Fix graph not detecting errors when GraphExecutor::run fails (baidu#110)

* In extreme cases such as when the thread pool is full, GraphExecutor::run
may return an error. Previously, the graph did not detect these errors,
which could cause other nodes to not execute without reporting any error.
* Also update .gitignore to exclude bazel build artifacts and module files

Author: skyan

.gitignore

@@ -1,2 +1,10 @@
 .idea/
-cmake-build-*
+cmake-build-*
+bazel-bin
+bazel-genfiles
+bazel-out
+bazel-testlogs
+bazel-workspace
+bazel-babylon
+MODULE.bazel
+MODULE.bazel.lock

src/babylon/anyflow/executor.cpp

@@ -52,18 +52,16 @@ Closure ThreadPoolGraphExecutor::create_closure() noexcept {
 
 int ThreadPoolGraphExecutor::run(GraphVertex* vertex,
                                  GraphVertexClosure&& closure) noexcept {
-  _executor.submit([captured_closure = ::std::move(closure), vertex]() mutable {
+  return _executor.submit([captured_closure = ::std::move(closure), vertex]() mutable {
     vertex->run(::std::move(captured_closure));
   });
-  return 0;
 }
 
 int ThreadPoolGraphExecutor::run(ClosureContext* closure,
                                  Closure::Callback* callback) noexcept {
-  _executor.submit([=] {
+  return _executor.submit([=] {
     closure->run(callback);
   });
-  return 0;
 }
 
 } // namespace anyflow

src/babylon/anyflow/vertex.cpp

@@ -230,8 +230,13 @@ void GraphVertex::invoke(VertexStack& runnable_vertexes) noexcept {
       _runnable_vertexes = &runnable_vertexes;
       run(GraphVertexClosure(*_closure, *this));
     } else {
-      _builder->graph().executor().run(this,
-                                       GraphVertexClosure(*_closure, *this));
+      GraphVertexClosure closure(*_closure, *this);
+      if (ABSL_PREDICT_FALSE(0 != _builder->graph().executor().run(this,
+                                                                   ::std::move(closure)))) {
+        // executor.run 返回失败时，closure 可能已被 move，需要重新创建来标记错误
+        GraphVertexClosure error_closure(*_closure, *this);
+        error_closure.done(-1);
+      }
     }
   } else {
     // 不允许平凡模式情况下，不设置_runnable_vertexes