fixup: context change reentrancy considerations

Signed-off-by: Todd Baert <todd.baert@dynatrace.com>

specification.json

@@ -1025,14 +1025,14 @@
                 {
                     "id": "Conditional Requirement 5.3.4.2",
                     "machine_id": "conditional_requirement_5_3_4_2",
-                    "content": "If the provider's `on context changed` function terminates normally, associated `PROVIDER_CONTEXT_CHANGED` handlers MUST run.",
+                    "content": "If the provider's `on context changed` function terminates normally, and no other invocations have yet to terminate, associated `PROVIDER_CONTEXT_CHANGED` handlers MUST run.",
                     "RFC 2119 keyword": "MUST",
                     "children": []
                 },
                 {
                     "id": "Conditional Requirement 5.3.4.3",
                     "machine_id": "conditional_requirement_5_3_4_3",
-                    "content": "If the provider's `on context changed` function terminates abnormally, associated `PROVIDER_ERROR` handlers MUST run.",
+                    "content": "If the provider's `on context changed` function terminates abnormally, and no other invocations have yet to terminate, associated `PROVIDER_ERROR` handlers MUST run.",
                     "RFC 2119 keyword": "MUST",
                     "children": []
                 }

specification/sections/05-events.md

@@ -202,18 +202,19 @@ see: [provider event types](../types.md#provider-events), [provider events](#51-
 
 ##### Conditional Requirement 5.3.4.2
 
-> If the provider's `on context changed` function terminates normally, associated `PROVIDER_CONTEXT_CHANGED` handlers **MUST** run.
+> If the provider's `on context changed` function terminates normally, and no other invocations have yet to terminate, associated `PROVIDER_CONTEXT_CHANGED` handlers **MUST** run.
 
 The implementation must run any `PROVIDER_CONTEXT_CHANGED` handlers associated with the provider after the provider has reconciled its state and returned from the `on context changed` function.
 The `PROVIDER_CONTEXT_CHANGED` is not emitted from the provider itself; the SDK implementation must run the `PROVIDER_CONTEXT_CHANGED` handlers if the `on context changed` function terminates normally.
-
+It's possible that the `on context changed` function is invoked simultaneously or in quick succession; in this case the SDK will only run the `PROVIDER_CONTEXT_CHANGED` handlers after all reentrant invocations have terminated, and the last to terminate was successful (terminated normally).
 see: [provider event types](../types.md#provider-events), [provider events](#51-provider-events), [provider context reconciliation](02-providers.md#26-provider-context-reconciliation)
 
 ##### Conditional Requirement 5.3.4.3
 
-> If the provider's `on context changed` function terminates abnormally, associated `PROVIDER_ERROR` handlers **MUST** run.
+> If the provider's `on context changed` function terminates abnormally, and no other invocations have yet to terminate, associated `PROVIDER_ERROR` handlers **MUST** run.
 
 The `PROVIDER_ERROR` is not emitted from the provider itself; the SDK implementation must run the `PROVIDER_ERROR` handlers if the `on context changed` throws or otherwise signals an error.
+It's possible that the `on context changed` function is invoked simultaneously or in quick succession; in this case the SDK will only run the `PROVIDER_ERROR` handlers after all reentrant invocations have terminated, and the last to terminate was unsuccessful (terminated abnormally).
 
 see: [provider event types](../types.md#provider-events), [provider events](#51-provider-events), [provider context reconciliation](02-providers.md#26-provider-context-reconciliation)