Comments and format

include/grpc++/impl/codegen/server_context.h

@@ -105,7 +105,15 @@ class ServerContext {
 
   bool IsCancelled() const;
 
-  // Best-effort API to cancel the call from the server.
+  // Cancel the Call from the server. This is a best-effort API and depending on
+  // when this is called, the Call may still appear successful to the client.
+  // For example, if called on a separate thread, it might race with the
+  // server handler which might return success to the client before TryCancel()
+  // was called.
+  //
+  // It is the caller's responsibility to prevent such races and ensure that the
+  // serverhandler returns Status::CANCELLED if TryCancel() is called (unless
+  // the serverhandler is already returning an error code)
   void TryCancel() const;
 
   const std::multimap<grpc::string_ref, grpc::string_ref>& client_metadata() {

test/cpp/end2end/end2end_test.cc

@@ -797,8 +797,6 @@ TEST_P(End2endServerTryCancelTest, BidiStreamServerCancelAfter) {
   TestBidiStreamServerCancel(CANCEL_AFTER_PROCESSING, 5);
 }
 
-// =====
-
 TEST_P(End2endTest, RequestStreamOneRequest) {
   ResetStub();
   EchoRequest request;