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_xxsubinterpretersmodule.c
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2648 lines (2327 loc) · 67.3 KB
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/* interpreters module */
/* low-level access to interpreter primitives */
#ifndef Py_BUILD_CORE_BUILTIN
# define Py_BUILD_CORE_MODULE 1
#endif
#include "Python.h"
#include "pycore_frame.h"
#include "pycore_pystate.h" // _PyThreadState_GET()
#include "pycore_interpreteridobject.h"
static char *
_copy_raw_string(PyObject *strobj)
{
const char *str = PyUnicode_AsUTF8(strobj);
if (str == NULL) {
return NULL;
}
char *copied = PyMem_Malloc(strlen(str)+1);
if (copied == NULL) {
PyErr_NoMemory();
return NULL;
}
strcpy(copied, str);
return copied;
}
static PyInterpreterState *
_get_current(void)
{
// PyInterpreterState_Get() aborts if lookup fails, so don't need
// to check the result for NULL.
return PyInterpreterState_Get();
}
/* data-sharing-specific code ***********************************************/
struct _sharednsitem {
char *name;
_PyCrossInterpreterData data;
};
static void _sharednsitem_clear(struct _sharednsitem *); // forward
static int
_sharednsitem_init(struct _sharednsitem *item, PyObject *key, PyObject *value)
{
item->name = _copy_raw_string(key);
if (item->name == NULL) {
return -1;
}
if (_PyObject_GetCrossInterpreterData(value, &item->data) != 0) {
_sharednsitem_clear(item);
return -1;
}
return 0;
}
static void
_sharednsitem_clear(struct _sharednsitem *item)
{
if (item->name != NULL) {
PyMem_Free(item->name);
item->name = NULL;
}
_PyCrossInterpreterData_Release(&item->data);
}
static int
_sharednsitem_apply(struct _sharednsitem *item, PyObject *ns)
{
PyObject *name = PyUnicode_FromString(item->name);
if (name == NULL) {
return -1;
}
PyObject *value = _PyCrossInterpreterData_NewObject(&item->data);
if (value == NULL) {
Py_DECREF(name);
return -1;
}
int res = PyDict_SetItem(ns, name, value);
Py_DECREF(name);
Py_DECREF(value);
return res;
}
typedef struct _sharedns {
Py_ssize_t len;
struct _sharednsitem* items;
} _sharedns;
static _sharedns *
_sharedns_new(Py_ssize_t len)
{
_sharedns *shared = PyMem_NEW(_sharedns, 1);
if (shared == NULL) {
PyErr_NoMemory();
return NULL;
}
shared->len = len;
shared->items = PyMem_NEW(struct _sharednsitem, len);
if (shared->items == NULL) {
PyErr_NoMemory();
PyMem_Free(shared);
return NULL;
}
return shared;
}
static void
_sharedns_free(_sharedns *shared)
{
for (Py_ssize_t i=0; i < shared->len; i++) {
_sharednsitem_clear(&shared->items[i]);
}
PyMem_Free(shared->items);
PyMem_Free(shared);
}
static _sharedns *
_get_shared_ns(PyObject *shareable)
{
if (shareable == NULL || shareable == Py_None) {
return NULL;
}
Py_ssize_t len = PyDict_Size(shareable);
if (len == 0) {
return NULL;
}
_sharedns *shared = _sharedns_new(len);
if (shared == NULL) {
return NULL;
}
Py_ssize_t pos = 0;
for (Py_ssize_t i=0; i < len; i++) {
PyObject *key, *value;
if (PyDict_Next(shareable, &pos, &key, &value) == 0) {
break;
}
if (_sharednsitem_init(&shared->items[i], key, value) != 0) {
break;
}
}
if (PyErr_Occurred()) {
_sharedns_free(shared);
return NULL;
}
return shared;
}
static int
_sharedns_apply(_sharedns *shared, PyObject *ns)
{
for (Py_ssize_t i=0; i < shared->len; i++) {
if (_sharednsitem_apply(&shared->items[i], ns) != 0) {
return -1;
}
}
return 0;
}
// Ultimately we'd like to preserve enough information about the
// exception and traceback that we could re-constitute (or at least
// simulate, a la traceback.TracebackException), and even chain, a copy
// of the exception in the calling interpreter.
typedef struct _sharedexception {
char *name;
char *msg;
} _sharedexception;
static _sharedexception *
_sharedexception_new(void)
{
_sharedexception *err = PyMem_NEW(_sharedexception, 1);
if (err == NULL) {
PyErr_NoMemory();
return NULL;
}
err->name = NULL;
err->msg = NULL;
return err;
}
static void
_sharedexception_clear(_sharedexception *exc)
{
if (exc->name != NULL) {
PyMem_Free(exc->name);
}
if (exc->msg != NULL) {
PyMem_Free(exc->msg);
}
}
static void
_sharedexception_free(_sharedexception *exc)
{
_sharedexception_clear(exc);
PyMem_Free(exc);
}
static _sharedexception *
_sharedexception_bind(PyObject *exctype, PyObject *exc, PyObject *tb)
{
assert(exctype != NULL);
char *failure = NULL;
_sharedexception *err = _sharedexception_new();
if (err == NULL) {
goto finally;
}
PyObject *name = PyUnicode_FromFormat("%S", exctype);
if (name == NULL) {
failure = "unable to format exception type name";
goto finally;
}
err->name = _copy_raw_string(name);
Py_DECREF(name);
if (err->name == NULL) {
if (PyErr_ExceptionMatches(PyExc_MemoryError)) {
failure = "out of memory copying exception type name";
} else {
failure = "unable to encode and copy exception type name";
}
goto finally;
}
if (exc != NULL) {
PyObject *msg = PyUnicode_FromFormat("%S", exc);
if (msg == NULL) {
failure = "unable to format exception message";
goto finally;
}
err->msg = _copy_raw_string(msg);
Py_DECREF(msg);
if (err->msg == NULL) {
if (PyErr_ExceptionMatches(PyExc_MemoryError)) {
failure = "out of memory copying exception message";
} else {
failure = "unable to encode and copy exception message";
}
goto finally;
}
}
finally:
if (failure != NULL) {
PyErr_Clear();
if (err->name != NULL) {
PyMem_Free(err->name);
err->name = NULL;
}
err->msg = failure;
}
return err;
}
static void
_sharedexception_apply(_sharedexception *exc, PyObject *wrapperclass)
{
if (exc->name != NULL) {
if (exc->msg != NULL) {
PyErr_Format(wrapperclass, "%s: %s", exc->name, exc->msg);
}
else {
PyErr_SetString(wrapperclass, exc->name);
}
}
else if (exc->msg != NULL) {
PyErr_SetString(wrapperclass, exc->msg);
}
else {
PyErr_SetNone(wrapperclass);
}
}
/* channel-specific code ****************************************************/
#define CHANNEL_SEND 1
#define CHANNEL_BOTH 0
#define CHANNEL_RECV -1
static PyObject *ChannelError;
static PyObject *ChannelNotFoundError;
static PyObject *ChannelClosedError;
static PyObject *ChannelEmptyError;
static PyObject *ChannelNotEmptyError;
static int
channel_exceptions_init(PyObject *ns)
{
// XXX Move the exceptions into per-module memory?
// A channel-related operation failed.
ChannelError = PyErr_NewException("_xxsubinterpreters.ChannelError",
PyExc_RuntimeError, NULL);
if (ChannelError == NULL) {
return -1;
}
if (PyDict_SetItemString(ns, "ChannelError", ChannelError) != 0) {
return -1;
}
// An operation tried to use a channel that doesn't exist.
ChannelNotFoundError = PyErr_NewException(
"_xxsubinterpreters.ChannelNotFoundError", ChannelError, NULL);
if (ChannelNotFoundError == NULL) {
return -1;
}
if (PyDict_SetItemString(ns, "ChannelNotFoundError", ChannelNotFoundError) != 0) {
return -1;
}
// An operation tried to use a closed channel.
ChannelClosedError = PyErr_NewException(
"_xxsubinterpreters.ChannelClosedError", ChannelError, NULL);
if (ChannelClosedError == NULL) {
return -1;
}
if (PyDict_SetItemString(ns, "ChannelClosedError", ChannelClosedError) != 0) {
return -1;
}
// An operation tried to pop from an empty channel.
ChannelEmptyError = PyErr_NewException(
"_xxsubinterpreters.ChannelEmptyError", ChannelError, NULL);
if (ChannelEmptyError == NULL) {
return -1;
}
if (PyDict_SetItemString(ns, "ChannelEmptyError", ChannelEmptyError) != 0) {
return -1;
}
// An operation tried to close a non-empty channel.
ChannelNotEmptyError = PyErr_NewException(
"_xxsubinterpreters.ChannelNotEmptyError", ChannelError, NULL);
if (ChannelNotEmptyError == NULL) {
return -1;
}
if (PyDict_SetItemString(ns, "ChannelNotEmptyError", ChannelNotEmptyError) != 0) {
return -1;
}
return 0;
}
/* the channel queue */
struct _channelitem;
typedef struct _channelitem {
_PyCrossInterpreterData *data;
struct _channelitem *next;
} _channelitem;
static _channelitem *
_channelitem_new(void)
{
_channelitem *item = PyMem_NEW(_channelitem, 1);
if (item == NULL) {
PyErr_NoMemory();
return NULL;
}
item->data = NULL;
item->next = NULL;
return item;
}
static void
_channelitem_clear(_channelitem *item)
{
if (item->data != NULL) {
_PyCrossInterpreterData_Release(item->data);
PyMem_Free(item->data);
item->data = NULL;
}
item->next = NULL;
}
static void
_channelitem_free(_channelitem *item)
{
_channelitem_clear(item);
PyMem_Free(item);
}
static void
_channelitem_free_all(_channelitem *item)
{
while (item != NULL) {
_channelitem *last = item;
item = item->next;
_channelitem_free(last);
}
}
static _PyCrossInterpreterData *
_channelitem_popped(_channelitem *item)
{
_PyCrossInterpreterData *data = item->data;
item->data = NULL;
_channelitem_free(item);
return data;
}
typedef struct _channelqueue {
int64_t count;
_channelitem *first;
_channelitem *last;
} _channelqueue;
static _channelqueue *
_channelqueue_new(void)
{
_channelqueue *queue = PyMem_NEW(_channelqueue, 1);
if (queue == NULL) {
PyErr_NoMemory();
return NULL;
}
queue->count = 0;
queue->first = NULL;
queue->last = NULL;
return queue;
}
static void
_channelqueue_clear(_channelqueue *queue)
{
_channelitem_free_all(queue->first);
queue->count = 0;
queue->first = NULL;
queue->last = NULL;
}
static void
_channelqueue_free(_channelqueue *queue)
{
_channelqueue_clear(queue);
PyMem_Free(queue);
}
static int
_channelqueue_put(_channelqueue *queue, _PyCrossInterpreterData *data)
{
_channelitem *item = _channelitem_new();
if (item == NULL) {
return -1;
}
item->data = data;
queue->count += 1;
if (queue->first == NULL) {
queue->first = item;
}
else {
queue->last->next = item;
}
queue->last = item;
return 0;
}
static _PyCrossInterpreterData *
_channelqueue_get(_channelqueue *queue)
{
_channelitem *item = queue->first;
if (item == NULL) {
return NULL;
}
queue->first = item->next;
if (queue->last == item) {
queue->last = NULL;
}
queue->count -= 1;
return _channelitem_popped(item);
}
/* channel-interpreter associations */
struct _channelend;
typedef struct _channelend {
struct _channelend *next;
int64_t interp;
int open;
} _channelend;
static _channelend *
_channelend_new(int64_t interp)
{
_channelend *end = PyMem_NEW(_channelend, 1);
if (end == NULL) {
PyErr_NoMemory();
return NULL;
}
end->next = NULL;
end->interp = interp;
end->open = 1;
return end;
}
static void
_channelend_free(_channelend *end)
{
PyMem_Free(end);
}
static void
_channelend_free_all(_channelend *end)
{
while (end != NULL) {
_channelend *last = end;
end = end->next;
_channelend_free(last);
}
}
static _channelend *
_channelend_find(_channelend *first, int64_t interp, _channelend **pprev)
{
_channelend *prev = NULL;
_channelend *end = first;
while (end != NULL) {
if (end->interp == interp) {
break;
}
prev = end;
end = end->next;
}
if (pprev != NULL) {
*pprev = prev;
}
return end;
}
typedef struct _channelassociations {
// Note that the list entries are never removed for interpreter
// for which the channel is closed. This should not be a problem in
// practice. Also, a channel isn't automatically closed when an
// interpreter is destroyed.
int64_t numsendopen;
int64_t numrecvopen;
_channelend *send;
_channelend *recv;
} _channelends;
static _channelends *
_channelends_new(void)
{
_channelends *ends = PyMem_NEW(_channelends, 1);
if (ends== NULL) {
return NULL;
}
ends->numsendopen = 0;
ends->numrecvopen = 0;
ends->send = NULL;
ends->recv = NULL;
return ends;
}
static void
_channelends_clear(_channelends *ends)
{
_channelend_free_all(ends->send);
ends->send = NULL;
ends->numsendopen = 0;
_channelend_free_all(ends->recv);
ends->recv = NULL;
ends->numrecvopen = 0;
}
static void
_channelends_free(_channelends *ends)
{
_channelends_clear(ends);
PyMem_Free(ends);
}
static _channelend *
_channelends_add(_channelends *ends, _channelend *prev, int64_t interp,
int send)
{
_channelend *end = _channelend_new(interp);
if (end == NULL) {
return NULL;
}
if (prev == NULL) {
if (send) {
ends->send = end;
}
else {
ends->recv = end;
}
}
else {
prev->next = end;
}
if (send) {
ends->numsendopen += 1;
}
else {
ends->numrecvopen += 1;
}
return end;
}
static int
_channelends_associate(_channelends *ends, int64_t interp, int send)
{
_channelend *prev;
_channelend *end = _channelend_find(send ? ends->send : ends->recv,
interp, &prev);
if (end != NULL) {
if (!end->open) {
PyErr_SetString(ChannelClosedError, "channel already closed");
return -1;
}
// already associated
return 0;
}
if (_channelends_add(ends, prev, interp, send) == NULL) {
return -1;
}
return 0;
}
static int
_channelends_is_open(_channelends *ends)
{
if (ends->numsendopen != 0 || ends->numrecvopen != 0) {
return 1;
}
if (ends->send == NULL && ends->recv == NULL) {
return 1;
}
return 0;
}
static void
_channelends_close_end(_channelends *ends, _channelend *end, int send)
{
end->open = 0;
if (send) {
ends->numsendopen -= 1;
}
else {
ends->numrecvopen -= 1;
}
}
static int
_channelends_close_interpreter(_channelends *ends, int64_t interp, int which)
{
_channelend *prev;
_channelend *end;
if (which >= 0) { // send/both
end = _channelend_find(ends->send, interp, &prev);
if (end == NULL) {
// never associated so add it
end = _channelends_add(ends, prev, interp, 1);
if (end == NULL) {
return -1;
}
}
_channelends_close_end(ends, end, 1);
}
if (which <= 0) { // recv/both
end = _channelend_find(ends->recv, interp, &prev);
if (end == NULL) {
// never associated so add it
end = _channelends_add(ends, prev, interp, 0);
if (end == NULL) {
return -1;
}
}
_channelends_close_end(ends, end, 0);
}
return 0;
}
static void
_channelends_close_all(_channelends *ends, int which, int force)
{
// XXX Handle the ends.
// XXX Handle force is True.
// Ensure all the "send"-associated interpreters are closed.
_channelend *end;
for (end = ends->send; end != NULL; end = end->next) {
_channelends_close_end(ends, end, 1);
}
// Ensure all the "recv"-associated interpreters are closed.
for (end = ends->recv; end != NULL; end = end->next) {
_channelends_close_end(ends, end, 0);
}
}
/* channels */
struct _channel;
struct _channel_closing;
static void _channel_clear_closing(struct _channel *);
static void _channel_finish_closing(struct _channel *);
typedef struct _channel {
PyThread_type_lock mutex;
_channelqueue *queue;
_channelends *ends;
int open;
struct _channel_closing *closing;
} _PyChannelState;
static _PyChannelState *
_channel_new(void)
{
_PyChannelState *chan = PyMem_NEW(_PyChannelState, 1);
if (chan == NULL) {
return NULL;
}
chan->mutex = PyThread_allocate_lock();
if (chan->mutex == NULL) {
PyMem_Free(chan);
PyErr_SetString(ChannelError,
"can't initialize mutex for new channel");
return NULL;
}
chan->queue = _channelqueue_new();
if (chan->queue == NULL) {
PyMem_Free(chan);
return NULL;
}
chan->ends = _channelends_new();
if (chan->ends == NULL) {
_channelqueue_free(chan->queue);
PyMem_Free(chan);
return NULL;
}
chan->open = 1;
chan->closing = NULL;
return chan;
}
static void
_channel_free(_PyChannelState *chan)
{
_channel_clear_closing(chan);
PyThread_acquire_lock(chan->mutex, WAIT_LOCK);
_channelqueue_free(chan->queue);
_channelends_free(chan->ends);
PyThread_release_lock(chan->mutex);
PyThread_free_lock(chan->mutex);
PyMem_Free(chan);
}
static int
_channel_add(_PyChannelState *chan, int64_t interp,
_PyCrossInterpreterData *data)
{
int res = -1;
PyThread_acquire_lock(chan->mutex, WAIT_LOCK);
if (!chan->open) {
PyErr_SetString(ChannelClosedError, "channel closed");
goto done;
}
if (_channelends_associate(chan->ends, interp, 1) != 0) {
goto done;
}
if (_channelqueue_put(chan->queue, data) != 0) {
goto done;
}
res = 0;
done:
PyThread_release_lock(chan->mutex);
return res;
}
static _PyCrossInterpreterData *
_channel_next(_PyChannelState *chan, int64_t interp)
{
_PyCrossInterpreterData *data = NULL;
PyThread_acquire_lock(chan->mutex, WAIT_LOCK);
if (!chan->open) {
PyErr_SetString(ChannelClosedError, "channel closed");
goto done;
}
if (_channelends_associate(chan->ends, interp, 0) != 0) {
goto done;
}
data = _channelqueue_get(chan->queue);
if (data == NULL && !PyErr_Occurred() && chan->closing != NULL) {
chan->open = 0;
}
done:
PyThread_release_lock(chan->mutex);
if (chan->queue->count == 0) {
_channel_finish_closing(chan);
}
return data;
}
static int
_channel_close_interpreter(_PyChannelState *chan, int64_t interp, int end)
{
PyThread_acquire_lock(chan->mutex, WAIT_LOCK);
int res = -1;
if (!chan->open) {
PyErr_SetString(ChannelClosedError, "channel already closed");
goto done;
}
if (_channelends_close_interpreter(chan->ends, interp, end) != 0) {
goto done;
}
chan->open = _channelends_is_open(chan->ends);
res = 0;
done:
PyThread_release_lock(chan->mutex);
return res;
}
static int
_channel_close_all(_PyChannelState *chan, int end, int force)
{
int res = -1;
PyThread_acquire_lock(chan->mutex, WAIT_LOCK);
if (!chan->open) {
PyErr_SetString(ChannelClosedError, "channel already closed");
goto done;
}
if (!force && chan->queue->count > 0) {
PyErr_SetString(ChannelNotEmptyError,
"may not be closed if not empty (try force=True)");
goto done;
}
chan->open = 0;
// We *could* also just leave these in place, since we've marked
// the channel as closed already.
_channelends_close_all(chan->ends, end, force);
res = 0;
done:
PyThread_release_lock(chan->mutex);
return res;
}
/* the set of channels */
struct _channelref;
typedef struct _channelref {
int64_t id;
_PyChannelState *chan;
struct _channelref *next;
Py_ssize_t objcount;
} _channelref;
static _channelref *
_channelref_new(int64_t id, _PyChannelState *chan)
{
_channelref *ref = PyMem_NEW(_channelref, 1);
if (ref == NULL) {
return NULL;
}
ref->id = id;
ref->chan = chan;
ref->next = NULL;
ref->objcount = 0;
return ref;
}
//static void
//_channelref_clear(_channelref *ref)
//{
// ref->id = -1;
// ref->chan = NULL;
// ref->next = NULL;
// ref->objcount = 0;
//}
static void
_channelref_free(_channelref *ref)
{
if (ref->chan != NULL) {
_channel_clear_closing(ref->chan);
}
//_channelref_clear(ref);
PyMem_Free(ref);
}
static _channelref *
_channelref_find(_channelref *first, int64_t id, _channelref **pprev)
{
_channelref *prev = NULL;
_channelref *ref = first;
while (ref != NULL) {
if (ref->id == id) {
break;
}
prev = ref;
ref = ref->next;
}
if (pprev != NULL) {
*pprev = prev;
}
return ref;
}
typedef struct _channels {
PyThread_type_lock mutex;
_channelref *head;
int64_t numopen;
int64_t next_id;
} _channels;
static int
_channels_init(_channels *channels)
{
if (channels->mutex == NULL) {
channels->mutex = PyThread_allocate_lock();
if (channels->mutex == NULL) {
PyErr_SetString(ChannelError,
"can't initialize mutex for channel management");
return -1;
}
}
channels->head = NULL;
channels->numopen = 0;
channels->next_id = 0;
return 0;
}
static int64_t
_channels_next_id(_channels *channels) // needs lock
{
int64_t id = channels->next_id;
if (id < 0) {
/* overflow */
PyErr_SetString(ChannelError,
"failed to get a channel ID");
return -1;
}
channels->next_id += 1;
return id;
}
static _PyChannelState *
_channels_lookup(_channels *channels, int64_t id, PyThread_type_lock *pmutex)
{
_PyChannelState *chan = NULL;
PyThread_acquire_lock(channels->mutex, WAIT_LOCK);
if (pmutex != NULL) {
*pmutex = NULL;
}
_channelref *ref = _channelref_find(channels->head, id, NULL);
if (ref == NULL) {
PyErr_Format(ChannelNotFoundError, "channel %" PRId64 " not found", id);
goto done;
}
if (ref->chan == NULL || !ref->chan->open) {
PyErr_Format(ChannelClosedError, "channel %" PRId64 " closed", id);
goto done;
}
if (pmutex != NULL) {
// The mutex will be closed by the caller.
*pmutex = channels->mutex;
}
chan = ref->chan;
done:
if (pmutex == NULL || *pmutex == NULL) {
PyThread_release_lock(channels->mutex);
}
return chan;
}