible determines whether two sdkapi.Descriptors are considered
+// the same for the purpose of uniqueness checking.
+func Compatible(candidate, existing sdkapi.Descriptor) bool {
+	return candidate.InstrumentKind() == existing.InstrumentKind() &&
+		candidate.NumberKind() == existing.NumberKind()
+}
+
+// checkUniqueness returns an ErrMetricKindMismatch error if there is
+// a conflict between a descriptor that was already registered and the
+// `descriptor` argument.  If there is an existing compatible
+// registration, this returns the already-registered instrument.  If
+// there is no conflict and no prior registration, returns (nil, nil).
+func (u *UniqueInstrumentMeterImpl) checkUniqueness(descriptor sdkapi.Descriptor) (sdkapi.InstrumentImpl, error) {
+	impl, ok := u.state[descriptor.Name()]
+	if !ok {
+		return nil, nil
+	}
+
+	if !Compatible(descriptor, impl.Descriptor()) {
+		return nil, NewMetricKindMismatchError(impl.Descriptor())
+	}
+
+	return impl, nil
+}
+
+// NewSyncInstrument implements sdkapi.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) NewSyncInstrument(descriptor sdkapi.Descriptor) (sdkapi.SyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(sdkapi.SyncImpl), nil
+	}
+
+	syncInst, err := u.impl.NewSyncInstrument(descriptor)
+	if err != nil {
+		return nil, err
+	}
+	u.state[descriptor.Name()] = syncInst
+	return syncInst, nil
+}
+
+// NewAsyncInstrument implements sdkapi.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) NewAsyncInstrument(
+	descriptor sdkapi.Descriptor,
+	runner sdkapi.AsyncRunner,
+) (sdkapi.AsyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(sdkapi.AsyncImpl), nil
+	}
+
+	asyncInst, err := u.impl.NewAsyncInstrument(descriptor, runner)
+	if err != nil {
+		return nil, err
+	}
+	u.state[descriptor.Name()] = asyncInst
+	return asyncInst, nil
+}

vendor/go.opentelemetry.io/otel/internal/rawhelpers.go

@@ -0,0 +1,55 @@
+// Copyright The 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.
+
+package internal // import "go.opentelemetry.io/otel/internal"
+
+import (
+	"math"
+	"unsafe"
+)
+
+func BoolToRaw(b bool) uint64 {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+func RawToBool(r uint64) bool {
+	return r != 0
+}
+
+func Int64ToRaw(i int64) uint64 {
+	return uint64(i)
+}
+
+func RawToInt64(r uint64) int64 {
+	return int64(r)
+}
+
+func Float64ToRaw(f float64) uint64 {
+	return math.Float64bits(f)
+}
+
+func RawToFloat64(r uint64) float64 {
+	return math.Float64frombits(r)
+}
+
+func RawPtrToFloat64Ptr(r *uint64) *float64 {
+	return (*float64)(unsafe.Pointer(r))
+}
+
+func RawPtrToInt64Ptr(r *uint64) *int64 {
+	return (*int64)(unsafe.Pointer(r))
+}