Skip to content

Commit

Permalink
Changes necessary for hot reload to work
Browse files Browse the repository at this point in the history
  • Loading branch information
dsnopek committed Sep 13, 2023
1 parent 6caf490 commit dee91d4
Show file tree
Hide file tree
Showing 7 changed files with 61 additions and 0 deletions.
2 changes: 2 additions & 0 deletions gdextension/gdextension_interface.h
Original file line number Diff line number Diff line change
Expand Up @@ -266,6 +266,7 @@ typedef void (*GDExtensionClassReference)(GDExtensionClassInstancePtr p_instance
typedef void (*GDExtensionClassUnreference)(GDExtensionClassInstancePtr p_instance);
typedef void (*GDExtensionClassCallVirtual)(GDExtensionClassInstancePtr p_instance, const GDExtensionConstTypePtr *p_args, GDExtensionTypePtr r_ret);
typedef GDExtensionObjectPtr (*GDExtensionClassCreateInstance)(void *p_userdata);
typedef GDExtensionClassInstancePtr (*GDExtensionClassRecreateInstance)(void *p_userdata, GDExtensionObjectPtr p_object);
typedef void (*GDExtensionClassFreeInstance)(void *p_userdata, GDExtensionClassInstancePtr p_instance);
typedef GDExtensionClassCallVirtual (*GDExtensionClassGetVirtual)(void *p_userdata, GDExtensionConstStringNamePtr p_name);

Expand Down Expand Up @@ -306,6 +307,7 @@ typedef struct {
GDExtensionClassUnreference unreference_func;
GDExtensionClassCreateInstance create_instance_func; // (Default) constructor; mandatory. If the class is not instantiable, consider making it virtual or abstract.
GDExtensionClassFreeInstance free_instance_func; // Destructor; mandatory.
GDExtensionClassRecreateInstance recreate_instance_func;
GDExtensionClassGetVirtual get_virtual_func; // Queries a virtual function by name and returns a callback to invoke the requested virtual function.
GDExtensionClassGetRID get_rid_func;
void *class_userdata; // Per-class user data, later accessible in instance bindings.
Expand Down
24 changes: 24 additions & 0 deletions include/godot_cpp/classes/wrapped.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,15 @@ class Wrapped {
friend void postinitialize_handler(Wrapped *);

protected:
#ifdef HOT_RELOAD_ENABLED
struct RecreateInstance {
GDExtensionClassInstancePtr wrapper;
GDExtensionObjectPtr owner;
RecreateInstance *next;
};
inline static RecreateInstance *recreate_instance = nullptr;
#endif

virtual const StringName *_get_extension_class_name() const; // This is needed to retrieve the class name before the godot object has its _extension and _extension_instance members assigned.
virtual const GDExtensionInstanceBindingCallbacks *_get_bindings_callbacks() const = 0;

Expand Down Expand Up @@ -106,6 +115,17 @@ void free_c_property_list(GDExtensionPropertyInfo *plist);

} // namespace godot

#ifdef HOT_RELOAD_ENABLED
#define _GDCLASS_RECREATE(m_class, m_inherits) \
m_class *new_instance = (m_class *)memalloc(sizeof(m_class)); \
Wrapped::RecreateInstance recreate_data = { new_instance, obj, Wrapped::recreate_instance }; \
Wrapped::recreate_instance = &recreate_data; \
memnew_placement(new_instance, m_class); \
return new_instance;
#else
#define _GDCLASS_RECREATE(m_class, m_inherits) return nullptr;
#endif

// Use this on top of your own classes.
// Note: the trail of `***` is to keep sane diffs in PRs, because clang-format otherwise moves every `\` which makes
// every line of the macro different
Expand Down Expand Up @@ -193,6 +213,10 @@ public:
return new_object->_owner; \
} \
\
static GDExtensionClassInstancePtr recreate(void *data, GDExtensionObjectPtr obj) { \
_GDCLASS_RECREATE(m_class, m_inherits); \
} \
\
static void notification_bind(GDExtensionClassInstancePtr p_instance, int32_t p_what, GDExtensionBool p_reversed) { \
if (p_instance && m_class::_get_notification()) { \
if (m_class::_get_notification() != m_inherits::_get_notification()) { \
Expand Down
1 change: 1 addition & 0 deletions include/godot_cpp/core/class_db.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -193,6 +193,7 @@ void ClassDB::_register_class(bool p_virtual, bool p_exposed) {
nullptr, // GDExtensionClassUnreference unreference_func;
T::create, // GDExtensionClassCreateInstance create_instance_func; /* this one is mandatory */
T::free, // GDExtensionClassFreeInstance free_instance_func; /* this one is mandatory */
T::recreate, // GDExtensionClassRecreateInstance recreate_instance_func;
&ClassDB::get_virtual_func, // GDExtensionClassGetVirtual get_virtual_func;
nullptr, // GDExtensionClassGetRID get_rid;
(void *)&T::get_class_static(), // void *class_userdata;
Expand Down
17 changes: 17 additions & 0 deletions src/classes/wrapped.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,23 @@ void Wrapped::_postinitialize() {
}

Wrapped::Wrapped(const StringName p_godot_class) {
#ifdef HOT_RELOAD_ENABLED
if (unlikely(Wrapped::recreate_instance)) {
RecreateInstance *recreate_data = Wrapped::recreate_instance;
RecreateInstance *previous = nullptr;
while (recreate_data) {
if (recreate_data->wrapper == this) {
_owner = recreate_data->owner;
if (previous) {
previous->next = recreate_data->next;
}
return;
}
previous = recreate_data;
recreate_data = recreate_data->next;
}
}
#endif
_owner = godot::internal::gdextension_interface_classdb_construct_object(reinterpret_cast<GDExtensionConstStringNamePtr>(p_godot_class._native_ptr()));
}

Expand Down
3 changes: 3 additions & 0 deletions src/core/class_db.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -354,6 +354,9 @@ void ClassDB::deinitialize(GDExtensionInitializationLevel p_level) {
for (auto method : cl.method_map) {
memdelete(method.second);
}

classes.erase(*i);
class_register_order.erase((i + 1).base());
}
}

Expand Down
11 changes: 11 additions & 0 deletions tools/godotcpp.py
Original file line number Diff line number Diff line change
Expand Up @@ -175,6 +175,14 @@ def options(opts, env):
)
)

opts.Add(
BoolVariable(
key="use_hot_reload",
help="Enable the extra accounting required to support hot reload.",
default=(env.get("target", "template_debug") != "template_release"),
)
)

# Add platform options
for pl in platforms:
tool = Tool(pl, toolpath=["tools"])
Expand Down Expand Up @@ -231,6 +239,9 @@ def generate(env):

print("Building for architecture " + env["arch"] + " on platform " + env["platform"])

if env["use_hot_reload"]:
env.Append(CPPDEFINES=["HOT_RELOAD_ENABLED"])

tool = Tool(env["platform"], toolpath=["tools"])

if tool is None or not tool.exists(env):
Expand Down
3 changes: 3 additions & 0 deletions tools/linux.py
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,9 @@ def generate(env):
if env["use_llvm"]:
clang.generate(env)
clangxx.generate(env)
elif env["use_hot_reload"]:
# Required for extensions to truly unload.
env.Append(CXXFLAGS=["-fno-gnu-unique"])

env.Append(CCFLAGS=["-fPIC", "-Wwrite-strings"])
env.Append(LINKFLAGS=["-Wl,-R,'$$ORIGIN'"])
Expand Down

0 comments on commit dee91d4

Please sign in to comment.