Fix building with SIMPLE_THREADS=1

dtool/src/dtoolbase/dtoolbase.cxx

@@ -62,4 +62,12 @@ default_thread_consider_yield() {
 void (*global_thread_yield)() = default_thread_yield;
 void (*global_thread_consider_yield)() = default_thread_consider_yield;
 
+#ifdef HAVE_PYTHON
+static PyThreadState *
+default_thread_state_swap(PyThreadState *state) {
+  return nullptr;
+}
+PyThreadState *(*global_thread_state_swap)(PyThreadState *tstate) = default_thread_state_swap;
+#endif  // HAVE_PYTHON
+
 #endif  // HAVE_THREADS && SIMPLE_THREADS

dtool/src/dtoolbase/dtoolbase_cc.h

@@ -233,6 +233,15 @@ INLINE void thread_consider_yield() {
   (*global_thread_consider_yield)();
 }
 
+#ifdef HAVE_PYTHON
+typedef struct _ts PyThreadState;
+extern EXPCL_DTOOL_DTOOLBASE PyThreadState *(*global_thread_state_swap)(PyThreadState *tstate);
+
+INLINE PyThreadState *thread_state_swap(PyThreadState *tstate) {
+  return (*global_thread_state_swap)(tstate);
+}
+#endif  // HAVE_PYTHON
+
 #else
 
 INLINE void thread_yield() {

dtool/src/interrogatedb/py_panda.cxx

@@ -752,6 +752,11 @@ PyObject *Dtool_PyModuleInitHelper(LibraryDef *defs[], const char *modulename) {
     ExecutionEnvironment::shadow_environment_variable("MAIN_DIR", main_dir.to_os_specific());
     PyErr_Clear();
     initialized_main_dir = true;
+
+    // Also, while we are at it, initialize the thread swap hook.
+#if defined(HAVE_THREADS) && defined(SIMPLE_THREADS)
+    global_thread_state_swap = PyThreadState_Swap;
+#endif
   }
 
   PyModule_AddIntConstant(module, "Dtool_PyNativeInterface", 1);

dtool/src/parser-inc/Python.h

@@ -28,7 +28,7 @@ typedef _typeobject PyTypeObject;
 typedef struct {} PyStringObject;
 typedef struct {} PyUnicodeObject;
 
-class PyThreadState;
+typedef struct _ts PyThreadState;
 typedef int Py_ssize_t;
 typedef struct bufferinfo Py_buffer;
 

panda/src/pipeline/threadSimpleImpl.I

@@ -51,14 +51,6 @@ is_threading_supported() {
   return true;
 }
 
-/**
- *
- */
-INLINE bool ThreadSimpleImpl::
-is_true_threads() {
-  return (is_os_threads != 0);
-}
-
 /**
  *
  */

panda/src/pipeline/threadSimpleImpl.cxx

@@ -141,8 +141,8 @@ start(ThreadPriority priority, bool joinable) {
 
 #ifdef HAVE_PYTHON
   // Query the current Python thread state.
-  _python_state = PyThreadState_Swap(nullptr);
-  PyThreadState_Swap(_python_state);
+  _python_state = thread_state_swap(nullptr);
+  thread_state_swap(_python_state);
 #endif  // HAVE_PYTHON
 
   init_thread_context(_context, _stack, _stack_size, st_begin_thread, this);
@@ -201,6 +201,14 @@ prepare_for_exit() {
   manager->prepare_for_exit();
 }
 
+/**
+ *
+ */
+bool ThreadSimpleImpl::
+is_true_threads() {
+  return (is_os_threads != 0);
+}
+
 /**
  *
  */
@@ -238,7 +246,7 @@ st_begin_thread(void *data) {
 void ThreadSimpleImpl::
 begin_thread() {
 #ifdef HAVE_PYTHON
-  PyThreadState_Swap(_python_state);
+  thread_state_swap(_python_state);
 #endif  // HAVE_PYTHON
 
 #ifdef HAVE_POSIX_THREADS

panda/src/pipeline/threadSimpleImpl.h

@@ -63,7 +63,7 @@ public:
 
   INLINE static void bind_thread(Thread *thread);
   INLINE static bool is_threading_supported();
-  INLINE static bool is_true_threads();
+  static bool is_true_threads();
   INLINE static bool is_simple_threads();
   INLINE static void sleep(double seconds);
   INLINE static void yield();

panda/src/pipeline/threadSimpleManager.cxx

@@ -237,7 +237,7 @@ next_context() {
 
 #ifdef HAVE_PYTHON
   // Save the current Python thread state.
-  _current_thread->_python_state = PyThreadState_Swap(nullptr);
+  _current_thread->_python_state = thread_state_swap(nullptr);
 #endif  // HAVE_PYTHON
 
 #ifdef DO_PSTATS
@@ -258,7 +258,7 @@ next_context() {
 #endif  // DO_PSTATS
 
 #ifdef HAVE_PYTHON
-  PyThreadState_Swap(_current_thread->_python_state);
+  thread_state_swap(_current_thread->_python_state);
 #endif  // HAVE_PYTHON
 }
 
@@ -470,16 +470,6 @@ init_pointers() {
     _pointers_initialized = true;
     _global_ptr = new ThreadSimpleManager;
     Thread::get_main_thread();
-
-#ifdef HAVE_PYTHON
-    // Ensure that the Python threading system is initialized and ready to go.
-
-#if PY_VERSION_HEX >= 0x03020000
-    Py_Initialize();
-#endif
-
-    PyEval_InitThreads();
-#endif
   }
 }