Add threads.mutex member to PyInterpreState

Author: rruuaanng

Include/internal/pycore_interp.h

@@ -139,6 +139,8 @@ struct _is {
            or the size specified by the THREAD_STACK_SIZE macro. */
         /* Used in Python/thread.c. */
         size_t stacksize;
+        /* The mutex lock of the current executing thread. */
+        PyMutex mutex;
     } threads;
 
     /* Reference to the _PyRuntime global variable. This field exists

Include/internal/pycore_pystate.h

@@ -263,6 +263,11 @@ extern int _PyOS_InterruptOccurred(PyThreadState *tstate);
 #define HEAD_UNLOCK(runtime) \
     PyMutex_Unlock(&(runtime)->interpreters.mutex)
 
+#define INTERP_THREAD_LOCK(interpstate) \
+    PyMutex_LockFlags(&(interpstate)->threads.mutex, _Py_LOCK_DONT_DETACH)
+#define INTERP_THREAD_UNLOCK(interpstate) \
+    PyMutex_Unlock(&(interpstate)->threads.mutex)
+
 // Get the configuration of the current interpreter.
 // The caller must hold the GIL.
 // Export for test_peg_generator.