gh-108634: PyInterpreterState_New() no longer calls Py_FatalError() (#108748)

pycore_create_interpreter() now returns a status, rather than
calling Py_FatalError().

* PyInterpreterState_New() now calls Py_ExitStatusException() instead
  of calling Py_FatalError() directly.
* Replace Py_FatalError() with PyStatus in init_interpreter() and
  _PyObject_InitState().
* _PyErr_SetFromPyStatus() now raises RuntimeError, instead of
  ValueError. It can now call PyErr_NoMemory(), raise MemoryError,
  if it detects _PyStatus_NO_MEMORY() error message.

1 files changed, 62 insertions, 35 deletions

diff --git a/Python/pystate.c b/Python/pystate.c
index 4a8808f..46ea2c4 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -426,13 +426,11 @@ init_runtime(_PyRuntimeState *runtime,
              Py_ssize_t unicode_next_index,
              PyThread_type_lock locks[NUMLOCKS])
 {
-    if (runtime->_initialized) {
-        Py_FatalError("runtime already initialized");
-    }
-    assert(!runtime->preinitializing &&
-           !runtime->preinitialized &&
-           !runtime->core_initialized &&
-           !runtime->initialized);
+    assert(!runtime->preinitializing);
+    assert(!runtime->preinitialized);
+    assert(!runtime->core_initialized);
+    assert(!runtime->initialized);
+    assert(!runtime->_initialized);
 
     runtime->open_code_hook = open_code_hook;
     runtime->open_code_userdata = open_code_userdata;
@@ -476,6 +474,7 @@ _PyRuntimeState_Init(_PyRuntimeState *runtime)
         // Py_Initialize() must be running again.
         // Reset to _PyRuntimeState_INIT.
         memcpy(runtime, &initial, sizeof(*runtime));
+        assert(!runtime->_initialized);
     }
 
     if (gilstate_tss_init(runtime) != 0) {
@@ -647,14 +646,14 @@ free_interpreter(PyInterpreterState *interp)
    main interpreter.  We fix those fields here, in addition
    to the other dynamically initialized fields.
   */
-static void
+static PyStatus
 init_interpreter(PyInterpreterState *interp,
                  _PyRuntimeState *runtime, int64_t id,
                  PyInterpreterState *next,
                  PyThread_type_lock pending_lock)
 {
     if (interp->_initialized) {
-        Py_FatalError("interpreter already initialized");
+        return _PyStatus_ERR("interpreter already initialized");
     }
 
     assert(runtime != NULL);
@@ -675,7 +674,10 @@ init_interpreter(PyInterpreterState *interp,
         memcpy(&interp->obmalloc.pools.used, temp, sizeof(temp));
     }
 
-    _PyObject_InitState(interp);
+    PyStatus status = _PyObject_InitState(interp);
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
 
     _PyEval_InitState(interp, pending_lock);
     _PyGC_InitState(&interp->gc);
@@ -701,42 +703,44 @@ init_interpreter(PyInterpreterState *interp,
     }
     interp->f_opcode_trace_set = false;
     interp->_initialized = 1;
+    return _PyStatus_OK();
 }
 
-PyInterpreterState *
-PyInterpreterState_New(void)
+
+PyStatus
+_PyInterpreterState_New(PyThreadState *tstate, PyInterpreterState **pinterp)
 {
-    PyInterpreterState *interp;
+    *pinterp = NULL;
+
+    // Don't get runtime from tstate since tstate can be NULL
     _PyRuntimeState *runtime = &_PyRuntime;
-    PyThreadState *tstate = current_fast_get(runtime);
 
-    /* tstate is NULL when Py_InitializeFromConfig() calls
-       PyInterpreterState_New() to create the main interpreter. */
-    if (_PySys_Audit(tstate, "cpython.PyInterpreterState_New", NULL) < 0) {
-        return NULL;
+    // tstate is NULL when pycore_create_interpreter() calls
+    // _PyInterpreterState_New() to create the main interpreter.
+    if (tstate != NULL) {
+        if (_PySys_Audit(tstate, "cpython.PyInterpreterState_New", NULL) < 0) {
+            return _PyStatus_ERR("sys.audit failed");
+        }
     }
 
     PyThread_type_lock pending_lock = PyThread_allocate_lock();
     if (pending_lock == NULL) {
-        if (tstate != NULL) {
-            _PyErr_NoMemory(tstate);
-        }
-        return NULL;
+        return _PyStatus_NO_MEMORY();
     }
 
-    /* Don't get runtime from tstate since tstate can be NULL. */
-    struct pyinterpreters *interpreters = &runtime->interpreters;
-
     /* We completely serialize creation of multiple interpreters, since
        it simplifies things here and blocking concurrent calls isn't a problem.
        Regardless, we must fully block subinterpreter creation until
        after the main interpreter is created. */
     HEAD_LOCK(runtime);
 
+    struct pyinterpreters *interpreters = &runtime->interpreters;
     int64_t id = interpreters->next_id;
     interpreters->next_id += 1;
 
     // Allocate the interpreter and add it to the runtime state.
+    PyInterpreterState *interp;
+    PyStatus status;
     PyInterpreterState *old_head = interpreters->head;
     if (old_head == NULL) {
         // We are creating the main interpreter.
@@ -755,36 +759,59 @@ PyInterpreterState_New(void)
 
         interp = alloc_interpreter();
         if (interp == NULL) {
+            status = _PyStatus_NO_MEMORY();
             goto error;
         }
         // Set to _PyInterpreterState_INIT.
-        memcpy(interp, &initial._main_interpreter,
-               sizeof(*interp));
+        memcpy(interp, &initial._main_interpreter, sizeof(*interp));
 
         if (id < 0) {
             /* overflow or Py_Initialize() not called yet! */
-            if (tstate != NULL) {
-                _PyErr_SetString(tstate, PyExc_RuntimeError,
-                                 "failed to get an interpreter ID");
-            }
+            status = _PyStatus_ERR("failed to get an interpreter ID");
             goto error;
         }
     }
     interpreters->head = interp;
 
-    init_interpreter(interp, runtime, id, old_head, pending_lock);
+    status = init_interpreter(interp, runtime,
+                              id, old_head, pending_lock);
+    if (_PyStatus_EXCEPTION(status)) {
+        goto error;
+    }
+    pending_lock = NULL;
 
     HEAD_UNLOCK(runtime);
-    return interp;
+
+    assert(interp != NULL);
+    *pinterp = interp;
+    return _PyStatus_OK();
 
 error:
     HEAD_UNLOCK(runtime);
 
-    PyThread_free_lock(pending_lock);
+    if (pending_lock != NULL) {
+        PyThread_free_lock(pending_lock);
+    }
     if (interp != NULL) {
         free_interpreter(interp);
     }
-    return NULL;
+    return status;
+}
+
+
+PyInterpreterState *
+PyInterpreterState_New(void)
+{
+    // tstate can be NULL
+    PyThreadState *tstate = current_fast_get(&_PyRuntime);
+
+    PyInterpreterState *interp;
+    PyStatus status = _PyInterpreterState_New(tstate, &interp);
+    if (_PyStatus_EXCEPTION(status)) {
+        Py_ExitStatusException(status);
+    }
+    assert(interp != NULL);
+    return interp;
 }