[Python-checkins] gh-59956: Fix Function Groupings in pystate.c (gh-101172)
ericsnowcurrently
webhook-mailer at python.org
Thu Jan 19 19:23:59 EST 2023
https://github.com/python/cpython/commit/f30c94024f305d7d0ebb34fdd0f422442cfb0047
commit: f30c94024f305d7d0ebb34fdd0f422442cfb0047
branch: main
author: Eric Snow <ericsnowcurrently at gmail.com>
committer: ericsnowcurrently <ericsnowcurrently at gmail.com>
date: 2023-01-19T17:23:53-07:00
summary:
gh-59956: Fix Function Groupings in pystate.c (gh-101172)
This is a follow-up to gh-101161. The objective is to make it easier to read Python/pystate.c by grouping the functions there in a consistent way. This exclusively involves moving code around and adding various kinds of comments.
https://github.com/python/cpython/issues/59956
files:
M Python/pystate.c
diff --git a/Python/pystate.c b/Python/pystate.c
index 756c1c73330d..464e5d63e4c4 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -41,19 +41,36 @@ extern "C" {
static void _PyThreadState_Delete(PyThreadState *tstate, int check_current);
-/* the current thread state */
+/****************************************/
+/* helpers for the current thread state */
+/****************************************/
+
+// API for the current thread state is further down.
+
+/* "current" means one of:
+ - bound to the current OS thread
+ - holds the GIL
+ */
+
+//-------------------------------------------------
+// a highly efficient lookup for the current thread
+//-------------------------------------------------
+
+/*
+ The stored thread state is set by PyThraedState_Swap().
+
+ For each of these functions, the GIL mus be held by the current thread.
+ */
static inline PyThreadState *
current_fast_get(_PyRuntimeState *runtime)
{
- // The GIL must be held by the current thread.
return (PyThreadState*)_Py_atomic_load_relaxed(&runtime->tstate_current);
}
static inline void
current_fast_set(_PyRuntimeState *runtime, PyThreadState *tstate)
{
- // The GIL must be held by the current thread.
assert(tstate != NULL);
_Py_atomic_store_relaxed(&runtime->tstate_current, (uintptr_t)tstate);
}
@@ -61,11 +78,20 @@ current_fast_set(_PyRuntimeState *runtime, PyThreadState *tstate)
static inline void
current_fast_clear(_PyRuntimeState *runtime)
{
- // The GIL must be held by the current thread.
_Py_atomic_store_relaxed(&runtime->tstate_current, (uintptr_t)NULL);
}
+//------------------------------------------------
+// the thread state bound to the current OS thread
+//------------------------------------------------
+
+/*
+ The stored thread state is set by bind_tstate() (AKA PyThreadState_Bind().
+
+ The GIL does no need to be held for these.
+ */
+
static int
current_tss_initialized(_PyRuntimeState *runtime)
{
@@ -148,6 +174,7 @@ current_tss_reinit(_PyRuntimeState *runtime)
}
#endif
+
static void
bind_tstate(PyThreadState *tstate)
{
@@ -213,6 +240,11 @@ unbind_tstate(PyThreadState *tstate)
tstate->_status = PyThreadState_UNBOUND;
}
+
+//----------------------------------------------
+// the thread state that currently holds the GIL
+//----------------------------------------------
+
/* This is not exported, as it is not reliable! It can only
ever be compared to the state for the *current* thread.
* If not equal, then it doesn't matter that the actual
@@ -234,7 +266,13 @@ holds_gil(PyThreadState *tstate)
}
-/* the global runtime */
+/****************************/
+/* the global runtime state */
+/****************************/
+
+//----------
+// lifecycle
+//----------
/* Suppress deprecation warning for PyBytesObject.ob_shash */
_Py_COMP_DIAG_PUSH
@@ -438,6 +476,16 @@ _PyRuntimeState_ReInitThreads(_PyRuntimeState *runtime)
#endif
+/*************************************/
+/* the per-interpreter runtime state */
+/*************************************/
+
+//----------
+// lifecycle
+//----------
+
+/* Calling this indicates that the runtime is ready to create interpreters. */
+
PyStatus
_PyInterpreterState_Enable(_PyRuntimeState *runtime)
{
@@ -464,6 +512,7 @@ _PyInterpreterState_Enable(_PyRuntimeState *runtime)
return _PyStatus_OK();
}
+
static PyInterpreterState *
alloc_interpreter(void)
{
@@ -798,19 +847,40 @@ _PyInterpreterState_DeleteExceptMain(_PyRuntimeState *runtime)
#endif
-PyInterpreterState *
-PyInterpreterState_Get(void)
+// Used by finalize_modules()
+void
+_PyInterpreterState_ClearModules(PyInterpreterState *interp)
{
- PyThreadState *tstate = current_fast_get(&_PyRuntime);
- _Py_EnsureTstateNotNULL(tstate);
- PyInterpreterState *interp = tstate->interp;
- if (interp == NULL) {
- Py_FatalError("no current interpreter");
+ if (!interp->modules_by_index) {
+ return;
+ }
+
+ Py_ssize_t i;
+ for (i = 0; i < PyList_GET_SIZE(interp->modules_by_index); i++) {
+ PyObject *m = PyList_GET_ITEM(interp->modules_by_index, i);
+ if (PyModule_Check(m)) {
+ /* cleanup the saved copy of module dicts */
+ PyModuleDef *md = PyModule_GetDef(m);
+ if (md) {
+ Py_CLEAR(md->m_base.m_copy);
+ }
+ }
+ }
+
+ /* Setting modules_by_index to NULL could be dangerous, so we
+ clear the list instead. */
+ if (PyList_SetSlice(interp->modules_by_index,
+ 0, PyList_GET_SIZE(interp->modules_by_index),
+ NULL)) {
+ PyErr_WriteUnraisable(interp->modules_by_index);
}
- return interp;
}
+//----------
+// accessors
+//----------
+
int64_t
PyInterpreterState_GetID(PyInterpreterState *interp)
{
@@ -822,41 +892,6 @@ PyInterpreterState_GetID(PyInterpreterState *interp)
}
-static PyInterpreterState *
-interp_look_up_id(_PyRuntimeState *runtime, int64_t requested_id)
-{
- PyInterpreterState *interp = runtime->interpreters.head;
- while (interp != NULL) {
- int64_t id = PyInterpreterState_GetID(interp);
- if (id < 0) {
- return NULL;
- }
- if (requested_id == id) {
- return interp;
- }
- interp = PyInterpreterState_Next(interp);
- }
- return NULL;
-}
-
-PyInterpreterState *
-_PyInterpreterState_LookUpID(int64_t requested_id)
-{
- PyInterpreterState *interp = NULL;
- if (requested_id >= 0) {
- _PyRuntimeState *runtime = &_PyRuntime;
- HEAD_LOCK(runtime);
- interp = interp_look_up_id(runtime, requested_id);
- HEAD_UNLOCK(runtime);
- }
- if (interp == NULL && !PyErr_Occurred()) {
- PyErr_Format(PyExc_RuntimeError,
- "unrecognized interpreter ID %lld", requested_id);
- }
- return interp;
-}
-
-
int
_PyInterpreterState_IDInitref(PyInterpreterState *interp)
{
@@ -945,6 +980,76 @@ PyInterpreterState_GetDict(PyInterpreterState *interp)
return interp->dict;
}
+
+//-----------------------------
+// look up an interpreter state
+//-----------------------------
+
+/* Return the interpreter associated with the current OS thread.
+
+ The GIL must be held.
+ */
+
+PyInterpreterState *
+PyInterpreterState_Get(void)
+{
+ PyThreadState *tstate = current_fast_get(&_PyRuntime);
+ _Py_EnsureTstateNotNULL(tstate);
+ PyInterpreterState *interp = tstate->interp;
+ if (interp == NULL) {
+ Py_FatalError("no current interpreter");
+ }
+ return interp;
+}
+
+
+static PyInterpreterState *
+interp_look_up_id(_PyRuntimeState *runtime, int64_t requested_id)
+{
+ PyInterpreterState *interp = runtime->interpreters.head;
+ while (interp != NULL) {
+ int64_t id = PyInterpreterState_GetID(interp);
+ if (id < 0) {
+ return NULL;
+ }
+ if (requested_id == id) {
+ return interp;
+ }
+ interp = PyInterpreterState_Next(interp);
+ }
+ return NULL;
+}
+
+/* Return the interpreter state with the given ID.
+
+ Fail with RuntimeError if the interpreter is not found. */
+
+PyInterpreterState *
+_PyInterpreterState_LookUpID(int64_t requested_id)
+{
+ PyInterpreterState *interp = NULL;
+ if (requested_id >= 0) {
+ _PyRuntimeState *runtime = &_PyRuntime;
+ HEAD_LOCK(runtime);
+ interp = interp_look_up_id(runtime, requested_id);
+ HEAD_UNLOCK(runtime);
+ }
+ if (interp == NULL && !PyErr_Occurred()) {
+ PyErr_Format(PyExc_RuntimeError,
+ "unrecognized interpreter ID %lld", requested_id);
+ }
+ return interp;
+}
+
+
+/********************************/
+/* the per-thread runtime state */
+/********************************/
+
+//----------
+// lifecycle
+//----------
+
/* Minimum size of data stack chunk */
#define DATA_STACK_CHUNK_SIZE (16*1024)
@@ -1106,140 +1211,6 @@ _PyThreadState_Init(PyThreadState *tstate)
Py_FatalError("_PyThreadState_Init() is for internal use only");
}
-void
-_PyThreadState_Bind(PyThreadState *tstate)
-{
- bind_tstate(tstate);
-}
-
-PyObject*
-PyState_FindModule(PyModuleDef* module)
-{
- Py_ssize_t index = module->m_base.m_index;
- PyInterpreterState *state = _PyInterpreterState_GET();
- PyObject *res;
- if (module->m_slots) {
- return NULL;
- }
- if (index == 0)
- return NULL;
- if (state->modules_by_index == NULL)
- return NULL;
- if (index >= PyList_GET_SIZE(state->modules_by_index))
- return NULL;
- res = PyList_GET_ITEM(state->modules_by_index, index);
- return res==Py_None ? NULL : res;
-}
-
-int
-_PyState_AddModule(PyThreadState *tstate, PyObject* module, PyModuleDef* def)
-{
- if (!def) {
- assert(_PyErr_Occurred(tstate));
- return -1;
- }
- if (def->m_slots) {
- _PyErr_SetString(tstate,
- PyExc_SystemError,
- "PyState_AddModule called on module with slots");
- return -1;
- }
-
- PyInterpreterState *interp = tstate->interp;
- if (!interp->modules_by_index) {
- interp->modules_by_index = PyList_New(0);
- if (!interp->modules_by_index) {
- return -1;
- }
- }
-
- while (PyList_GET_SIZE(interp->modules_by_index) <= def->m_base.m_index) {
- if (PyList_Append(interp->modules_by_index, Py_None) < 0) {
- return -1;
- }
- }
-
- return PyList_SetItem(interp->modules_by_index,
- def->m_base.m_index, Py_NewRef(module));
-}
-
-int
-PyState_AddModule(PyObject* module, PyModuleDef* def)
-{
- if (!def) {
- Py_FatalError("module definition is NULL");
- return -1;
- }
-
- PyThreadState *tstate = current_fast_get(&_PyRuntime);
- PyInterpreterState *interp = tstate->interp;
- Py_ssize_t index = def->m_base.m_index;
- if (interp->modules_by_index &&
- index < PyList_GET_SIZE(interp->modules_by_index) &&
- module == PyList_GET_ITEM(interp->modules_by_index, index))
- {
- _Py_FatalErrorFormat(__func__, "module %p already added", module);
- return -1;
- }
- return _PyState_AddModule(tstate, module, def);
-}
-
-int
-PyState_RemoveModule(PyModuleDef* def)
-{
- PyThreadState *tstate = current_fast_get(&_PyRuntime);
- PyInterpreterState *interp = tstate->interp;
-
- if (def->m_slots) {
- _PyErr_SetString(tstate,
- PyExc_SystemError,
- "PyState_RemoveModule called on module with slots");
- return -1;
- }
-
- Py_ssize_t index = def->m_base.m_index;
- if (index == 0) {
- Py_FatalError("invalid module index");
- }
- if (interp->modules_by_index == NULL) {
- Py_FatalError("Interpreters module-list not accessible.");
- }
- if (index > PyList_GET_SIZE(interp->modules_by_index)) {
- Py_FatalError("Module index out of bounds.");
- }
-
- return PyList_SetItem(interp->modules_by_index, index, Py_NewRef(Py_None));
-}
-
-// Used by finalize_modules()
-void
-_PyInterpreterState_ClearModules(PyInterpreterState *interp)
-{
- if (!interp->modules_by_index) {
- return;
- }
-
- Py_ssize_t i;
- for (i = 0; i < PyList_GET_SIZE(interp->modules_by_index); i++) {
- PyObject *m = PyList_GET_ITEM(interp->modules_by_index, i);
- if (PyModule_Check(m)) {
- /* cleanup the saved copy of module dicts */
- PyModuleDef *md = PyModule_GetDef(m);
- if (md) {
- Py_CLEAR(md->m_base.m_copy);
- }
- }
- }
-
- /* Setting modules_by_index to NULL could be dangerous, so we
- clear the list instead. */
- if (PyList_SetSlice(interp->modules_by_index,
- 0, PyList_GET_SIZE(interp->modules_by_index),
- NULL)) {
- PyErr_WriteUnraisable(interp->modules_by_index);
- }
-}
-
void
PyThreadState_Clear(PyThreadState *tstate)
{
@@ -1406,59 +1377,9 @@ _PyThreadState_DeleteExcept(_PyRuntimeState *runtime, PyThreadState *tstate)
}
-PyThreadState *
-_PyThreadState_UncheckedGet(void)
-{
- return current_fast_get(&_PyRuntime);
-}
-
-
-PyThreadState *
-PyThreadState_Get(void)
-{
- PyThreadState *tstate = current_fast_get(&_PyRuntime);
- _Py_EnsureTstateNotNULL(tstate);
- return tstate;
-}
-
-
-PyThreadState *
-_PyThreadState_Swap(_PyRuntimeState *runtime, PyThreadState *newts)
-{
- PyThreadState *oldts = current_fast_get(runtime);
-
- if (newts == NULL) {
- current_fast_clear(runtime);
- }
- else {
- current_fast_set(runtime, newts);
- }
- /* It should not be possible for more than one thread state
- to be used for a thread. Check this the best we can in debug
- builds.
- */
- // XXX The above isn't true when multiple interpreters are involved.
-#if defined(Py_DEBUG)
- if (newts && current_tss_initialized(runtime)) {
- /* This can be called from PyEval_RestoreThread(). Similar
- to it, we need to ensure errno doesn't change.
- */
- int err = errno;
- PyThreadState *check = current_tss_get(runtime);
- if (check && check->interp == newts->interp && check != newts) {
- Py_FatalError("Invalid thread state for this thread");
- }
- errno = err;
- }
-#endif
- return oldts;
-}
-
-PyThreadState *
-PyThreadState_Swap(PyThreadState *newts)
-{
- return _PyThreadState_Swap(&_PyRuntime, newts);
-}
+//----------
+// accessors
+//----------
/* An extension mechanism to store arbitrary additional per-thread state.
PyThreadState_GetDict() returns a dictionary that can be used to hold such
@@ -1523,6 +1444,10 @@ PyThreadState_GetID(PyThreadState *tstate)
}
+//----------
+// other API
+//----------
+
/* Asynchronously raise an exception in a thread.
Requested by Just van Rossum and Alex Martelli.
To prevent naive misuse, you must write your own extension
@@ -1531,6 +1456,8 @@ PyThreadState_GetID(PyThreadState *tstate)
match any known thread id). Can be called with exc=NULL to clear an
existing async exception. This raises no exceptions. */
+// XXX Move this to Python/ceval_gil.c?
+// XXX Deprecate this.
int
PyThreadState_SetAsyncExc(unsigned long id, PyObject *exc)
{
@@ -1568,8 +1495,79 @@ PyThreadState_SetAsyncExc(unsigned long id, PyObject *exc)
return 0;
}
-/* Routines for advanced debuggers, requested by David Beazley.
- Don't use unless you know what you are doing! */
+
+//---------------------------------
+// API for the current thread state
+//---------------------------------
+
+PyThreadState *
+_PyThreadState_UncheckedGet(void)
+{
+ return current_fast_get(&_PyRuntime);
+}
+
+
+PyThreadState *
+PyThreadState_Get(void)
+{
+ PyThreadState *tstate = current_fast_get(&_PyRuntime);
+ _Py_EnsureTstateNotNULL(tstate);
+ return tstate;
+}
+
+
+PyThreadState *
+_PyThreadState_Swap(_PyRuntimeState *runtime, PyThreadState *newts)
+{
+ PyThreadState *oldts = current_fast_get(runtime);
+
+ if (newts == NULL) {
+ current_fast_clear(runtime);
+ }
+ else {
+ current_fast_set(runtime, newts);
+ }
+ /* It should not be possible for more than one thread state
+ to be used for a thread. Check this the best we can in debug
+ builds.
+ */
+ // XXX The above isn't true when multiple interpreters are involved.
+#if defined(Py_DEBUG)
+ if (newts && current_tss_initialized(runtime)) {
+ /* This can be called from PyEval_RestoreThread(). Similar
+ to it, we need to ensure errno doesn't change.
+ */
+ int err = errno;
+ PyThreadState *check = current_tss_get(runtime);
+ if (check && check->interp == newts->interp && check != newts) {
+ Py_FatalError("Invalid thread state for this thread");
+ }
+ errno = err;
+ }
+#endif
+ return oldts;
+}
+
+PyThreadState *
+PyThreadState_Swap(PyThreadState *newts)
+{
+ return _PyThreadState_Swap(&_PyRuntime, newts);
+}
+
+
+void
+_PyThreadState_Bind(PyThreadState *tstate)
+{
+ bind_tstate(tstate);
+}
+
+
+/***********************************/
+/* routines for advanced debuggers */
+/***********************************/
+
+// (requested by David Beazley)
+// Don't use unless you know what you are doing!
PyInterpreterState *
PyInterpreterState_Head(void)
@@ -1598,6 +1596,11 @@ PyThreadState_Next(PyThreadState *tstate) {
return tstate->next;
}
+
+/********************************************/
+/* reporting execution state of all threads */
+/********************************************/
+
/* The implementation of sys._current_frames(). This is intended to be
called with the GIL held, as it will be when called via
sys._current_frames(). It's possible it would work fine even without
@@ -1659,6 +1662,11 @@ _PyThread_CurrentFrames(void)
return result;
}
+/* The implementation of sys._current_exceptions(). This is intended to be
+ called with the GIL held, as it will be when called via
+ sys._current_exceptions(). It's possible it would work fine even without
+ the GIL held, but haven't thought enough about that.
+*/
PyObject *
_PyThread_CurrentExceptions(void)
{
@@ -1718,7 +1726,114 @@ _PyThread_CurrentExceptions(void)
return result;
}
+
+/****************/
+/* module state */
+/****************/
+
+PyObject*
+PyState_FindModule(PyModuleDef* module)
+{
+ Py_ssize_t index = module->m_base.m_index;
+ PyInterpreterState *state = _PyInterpreterState_GET();
+ PyObject *res;
+ if (module->m_slots) {
+ return NULL;
+ }
+ if (index == 0)
+ return NULL;
+ if (state->modules_by_index == NULL)
+ return NULL;
+ if (index >= PyList_GET_SIZE(state->modules_by_index))
+ return NULL;
+ res = PyList_GET_ITEM(state->modules_by_index, index);
+ return res==Py_None ? NULL : res;
+}
+
+int
+_PyState_AddModule(PyThreadState *tstate, PyObject* module, PyModuleDef* def)
+{
+ if (!def) {
+ assert(_PyErr_Occurred(tstate));
+ return -1;
+ }
+ if (def->m_slots) {
+ _PyErr_SetString(tstate,
+ PyExc_SystemError,
+ "PyState_AddModule called on module with slots");
+ return -1;
+ }
+
+ PyInterpreterState *interp = tstate->interp;
+ if (!interp->modules_by_index) {
+ interp->modules_by_index = PyList_New(0);
+ if (!interp->modules_by_index) {
+ return -1;
+ }
+ }
+
+ while (PyList_GET_SIZE(interp->modules_by_index) <= def->m_base.m_index) {
+ if (PyList_Append(interp->modules_by_index, Py_None) < 0) {
+ return -1;
+ }
+ }
+
+ return PyList_SetItem(interp->modules_by_index,
+ def->m_base.m_index, Py_NewRef(module));
+}
+
+int
+PyState_AddModule(PyObject* module, PyModuleDef* def)
+{
+ if (!def) {
+ Py_FatalError("module definition is NULL");
+ return -1;
+ }
+
+ PyThreadState *tstate = current_fast_get(&_PyRuntime);
+ PyInterpreterState *interp = tstate->interp;
+ Py_ssize_t index = def->m_base.m_index;
+ if (interp->modules_by_index &&
+ index < PyList_GET_SIZE(interp->modules_by_index) &&
+ module == PyList_GET_ITEM(interp->modules_by_index, index))
+ {
+ _Py_FatalErrorFormat(__func__, "module %p already added", module);
+ return -1;
+ }
+ return _PyState_AddModule(tstate, module, def);
+}
+
+int
+PyState_RemoveModule(PyModuleDef* def)
+{
+ PyThreadState *tstate = current_fast_get(&_PyRuntime);
+ PyInterpreterState *interp = tstate->interp;
+
+ if (def->m_slots) {
+ _PyErr_SetString(tstate,
+ PyExc_SystemError,
+ "PyState_RemoveModule called on module with slots");
+ return -1;
+ }
+
+ Py_ssize_t index = def->m_base.m_index;
+ if (index == 0) {
+ Py_FatalError("invalid module index");
+ }
+ if (interp->modules_by_index == NULL) {
+ Py_FatalError("Interpreters module-list not accessible.");
+ }
+ if (index > PyList_GET_SIZE(interp->modules_by_index)) {
+ Py_FatalError("Module index out of bounds.");
+ }
+
+ return PyList_SetItem(interp->modules_by_index, index, Py_NewRef(Py_None));
+}
+
+
+/***********************************/
/* Python "auto thread state" API. */
+/***********************************/
/* Internal initialization/finalization functions called by
Py_Initialize/Py_FinalizeEx
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