caddy/modules/caddyhttp/tracing/tracerprovider.go

64 lines
1.7 KiB
Go

package tracing
import (
"context"
"fmt"
"sync"
sdktrace "go.opentelemetry.io/otel/sdk/trace"
"go.uber.org/zap"
)
// globalTracerProvider stores global tracer provider and is responsible for graceful shutdown when nobody is using it.
var globalTracerProvider = &tracerProvider{}
type tracerProvider struct {
mu sync.Mutex
tracerProvider *sdktrace.TracerProvider
tracerProvidersCounter int
}
// getTracerProvider create or return an existing global TracerProvider
func (t *tracerProvider) getTracerProvider(opts ...sdktrace.TracerProviderOption) *sdktrace.TracerProvider {
t.mu.Lock()
defer t.mu.Unlock()
t.tracerProvidersCounter++
if t.tracerProvider == nil {
t.tracerProvider = sdktrace.NewTracerProvider(
opts...,
)
}
return t.tracerProvider
}
// cleanupTracerProvider gracefully shutdown a TracerProvider
func (t *tracerProvider) cleanupTracerProvider(logger *zap.Logger) error {
t.mu.Lock()
defer t.mu.Unlock()
if t.tracerProvidersCounter > 0 {
t.tracerProvidersCounter--
}
if t.tracerProvidersCounter == 0 {
if t.tracerProvider != nil {
// tracerProvider.ForceFlush SHOULD be invoked according to https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/sdk.md#forceflush
if err := t.tracerProvider.ForceFlush(context.Background()); err != nil {
logger.Error("forcing flush", zap.Error(err))
}
// tracerProvider.Shutdown MUST be invoked according to https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/sdk.md#shutdown
if err := t.tracerProvider.Shutdown(context.Background()); err != nil {
return fmt.Errorf("tracerProvider shutdown error: %w", err)
}
}
t.tracerProvider = nil
}
return nil
}