Revert "Move global metric back to otel/metric/global for minor release (#3986)" (#4039)

* Revert "Move global metric back to `otel/metric/global` for minor release (#3986)"

This reverts commit 8dba38e02f.

* Add changes to changelog

* Fix versions and go mod tidy

* Run go-mod-tidy

CHANGELOG.md

@@ -8,11 +8,23 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Added
+
+- Support global `MeterProvider` in `go.opentelemetry.io/otel`. (#4039)
+  - Use `Meter` for a `metric.Meter` from the global `metric.MeterProvider`.
+  - Use `GetMeterProivder` for a global `metric.MeterProvider`.
+  - Use `SetMeterProivder` to set the global `metric.MeterProvider`.
+
 ### Changed
 
 - Move the `go.opentelemetry.io/otel/metric` module to the `stable-v1` module set.
   This stages the metric API to be released as a stable module. (#4038)
 
+### Removed
+
+- The `go.opentelemetry.io/otel/metric/global` package is removed.
+  Use `go.opentelemetry.io/otel` instead. (#4039)
+
 ## [1.15.1/0.38.1] 2023-05-02
 
 ### Fixed

bridge/opentracing/go.mod

@@ -18,5 +18,8 @@ require (
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+replace go.opentelemetry.io/otel/metric => ../../metric

bridge/opentracing/test/go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	go.opentelemetry.io/otel/trace v1.15.1 // indirect
 	golang.org/x/net v0.8.0 // indirect
 	golang.org/x/sys v0.7.0 // indirect
@@ -31,3 +32,5 @@ require (
 	google.golang.org/protobuf v1.30.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+replace go.opentelemetry.io/otel/metric => ../../../metric

example/fib/go.mod

@@ -12,6 +12,7 @@ require (
 require (
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 )
 
@@ -22,3 +23,5 @@ replace go.opentelemetry.io/otel/exporters/stdout/stdouttrace => ../../exporters
 replace go.opentelemetry.io/otel/sdk => ../../sdk
 
 replace go.opentelemetry.io/otel/trace => ../../trace
+
+replace go.opentelemetry.io/otel/metric => ../../metric

example/jaeger/go.mod

@@ -17,8 +17,11 @@ require (
 require (
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	go.opentelemetry.io/otel/trace v1.15.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 )
 
 replace go.opentelemetry.io/otel/trace => ../../trace
+
+replace go.opentelemetry.io/otel/metric => ../../metric

example/namedtracer/go.mod

@@ -17,9 +17,12 @@ require (
 
 require (
 	github.com/go-logr/logr v1.2.4 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 )
 
 replace go.opentelemetry.io/otel/trace => ../../trace
 
 replace go.opentelemetry.io/otel/exporters/stdout/stdouttrace => ../../exporters/stdout/stdouttrace
+
+replace go.opentelemetry.io/otel/metric => ../../metric

example/otel-collector/go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.15.1 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.15.1 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
 	golang.org/x/net v0.8.0 // indirect
 	golang.org/x/sys v0.7.0 // indirect
@@ -38,3 +39,5 @@ replace go.opentelemetry.io/otel/exporters/otlp/otlptrace => ../../exporters/otl
 replace go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc => ../../exporters/otlp/otlptrace/otlptracegrpc
 
 replace go.opentelemetry.io/otel/exporters/otlp/internal/retry => ../../exporters/otlp/internal/retry
+
+replace go.opentelemetry.io/otel/metric => ../../metric

example/passthrough/go.mod

@@ -12,6 +12,7 @@ require (
 require (
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 )
 
@@ -22,3 +23,5 @@ replace (
 )
 
 replace go.opentelemetry.io/otel/exporters/stdout/stdouttrace => ../../exporters/stdout/stdouttrace
+
+replace go.opentelemetry.io/otel/metric => ../../metric

example/zipkin/go.mod

@@ -19,7 +19,10 @@ require (
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/openzipkin/zipkin-go v0.4.1 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 )
 
 replace go.opentelemetry.io/otel/trace => ../../trace
+
+replace go.opentelemetry.io/otel/metric => ../../metric

exporters/jaeger/go.mod

@@ -16,6 +16,7 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/objx v0.5.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
@@ -25,3 +26,5 @@ replace go.opentelemetry.io/otel/trace => ../../trace
 replace go.opentelemetry.io/otel => ../..
 
 replace go.opentelemetry.io/otel/sdk => ../../sdk
+
+replace go.opentelemetry.io/otel/metric => ../../metric

exporters/otlp/otlpmetric/otlpmetricgrpc/example_test.go

@@ -17,8 +17,8 @@ package otlpmetricgrpc_test
 import (
 	"context"
 
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
-	"go.opentelemetry.io/otel/metric/global"
 	"go.opentelemetry.io/otel/sdk/metric"
 )
 
@@ -35,7 +35,7 @@ func Example() {
 			panic(err)
 		}
 	}()
-	global.SetMeterProvider(meterProvider)
+	otel.SetMeterProvider(meterProvider)
 
 	// From here, the meterProvider can be used by instrumentation to collect
 	// telemetry.

exporters/otlp/otlpmetric/otlpmetricgrpc/go.mod

@@ -9,7 +9,6 @@ require (
 	go.opentelemetry.io/otel v1.15.1
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.15.1
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.38.1
-	go.opentelemetry.io/otel/metric v0.38.1
 	go.opentelemetry.io/otel/sdk/metric v0.38.1
 	go.opentelemetry.io/proto/otlp v0.19.0
 	google.golang.org/genproto v0.0.0-20230110181048-76db0878b65f
@@ -26,6 +25,7 @@ require (
 	github.com/google/go-cmp v0.5.9 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	go.opentelemetry.io/otel/sdk v1.15.1 // indirect
 	go.opentelemetry.io/otel/trace v1.15.1 // indirect
 	golang.org/x/net v0.8.0 // indirect

exporters/otlp/otlpmetric/otlpmetrichttp/example_test.go

@@ -17,8 +17,8 @@ package otlpmetrichttp_test
 import (
 	"context"
 
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
-	"go.opentelemetry.io/otel/metric/global"
 	"go.opentelemetry.io/otel/sdk/metric"
 )
 
@@ -35,7 +35,7 @@ func Example() {
 			panic(err)
 		}
 	}()
-	global.SetMeterProvider(meterProvider)
+	otel.SetMeterProvider(meterProvider)
 
 	// From here, the meterProvider can be used by instrumentation to collect
 	// telemetry.

exporters/otlp/otlpmetric/otlpmetrichttp/go.mod

@@ -9,7 +9,6 @@ require (
 	go.opentelemetry.io/otel v1.15.1
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.15.1
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.38.1
-	go.opentelemetry.io/otel/metric v0.38.1
 	go.opentelemetry.io/otel/sdk/metric v0.38.1
 	go.opentelemetry.io/proto/otlp v0.19.0
 	google.golang.org/protobuf v1.30.0
@@ -24,6 +23,7 @@ require (
 	github.com/google/go-cmp v0.5.9 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	go.opentelemetry.io/otel/sdk v1.15.1 // indirect
 	go.opentelemetry.io/otel/trace v1.15.1 // indirect
 	golang.org/x/net v0.8.0 // indirect

exporters/otlp/otlptrace/go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/net v0.8.0 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 	golang.org/x/text v0.8.0 // indirect
@@ -36,3 +37,5 @@ replace go.opentelemetry.io/otel/sdk => ../../../sdk
 replace go.opentelemetry.io/otel/trace => ../../../trace
 
 replace go.opentelemetry.io/otel/exporters/otlp/internal/retry => ../internal/retry
+
+replace go.opentelemetry.io/otel/metric => ../../../metric

exporters/otlp/otlptrace/otlptracegrpc/go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	go.opentelemetry.io/otel/trace v1.15.1 // indirect
 	golang.org/x/net v0.8.0 // indirect
 	golang.org/x/sys v0.7.0 // indirect
@@ -39,3 +40,5 @@ replace go.opentelemetry.io/otel/exporters/otlp/otlptrace => ../
 replace go.opentelemetry.io/otel/trace => ../../../../trace
 
 replace go.opentelemetry.io/otel/exporters/otlp/internal/retry => ../../internal/retry
+
+replace go.opentelemetry.io/otel/metric => ../../../../metric

exporters/otlp/otlptrace/otlptracehttp/go.mod

@@ -21,6 +21,7 @@ require (
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/net v0.8.0 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 	golang.org/x/text v0.8.0 // indirect
@@ -38,3 +39,5 @@ replace go.opentelemetry.io/otel/sdk => ../../../../sdk
 replace go.opentelemetry.io/otel/trace => ../../../../trace
 
 replace go.opentelemetry.io/otel/exporters/otlp/internal/retry => ../../internal/retry
+
+replace go.opentelemetry.io/otel/metric => ../../../../metric

exporters/stdout/stdouttrace/go.mod

@@ -19,8 +19,11 @@ require (
 	github.com/go-logr/logr v1.2.4 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 
 replace go.opentelemetry.io/otel/trace => ../../../trace
+
+replace go.opentelemetry.io/otel/metric => ../../../metric

exporters/zipkin/go.mod

@@ -16,6 +16,7 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	golang.org/x/sys v0.7.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
@@ -25,3 +26,5 @@ replace go.opentelemetry.io/otel/trace => ../../trace
 replace go.opentelemetry.io/otel => ../..
 
 replace go.opentelemetry.io/otel/sdk => ../../sdk
+
+replace go.opentelemetry.io/otel/metric => ../../metric

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/go-logr/stdr v1.2.2
 	github.com/google/go-cmp v0.5.9
 	github.com/stretchr/testify v1.8.2
+	go.opentelemetry.io/otel/metric v0.38.1
 	go.opentelemetry.io/otel/trace v1.15.1
 )
 
@@ -17,3 +18,5 @@ require (
 )
 
 replace go.opentelemetry.io/otel/trace => ./trace
+
+replace go.opentelemetry.io/otel/metric => ./metric

internal/global/instruments.go

@@ -12,13 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package global // import "go.opentelemetry.io/otel/metric/internal/global"
+package global // import "go.opentelemetry.io/otel/internal/global"
 
 import (
 	"context"
 	"sync/atomic"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/metric/embedded"
 )
@@ -44,7 +43,7 @@ var _ metric.Float64ObservableCounter = (*afCounter)(nil)
 func (i *afCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64ObservableCounter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -73,7 +72,7 @@ var _ metric.Float64ObservableUpDownCounter = (*afUpDownCounter)(nil)
 func (i *afUpDownCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64ObservableUpDownCounter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -102,7 +101,7 @@ var _ metric.Float64ObservableGauge = (*afGauge)(nil)
 func (i *afGauge) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64ObservableGauge(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -131,7 +130,7 @@ var _ metric.Int64ObservableCounter = (*aiCounter)(nil)
 func (i *aiCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64ObservableCounter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -160,7 +159,7 @@ var _ metric.Int64ObservableUpDownCounter = (*aiUpDownCounter)(nil)
 func (i *aiUpDownCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64ObservableUpDownCounter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -189,7 +188,7 @@ var _ metric.Int64ObservableGauge = (*aiGauge)(nil)
 func (i *aiGauge) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64ObservableGauge(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -217,7 +216,7 @@ var _ metric.Float64Counter = (*sfCounter)(nil)
 func (i *sfCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64Counter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -243,7 +242,7 @@ var _ metric.Float64UpDownCounter = (*sfUpDownCounter)(nil)
 func (i *sfUpDownCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64UpDownCounter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -269,7 +268,7 @@ var _ metric.Float64Histogram = (*sfHistogram)(nil)
 func (i *sfHistogram) setDelegate(m metric.Meter) {
 	ctr, err := m.Float64Histogram(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -295,7 +294,7 @@ var _ metric.Int64Counter = (*siCounter)(nil)
 func (i *siCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64Counter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -321,7 +320,7 @@ var _ metric.Int64UpDownCounter = (*siUpDownCounter)(nil)
 func (i *siUpDownCounter) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64UpDownCounter(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)
@@ -347,7 +346,7 @@ var _ metric.Int64Histogram = (*siHistogram)(nil)
 func (i *siHistogram) setDelegate(m metric.Meter) {
 	ctr, err := m.Int64Histogram(i.name, i.opts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 		return
 	}
 	i.delegate.Store(ctr)

internal/global/meter.go

@@ -12,14 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package global // import "go.opentelemetry.io/otel/metric/internal/global"
+package global // import "go.opentelemetry.io/otel/internal/global"
 
 import (
 	"container/list"
 	"sync"
 	"sync/atomic"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/metric/embedded"
 )
@@ -37,11 +36,6 @@ type meterProvider struct {
 	delegate metric.MeterProvider
 }
 
-type il struct {
-	name    string
-	version string
-}
-
 // setDelegate configures p to delegate all MeterProvider functionality to
 // provider.
 //
@@ -340,7 +334,7 @@ func (c *registration) setDelegate(m metric.Meter) {
 
 	reg, err := m.RegisterCallback(c.function, insts...)
 	if err != nil {
-		otel.Handle(err)
+		GetErrorHandler().Handle(err)
 	}
 
 	c.unreg = reg.Unregister

internal/global/meter_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package global // import "go.opentelemetry.io/otel/metric/internal/global"
+package global // import "go.opentelemetry.io/otel/internal/global"
 
 import (
 	"context"

internal/global/meter_types_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package global // import "go.opentelemetry.io/otel/metric/internal/global"
+package global // import "go.opentelemetry.io/otel/internal/global"
 
 import (
 	"context"

internal/global/state.go

@@ -19,6 +19,7 @@ import (
 	"sync"
 	"sync/atomic"
 
+	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/trace"
 )
@@ -31,14 +32,20 @@ type (
 	propagatorsHolder struct {
 		tm propagation.TextMapPropagator
 	}
+
+	meterProviderHolder struct {
+		mp metric.MeterProvider
+	}
 )
 
 var (
-	globalTracer      = defaultTracerValue()
-	globalPropagators = defaultPropagatorsValue()
+	globalTracer        = defaultTracerValue()
+	globalPropagators   = defaultPropagatorsValue()
+	globalMeterProvider = defaultMeterProvider()
 
 	delegateTraceOnce             sync.Once
 	delegateTextMapPropagatorOnce sync.Once
+	delegateMeterOnce             sync.Once
 )
 
 // TracerProvider is the internal implementation for global.TracerProvider.
@@ -102,6 +109,34 @@ func SetTextMapPropagator(p propagation.TextMapPropagator) {
 	globalPropagators.Store(propagatorsHolder{tm: p})
 }
 
+// MeterProvider is the internal implementation for global.MeterProvider.
+func MeterProvider() metric.MeterProvider {
+	return globalMeterProvider.Load().(meterProviderHolder).mp
+}
+
+// SetMeterProvider is the internal implementation for global.SetMeterProvider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	current := MeterProvider()
+	if _, cOk := current.(*meterProvider); cOk {
+		if _, mpOk := mp.(*meterProvider); mpOk && current == mp {
+			// Do not assign the default delegating MeterProvider to delegate
+			// to itself.
+			Error(
+				errors.New("no delegate configured in meter provider"),
+				"Setting meter provider to it's current value. No delegate will be configured",
+			)
+			return
+		}
+	}
+
+	delegateMeterOnce.Do(func() {
+		if def, ok := current.(*meterProvider); ok {
+			def.setDelegate(mp)
+		}
+	})
+	globalMeterProvider.Store(meterProviderHolder{mp: mp})
+}
+
 func defaultTracerValue() *atomic.Value {
 	v := &atomic.Value{}
 	v.Store(tracerProviderHolder{tp: &tracerProvider{}})
@@ -113,3 +148,9 @@ func defaultPropagatorsValue() *atomic.Value {
 	v.Store(propagatorsHolder{tm: newTextMapPropagator()})
 	return v
 }
+
+func defaultMeterProvider() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(meterProviderHolder{mp: &meterProvider{}})
+	return v
+}

internal/global/state_test.go

@@ -19,6 +19,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/noop"
 	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/trace"
 )
@@ -29,6 +31,12 @@ type nonComparableTracerProvider struct {
 	nonComparable func() //nolint:structcheck,unused  // This is not called.
 }
 
+type nonComparableMeterProvider struct {
+	metric.MeterProvider
+
+	nonComparable func() //nolint:structcheck,unused  // This is not called.
+}
+
 func TestSetTracerProvider(t *testing.T) {
 	t.Run("Set With default is a noop", func(t *testing.T) {
 		ResetForTest(t)
@@ -125,3 +133,53 @@ func TestSetTextMapPropagator(t *testing.T) {
 		assert.NotPanics(t, func() { SetTextMapPropagator(prop) })
 	})
 }
+
+func TestSetMeterProvider(t *testing.T) {
+	t.Run("Set With default is a noop", func(t *testing.T) {
+		ResetForTest(t)
+
+		SetMeterProvider(MeterProvider())
+
+		mp, ok := MeterProvider().(*meterProvider)
+		if !ok {
+			t.Fatal("Global MeterProvider should be the default meter provider")
+		}
+
+		if mp.delegate != nil {
+			t.Fatal("meter provider should not delegate when setting itself")
+		}
+	})
+
+	t.Run("First Set() should replace the delegate", func(t *testing.T) {
+		ResetForTest(t)
+
+		SetMeterProvider(noop.NewMeterProvider())
+
+		_, ok := MeterProvider().(*meterProvider)
+		if ok {
+			t.Fatal("Global MeterProvider was not changed")
+		}
+	})
+
+	t.Run("Set() should delegate existing Meter Providers", func(t *testing.T) {
+		ResetForTest(t)
+
+		mp := MeterProvider()
+
+		SetMeterProvider(noop.NewMeterProvider())
+
+		dmp := mp.(*meterProvider)
+
+		if dmp.delegate == nil {
+			t.Fatal("The delegated meter providers should have a delegate")
+		}
+	})
+
+	t.Run("non-comparable types should not panic", func(t *testing.T) {
+		ResetForTest(t)
+
+		mp := nonComparableMeterProvider{}
+		SetMeterProvider(mp)
+		assert.NotPanics(t, func() { SetMeterProvider(mp) })
+	})
+}

internal/global/util_test.go

@@ -25,7 +25,9 @@ func ResetForTest(t testing.TB) {
 	t.Cleanup(func() {
 		globalTracer = defaultTracerValue()
 		globalPropagators = defaultPropagatorsValue()
+		globalMeterProvider = defaultMeterProvider()
 		delegateTraceOnce = sync.Once{}
 		delegateTextMapPropagatorOnce = sync.Once{}
+		delegateMeterOnce = sync.Once{}
 	})
 }

metric.go

@@ -12,11 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package global // import "go.opentelemetry.io/otel/metric/global"
+package otel // import "go.opentelemetry.io/otel"
 
 import (
+	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/internal/global"
 )
 
 // Meter returns a Meter from the global MeterProvider. The name must be the
@@ -32,14 +32,18 @@ import (
 // the new MeterProvider.
 //
 // This is short for GetMeterProvider().Meter(name).
-func Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
-	return MeterProvider().Meter(instrumentationName, opts...)
+func Meter(name string, opts ...metric.MeterOption) metric.Meter {
+	return GetMeterProvider().Meter(name, opts...)
 }
 
-// MeterProvider returns the registered global meter provider.
+// GetMeterProvider returns the registered global meter provider.
 //
-// If no global MeterProvider has been registered, a No-op MeterProvider implementation is returned. When a global MeterProvider is registered for the first time, the returned MeterProvider, and all the Meters it has created or will create, are recreated automatically from the new MeterProvider.
-func MeterProvider() metric.MeterProvider {
+// If no global GetMeterProvider has been registered, a No-op GetMeterProvider
+// implementation is returned. When a global GetMeterProvider is registered for
+// the first time, the returned GetMeterProvider, and all the Meters it has
+// created or will create, are recreated automatically from the new
+// GetMeterProvider.
+func GetMeterProvider() metric.MeterProvider {
 	return global.MeterProvider()
 }
 

metric/example_test.go

@@ -20,14 +20,14 @@ import (
 	"runtime"
 	"time"
 
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/global"
 )
 
 func ExampleMeter_synchronous() {
 	// Create a histogram using the global MeterProvider.
-	workDuration, err := global.Meter("go.opentelemetry.io/otel/metric#SyncExample").Int64Histogram(
+	workDuration, err := otel.Meter("go.opentelemetry.io/otel/metric#SyncExample").Int64Histogram(
 		"workDuration",
 		metric.WithUnit("ms"))
 	if err != nil {
@@ -43,7 +43,7 @@ func ExampleMeter_synchronous() {
 }
 
 func ExampleMeter_asynchronous_single() {
-	meter := global.Meter("go.opentelemetry.io/otel/metric#AsyncExample")
+	meter := otel.Meter("go.opentelemetry.io/otel/metric#AsyncExample")
 
 	_, err := meter.Int64ObservableGauge(
 		"DiskUsage",
@@ -73,7 +73,7 @@ func ExampleMeter_asynchronous_single() {
 }
 
 func ExampleMeter_asynchronous_multiple() {
-	meter := global.Meter("go.opentelemetry.io/otel/metric#MultiAsyncExample")
+	meter := otel.Meter("go.opentelemetry.io/otel/metric#MultiAsyncExample")
 
 	// This is just a sample of memory stats to record from the Memstats
 	heapAlloc, _ := meter.Int64ObservableUpDownCounter("heapAllocs")

metric/internal/global/state.go

@@ -1,68 +0,0 @@
-// 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
-//
-//     htmp://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/metric/internal/global"
-
-import (
-	"errors"
-	"sync"
-	"sync/atomic"
-
-	"go.opentelemetry.io/otel/internal/global"
-	"go.opentelemetry.io/otel/metric"
-)
-
-var (
-	globalMeterProvider = defaultMeterProvider()
-
-	delegateMeterOnce sync.Once
-)
-
-type meterProviderHolder struct {
-	mp metric.MeterProvider
-}
-
-// MeterProvider is the internal implementation for global.MeterProvider.
-func MeterProvider() metric.MeterProvider {
-	return globalMeterProvider.Load().(meterProviderHolder).mp
-}
-
-// SetMeterProvider is the internal implementation for global.SetMeterProvider.
-func SetMeterProvider(mp metric.MeterProvider) {
-	current := MeterProvider()
-	if _, cOk := current.(*meterProvider); cOk {
-		if _, mpOk := mp.(*meterProvider); mpOk && current == mp {
-			// Do not assign the default delegating MeterProvider to delegate
-			// to itself.
-			global.Error(
-				errors.New("no delegate configured in meter provider"),
-				"Setting meter provider to it's current value. No delegate will be configured",
-			)
-			return
-		}
-	}
-
-	delegateMeterOnce.Do(func() {
-		if def, ok := current.(*meterProvider); ok {
-			def.setDelegate(mp)
-		}
-	})
-	globalMeterProvider.Store(meterProviderHolder{mp: mp})
-}
-
-func defaultMeterProvider() *atomic.Value {
-	v := &atomic.Value{}
-	v.Store(meterProviderHolder{mp: &meterProvider{}})
-	return v
-}

metric/internal/global/state_test.go

@@ -1,87 +0,0 @@
-// 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/metric/internal/global"
-
-import (
-	"sync"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-
-	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/noop"
-)
-
-func resetGlobalMeterProvider() {
-	globalMeterProvider = defaultMeterProvider()
-	delegateMeterOnce = sync.Once{}
-}
-
-type nonComparableMeterProvider struct {
-	metric.MeterProvider
-
-	nonComparable func() //nolint:structcheck,unused  // This is not called.
-}
-
-func TestSetMeterProvider(t *testing.T) {
-	t.Cleanup(resetGlobalMeterProvider)
-
-	t.Run("Set With default is a noop", func(t *testing.T) {
-		resetGlobalMeterProvider()
-		SetMeterProvider(MeterProvider())
-
-		mp, ok := MeterProvider().(*meterProvider)
-		if !ok {
-			t.Fatal("Global MeterProvider should be the default meter provider")
-		}
-
-		if mp.delegate != nil {
-			t.Fatal("meter provider should not delegate when setting itself")
-		}
-	})
-
-	t.Run("First Set() should replace the delegate", func(t *testing.T) {
-		resetGlobalMeterProvider()
-
-		SetMeterProvider(noop.NewMeterProvider())
-
-		_, ok := MeterProvider().(*meterProvider)
-		if ok {
-			t.Fatal("Global MeterProvider was not changed")
-		}
-	})
-
-	t.Run("Set() should delegate existing Meter Providers", func(t *testing.T) {
-		resetGlobalMeterProvider()
-
-		mp := MeterProvider()
-
-		SetMeterProvider(noop.NewMeterProvider())
-
-		dmp := mp.(*meterProvider)
-
-		if dmp.delegate == nil {
-			t.Fatal("The delegated meter providers should have a delegate")
-		}
-	})
-
-	t.Run("non-comparable types should not panic", func(t *testing.T) {
-		resetGlobalMeterProvider()
-
-		mp := nonComparableMeterProvider{}
-		SetMeterProvider(mp)
-		assert.NotPanics(t, func() { SetMeterProvider(mp) })
-	})
-}

metric_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package global // import "go.opentelemetry.io/otel/metric/global"
+package otel // import "go.opentelemetry.io/otel"
 
 import (
 	"testing"
@@ -38,6 +38,6 @@ func TestMultipleGlobalMeterProvider(t *testing.T) {
 	SetMeterProvider(&p1)
 	SetMeterProvider(p2)
 
-	got := MeterProvider()
+	got := GetMeterProvider()
 	assert.Equal(t, p2, got)
 }

sdk/go.mod

@@ -17,7 +17,10 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v0.38.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 
 replace go.opentelemetry.io/otel/trace => ../trace
+
+replace go.opentelemetry.io/otel/metric => ../metric

sdk/metric/example_test.go

@@ -18,7 +18,7 @@ import (
 	"context"
 	"log"
 
-	"go.opentelemetry.io/otel/metric/global"
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/resource"
 	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
@@ -42,7 +42,7 @@ func Example() {
 		metric.WithResource(res),
 		metric.WithReader(reader),
 	)
-	global.SetMeterProvider(meterProvider)
+	otel.SetMeterProvider(meterProvider)
 	defer func() {
 		err := meterProvider.Shutdown(context.Background())
 		if err != nil {

sdk/metric/meter_test.go

@@ -29,7 +29,6 @@ import (
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/global"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
@@ -630,7 +629,7 @@ func TestGlobalInstRegisterCallback(t *testing.T) {
 	otel.SetLogger(logr.New(l))
 
 	const mtrName = "TestGlobalInstRegisterCallback"
-	preMtr := global.Meter(mtrName)
+	preMtr := otel.Meter(mtrName)
 	preInt64Ctr, err := preMtr.Int64ObservableCounter("pre.int64.counter")
 	require.NoError(t, err)
 	preFloat64Ctr, err := preMtr.Float64ObservableCounter("pre.float64.counter")
@@ -638,9 +637,9 @@ func TestGlobalInstRegisterCallback(t *testing.T) {
 
 	rdr := NewManualReader()
 	mp := NewMeterProvider(WithReader(rdr), WithResource(resource.Empty()))
-	global.SetMeterProvider(mp)
+	otel.SetMeterProvider(mp)
 
-	postMtr := global.Meter(mtrName)
+	postMtr := otel.Meter(mtrName)
 	postInt64Ctr, err := postMtr.Int64ObservableCounter("post.int64.counter")
 	require.NoError(t, err)
 	postFloat64Ctr, err := postMtr.Float64ObservableCounter("post.float64.counter")

trace/go.mod

@@ -15,3 +15,5 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+replace go.opentelemetry.io/otel/metric => ../metric