Optimize span_processor_with_async_runtime to use read locks for shutdown operations

Co-authored-by: lalitb <[email protected]>

Author: Copilot

opentelemetry-sdk/src/logs/in_memory_exporter.rs

@@ -132,6 +132,7 @@ impl InMemoryLogExporterBuilder {
 
     /// If set, the records will not be [`InMemoryLogExporter::reset`] on shutdown.
     #[cfg(test)]
+    #[allow(dead_code)]
     pub(crate) fn keep_records_on_shutdown(self) -> Self {
         Self {
             reset_on_shutdown: false,

opentelemetry-sdk/src/logs/logger_provider.rs

@@ -607,8 +607,8 @@ mod tests {
         tracer.in_span("test-span", |cx| {
             let ambient_ctxt = cx.span().span_context().clone();
             let explicit_ctxt = TraceContext {
-                trace_id: TraceId::from_u128(13),
-                span_id: SpanId::from_u64(14),
+                trace_id: TraceId::from_bytes([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 13]),
+                span_id: SpanId::from_bytes([0, 0, 0, 0, 0, 0, 0, 14]),
                 trace_flags: None,
             };
 

opentelemetry-sdk/src/trace/span_processor_with_async_runtime.rs

@@ -191,9 +191,6 @@ struct BatchSpanProcessorInternal<E, R> {
     export_tasks: FuturesUnordered<BoxFuture<'static, OTelSdkResult>>,
     runtime: R,
     config: BatchConfig,
-    // TODO: Redesign the `SpanExporter` trait to use immutable references (`&self`)
-    // for all methods. This would allow us to remove the `RwLock` and just use `Arc<E>`,
-    // similar to how `crate::logs::LogExporter` is implemented.
     exporter: Arc<RwLock<E>>,
 }
 
@@ -306,7 +303,7 @@ impl<E: SpanExporter + 'static, R: RuntimeChannel> BatchSpanProcessorInternal<E,
             // Stream has terminated or processor is shutdown, return to finish execution.
             BatchMessage::Shutdown(ch) => {
                 self.flush(Some(ch)).await;
-                let _ = self.exporter.write().await.shutdown();
+                let _ = self.exporter.read().await.shutdown();
                 return false;
             }
             // propagate the resource