bpo-33608: Factor out a private, per-interpreter _Py_AddPendingCall(). (GH-11617)
This involves moving the global "pending calls" state to PyInterpreterState.
https://bugs.python.org/issue33608
diff --git a/Python/ceval.c b/Python/ceval.c
index 439f4f1..4e139ce 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -96,61 +96,61 @@
/* This can set eval_breaker to 0 even though gil_drop_request became
1. We believe this is all right because the eval loop will release
the GIL eventually anyway. */
-#define COMPUTE_EVAL_BREAKER() \
+#define COMPUTE_EVAL_BREAKER(interp) \
_Py_atomic_store_relaxed( \
- &_PyRuntime.ceval.eval_breaker, \
+ &interp->ceval.eval_breaker, \
GIL_REQUEST | \
_Py_atomic_load_relaxed(&_PyRuntime.ceval.signals_pending) | \
- _Py_atomic_load_relaxed(&_PyRuntime.ceval.pending.calls_to_do) | \
- _PyRuntime.ceval.pending.async_exc)
+ _Py_atomic_load_relaxed(&interp->ceval.pending.calls_to_do) | \
+ interp->ceval.pending.async_exc)
-#define SET_GIL_DROP_REQUEST() \
+#define SET_GIL_DROP_REQUEST(interp) \
do { \
_Py_atomic_store_relaxed(&_PyRuntime.ceval.gil_drop_request, 1); \
- _Py_atomic_store_relaxed(&_PyRuntime.ceval.eval_breaker, 1); \
+ _Py_atomic_store_relaxed(&interp->ceval.eval_breaker, 1); \
} while (0)
-#define RESET_GIL_DROP_REQUEST() \
+#define RESET_GIL_DROP_REQUEST(interp) \
do { \
_Py_atomic_store_relaxed(&_PyRuntime.ceval.gil_drop_request, 0); \
- COMPUTE_EVAL_BREAKER(); \
+ COMPUTE_EVAL_BREAKER(interp); \
} while (0)
/* Pending calls are only modified under pending_lock */
-#define SIGNAL_PENDING_CALLS() \
+#define SIGNAL_PENDING_CALLS(interp) \
do { \
- _Py_atomic_store_relaxed(&_PyRuntime.ceval.pending.calls_to_do, 1); \
- _Py_atomic_store_relaxed(&_PyRuntime.ceval.eval_breaker, 1); \
+ _Py_atomic_store_relaxed(&interp->ceval.pending.calls_to_do, 1); \
+ _Py_atomic_store_relaxed(&interp->ceval.eval_breaker, 1); \
} while (0)
-#define UNSIGNAL_PENDING_CALLS() \
+#define UNSIGNAL_PENDING_CALLS(interp) \
do { \
- _Py_atomic_store_relaxed(&_PyRuntime.ceval.pending.calls_to_do, 0); \
- COMPUTE_EVAL_BREAKER(); \
+ _Py_atomic_store_relaxed(&interp->ceval.pending.calls_to_do, 0); \
+ COMPUTE_EVAL_BREAKER(interp); \
} while (0)
#define SIGNAL_PENDING_SIGNALS() \
do { \
_Py_atomic_store_relaxed(&_PyRuntime.ceval.signals_pending, 1); \
- _Py_atomic_store_relaxed(&_PyRuntime.ceval.eval_breaker, 1); \
+ _Py_atomic_store_relaxed(&_PyRuntime.interpreters.main->ceval.eval_breaker, 1); \
} while (0)
#define UNSIGNAL_PENDING_SIGNALS() \
do { \
_Py_atomic_store_relaxed(&_PyRuntime.ceval.signals_pending, 0); \
- COMPUTE_EVAL_BREAKER(); \
+ COMPUTE_EVAL_BREAKER(_PyRuntime.interpreters.main); \
} while (0)
-#define SIGNAL_ASYNC_EXC() \
+#define SIGNAL_ASYNC_EXC(interp) \
do { \
- _PyRuntime.ceval.pending.async_exc = 1; \
- _Py_atomic_store_relaxed(&_PyRuntime.ceval.eval_breaker, 1); \
+ interp->ceval.pending.async_exc = 1; \
+ _Py_atomic_store_relaxed(&interp->ceval.eval_breaker, 1); \
} while (0)
-#define UNSIGNAL_ASYNC_EXC() \
+#define UNSIGNAL_ASYNC_EXC(interp) \
do { \
- _PyRuntime.ceval.pending.async_exc = 0; \
- COMPUTE_EVAL_BREAKER(); \
+ interp->ceval.pending.async_exc = 0; \
+ COMPUTE_EVAL_BREAKER(interp); \
} while (0)
@@ -174,9 +174,6 @@
PyThread_init_thread();
create_gil();
take_gil(_PyThreadState_GET());
- _PyRuntime.ceval.pending.main_thread = PyThread_get_thread_ident();
- if (!_PyRuntime.ceval.pending.lock)
- _PyRuntime.ceval.pending.lock = PyThread_allocate_lock();
}
void
@@ -243,9 +240,11 @@
if (!gil_created())
return;
recreate_gil();
- _PyRuntime.ceval.pending.lock = PyThread_allocate_lock();
+ // This will be reset in make_pending_calls() below.
+ current_tstate->interp->ceval.pending.lock = NULL;
+
take_gil(current_tstate);
- _PyRuntime.ceval.pending.main_thread = PyThread_get_thread_ident();
+ _PyRuntime.main_thread = PyThread_get_thread_ident();
/* Destroy all threads except the current one */
_PyThreadState_DeleteExcept(current_tstate);
@@ -255,9 +254,9 @@
raised. */
void
-_PyEval_SignalAsyncExc(void)
+_PyEval_SignalAsyncExc(PyInterpreterState *interp)
{
- SIGNAL_ASYNC_EXC();
+ SIGNAL_ASYNC_EXC(interp);
}
PyThreadState *
@@ -323,17 +322,58 @@
SIGNAL_PENDING_SIGNALS();
}
+static int
+_add_pending_call(PyInterpreterState *interp, unsigned long thread_id, int (*func)(void *), void *arg)
+{
+ int i = interp->ceval.pending.last;
+ int j = (i + 1) % NPENDINGCALLS;
+ if (j == interp->ceval.pending.first) {
+ return -1; /* Queue full */
+ }
+ interp->ceval.pending.calls[i].thread_id = thread_id;
+ interp->ceval.pending.calls[i].func = func;
+ interp->ceval.pending.calls[i].arg = arg;
+ interp->ceval.pending.last = j;
+ return 0;
+}
+
+/* pop one item off the queue while holding the lock */
+static void
+_pop_pending_call(PyInterpreterState *interp, int (**func)(void *), void **arg)
+{
+ int i = interp->ceval.pending.first;
+ if (i == interp->ceval.pending.last) {
+ return; /* Queue empty */
+ }
+
+ *func = interp->ceval.pending.calls[i].func;
+ *arg = interp->ceval.pending.calls[i].arg;
+ interp->ceval.pending.first = (i + 1) % NPENDINGCALLS;
+
+ unsigned long thread_id = interp->ceval.pending.calls[i].thread_id;
+ if (thread_id && PyThread_get_thread_ident() != thread_id) {
+ // Thread mismatch, so move it to the end of the list
+ // and start over.
+ _Py_AddPendingCall(interp, thread_id, *func, *arg);
+ return;
+ }
+}
+
+int
+Py_AddPendingCall(int (*func)(void *), void *arg)
+{
+ PyInterpreterState *interp = _PyRuntime.interpreters.main;
+ return _Py_AddPendingCall(interp, _PyRuntime.main_thread, func, arg);
+}
+
/* This implementation is thread-safe. It allows
scheduling to be made from any thread, and even from an executing
callback.
*/
int
-Py_AddPendingCall(int (*func)(void *), void *arg)
+_Py_AddPendingCall(PyInterpreterState *interp, unsigned long thread_id, int (*func)(void *), void *arg)
{
- int i, j, result=0;
- PyThread_type_lock lock = _PyRuntime.ceval.pending.lock;
-
/* try a few times for the lock. Since this mechanism is used
* for signal handling (on the main thread), there is a (slim)
* chance that a signal is delivered on the same thread while we
@@ -345,7 +385,9 @@
* We also check for lock being NULL, in the unlikely case that
* this function is called before any bytecode evaluation takes place.
*/
+ PyThread_type_lock lock = interp->ceval.pending.lock;
if (lock != NULL) {
+ int i;
for (i = 0; i<100; i++) {
if (PyThread_acquire_lock(lock, NOWAIT_LOCK))
break;
@@ -354,17 +396,21 @@
return -1;
}
- i = _PyRuntime.ceval.pending.last;
- j = (i + 1) % NPENDINGCALLS;
- if (j == _PyRuntime.ceval.pending.first) {
- result = -1; /* Queue full */
- } else {
- _PyRuntime.ceval.pending.calls[i].func = func;
- _PyRuntime.ceval.pending.calls[i].arg = arg;
- _PyRuntime.ceval.pending.last = j;
+ int result = -1;
+ if (interp->finalizing) {
+ PyObject *exc, *val, *tb;
+ PyErr_Fetch(&exc, &val, &tb);
+ PyErr_SetString(PyExc_SystemError, "Py_AddPendingCall: cannot add pending calls (interpreter shutting down)");
+ PyErr_Print();
+ PyErr_Restore(exc, val, tb);
+ goto done;
}
+
+ result = _add_pending_call(interp, thread_id, func, arg);
/* signal main loop */
- SIGNAL_PENDING_CALLS();
+ SIGNAL_PENDING_CALLS(interp);
+
+done:
if (lock != NULL)
PyThread_release_lock(lock);
return result;
@@ -374,9 +420,7 @@
handle_signals(void)
{
/* Only handle signals on main thread. */
- if (_PyRuntime.ceval.pending.main_thread &&
- PyThread_get_thread_ident() != _PyRuntime.ceval.pending.main_thread)
- {
+ if (PyThread_get_thread_ident() != _PyRuntime.main_thread) {
return 0;
}
/*
@@ -396,17 +440,10 @@
}
static int
-make_pending_calls(void)
+make_pending_calls(PyInterpreterState *interp)
{
static int busy = 0;
- /* only service pending calls on main thread */
- if (_PyRuntime.ceval.pending.main_thread &&
- PyThread_get_thread_ident() != _PyRuntime.ceval.pending.main_thread)
- {
- return 0;
- }
-
/* don't perform recursive pending calls */
if (busy) {
return 0;
@@ -414,13 +451,13 @@
busy = 1;
/* unsignal before starting to call callbacks, so that any callback
added in-between re-signals */
- UNSIGNAL_PENDING_CALLS();
+ UNSIGNAL_PENDING_CALLS(interp);
int res = 0;
- if (!_PyRuntime.ceval.pending.lock) {
+ if (!interp->ceval.pending.lock) {
/* initial allocation of the lock */
- _PyRuntime.ceval.pending.lock = PyThread_allocate_lock();
- if (_PyRuntime.ceval.pending.lock == NULL) {
+ interp->ceval.pending.lock = PyThread_allocate_lock();
+ if (interp->ceval.pending.lock == NULL) {
res = -1;
goto error;
}
@@ -428,24 +465,18 @@
/* perform a bounded number of calls, in case of recursion */
for (int i=0; i<NPENDINGCALLS; i++) {
- int j;
- int (*func)(void *);
+ int (*func)(void *) = NULL;
void *arg = NULL;
/* pop one item off the queue while holding the lock */
- PyThread_acquire_lock(_PyRuntime.ceval.pending.lock, WAIT_LOCK);
- j = _PyRuntime.ceval.pending.first;
- if (j == _PyRuntime.ceval.pending.last) {
- func = NULL; /* Queue empty */
- } else {
- func = _PyRuntime.ceval.pending.calls[j].func;
- arg = _PyRuntime.ceval.pending.calls[j].arg;
- _PyRuntime.ceval.pending.first = (j + 1) % NPENDINGCALLS;
- }
- PyThread_release_lock(_PyRuntime.ceval.pending.lock);
+ PyThread_acquire_lock(interp->ceval.pending.lock, WAIT_LOCK);
+ _pop_pending_call(interp, &func, &arg);
+ PyThread_release_lock(interp->ceval.pending.lock);
+
/* having released the lock, perform the callback */
- if (func == NULL)
+ if (func == NULL) {
break;
+ }
res = func(arg);
if (res) {
goto error;
@@ -457,10 +488,18 @@
error:
busy = 0;
- SIGNAL_PENDING_CALLS();
+ SIGNAL_PENDING_CALLS(interp); /* We're not done yet */
return res;
}
+int
+_Py_MakePendingCalls(PyInterpreterState *interp)
+{
+ assert(PyGILState_Check());
+
+ return make_pending_calls(interp);
+}
+
/* Py_MakePendingCalls() is a simple wrapper for the sake
of backward-compatibility. */
int
@@ -475,12 +514,8 @@
return res;
}
- res = make_pending_calls();
- if (res != 0) {
- return res;
- }
-
- return 0;
+ PyInterpreterState *interp = _PyRuntime.interpreters.main;
+ return make_pending_calls(interp);
}
/* The interpreter's recursion limit */
@@ -687,7 +722,7 @@
#define DISPATCH() \
{ \
- if (!_Py_atomic_load_relaxed(&_PyRuntime.ceval.eval_breaker)) { \
+ if (!_Py_atomic_load_relaxed(&tstate->interp->ceval.eval_breaker)) { \
FAST_DISPATCH(); \
} \
continue; \
@@ -989,7 +1024,7 @@
async I/O handler); see Py_AddPendingCall() and
Py_MakePendingCalls() above. */
- if (_Py_atomic_load_relaxed(&_PyRuntime.ceval.eval_breaker)) {
+ if (_Py_atomic_load_relaxed(&(tstate->interp->ceval.eval_breaker))) {
opcode = _Py_OPCODE(*next_instr);
if (opcode == SETUP_FINALLY ||
opcode == SETUP_WITH ||
@@ -1022,9 +1057,9 @@
}
}
if (_Py_atomic_load_relaxed(
- &_PyRuntime.ceval.pending.calls_to_do))
+ &(tstate->interp->ceval.pending.calls_to_do)))
{
- if (make_pending_calls() != 0) {
+ if (_Py_MakePendingCalls(tstate->interp) != 0) {
goto error;
}
}
@@ -1056,7 +1091,7 @@
if (tstate->async_exc != NULL) {
PyObject *exc = tstate->async_exc;
tstate->async_exc = NULL;
- UNSIGNAL_ASYNC_EXC();
+ UNSIGNAL_ASYNC_EXC(tstate->interp);
PyErr_SetNone(exc);
Py_DECREF(exc);
goto error;