Support threads in the script debugger

* This implementation adds threads on the side of the client (script debugger).
* Some functions of the debugger are optimized.
* The profile is also now thread safe using atomics.
* The editor can switch between multiple threads when debugging.

This PR adds threaded support for the script language debugger. Every thread has its own thread local data and it will connect to the debugger using multiple thread IDs.
This means that, now, the editor can receive multiple threads entering debug mode at the same time.

1 files changed, 32 insertions, 22 deletions

diff --git a/modules/gdscript/gdscript_editor.cpp b/modules/gdscript/gdscript_editor.cpp
index 2a7346940b..47ceee3943 100644
--- a/modules/gdscript/gdscript_editor.cpp
+++ b/modules/gdscript/gdscript_editor.cpp
@@ -233,6 +233,10 @@ Script *GDScriptLanguage::create_script() const {
 
 /* DEBUGGER FUNCTIONS */
 
+thread_local int GDScriptLanguage::_debug_parse_err_line = -1;
+thread_local String GDScriptLanguage::_debug_parse_err_file;
+thread_local String GDScriptLanguage::_debug_error;
+
 bool GDScriptLanguage::debug_break_parse(const String &p_file, int p_line, const String &p_error) {
 	// break because of parse error
 
@@ -241,6 +245,9 @@ bool GDScriptLanguage::debug_break_parse(const String &p_file, int p_line, const
 		_debug_parse_err_file = p_file;
 		_debug_error = p_error;
 		EngineDebugger::get_script_debugger()->debug(this, false, true);
+		// Because this is thread local, clear the memory afterwards.
+		_debug_parse_err_file = String();
+		_debug_error = String();
 		return true;
 	} else {
 		return false;
@@ -248,12 +255,15 @@ bool GDScriptLanguage::debug_break_parse(const String &p_file, int p_line, const
 }
 
 bool GDScriptLanguage::debug_break(const String &p_error, bool p_allow_continue) {
-	if (EngineDebugger::is_active() && Thread::get_caller_id() == Thread::get_main_id()) {
+	if (EngineDebugger::is_active()) {
 		_debug_parse_err_line = -1;
 		_debug_parse_err_file = "";
 		_debug_error = p_error;
 		bool is_error_breakpoint = p_error != "Breakpoint";
 		EngineDebugger::get_script_debugger()->debug(this, p_allow_continue, is_error_breakpoint);
+		// Because this is thread local, clear the memory afterwards.
+		_debug_parse_err_file = String();
+		_debug_error = String();
 		return true;
 	} else {
 		return false;
@@ -269,7 +279,7 @@ int GDScriptLanguage::debug_get_stack_level_count() const {
 		return 1;
 	}
 
-	return _debug_call_stack_pos;
+	return _call_stack.stack_pos;
 }
 
 int GDScriptLanguage::debug_get_stack_level_line(int p_level) const {
@@ -277,11 +287,11 @@ int GDScriptLanguage::debug_get_stack_level_line(int p_level) const {
 		return _debug_parse_err_line;
 	}
 
-	ERR_FAIL_INDEX_V(p_level, _debug_call_stack_pos, -1);
+	ERR_FAIL_INDEX_V(p_level, _call_stack.stack_pos, -1);
 
-	int l = _debug_call_stack_pos - p_level - 1;
+	int l = _call_stack.stack_pos - p_level - 1;
 
-	return *(_call_stack[l].line);
+	return *(_call_stack.levels[l].line);
 }
 
 String GDScriptLanguage::debug_get_stack_level_function(int p_level) const {
@@ -289,9 +299,9 @@ String GDScriptLanguage::debug_get_stack_level_function(int p_level) const {
 		return "";
 	}
 
-	ERR_FAIL_INDEX_V(p_level, _debug_call_stack_pos, "");
-	int l = _debug_call_stack_pos - p_level - 1;
-	return _call_stack[l].function->get_name();
+	ERR_FAIL_INDEX_V(p_level, _call_stack.stack_pos, "");
+	int l = _call_stack.stack_pos - p_level - 1;
+	return _call_stack.levels[l].function->get_name();
 }
 
 String GDScriptLanguage::debug_get_stack_level_source(int p_level) const {
@@ -299,9 +309,9 @@ String GDScriptLanguage::debug_get_stack_level_source(int p_level) const {
 		return _debug_parse_err_file;
 	}
 
-	ERR_FAIL_INDEX_V(p_level, _debug_call_stack_pos, "");
-	int l = _debug_call_stack_pos - p_level - 1;
-	return _call_stack[l].function->get_source();
+	ERR_FAIL_INDEX_V(p_level, _call_stack.stack_pos, "");
+	int l = _call_stack.stack_pos - p_level - 1;
+	return _call_stack.levels[l].function->get_source();
 }
 
 void GDScriptLanguage::debug_get_stack_level_locals(int p_level, List<String> *p_locals, List<Variant> *p_values, int p_max_subitems, int p_max_depth) {
@@ -309,17 +319,17 @@ void GDScriptLanguage::debug_get_stack_level_locals(int p_level, List<String> *p
 		return;
 	}
 
-	ERR_FAIL_INDEX(p_level, _debug_call_stack_pos);
-	int l = _debug_call_stack_pos - p_level - 1;
+	ERR_FAIL_INDEX(p_level, _call_stack.stack_pos);
+	int l = _call_stack.stack_pos - p_level - 1;
 
-	GDScriptFunction *f = _call_stack[l].function;
+	GDScriptFunction *f = _call_stack.levels[l].function;
 
 	List<Pair<StringName, int>> locals;
 
-	f->debug_get_stack_member_state(*_call_stack[l].line, &locals);
+	f->debug_get_stack_member_state(*_call_stack.levels[l].line, &locals);
 	for (const Pair<StringName, int> &E : locals) {
 		p_locals->push_back(E.first);
-		p_values->push_back(_call_stack[l].stack[E.second]);
+		p_values->push_back(_call_stack.levels[l].stack[E.second]);
 	}
 }
 
@@ -328,10 +338,10 @@ void GDScriptLanguage::debug_get_stack_level_members(int p_level, List<String> *
 		return;
 	}
 
-	ERR_FAIL_INDEX(p_level, _debug_call_stack_pos);
-	int l = _debug_call_stack_pos - p_level - 1;
+	ERR_FAIL_INDEX(p_level, _call_stack.stack_pos);
+	int l = _call_stack.stack_pos - p_level - 1;
 
-	GDScriptInstance *instance = _call_stack[l].instance;
+	GDScriptInstance *instance = _call_stack.levels[l].instance;
 
 	if (!instance) {
 		return;
@@ -353,10 +363,10 @@ ScriptInstance *GDScriptLanguage::debug_get_stack_level_instance(int p_level) {
 		return nullptr;
 	}
 
-	ERR_FAIL_INDEX_V(p_level, _debug_call_stack_pos, nullptr);
+	ERR_FAIL_INDEX_V(p_level, _call_stack.stack_pos, nullptr);
 
-	int l = _debug_call_stack_pos - p_level - 1;
-	ScriptInstance *instance = _call_stack[l].instance;
+	int l = _call_stack.stack_pos - p_level - 1;
+	ScriptInstance *instance = _call_stack.levels[l].instance;
 
 	return instance;
 }