Add Sync bound on the LogExporter and SpanExporter traits (#1240)

Author: FSMaxB

opentelemetry-sdk/CHANGELOG.md

@@ -13,6 +13,7 @@
   is now the API crate. [#1226](https://github.com/open-telemetry/opentelemetry-rust/pull/1226)
 - Add in memory span exporter [#1216](https://github.com/open-telemetry/opentelemetry-rust/pull/1216)
 - Add in memory log exporter [#1231](https://github.com/open-telemetry/opentelemetry-rust/pull/1231)
+- Add `Sync` bound to the `SpanExporter` and `LogExporter` traits [#1240](https://github.com/open-telemetry/opentelemetry-rust/pull/1240)
 
 ### Removed
 

opentelemetry-sdk/src/export/logs/mod.rs

@@ -11,7 +11,7 @@ use std::{borrow::Cow, fmt::Debug};
 
 /// `LogExporter` defines the interface that log exporters should implement.
 #[async_trait]
-pub trait LogExporter: Send + Debug {
+pub trait LogExporter: Send + Sync + Debug {
     /// Exports a batch of [`LogData`].
     async fn export(&mut self, batch: Vec<LogData>) -> LogResult<()>;
     /// Shuts down the exporter.

opentelemetry-sdk/src/export/trace.rs

@@ -16,7 +16,7 @@ pub type ExportResult = Result<(), TraceError>;
 /// The goal of the interface is to minimize burden of implementation for
 /// protocol-dependent telemetry exporters. The protocol exporter is expected to
 /// be primarily a simple telemetry data encoder and transmitter.
-pub trait SpanExporter: Send + Debug {
+pub trait SpanExporter: Send + Sync + Debug {
     /// Exports a batch of readable spans. Protocol exporters that will
     /// implement this function are typically expected to serialize and transmit
     /// the data to the destination.

opentelemetry-sdk/src/testing/trace/mod.rs

@@ -11,13 +11,13 @@ use crate::{
     InstrumentationLibrary,
 };
 use async_trait::async_trait;
+use crossbeam_channel::{unbounded, Receiver, SendError, Sender};
 use futures_util::future::BoxFuture;
 pub use opentelemetry::testing::trace::TestSpan;
 use opentelemetry::trace::{
     SpanContext, SpanId, SpanKind, Status, TraceFlags, TraceId, TraceState,
 };
 use std::fmt::{Display, Formatter};
-use std::sync::mpsc::{channel, Receiver, Sender};
 
 pub fn new_test_export_span_data() -> SpanData {
     let config = Config::default();
@@ -70,8 +70,8 @@ impl SpanExporter for TestSpanExporter {
 }
 
 pub fn new_test_exporter() -> (TestSpanExporter, Receiver<SpanData>, Receiver<()>) {
-    let (tx_export, rx_export) = channel();
-    let (tx_shutdown, rx_shutdown) = channel();
+    let (tx_export, rx_export) = unbounded();
+    let (tx_shutdown, rx_shutdown) = unbounded();
     let exporter = TestSpanExporter {
         tx_export,
         tx_shutdown,
@@ -142,8 +142,8 @@ impl<T> From<tokio::sync::mpsc::error::SendError<T>> for TestExportError {
     }
 }
 
-impl<T> From<std::sync::mpsc::SendError<T>> for TestExportError {
-    fn from(err: std::sync::mpsc::SendError<T>) -> Self {
+impl<T> From<crossbeam_channel::SendError<T>> for TestExportError {
+    fn from(err: SendError<T>) -> Self {
         TestExportError(err.to_string())
     }
 }