[chore] update latest deps, ensure readme up to date (#1873)

* [chore] update latest deps, ensure readme up to date

* remove double entry

vendor/go.opentelemetry.io/otel/sdk/internal/env/env.go

@@ -70,8 +70,8 @@ const (
 // returned.
 func firstInt(defaultValue int, keys ...string) int {
 	for _, key := range keys {
-		value, ok := os.LookupEnv(key)
-		if !ok {
+		value := os.Getenv(key)
+		if value == "" {
 			continue
 		}
 
@@ -88,10 +88,10 @@ func firstInt(defaultValue int, keys ...string) int {
 }
 
 // IntEnvOr returns the int value of the environment variable with name key if
-// it exists and the value is an int. Otherwise, defaultValue is returned.
+// it exists, it is not empty, and the value is an int. Otherwise, defaultValue is returned.
 func IntEnvOr(key string, defaultValue int) int {
-	value, ok := os.LookupEnv(key)
-	if !ok {
+	value := os.Getenv(key)
+	if value == "" {
 		return defaultValue
 	}
 

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

@@ -14,16 +14,7 @@
 
 package internal // import "go.opentelemetry.io/otel/sdk/internal"
 
-import (
-	"fmt"
-	"time"
-
-	"go.opentelemetry.io/otel"
-)
-
-// UserAgent is the user agent to be added to the outgoing
-// requests from the exporters.
-var UserAgent = fmt.Sprintf("opentelemetry-go/%s", otel.Version())
+import "time"
 
 // MonotonicEndTime returns the end time at present
 // but offset from start, monotonically.

vendor/go.opentelemetry.io/otel/sdk/resource/auto.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strings"
 )
 
 var (
@@ -45,28 +46,65 @@ type Detector interface {
 // Detect calls all input detectors sequentially and merges each result with the previous one.
 // It returns the merged error too.
 func Detect(ctx context.Context, detectors ...Detector) (*Resource, error) {
-	var autoDetectedRes *Resource
-	var errInfo []string
+	r := new(Resource)
+	return r, detect(ctx, r, detectors)
+}
+
+// detect runs all detectors using ctx and merges the result into res. This
+// assumes res is allocated and not nil, it will panic otherwise.
+func detect(ctx context.Context, res *Resource, detectors []Detector) error {
+	var (
+		r    *Resource
+		errs detectErrs
+		err  error
+	)
+
 	for _, detector := range detectors {
 		if detector == nil {
 			continue
 		}
-		res, err := detector.Detect(ctx)
+		r, err = detector.Detect(ctx)
 		if err != nil {
-			errInfo = append(errInfo, err.Error())
+			errs = append(errs, err)
 			if !errors.Is(err, ErrPartialResource) {
 				continue
 			}
 		}
-		autoDetectedRes, err = Merge(autoDetectedRes, res)
+		r, err = Merge(res, r)
 		if err != nil {
-			errInfo = append(errInfo, err.Error())
+			errs = append(errs, err)
 		}
+		*res = *r
 	}
 
-	var aggregatedError error
-	if len(errInfo) > 0 {
-		aggregatedError = fmt.Errorf("detecting resources: %s", errInfo)
+	if len(errs) == 0 {
+		return nil
 	}
-	return autoDetectedRes, aggregatedError
+	return errs
+}
+
+type detectErrs []error
+
+func (e detectErrs) Error() string {
+	errStr := make([]string, len(e))
+	for i, err := range e {
+		errStr[i] = fmt.Sprintf("* %s", err)
+	}
+
+	format := "%d errors occurred detecting resource:\n\t%s"
+	return fmt.Sprintf(format, len(e), strings.Join(errStr, "\n\t"))
+}
+
+func (e detectErrs) Unwrap() error {
+	switch len(e) {
+	case 0:
+		return nil
+	case 1:
+		return e[0]
+	}
+	return e[1:]
+}
+
+func (e detectErrs) Is(target error) bool {
+	return len(e) != 0 && errors.Is(e[0], target)
 }

vendor/go.opentelemetry.io/otel/sdk/resource/builtin.go

@@ -20,8 +20,8 @@ import (
 	"os"
 	"path/filepath"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk"
 	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
 )
 
@@ -62,7 +62,7 @@ func (telemetrySDK) Detect(context.Context) (*Resource, error) {
 		semconv.SchemaURL,
 		semconv.TelemetrySDKName("opentelemetry"),
 		semconv.TelemetrySDKLanguageGo,
-		semconv.TelemetrySDKVersion(otel.Version()),
+		semconv.TelemetrySDKVersion(sdk.Version()),
 	), nil
 }
 

vendor/go.opentelemetry.io/otel/sdk/resource/config.go

@@ -71,6 +71,11 @@ func WithHost() Option {
 	return WithDetectors(host{})
 }
 
+// WithHostID adds host ID information to the configured resource.
+func WithHostID() Option {
+	return WithDetectors(hostIDDetector{})
+}
+
 // WithTelemetrySDK adds TelemetrySDK version info to the configured resource.
 func WithTelemetrySDK() Option {
 	return WithDetectors(telemetrySDK{})

vendor/go.opentelemetry.io/otel/sdk/resource/doc.go

@@ -25,4 +25,7 @@
 // OTEL_RESOURCE_ATTRIBUTES the FromEnv Detector can be used. It will interpret
 // the value as a list of comma delimited key/value pairs
 // (e.g. `<key1>=<value1>,<key2>=<value2>,...`).
+//
+// While this package provides a stable API,
+// the attributes added by resource detectors may change.
 package resource // import "go.opentelemetry.io/otel/sdk/resource"

vendor/go.opentelemetry.io/otel/sdk/resource/env.go

@@ -82,23 +82,23 @@ func constructOTResources(s string) (*Resource, error) {
 		return Empty(), nil
 	}
 	pairs := strings.Split(s, ",")
-	attrs := []attribute.KeyValue{}
+	var attrs []attribute.KeyValue
 	var invalid []string
 	for _, p := range pairs {
-		field := strings.SplitN(p, "=", 2)
-		if len(field) != 2 {
+		k, v, found := strings.Cut(p, "=")
+		if !found {
 			invalid = append(invalid, p)
 			continue
 		}
-		k := strings.TrimSpace(field[0])
-		v, err := url.QueryUnescape(strings.TrimSpace(field[1]))
+		key := strings.TrimSpace(k)
+		val, err := url.QueryUnescape(strings.TrimSpace(v))
 		if err != nil {
 			// Retain original value if decoding fails, otherwise it will be
 			// an empty string.
-			v = field[1]
+			val = v
 			otel.Handle(err)
 		}
-		attrs = append(attrs, attribute.String(k, v))
+		attrs = append(attrs, attribute.String(key, val))
 	}
 	var err error
 	if len(invalid) > 0 {

vendor/go.opentelemetry.io/otel/sdk/resource/host_id.go

@@ -0,0 +1,120 @@
+// 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 resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
+)
+
+type hostIDProvider func() (string, error)
+
+var defaultHostIDProvider hostIDProvider = platformHostIDReader.read
+
+var hostID = defaultHostIDProvider
+
+type hostIDReader interface {
+	read() (string, error)
+}
+
+type fileReader func(string) (string, error)
+
+type commandExecutor func(string, ...string) (string, error)
+
+// hostIDReaderBSD implements hostIDReader.
+type hostIDReaderBSD struct {
+	execCommand commandExecutor
+	readFile    fileReader
+}
+
+// read attempts to read the machine-id from /etc/hostid. If not found it will
+// execute `kenv -q smbios.system.uuid`. If neither location yields an id an
+// error will be returned.
+func (r *hostIDReaderBSD) read() (string, error) {
+	if result, err := r.readFile("/etc/hostid"); err == nil {
+		return strings.TrimSpace(result), nil
+	}
+
+	if result, err := r.execCommand("kenv", "-q", "smbios.system.uuid"); err == nil {
+		return strings.TrimSpace(result), nil
+	}
+
+	return "", errors.New("host id not found in: /etc/hostid or kenv")
+}
+
+// hostIDReaderDarwin implements hostIDReader.
+type hostIDReaderDarwin struct {
+	execCommand commandExecutor
+}
+
+// read executes `ioreg -rd1 -c "IOPlatformExpertDevice"` and parses host id
+// from the IOPlatformUUID line. If the command fails or the uuid cannot be
+// parsed an error will be returned.
+func (r *hostIDReaderDarwin) read() (string, error) {
+	result, err := r.execCommand("ioreg", "-rd1", "-c", "IOPlatformExpertDevice")
+	if err != nil {
+		return "", err
+	}
+
+	lines := strings.Split(result, "\n")
+	for _, line := range lines {
+		if strings.Contains(line, "IOPlatformUUID") {
+			parts := strings.Split(line, " = ")
+			if len(parts) == 2 {
+				return strings.Trim(parts[1], "\""), nil
+			}
+			break
+		}
+	}
+
+	return "", errors.New("could not parse IOPlatformUUID")
+}
+
+type hostIDReaderLinux struct {
+	readFile fileReader
+}
+
+// read attempts to read the machine-id from /etc/machine-id followed by
+// /var/lib/dbus/machine-id. If neither location yields an ID an error will
+// be returned.
+func (r *hostIDReaderLinux) read() (string, error) {
+	if result, err := r.readFile("/etc/machine-id"); err == nil {
+		return strings.TrimSpace(result), nil
+	}
+
+	if result, err := r.readFile("/var/lib/dbus/machine-id"); err == nil {
+		return strings.TrimSpace(result), nil
+	}
+
+	return "", errors.New("host id not found in: /etc/machine-id or /var/lib/dbus/machine-id")
+}
+
+type hostIDDetector struct{}
+
+// Detect returns a *Resource containing the platform specific host id.
+func (hostIDDetector) Detect(ctx context.Context) (*Resource, error) {
+	hostID, err := hostID()
+	if err != nil {
+		return nil, err
+	}
+
+	return NewWithAttributes(
+		semconv.SchemaURL,
+		semconv.HostID(hostID),
+	), nil
+}

vendor/go.opentelemetry.io/otel/sdk/resource/host_id_bsd.go

@@ -0,0 +1,23 @@
+// 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.
+
+//go:build dragonfly || freebsd || netbsd || openbsd || solaris
+// +build dragonfly freebsd netbsd openbsd solaris
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+var platformHostIDReader hostIDReader = &hostIDReaderBSD{
+	execCommand: execCommand,
+	readFile:    readFile,
+}

vendor/go.opentelemetry.io/otel/sdk/resource/host_id_darwin.go

@@ -0,0 +1,19 @@
+// 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 resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+var platformHostIDReader hostIDReader = &hostIDReaderDarwin{
+	execCommand: execCommand,
+}

vendor/go.opentelemetry.io/otel/sdk/resource/host_id_exec.go

@@ -0,0 +1,29 @@
+// 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.
+
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd || solaris
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import "os/exec"
+
+func execCommand(name string, arg ...string) (string, error) {
+	cmd := exec.Command(name, arg...)
+	b, err := cmd.Output()
+	if err != nil {
+		return "", err
+	}
+
+	return string(b), nil
+}

vendor/go.opentelemetry.io/otel/sdk/resource/host_id_linux.go

@@ -0,0 +1,22 @@
+// 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.
+
+//go:build linux
+// +build linux
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+var platformHostIDReader hostIDReader = &hostIDReaderLinux{
+	readFile: readFile,
+}

vendor/go.opentelemetry.io/otel/sdk/resource/host_id_readfile.go

@@ -0,0 +1,28 @@
+// 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.
+
+//go:build linux || dragonfly || freebsd || netbsd || openbsd || solaris
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import "os"
+
+func readFile(filename string) (string, error) {
+	b, err := os.ReadFile(filename)
+	if err != nil {
+		return "", nil
+	}
+
+	return string(b), nil
+}

vendor/go.opentelemetry.io/otel/sdk/resource/host_id_unsupported.go

@@ -0,0 +1,36 @@
+// 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.
+
+// +build !darwin
+// +build !dragonfly
+// +build !freebsd
+// +build !linux
+// +build !netbsd
+// +build !openbsd
+// +build !solaris
+// +build !windows
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+// hostIDReaderUnsupported is a placeholder implementation for operating systems
+// for which this project currently doesn't support host.id
+// attribute detection. See build tags declaration early on this file
+// for a list of unsupported OSes.
+type hostIDReaderUnsupported struct{}
+
+func (*hostIDReaderUnsupported) read() (string, error) {
+	return "<unknown>", nil
+}
+
+var platformHostIDReader hostIDReader = &hostIDReaderUnsupported{}

vendor/go.opentelemetry.io/otel/sdk/resource/host_id_windows.go

@@ -0,0 +1,48 @@
+// 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.
+
+//go:build windows
+// +build windows
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"golang.org/x/sys/windows/registry"
+)
+
+// implements hostIDReader
+type hostIDReaderWindows struct{}
+
+// read reads MachineGuid from the windows registry key:
+// SOFTWARE\Microsoft\Cryptography
+func (*hostIDReaderWindows) read() (string, error) {
+	k, err := registry.OpenKey(
+		registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Cryptography`,
+		registry.QUERY_VALUE|registry.WOW64_64KEY,
+	)
+
+	if err != nil {
+		return "", err
+	}
+	defer k.Close()
+
+	guid, _, err := k.GetStringValue("MachineGuid")
+	if err != nil {
+		return "", err
+	}
+
+	return guid, nil
+}
+
+var platformHostIDReader hostIDReader = &hostIDReaderWindows{}

vendor/go.opentelemetry.io/otel/sdk/resource/os_release_unix.go

@@ -85,14 +85,14 @@ func skip(line string) bool {
 // parse attempts to split the provided line on the first '=' character, and then
 // sanitize each side of the split before returning them as a key-value pair.
 func parse(line string) (string, string, bool) {
-	parts := strings.SplitN(line, "=", 2)
+	k, v, found := strings.Cut(line, "=")
 
-	if len(parts) != 2 || len(parts[0]) == 0 {
+	if !found || len(k) == 0 {
 		return "", "", false
 	}
 
-	key := strings.TrimSpace(parts[0])
-	value := unescape(unquote(strings.TrimSpace(parts[1])))
+	key := strings.TrimSpace(k)
+	value := unescape(unquote(strings.TrimSpace(v)))
 
 	return key, value, true
 }

vendor/go.opentelemetry.io/otel/sdk/resource/resource.go

@@ -17,7 +17,6 @@ package resource // import "go.opentelemetry.io/otel/sdk/resource"
 import (
 	"context"
 	"errors"
-	"fmt"
 	"sync"
 
 	"go.opentelemetry.io/otel"
@@ -51,17 +50,8 @@ func New(ctx context.Context, opts ...Option) (*Resource, error) {
 		cfg = opt.apply(cfg)
 	}
 
-	resource, err := Detect(ctx, cfg.detectors...)
-
-	var err2 error
-	resource, err2 = Merge(resource, &Resource{schemaURL: cfg.schemaURL})
-	if err == nil {
-		err = err2
-	} else if err2 != nil {
-		err = fmt.Errorf("detecting resources: %s", []string{err.Error(), err2.Error()})
-	}
-
-	return resource, err
+	r := &Resource{schemaURL: cfg.schemaURL}
+	return r, detect(ctx, r, cfg.detectors)
 }
 
 // NewWithAttributes creates a resource from attrs and associates the resource with a
@@ -84,7 +74,7 @@ func NewSchemaless(attrs ...attribute.KeyValue) *Resource {
 	}
 
 	// Ensure attributes comply with the specification:
-	// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.0.1/specification/common/common.md#attributes
+	// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.20.0/specification/common/README.md#attribute
 	s, _ := attribute.NewSetWithFiltered(attrs, func(kv attribute.KeyValue) bool {
 		return kv.Valid()
 	})
@@ -164,7 +154,7 @@ func (r *Resource) Equal(eq *Resource) bool {
 // if resource b's value is empty.
 //
 // The SchemaURL of the resources will be merged according to the spec rules:
-// https://github.com/open-telemetry/opentelemetry-specification/blob/bad49c714a62da5493f2d1d9bafd7ebe8c8ce7eb/specification/resource/sdk.md#merge
+// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.20.0/specification/resource/sdk.md#merge
 // If the resources have different non-empty schemaURL an empty resource and an error
 // will be returned.
 func Merge(a, b *Resource) (*Resource, error) {

vendor/go.opentelemetry.io/otel/sdk/trace/batch_span_processor.go

@@ -91,7 +91,7 @@ var _ SpanProcessor = (*batchSpanProcessor)(nil)
 // NewBatchSpanProcessor creates a new SpanProcessor that will send completed
 // span batches to the exporter with the supplied options.
 //
-// If the exporter is nil, the span processor will preform no action.
+// If the exporter is nil, the span processor will perform no action.
 func NewBatchSpanProcessor(exporter SpanExporter, options ...BatchSpanProcessorOption) SpanProcessor {
 	maxQueueSize := env.BatchSpanProcessorMaxQueueSize(DefaultMaxQueueSize)
 	maxExportBatchSize := env.BatchSpanProcessorMaxExportBatchSize(DefaultMaxExportBatchSize)

vendor/go.opentelemetry.io/otel/sdk/trace/provider.go

@@ -75,8 +75,9 @@ func (cfg tracerProviderConfig) MarshalLog() interface{} {
 type TracerProvider struct {
 	mu             sync.Mutex
 	namedTracer    map[instrumentation.Scope]*tracer
-	spanProcessors atomic.Value
-	isShutdown     bool
+	spanProcessors atomic.Pointer[spanProcessorStates]
+
+	isShutdown atomic.Bool
 
 	// These fields are not protected by the lock mu. They are assumed to be
 	// immutable after creation of the TracerProvider.
@@ -119,11 +120,11 @@ func NewTracerProvider(opts ...TracerProviderOption) *TracerProvider {
 	}
 	global.Info("TracerProvider created", "config", o)
 
-	spss := spanProcessorStates{}
+	spss := make(spanProcessorStates, 0, len(o.processors))
 	for _, sp := range o.processors {
 		spss = append(spss, newSpanProcessorState(sp))
 	}
-	tp.spanProcessors.Store(spss)
+	tp.spanProcessors.Store(&spss)
 
 	return tp
 }
@@ -136,10 +137,11 @@ func NewTracerProvider(opts ...TracerProviderOption) *TracerProvider {
 //
 // This method is safe to be called concurrently.
 func (p *TracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.Tracer {
+	// This check happens before the mutex is acquired to avoid deadlocking if Tracer() is called from within Shutdown().
+	if p.isShutdown.Load() {
+		return trace.NewNoopTracerProvider().Tracer(name, opts...)
+	}
 	c := trace.NewTracerConfig(opts...)
-
-	p.mu.Lock()
-	defer p.mu.Unlock()
 	if name == "" {
 		name = defaultTracerName
 	}
@@ -148,44 +150,74 @@ func (p *TracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.T
 		Version:   c.InstrumentationVersion(),
 		SchemaURL: c.SchemaURL(),
 	}
-	t, ok := p.namedTracer[is]
-	if !ok {
-		t = &tracer{
-			provider:             p,
-			instrumentationScope: is,
+
+	t, ok := func() (trace.Tracer, bool) {
+		p.mu.Lock()
+		defer p.mu.Unlock()
+		// Must check the flag after acquiring the mutex to avoid returning a valid tracer if Shutdown() ran
+		// after the first check above but before we acquired the mutex.
+		if p.isShutdown.Load() {
+			return trace.NewNoopTracerProvider().Tracer(name, opts...), true
 		}
-		p.namedTracer[is] = t
-		global.Info("Tracer created", "name", name, "version", c.InstrumentationVersion(), "schemaURL", c.SchemaURL())
+		t, ok := p.namedTracer[is]
+		if !ok {
+			t = &tracer{
+				provider:             p,
+				instrumentationScope: is,
+			}
+			p.namedTracer[is] = t
+		}
+		return t, ok
+	}()
+	if !ok {
+		// This code is outside the mutex to not hold the lock while calling third party logging code:
+		// - That code may do slow things like I/O, which would prolong the duration the lock is held,
+		//   slowing down all tracing consumers.
+		// - Logging code may be instrumented with tracing and deadlock because it could try
+		//   acquiring the same non-reentrant mutex.
+		global.Info("Tracer created", "name", name, "version", is.Version, "schemaURL", is.SchemaURL)
 	}
 	return t
 }
 
 // RegisterSpanProcessor adds the given SpanProcessor to the list of SpanProcessors.
 func (p *TracerProvider) RegisterSpanProcessor(sp SpanProcessor) {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-	if p.isShutdown {
+	// This check prevents calls during a shutdown.
+	if p.isShutdown.Load() {
 		return
 	}
-	newSPS := spanProcessorStates{}
-	newSPS = append(newSPS, p.spanProcessors.Load().(spanProcessorStates)...)
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	// This check prevents calls after a shutdown.
+	if p.isShutdown.Load() {
+		return
+	}
+
+	current := p.getSpanProcessors()
+	newSPS := make(spanProcessorStates, 0, len(current)+1)
+	newSPS = append(newSPS, current...)
 	newSPS = append(newSPS, newSpanProcessorState(sp))
-	p.spanProcessors.Store(newSPS)
+	p.spanProcessors.Store(&newSPS)
 }
 
 // UnregisterSpanProcessor removes the given SpanProcessor from the list of SpanProcessors.
 func (p *TracerProvider) UnregisterSpanProcessor(sp SpanProcessor) {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-	if p.isShutdown {
+	// This check prevents calls during a shutdown.
+	if p.isShutdown.Load() {
 		return
 	}
-	old := p.spanProcessors.Load().(spanProcessorStates)
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	// This check prevents calls after a shutdown.
+	if p.isShutdown.Load() {
+		return
+	}
+	old := p.getSpanProcessors()
 	if len(old) == 0 {
 		return
 	}
-	spss := spanProcessorStates{}
-	spss = append(spss, old...)
+	spss := make(spanProcessorStates, len(old))
+	copy(spss, old)
 
 	// stop the span processor if it is started and remove it from the list
 	var stopOnce *spanProcessorState
@@ -209,13 +241,13 @@ func (p *TracerProvider) UnregisterSpanProcessor(sp SpanProcessor) {
 	spss[len(spss)-1] = nil
 	spss = spss[:len(spss)-1]
 
-	p.spanProcessors.Store(spss)
+	p.spanProcessors.Store(&spss)
 }
 
 // ForceFlush immediately exports all spans that have not yet been exported for
 // all the registered span processors.
 func (p *TracerProvider) ForceFlush(ctx context.Context) error {
-	spss := p.spanProcessors.Load().(spanProcessorStates)
+	spss := p.getSpanProcessors()
 	if len(spss) == 0 {
 		return nil
 	}
@@ -236,18 +268,21 @@ func (p *TracerProvider) ForceFlush(ctx context.Context) error {
 
 // Shutdown shuts down TracerProvider. All registered span processors are shut down
 // in the order they were registered and any held computational resources are released.
+// After Shutdown is called, all methods are no-ops.
 func (p *TracerProvider) Shutdown(ctx context.Context) error {
-	spss := p.spanProcessors.Load().(spanProcessorStates)
-	if len(spss) == 0 {
+	// This check prevents deadlocks in case of recursive shutdown.
+	if p.isShutdown.Load() {
+		return nil
+	}
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	// This check prevents calls after a shutdown has already been done concurrently.
+	if !p.isShutdown.CompareAndSwap(false, true) { // did toggle?
 		return nil
 	}
 
-	p.mu.Lock()
-	defer p.mu.Unlock()
-	p.isShutdown = true
-
 	var retErr error
-	for _, sps := range spss {
+	for _, sps := range p.getSpanProcessors() {
 		select {
 		case <-ctx.Done():
 			return ctx.Err()
@@ -267,10 +302,14 @@ func (p *TracerProvider) Shutdown(ctx context.Context) error {
 			}
 		}
 	}
-	p.spanProcessors.Store(spanProcessorStates{})
+	p.spanProcessors.Store(&spanProcessorStates{})
 	return retErr
 }
 
+func (p *TracerProvider) getSpanProcessors() spanProcessorStates {
+	return *(p.spanProcessors.Load())
+}
+
 // TracerProviderOption configures a TracerProvider.
 type TracerProviderOption interface {
 	apply(tracerProviderConfig) tracerProviderConfig

vendor/go.opentelemetry.io/otel/sdk/trace/simple_span_processor.go

@@ -19,12 +19,13 @@ import (
 	"sync"
 
 	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/internal/global"
 )
 
 // simpleSpanProcessor is a SpanProcessor that synchronously sends all
 // completed Spans to a trace.Exporter immediately.
 type simpleSpanProcessor struct {
-	exporterMu sync.RWMutex
+	exporterMu sync.Mutex
 	exporter   SpanExporter
 	stopOnce   sync.Once
 }
@@ -43,6 +44,8 @@ func NewSimpleSpanProcessor(exporter SpanExporter) SpanProcessor {
 	ssp := &simpleSpanProcessor{
 		exporter: exporter,
 	}
+	global.Warn("SimpleSpanProcessor is not recommended for production use, consider using BatchSpanProcessor instead.")
+
 	return ssp
 }
 
@@ -51,8 +54,8 @@ func (ssp *simpleSpanProcessor) OnStart(context.Context, ReadWriteSpan) {}
 
 // OnEnd immediately exports a ReadOnlySpan.
 func (ssp *simpleSpanProcessor) OnEnd(s ReadOnlySpan) {
-	ssp.exporterMu.RLock()
-	defer ssp.exporterMu.RUnlock()
+	ssp.exporterMu.Lock()
+	defer ssp.exporterMu.Unlock()
 
 	if ssp.exporter != nil && s.SpanContext().TraceFlags().IsSampled() {
 		if err := ssp.exporter.ExportSpans(context.Background(), []ReadOnlySpan{s}); err != nil {

vendor/go.opentelemetry.io/otel/sdk/trace/span.go

@@ -302,7 +302,7 @@ func (s *recordingSpan) addOverCapAttrs(limit int, attrs []attribute.KeyValue) {
 // most a length of limit. Each string slice value is truncated in this fashion
 // (the slice length itself is unaffected).
 //
-// No truncation is perfromed for a negative limit.
+// No truncation is performed for a negative limit.
 func truncateAttr(limit int, attr attribute.KeyValue) attribute.KeyValue {
 	if limit < 0 {
 		return attr
@@ -410,7 +410,7 @@ func (s *recordingSpan) End(options ...trace.SpanEndOption) {
 	}
 	s.mu.Unlock()
 
-	sps := s.tracer.provider.spanProcessors.Load().(spanProcessorStates)
+	sps := s.tracer.provider.getSpanProcessors()
 	if len(sps) == 0 {
 		return
 	}

vendor/go.opentelemetry.io/otel/sdk/trace/span_exporter.go

@@ -38,7 +38,7 @@ type SpanExporter interface {
 	// must never be done outside of a new major release.
 
 	// Shutdown notifies the exporter of a pending halt to operations. The
-	// exporter is expected to preform any cleanup or synchronization it
+	// exporter is expected to perform any cleanup or synchronization it
 	// requires while honoring all timeouts and cancellations contained in
 	// the passed context.
 	Shutdown(ctx context.Context) error

vendor/go.opentelemetry.io/otel/sdk/trace/span_processor.go

@@ -62,11 +62,11 @@ type SpanProcessor interface {
 
 type spanProcessorState struct {
 	sp    SpanProcessor
-	state *sync.Once
+	state sync.Once
 }
 
 func newSpanProcessorState(sp SpanProcessor) *spanProcessorState {
-	return &spanProcessorState{sp: sp, state: &sync.Once{}}
+	return &spanProcessorState{sp: sp}
 }
 
 type spanProcessorStates []*spanProcessorState

vendor/go.opentelemetry.io/otel/sdk/trace/tracer.go

@@ -51,7 +51,7 @@ func (tr *tracer) Start(ctx context.Context, name string, options ...trace.SpanS
 
 	s := tr.newSpan(ctx, name, &config)
 	if rw, ok := s.(ReadWriteSpan); ok && s.IsRecording() {
-		sps := tr.provider.spanProcessors.Load().(spanProcessorStates)
+		sps := tr.provider.getSpanProcessors()
 		for _, sp := range sps {
 			sp.sp.OnStart(ctx, rw)
 		}

vendor/go.opentelemetry.io/otel/sdk/trace/version.go

@@ -0,0 +1,20 @@
+// 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 trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+// version is the current release version of the metric SDK in use.
+func version() string {
+	return "1.16.0-rc.1"
+}

vendor/go.opentelemetry.io/otel/sdk/version.go

@@ -0,0 +1,20 @@
+// 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 sdk // import "go.opentelemetry.io/otel/sdk"
+
+// Version is the current release version of the OpenTelemetry SDK in use.
+func Version() string {
+	return "1.16.0"
+}