[DEBUG] print modifed flags (#53243)

* print modifed flags

* fix ref, opt print

* fix default getter

* fix ut

paddle/fluid/pybind/global_value_getter_setter.cc

@@ -64,6 +64,11 @@ class PYBIND11_HIDDEN GlobalVarGetterSetterRegistry {
     return [&]() -> py::object { return py::cast(var); };
   }
 
+  template <typename T>
+  static Getter CreateDefaultValueGetter(const T &var) {
+    return [=]() -> py::object { return py::cast(var); };
+  }
+
   template <typename T>
   static Setter CreateSetter(T *var) {
     return [var](const py::object &obj) { *var = py::cast<T>(obj); };
@@ -71,14 +76,23 @@ class PYBIND11_HIDDEN GlobalVarGetterSetterRegistry {
 
  private:
   struct VarInfo {
-    VarInfo(bool is_public, const Getter &getter)
-        : is_public(is_public), getter(getter) {}
+    VarInfo(bool is_public, const Getter &getter, const Getter &default_getter)
+        : is_public(is_public),
+          getter(getter),
+          default_getter(default_getter) {}
 
-    VarInfo(bool is_public, const Getter &getter, const Setter &setter)
-        : is_public(is_public), getter(getter), setter(setter) {}
+    VarInfo(bool is_public,
+            const Getter &getter,
+            const Getter &default_getter,
+            const Setter &setter)
+        : is_public(is_public),
+          getter(getter),
+          default_getter(default_getter),
+          setter(setter) {}
 
     const bool is_public;
     const Getter getter;
+    const Getter default_getter;
     const Setter setter;
   };
 
@@ -87,7 +101,10 @@ class PYBIND11_HIDDEN GlobalVarGetterSetterRegistry {
 
   static GlobalVarGetterSetterRegistry *MutableInstance() { return &instance_; }
 
-  void Register(const std::string &name, bool is_public, const Getter &getter) {
+  void Register(const std::string &name,
+                bool is_public,
+                const Getter &getter,
+                const Getter &default_getter) {
     PADDLE_ENFORCE_EQ(
         HasGetterMethod(name),
         false,
@@ -96,12 +113,13 @@ class PYBIND11_HIDDEN GlobalVarGetterSetterRegistry {
     PADDLE_ENFORCE_NOT_NULL(getter,
                             platform::errors::InvalidArgument(
                                 "Getter of %s should not be null", name));
-    var_infos_.insert({name, VarInfo(is_public, getter)});
+    var_infos_.insert({name, VarInfo(is_public, getter, default_getter)});
   }
 
   void Register(const std::string &name,
                 bool is_public,
                 const Getter &getter,
+                const Getter &default_getter,
                 const Setter &setter) {
     PADDLE_ENFORCE_EQ(
         HasGetterMethod(name),
@@ -122,7 +140,8 @@ class PYBIND11_HIDDEN GlobalVarGetterSetterRegistry {
     PADDLE_ENFORCE_NOT_NULL(setter,
                             platform::errors::InvalidArgument(
                                 "Setter of %s should not be null", name));
-    var_infos_.insert({name, VarInfo(is_public, getter, setter)});
+    var_infos_.insert(
+        {name, VarInfo(is_public, getter, default_getter, setter)});
   }
 
   const Getter &GetterMethod(const std::string &name) const {
@@ -133,6 +152,14 @@ class PYBIND11_HIDDEN GlobalVarGetterSetterRegistry {
     return var_infos_.at(name).getter;
   }
 
+  const Getter &DefaultGetterMethod(const std::string &name) const {
+    PADDLE_ENFORCE_EQ(
+        HasGetterMethod(name),
+        true,
+        platform::errors::NotFound("Cannot find global variable %s", name));
+    return var_infos_.at(name).default_getter;
+  }
+
   py::object GetOrReturnDefaultValue(const std::string &name,
                                      const py::object &default_value) const {
     if (HasGetterMethod(name)) {
@@ -142,6 +169,14 @@ class PYBIND11_HIDDEN GlobalVarGetterSetterRegistry {
     }
   }
 
+  py::object GetDefaultValue(const std::string &name) const {
+    if (HasGetterMethod(name)) {
+      return DefaultGetterMethod(name)();
+    } else {
+      return py::cast(Py_None);
+    }
+  }
+
   py::object Get(const std::string &name) const { return GetterMethod(name)(); }
 
   const Setter &SetterMethod(const std::string &name) const {
@@ -198,6 +233,9 @@ void BindGlobalValueGetterSetter(pybind11::module *module) {
       .def("__contains__", &GlobalVarGetterSetterRegistry::HasGetterMethod)
       .def("keys", &GlobalVarGetterSetterRegistry::Keys)
       .def("is_public", &GlobalVarGetterSetterRegistry::IsPublic)
+      .def("get_default",
+           &GlobalVarGetterSetterRegistry::GetDefaultValue,
+           py::arg("key"))
       .def("get",
            &GlobalVarGetterSetterRegistry::GetOrReturnDefaultValue,
            py::arg("key"),
@@ -212,9 +250,11 @@ void BindGlobalValueGetterSetter(pybind11::module *module) {
 #define REGISTER_PUBLIC_GLOBAL_VAR(var)                                \
   do {                                                                 \
     auto *instance = GlobalVarGetterSetterRegistry::MutableInstance(); \
-    instance->Register(#var,                                               \
+    instance->Register(                                                \
+        #var,                                                          \
         /*is_public=*/true,                                            \
         GlobalVarGetterSetterRegistry::CreateGetter(var),              \
+        GlobalVarGetterSetterRegistry::CreateDefaultValueGetter(var),  \
         GlobalVarGetterSetterRegistry::CreateSetter(&var));            \
   } while (0)
 
@@ -225,18 +265,25 @@ struct RegisterGetterSetterVisitor {
       : name_(name), is_writable_(is_writable), value_ptr_(value_ptr) {}
 
   template <typename T>
-  void operator()(const T &) const {
+  void operator()(const T &default_value) const {
     auto &value = *static_cast<T *>(value_ptr_);
     auto *instance = GlobalVarGetterSetterRegistry::MutableInstance();
     bool is_public = is_writable_;  // currently, all writable vars are public
     if (is_writable_) {
-      instance->Register(name_,
+      instance->Register(
+          name_,
           is_public,
           GlobalVarGetterSetterRegistry::CreateGetter(value),
+          GlobalVarGetterSetterRegistry::CreateDefaultValueGetter(
+              default_value),
           GlobalVarGetterSetterRegistry::CreateSetter(&value));
     } else {
       instance->Register(
-          name_, is_public, GlobalVarGetterSetterRegistry::CreateGetter(value));
+          name_,
+          is_public,
+          GlobalVarGetterSetterRegistry::CreateGetter(value),
+          GlobalVarGetterSetterRegistry::CreateDefaultValueGetter(
+              default_value));
     }
   }
 

python/paddle/distributed/parallel.py

@@ -14,9 +14,10 @@
 
 import itertools
 import os
+import sys
 import time
 import warnings
-from collections import OrderedDict
+from collections import OrderedDict, namedtuple
 from contextlib import contextmanager
 from multiprocessing import Manager  # noqa: F401
 from multiprocessing import Process  # noqa: F401
@@ -905,6 +906,31 @@ def _check_var_exists(var_name):
         )
 
 
+def _get_modified_flags():
+    ret = []
+    FLAGS = namedtuple('FLAGS', ['name', 'current_value', 'default_value'])
+    global_flags = core.globals()
+    for key in global_flags.keys():
+        value = global_flags.get(key)
+        default_value = global_flags.get_default(key)
+        if not value == default_value:
+            ret.append(FLAGS(key, value, default_value))
+    return ret
+
+
+def _print_modified_flags(modified_flags):
+    if len(modified_flags) > 0:
+        sys.stderr.write(
+            "======================= Modified FLAGS detected =======================\n"
+        )
+        for flag in modified_flags:
+            sys.stderr.write(str(flag))
+            sys.stderr.write("\n")
+        sys.stderr.write(
+            "=======================================================================\n"
+        )
+
+
 def init_parallel_env():
     """
 
@@ -967,6 +993,9 @@ def init_parallel_env():
 
     """
 
+    modified_flags = _get_modified_flags()
+    _print_modified_flags(modified_flags)
+
     # 0. get env & check world size
     global _global_parallel_env
     # when call init_parallel_env, need update `_global_parallel_env`