Use BatchSpanProcessor for console writer

Author: friendlymatthew

Cargo.toml

@@ -40,7 +40,7 @@ async-trait = "0.1.88"
 insta = "1.42.1"
 opentelemetry_sdk = { version = "0.29", default-features = false, features = ["testing"] }
 regex = "1.11.1"
-tokio = {version = "1.44.1", features = ["test-util"] }
+tokio = { version = "1.44.1", features = ["test-util"] }
 ulid = "1.2.0"
 
 [features]

src/config.rs

@@ -400,4 +400,19 @@ mod tests {
             super::ConsoleOptions::default().with_min_log_level(tracing::Level::DEBUG);
         assert_eq!(console_options.min_log_level, tracing::Level::DEBUG);
     }
+
+    #[tokio::test]
+    async fn test_console_with_tokio_sleep() {
+        // token is invalid, so exports will fail, but it was a necessary part of reproducing the issue
+        let shutdown_handler = crate::configure()
+            .local()
+            .with_token("abc123")
+            .install_panic_handler()
+            .finish()
+            .unwrap();
+
+        tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;
+
+        shutdown_handler.shutdown().ok();
+    }
 }

src/lib.rs

@@ -106,9 +106,7 @@ use bridges::tracing::LogfireTracingPendingSpanNotSentLayer;
 use config::get_base_url_from_token;
 use opentelemetry::trace::TracerProvider;
 use opentelemetry_sdk::metrics::{PeriodicReader, SdkMeterProvider};
-use opentelemetry_sdk::trace::{
-    BatchConfigBuilder, BatchSpanProcessor, SimpleSpanProcessor, SpanProcessor,
-};
+use opentelemetry_sdk::trace::{BatchConfigBuilder, BatchSpanProcessor, SpanProcessor};
 use opentelemetry_sdk::trace::{SdkTracerProvider, Tracer};
 use thiserror::Error;
 use tracing::Subscriber;
@@ -551,9 +549,15 @@ impl LogfireConfigBuilder {
             .map(Arc::new);
 
         if let Some(console_writer) = console_writer.clone() {
-            tracer_provider_builder = tracer_provider_builder.with_span_processor(
-                SimpleSpanProcessor::new(SimpleConsoleSpanExporter::new(console_writer)),
-            );
+            // Use BatchSpanProcessor instead of SimpleSpanProcessor to avoid deadlocks.
+            // BatchSpanProcessor uses a dedicated background thread, making it safer in async environments.
+            tracer_provider_builder =
+                tracer_provider_builder.with_span_processor(BatchSpanProcessor::new(
+                    SimpleConsoleSpanExporter::new(console_writer),
+                    BatchConfigBuilder::default()
+                        .with_scheduled_delay(Duration::ZERO)
+                        .build(),
+                ));
         }
 
         for span_processor in self.additional_span_processors {

tests/test_basic_exports.rs

@@ -1032,7 +1032,7 @@ fn test_basic_span() {
                         "code.lineno",
                     ),
                     value: I64(
-                        694,
+                        698,
                     ),
                 },
                 KeyValue {