Add normative language for logging API/SDK concurrency

CHANGELOG.md

@@ -25,6 +25,8 @@ release.
 
 - Add optional `Exception` parameter to Emit LogRecord.
   ([#4824](https://github.com/open-telemetry/opentelemetry-specification/pull/4824))
+- Add normative language to the Logging API/SDK spec concurrency requirements.
+  ([#4885](https://github.com/open-telemetry/opentelemetry-specification/pull/4885))
 
 ### Baggage
 

specification/logs/api.md

@@ -169,9 +169,11 @@ provide it.
 For languages which support concurrent execution the Logs APIs provide
 specific guarantees and safeties.
 
-**LoggerProvider** - all methods are safe to be called concurrently.
+**LoggerProvider** - all methods MUST be documented that implementations need to
+be safe for concurrent use by default.
 
-**Logger** - all methods are safe to be called concurrently.
+**Logger** - all methods MUST be documented that implementations need to
+be safe for concurrent use by default.
 
 ## Ergonomic API
 

specification/logs/sdk.md

@@ -41,6 +41,7 @@ weight: 3
     + [Export](#export)
     + [ForceFlush](#forceflush-2)
     + [Shutdown](#shutdown-1)
+- [Concurrency requirements](#concurrency-requirements)
 
 <!-- tocstop -->
 
@@ -643,3 +644,18 @@ and the destination is unavailable). [OpenTelemetry SDK](../overview.md#sdk)
 authors MAY decide if they want to make the shutdown timeout configurable.
 
 - [OTEP0150 Logging Library SDK Prototype Specification](../../oteps/logs/0150-logging-library-sdk.md)
+
+## Concurrency requirements
+
+**Status**: [Stable](../document-status.md)
+
+For languages which support concurrent execution the Logging SDKs provide
+specific guarantees and safeties.
+
+**LoggerProvider** - Logger creation, `ForceFlush` and `Shutdown` MUST be safe
+to be called concurrently.
+
+**Logger** - all methods MUST be safe to be called concurrently.
+
+**LogRecordExporter** - `ForceFlush` and `Shutdown` MUST be safe to be called
+concurrently.