diff options
Diffstat (limited to 'Python/crossinterp.c')
| -rw-r--r-- | Python/crossinterp.c | 1134 |
1 files changed, 795 insertions, 339 deletions
diff --git a/Python/crossinterp.c b/Python/crossinterp.c index 7d7e6551c3f..5e73ab28f2b 100644 --- a/Python/crossinterp.c +++ b/Python/crossinterp.c @@ -10,6 +10,7 @@ #include "pycore_initconfig.h" // _PyStatus_OK() #include "pycore_namespace.h" // _PyNamespace_New() #include "pycore_pythonrun.h" // _Py_SourceAsString() +#include "pycore_setobject.h" // _PySet_NextEntry() #include "pycore_typeobject.h" // _PyStaticType_InitBuiltin() @@ -69,6 +70,17 @@ runpy_run_path(const char *filename, const char *modname) } +static void +set_exc_with_cause(PyObject *exctype, const char *msg) +{ + PyObject *cause = PyErr_GetRaisedException(); + PyErr_SetString(exctype, msg); + PyObject *exc = PyErr_GetRaisedException(); + PyException_SetCause(exc, cause); + PyErr_SetRaisedException(exc); +} + + static PyObject * pyerr_get_message(PyObject *exc) { @@ -209,16 +221,16 @@ _Py_CallInInterpreterAndRawFree(PyInterpreterState *interp, /* cross-interpreter data */ /**************************/ -/* registry of {type -> xidatafunc} */ +/* registry of {type -> _PyXIData_getdata_t} */ -/* For now we use a global registry of shareable classes. An - alternative would be to add a tp_* slot for a class's - xidatafunc. It would be simpler and more efficient. */ +/* For now we use a global registry of shareable classes. + An alternative would be to add a tp_* slot for a class's + _PyXIData_getdata_t. It would be simpler and more efficient. */ static void xid_lookup_init(_PyXIData_lookup_t *); static void xid_lookup_fini(_PyXIData_lookup_t *); struct _dlcontext; -static xidatafunc lookup_getdata(struct _dlcontext *, PyObject *); +static _PyXIData_getdata_t lookup_getdata(struct _dlcontext *, PyObject *); #include "crossinterp_data_lookup.h" @@ -342,7 +354,7 @@ _set_xid_lookup_failure(PyThreadState *tstate, PyObject *obj, const char *msg, set_notshareableerror(tstate, cause, 0, msg); } else { - msg = "%S does not support cross-interpreter data"; + msg = "%R does not support cross-interpreter data"; format_notshareableerror(tstate, cause, 0, msg, obj); } } @@ -355,8 +367,8 @@ _PyObject_CheckXIData(PyThreadState *tstate, PyObject *obj) if (get_lookup_context(tstate, &ctx) < 0) { return -1; } - xidatafunc getdata = lookup_getdata(&ctx, obj); - if (getdata == NULL) { + _PyXIData_getdata_t getdata = lookup_getdata(&ctx, obj); + if (getdata.basic == NULL && getdata.fallback == NULL) { if (!_PyErr_Occurred(tstate)) { _set_xid_lookup_failure(tstate, obj, NULL, NULL); } @@ -387,9 +399,9 @@ _check_xidata(PyThreadState *tstate, _PyXIData_t *xidata) return 0; } -int -_PyObject_GetXIData(PyThreadState *tstate, - PyObject *obj, _PyXIData_t *xidata) +static int +_get_xidata(PyThreadState *tstate, + PyObject *obj, xidata_fallback_t fallback, _PyXIData_t *xidata) { PyInterpreterState *interp = tstate->interp; @@ -397,6 +409,7 @@ _PyObject_GetXIData(PyThreadState *tstate, assert(xidata->obj == NULL); if (xidata->data != NULL || xidata->obj != NULL) { _PyErr_SetString(tstate, PyExc_ValueError, "xidata not cleared"); + return -1; } // Call the "getdata" func for the object. @@ -405,8 +418,8 @@ _PyObject_GetXIData(PyThreadState *tstate, return -1; } Py_INCREF(obj); - xidatafunc getdata = lookup_getdata(&ctx, obj); - if (getdata == NULL) { + _PyXIData_getdata_t getdata = lookup_getdata(&ctx, obj); + if (getdata.basic == NULL && getdata.fallback == NULL) { if (PyErr_Occurred()) { Py_DECREF(obj); return -1; @@ -418,7 +431,9 @@ _PyObject_GetXIData(PyThreadState *tstate, } return -1; } - int res = getdata(tstate, obj, xidata); + int res = getdata.basic != NULL + ? getdata.basic(tstate, obj, xidata) + : getdata.fallback(tstate, obj, fallback, xidata); Py_DECREF(obj); if (res != 0) { PyObject *cause = _PyErr_GetRaisedException(tstate); @@ -438,6 +453,51 @@ _PyObject_GetXIData(PyThreadState *tstate, return 0; } +int +_PyObject_GetXIDataNoFallback(PyThreadState *tstate, + PyObject *obj, _PyXIData_t *xidata) +{ + return _get_xidata(tstate, obj, _PyXIDATA_XIDATA_ONLY, xidata); +} + +int +_PyObject_GetXIData(PyThreadState *tstate, + PyObject *obj, xidata_fallback_t fallback, + _PyXIData_t *xidata) +{ + switch (fallback) { + case _PyXIDATA_XIDATA_ONLY: + return _get_xidata(tstate, obj, fallback, xidata); + case _PyXIDATA_FULL_FALLBACK: + if (_get_xidata(tstate, obj, fallback, xidata) == 0) { + return 0; + } + PyObject *exc = _PyErr_GetRaisedException(tstate); + if (PyFunction_Check(obj)) { + if (_PyFunction_GetXIData(tstate, obj, xidata) == 0) { + Py_DECREF(exc); + return 0; + } + _PyErr_Clear(tstate); + } + // We could try _PyMarshal_GetXIData() but we won't for now. + if (_PyPickle_GetXIData(tstate, obj, xidata) == 0) { + Py_DECREF(exc); + return 0; + } + // Raise the original exception. + _PyErr_SetRaisedException(tstate, exc); + return -1; + default: +#ifdef Py_DEBUG + Py_FatalError("unsupported xidata fallback option"); +#endif + _PyErr_SetString(tstate, PyExc_SystemError, + "unsupported xidata fallback option"); + return -1; + } +} + /* pickle C-API */ @@ -859,8 +919,15 @@ get_script_xidata(PyThreadState *tstate, PyObject *obj, int pure, } goto error; } +#ifdef Py_GIL_DISABLED + // Don't immortalize code constants to avoid memory leaks. + ((_PyThreadStateImpl *)tstate)->suppress_co_const_immortalization++; +#endif code = Py_CompileStringExFlags( script, filename, Py_file_input, &cf, optimize); +#ifdef Py_GIL_DISABLED + ((_PyThreadStateImpl *)tstate)->suppress_co_const_immortalization--; +#endif Py_XDECREF(ref); if (code == NULL) { goto error; @@ -1258,7 +1325,7 @@ _excinfo_normalize_type(struct _excinfo_type *info, } static void -_PyXI_excinfo_Clear(_PyXI_excinfo *info) +_PyXI_excinfo_clear(_PyXI_excinfo *info) { _excinfo_clear_type(&info->type); if (info->msg != NULL) { @@ -1308,7 +1375,7 @@ _PyXI_excinfo_InitFromException(_PyXI_excinfo *info, PyObject *exc) assert(exc != NULL); if (PyErr_GivenExceptionMatches(exc, PyExc_MemoryError)) { - _PyXI_excinfo_Clear(info); + _PyXI_excinfo_clear(info); return NULL; } const char *failure = NULL; @@ -1354,7 +1421,7 @@ _PyXI_excinfo_InitFromException(_PyXI_excinfo *info, PyObject *exc) error: assert(failure != NULL); - _PyXI_excinfo_Clear(info); + _PyXI_excinfo_clear(info); return failure; } @@ -1405,7 +1472,7 @@ _PyXI_excinfo_InitFromObject(_PyXI_excinfo *info, PyObject *obj) error: assert(failure != NULL); - _PyXI_excinfo_Clear(info); + _PyXI_excinfo_clear(info); return failure; } @@ -1600,7 +1667,7 @@ _PyXI_ExcInfoAsObject(_PyXI_excinfo *info) void _PyXI_ClearExcInfo(_PyXI_excinfo *info) { - _PyXI_excinfo_Clear(info); + _PyXI_excinfo_clear(info); } @@ -1616,14 +1683,9 @@ _PyXI_ApplyErrorCode(_PyXI_errcode code, PyInterpreterState *interp) PyThreadState *tstate = _PyThreadState_GET(); assert(!PyErr_Occurred()); + assert(code != _PyXI_ERR_NO_ERROR); + assert(code != _PyXI_ERR_UNCAUGHT_EXCEPTION); switch (code) { - case _PyXI_ERR_NO_ERROR: _Py_FALLTHROUGH; - case _PyXI_ERR_UNCAUGHT_EXCEPTION: - // There is nothing to apply. -#ifdef Py_DEBUG - Py_UNREACHABLE(); -#endif - return 0; case _PyXI_ERR_OTHER: // XXX msg? PyErr_SetNone(PyExc_InterpreterError); @@ -1643,12 +1705,20 @@ _PyXI_ApplyErrorCode(_PyXI_errcode code, PyInterpreterState *interp) PyErr_SetString(PyExc_InterpreterError, "failed to apply namespace to __main__"); break; + case _PyXI_ERR_PRESERVE_FAILURE: + PyErr_SetString(PyExc_InterpreterError, + "failed to preserve objects across session"); + break; + case _PyXI_ERR_EXC_PROPAGATION_FAILURE: + PyErr_SetString(PyExc_InterpreterError, + "failed to transfer exception between interpreters"); + break; case _PyXI_ERR_NOT_SHAREABLE: _set_xid_lookup_failure(tstate, NULL, NULL, NULL); break; default: #ifdef Py_DEBUG - Py_UNREACHABLE(); + Py_FatalError("unsupported error code"); #else PyErr_Format(PyExc_RuntimeError, "unsupported error code %d", code); #endif @@ -1692,7 +1762,7 @@ _PyXI_InitError(_PyXI_error *error, PyObject *excobj, _PyXI_errcode code) assert(excobj == NULL); assert(code != _PyXI_ERR_NO_ERROR); error->code = code; - _PyXI_excinfo_Clear(&error->uncaught); + _PyXI_excinfo_clear(&error->uncaught); } return failure; } @@ -1702,7 +1772,7 @@ _PyXI_ApplyError(_PyXI_error *error) { PyThreadState *tstate = PyThreadState_Get(); if (error->code == _PyXI_ERR_UNCAUGHT_EXCEPTION) { - // Raise an exception that proxies the propagated exception. + // We will raise an exception that proxies the propagated exception. return _PyXI_excinfo_AsObject(&error->uncaught); } else if (error->code == _PyXI_ERR_NOT_SHAREABLE) { @@ -1751,6 +1821,7 @@ typedef struct _sharednsitem { // in a different interpreter to release the XI data. } _PyXI_namespace_item; +#ifndef NDEBUG static int _sharednsitem_is_initialized(_PyXI_namespace_item *item) { @@ -1759,6 +1830,7 @@ _sharednsitem_is_initialized(_PyXI_namespace_item *item) } return 0; } +#endif static int _sharednsitem_init(_PyXI_namespace_item *item, PyObject *key) @@ -1786,7 +1858,8 @@ _sharednsitem_has_value(_PyXI_namespace_item *item, int64_t *p_interpid) } static int -_sharednsitem_set_value(_PyXI_namespace_item *item, PyObject *value) +_sharednsitem_set_value(_PyXI_namespace_item *item, PyObject *value, + xidata_fallback_t fallback) { assert(_sharednsitem_is_initialized(item)); assert(item->xidata == NULL); @@ -1795,7 +1868,7 @@ _sharednsitem_set_value(_PyXI_namespace_item *item, PyObject *value) return -1; } PyThreadState *tstate = PyThreadState_Get(); - if (_PyObject_GetXIData(tstate, value, item->xidata) != 0) { + if (_PyObject_GetXIData(tstate, value, fallback, item->xidata) < 0) { PyMem_RawFree(item->xidata); item->xidata = NULL; // The caller may want to propagate PyExc_NotShareableError @@ -1827,7 +1900,8 @@ _sharednsitem_clear(_PyXI_namespace_item *item) } static int -_sharednsitem_copy_from_ns(struct _sharednsitem *item, PyObject *ns) +_sharednsitem_copy_from_ns(struct _sharednsitem *item, PyObject *ns, + xidata_fallback_t fallback) { assert(item->name != NULL); assert(item->xidata == NULL); @@ -1839,7 +1913,7 @@ _sharednsitem_copy_from_ns(struct _sharednsitem *item, PyObject *ns) // When applied, this item will be set to the default (or fail). return 0; } - if (_sharednsitem_set_value(item, value) < 0) { + if (_sharednsitem_set_value(item, value, fallback) < 0) { return -1; } return 0; @@ -1869,156 +1943,212 @@ _sharednsitem_apply(_PyXI_namespace_item *item, PyObject *ns, PyObject *dflt) return res; } -struct _sharedns { - Py_ssize_t len; - _PyXI_namespace_item *items; -}; -static _PyXI_namespace * -_sharedns_new(void) -{ - _PyXI_namespace *ns = PyMem_RawCalloc(sizeof(_PyXI_namespace), 1); - if (ns == NULL) { - PyErr_NoMemory(); - return NULL; - } - *ns = (_PyXI_namespace){ 0 }; - return ns; -} +typedef struct { + Py_ssize_t maxitems; + Py_ssize_t numnames; + Py_ssize_t numvalues; + _PyXI_namespace_item items[1]; +} _PyXI_namespace; +#ifndef NDEBUG static int -_sharedns_is_initialized(_PyXI_namespace *ns) +_sharedns_check_counts(_PyXI_namespace *ns) { - if (ns->len == 0) { - assert(ns->items == NULL); + if (ns->maxitems <= 0) { + return 0; + } + if (ns->numnames < 0) { + return 0; + } + if (ns->numnames > ns->maxitems) { + return 0; + } + if (ns->numvalues < 0) { + return 0; + } + if (ns->numvalues > ns->numnames) { return 0; } - - assert(ns->len > 0); - assert(ns->items != NULL); - assert(_sharednsitem_is_initialized(&ns->items[0])); - assert(ns->len == 1 - || _sharednsitem_is_initialized(&ns->items[ns->len - 1])); return 1; } -#define HAS_COMPLETE_DATA 1 -#define HAS_PARTIAL_DATA 2 - static int -_sharedns_has_xidata(_PyXI_namespace *ns, int64_t *p_interpid) +_sharedns_check_consistency(_PyXI_namespace *ns) { - // We expect _PyXI_namespace to always be initialized. - assert(_sharedns_is_initialized(ns)); - int res = 0; - _PyXI_namespace_item *item0 = &ns->items[0]; - if (!_sharednsitem_is_initialized(item0)) { + if (!_sharedns_check_counts(ns)) { return 0; } - int64_t interpid0 = -1; - if (!_sharednsitem_has_value(item0, &interpid0)) { - return 0; + + Py_ssize_t i = 0; + _PyXI_namespace_item *item; + if (ns->numvalues > 0) { + item = &ns->items[0]; + if (!_sharednsitem_is_initialized(item)) { + return 0; + } + int64_t interpid0 = -1; + if (!_sharednsitem_has_value(item, &interpid0)) { + return 0; + } + i += 1; + for (; i < ns->numvalues; i++) { + item = &ns->items[i]; + if (!_sharednsitem_is_initialized(item)) { + return 0; + } + int64_t interpid = -1; + if (!_sharednsitem_has_value(item, &interpid)) { + return 0; + } + if (interpid != interpid0) { + return 0; + } + } } - if (ns->len > 1) { - // At this point we know it is has at least partial data. - _PyXI_namespace_item *itemN = &ns->items[ns->len-1]; - if (!_sharednsitem_is_initialized(itemN)) { - res = HAS_PARTIAL_DATA; - goto finally; + for (; i < ns->numnames; i++) { + item = &ns->items[i]; + if (!_sharednsitem_is_initialized(item)) { + return 0; } - int64_t interpidN = -1; - if (!_sharednsitem_has_value(itemN, &interpidN)) { - res = HAS_PARTIAL_DATA; - goto finally; + if (_sharednsitem_has_value(item, NULL)) { + return 0; } - assert(interpidN == interpid0); } - res = HAS_COMPLETE_DATA; - *p_interpid = interpid0; - -finally: - return res; + for (; i < ns->maxitems; i++) { + item = &ns->items[i]; + if (_sharednsitem_is_initialized(item)) { + return 0; + } + if (_sharednsitem_has_value(item, NULL)) { + return 0; + } + } + return 1; } +#endif -static void -_sharedns_clear(_PyXI_namespace *ns) +static _PyXI_namespace * +_sharedns_alloc(Py_ssize_t maxitems) { - if (!_sharedns_is_initialized(ns)) { - return; + if (maxitems < 0) { + if (!PyErr_Occurred()) { + PyErr_BadInternalCall(); + } + return NULL; + } + else if (maxitems == 0) { + PyErr_SetString(PyExc_ValueError, "empty namespaces not allowed"); + return NULL; } - // If the cross-interpreter data were allocated as part of - // _PyXI_namespace_item (instead of dynamically), this is where - // we would need verify that we are clearing the items in the - // correct interpreter, to avoid a race with releasing the XI data - // via a pending call. See _sharedns_has_xidata(). - for (Py_ssize_t i=0; i < ns->len; i++) { - _sharednsitem_clear(&ns->items[i]); + // Check for overflow. + size_t fixedsize = sizeof(_PyXI_namespace) - sizeof(_PyXI_namespace_item); + if ((size_t)maxitems > + ((size_t)PY_SSIZE_T_MAX - fixedsize) / sizeof(_PyXI_namespace_item)) + { + PyErr_NoMemory(); + return NULL; + } + + // Allocate the value, including items. + size_t size = fixedsize + sizeof(_PyXI_namespace_item) * maxitems; + + _PyXI_namespace *ns = PyMem_RawCalloc(size, 1); + if (ns == NULL) { + PyErr_NoMemory(); + return NULL; } - PyMem_RawFree(ns->items); - ns->items = NULL; - ns->len = 0; + ns->maxitems = maxitems; + assert(_sharedns_check_consistency(ns)); + return ns; } static void _sharedns_free(_PyXI_namespace *ns) { - _sharedns_clear(ns); + // If we weren't always dynamically allocating the cross-interpreter + // data in each item then we would need to use a pending call + // to call _sharedns_free(), to avoid the race between freeing + // the shared namespace and releasing the XI data. + assert(_sharedns_check_counts(ns)); + Py_ssize_t i = 0; + _PyXI_namespace_item *item; + if (ns->numvalues > 0) { + // One or more items may have interpreter-specific data. +#ifndef NDEBUG + int64_t interpid = PyInterpreterState_GetID(PyInterpreterState_Get()); + int64_t interpid_i; +#endif + for (; i < ns->numvalues; i++) { + item = &ns->items[i]; + assert(_sharednsitem_is_initialized(item)); + // While we do want to ensure consistency across items, + // technically they don't need to match the current + // interpreter. However, we keep the constraint for + // simplicity, by giving _PyXI_FreeNamespace() the exclusive + // responsibility of dealing with the owning interpreter. + assert(_sharednsitem_has_value(item, &interpid_i)); + assert(interpid_i == interpid); + _sharednsitem_clear(item); + } + } + for (; i < ns->numnames; i++) { + item = &ns->items[i]; + assert(_sharednsitem_is_initialized(item)); + assert(!_sharednsitem_has_value(item, NULL)); + _sharednsitem_clear(item); + } +#ifndef NDEBUG + for (; i < ns->maxitems; i++) { + item = &ns->items[i]; + assert(!_sharednsitem_is_initialized(item)); + assert(!_sharednsitem_has_value(item, NULL)); + } +#endif + PyMem_RawFree(ns); } -static int -_sharedns_init(_PyXI_namespace *ns, PyObject *names) +static _PyXI_namespace * +_create_sharedns(PyObject *names) { - assert(!_sharedns_is_initialized(ns)); assert(names != NULL); - Py_ssize_t len = PyDict_CheckExact(names) + Py_ssize_t numnames = PyDict_CheckExact(names) ? PyDict_Size(names) : PySequence_Size(names); - if (len < 0) { - return -1; - } - if (len == 0) { - PyErr_SetString(PyExc_ValueError, "empty namespaces not allowed"); - return -1; - } - assert(len > 0); - // Allocate the items. - _PyXI_namespace_item *items = - PyMem_RawCalloc(sizeof(struct _sharednsitem), len); - if (items == NULL) { - PyErr_NoMemory(); - return -1; + _PyXI_namespace *ns = _sharedns_alloc(numnames); + if (ns == NULL) { + return NULL; } + _PyXI_namespace_item *items = ns->items; // Fill in the names. - Py_ssize_t i = -1; if (PyDict_CheckExact(names)) { + Py_ssize_t i = 0; Py_ssize_t pos = 0; - for (i=0; i < len; i++) { - PyObject *key; - if (!PyDict_Next(names, &pos, &key, NULL)) { - // This should not be possible. - assert(0); - goto error; - } - if (_sharednsitem_init(&items[i], key) < 0) { + PyObject *name; + while(PyDict_Next(names, &pos, &name, NULL)) { + if (_sharednsitem_init(&items[i], name) < 0) { goto error; } + ns->numnames += 1; + i += 1; } } else if (PySequence_Check(names)) { - for (i=0; i < len; i++) { - PyObject *key = PySequence_GetItem(names, i); - if (key == NULL) { + for (Py_ssize_t i = 0; i < numnames; i++) { + PyObject *name = PySequence_GetItem(names, i); + if (name == NULL) { goto error; } - int res = _sharednsitem_init(&items[i], key); - Py_DECREF(key); + int res = _sharednsitem_init(&items[i], name); + Py_DECREF(name); if (res < 0) { goto error; } + ns->numnames += 1; } } else { @@ -2026,151 +2156,187 @@ _sharedns_init(_PyXI_namespace *ns, PyObject *names) "non-sequence namespace not supported"); goto error; } - - ns->items = items; - ns->len = len; - assert(_sharedns_is_initialized(ns)); - return 0; + assert(ns->numnames == ns->maxitems); + return ns; error: - for (Py_ssize_t j=0; j < i; j++) { - _sharednsitem_clear(&items[j]); + _sharedns_free(ns); + return NULL; +} + +static void _propagate_not_shareable_error(_PyXI_errcode *); + +static int +_fill_sharedns(_PyXI_namespace *ns, PyObject *nsobj, + xidata_fallback_t fallback, _PyXI_errcode *p_errcode) +{ + // All items are expected to be shareable. + assert(_sharedns_check_counts(ns)); + assert(ns->numnames == ns->maxitems); + assert(ns->numvalues == 0); + for (Py_ssize_t i=0; i < ns->maxitems; i++) { + if (_sharednsitem_copy_from_ns(&ns->items[i], nsobj, fallback) < 0) { + if (p_errcode != NULL) { + _propagate_not_shareable_error(p_errcode); + } + // Clear out the ones we set so far. + for (Py_ssize_t j=0; j < i; j++) { + _sharednsitem_clear_value(&ns->items[j]); + ns->numvalues -= 1; + } + return -1; + } + ns->numvalues += 1; } - PyMem_RawFree(items); - assert(!_sharedns_is_initialized(ns)); - return -1; + return 0; } -void -_PyXI_FreeNamespace(_PyXI_namespace *ns) +static int +_sharedns_free_pending(void *data) { - if (!_sharedns_is_initialized(ns)) { - return; - } + _sharedns_free((_PyXI_namespace *)data); + return 0; +} - int64_t interpid = -1; - if (!_sharedns_has_xidata(ns, &interpid)) { +static void +_destroy_sharedns(_PyXI_namespace *ns) +{ + assert(_sharedns_check_counts(ns)); + assert(ns->numnames == ns->maxitems); + if (ns->numvalues == 0) { _sharedns_free(ns); return; } - if (interpid == PyInterpreterState_GetID(PyInterpreterState_Get())) { + int64_t interpid0; + if (!_sharednsitem_has_value(&ns->items[0], &interpid0)) { + // This shouldn't have been possible. + // We can deal with it in _sharedns_free(). _sharedns_free(ns); + return; } - else { - // If we weren't always dynamically allocating the cross-interpreter - // data in each item then we would need to using a pending call - // to call _sharedns_free(), to avoid the race between freeing - // the shared namespace and releasing the XI data. + PyInterpreterState *interp = _PyInterpreterState_LookUpID(interpid0); + if (interp == PyInterpreterState_Get()) { _sharedns_free(ns); + return; } + + // One or more items may have interpreter-specific data. + // Currently the xidata for each value is dynamically allocated, + // so technically we don't need to worry about that. + // However, explicitly adding a pending call here is simpler. + (void)_Py_CallInInterpreter(interp, _sharedns_free_pending, ns); } -_PyXI_namespace * -_PyXI_NamespaceFromNames(PyObject *names) +static int +_apply_sharedns(_PyXI_namespace *ns, PyObject *nsobj, PyObject *dflt) { - if (names == NULL || names == Py_None) { - return NULL; + for (Py_ssize_t i=0; i < ns->maxitems; i++) { + if (_sharednsitem_apply(&ns->items[i], nsobj, dflt) != 0) { + return -1; + } } + return 0; +} - _PyXI_namespace *ns = _sharedns_new(); - if (ns == NULL) { - return NULL; - } - if (_sharedns_init(ns, names) < 0) { - PyMem_RawFree(ns); - if (PySequence_Size(names) == 0) { - PyErr_Clear(); - } - return NULL; - } +/*********************************/ +/* switched-interpreter sessions */ +/*********************************/ - return ns; -} +struct xi_session_error { + // This is set if the interpreter is entered and raised an exception + // that needs to be handled in some special way during exit. + _PyXI_errcode *override; + // This is set if exit captured an exception to propagate. + _PyXI_error *info; -#ifndef NDEBUG -static int _session_is_active(_PyXI_session *); -#endif -static void _propagate_not_shareable_error(_PyXI_session *); + // -- pre-allocated memory -- + _PyXI_error _info; + _PyXI_errcode _override; +}; -int -_PyXI_FillNamespaceFromDict(_PyXI_namespace *ns, PyObject *nsobj, - _PyXI_session *session) -{ - // session must be entered already, if provided. - assert(session == NULL || _session_is_active(session)); - assert(_sharedns_is_initialized(ns)); - for (Py_ssize_t i=0; i < ns->len; i++) { - _PyXI_namespace_item *item = &ns->items[i]; - if (_sharednsitem_copy_from_ns(item, nsobj) < 0) { - _propagate_not_shareable_error(session); - // Clear out the ones we set so far. - for (Py_ssize_t j=0; j < i; j++) { - _sharednsitem_clear_value(&ns->items[j]); - } - return -1; - } - } - return 0; -} +struct xi_session { +#define SESSION_UNUSED 0 +#define SESSION_ACTIVE 1 + int status; + int switched; + + // Once a session has been entered, this is the tstate that was + // current before the session. If it is different from cur_tstate + // then we must have switched interpreters. Either way, this will + // be the current tstate once we exit the session. + PyThreadState *prev_tstate; + // Once a session has been entered, this is the current tstate. + // It must be current when the session exits. + PyThreadState *init_tstate; + // This is true if init_tstate needs cleanup during exit. + int own_init_tstate; + + // This is true if, while entering the session, init_thread took + // "ownership" of the interpreter's __main__ module. This means + // it is the only thread that is allowed to run code there. + // (Caveat: for now, users may still run exec() against the + // __main__ module's dict, though that isn't advisable.) + int running; + // This is a cached reference to the __dict__ of the entered + // interpreter's __main__ module. It is looked up when at the + // beginning of the session as a convenience. + PyObject *main_ns; + + // This is a dict of objects that will be available (via sharing) + // once the session exits. Do not access this directly; use + // _PyXI_Preserve() and _PyXI_GetPreserved() instead; + PyObject *_preserved; + + struct xi_session_error error; +}; -// All items are expected to be shareable. -static _PyXI_namespace * -_PyXI_NamespaceFromDict(PyObject *nsobj, _PyXI_session *session) +_PyXI_session * +_PyXI_NewSession(void) { - // session must be entered already, if provided. - assert(session == NULL || _session_is_active(session)); - if (nsobj == NULL || nsobj == Py_None) { - return NULL; - } - if (!PyDict_CheckExact(nsobj)) { - PyErr_SetString(PyExc_TypeError, "expected a dict"); - return NULL; - } - - _PyXI_namespace *ns = _sharedns_new(); - if (ns == NULL) { + _PyXI_session *session = PyMem_RawCalloc(1, sizeof(_PyXI_session)); + if (session == NULL) { + PyErr_NoMemory(); return NULL; } + return session; +} - if (_sharedns_init(ns, nsobj) < 0) { - if (PyDict_Size(nsobj) == 0) { - PyMem_RawFree(ns); - PyErr_Clear(); - return NULL; - } - goto error; - } - - if (_PyXI_FillNamespaceFromDict(ns, nsobj, session) < 0) { - goto error; - } +void +_PyXI_FreeSession(_PyXI_session *session) +{ + assert(session->status == SESSION_UNUSED); + PyMem_RawFree(session); +} - return ns; -error: - assert(PyErr_Occurred() - || (session != NULL && session->error_override != NULL)); - _sharedns_free(ns); - return NULL; +static inline int +_session_is_active(_PyXI_session *session) +{ + return session->status == SESSION_ACTIVE; } -int -_PyXI_ApplyNamespace(_PyXI_namespace *ns, PyObject *nsobj, PyObject *dflt) +static int +_session_pop_error(_PyXI_session *session, struct xi_session_error *err) { - for (Py_ssize_t i=0; i < ns->len; i++) { - if (_sharednsitem_apply(&ns->items[i], nsobj, dflt) != 0) { - return -1; - } + if (session->error.info == NULL) { + assert(session->error.override == NULL); + *err = (struct xi_session_error){0}; + return 0; } - return 0; + *err = session->error; + err->info = &err->_info; + if (err->override != NULL) { + err->override = &err->_override; + } + session->error = (struct xi_session_error){0}; + return 1; } +static int _ensure_main_ns(_PyXI_session *, _PyXI_errcode *); +static inline void _session_set_error(_PyXI_session *, _PyXI_errcode); -/**********************/ -/* high-level helpers */ -/**********************/ /* enter/exit a cross-interpreter session */ @@ -2178,6 +2344,7 @@ static void _enter_session(_PyXI_session *session, PyInterpreterState *interp) { // Set here and cleared in _exit_session(). + assert(session->status == SESSION_UNUSED); assert(!session->own_init_tstate); assert(session->init_tstate == NULL); assert(session->prev_tstate == NULL); @@ -2185,22 +2352,29 @@ _enter_session(_PyXI_session *session, PyInterpreterState *interp) assert(!session->running); assert(session->main_ns == NULL); // Set elsewhere and cleared in _capture_current_exception(). - assert(session->error_override == NULL); - // Set elsewhere and cleared in _PyXI_ApplyCapturedException(). - assert(session->error == NULL); + assert(session->error.override == NULL); + // Set elsewhere and cleared in _PyXI_Exit(). + assert(session->error.info == NULL); // Switch to interpreter. PyThreadState *tstate = PyThreadState_Get(); PyThreadState *prev = tstate; - if (interp != tstate->interp) { + int same_interp = (interp == tstate->interp); + if (!same_interp) { tstate = _PyThreadState_NewBound(interp, _PyThreadState_WHENCE_EXEC); // XXX Possible GILState issues? - session->prev_tstate = PyThreadState_Swap(tstate); - assert(session->prev_tstate == prev); - session->own_init_tstate = 1; + PyThreadState *swapped = PyThreadState_Swap(tstate); + assert(swapped == prev); + (void)swapped; } - session->init_tstate = tstate; - session->prev_tstate = prev; + + *session = (_PyXI_session){ + .status = SESSION_ACTIVE, + .switched = !same_interp, + .init_tstate = tstate, + .prev_tstate = prev, + .own_init_tstate = !same_interp, + }; } static void @@ -2209,16 +2383,16 @@ _exit_session(_PyXI_session *session) PyThreadState *tstate = session->init_tstate; assert(tstate != NULL); assert(PyThreadState_Get() == tstate); + assert(!_PyErr_Occurred(tstate)); // Release any of the entered interpreters resources. - if (session->main_ns != NULL) { - Py_CLEAR(session->main_ns); - } + Py_CLEAR(session->main_ns); + Py_CLEAR(session->_preserved); // Ensure this thread no longer owns __main__. if (session->running) { _PyInterpreterState_SetNotRunningMain(tstate->interp); - assert(!PyErr_Occurred()); + assert(!_PyErr_Occurred(tstate)); session->running = 0; } @@ -2234,24 +2408,17 @@ _exit_session(_PyXI_session *session) else { assert(!session->own_init_tstate); } - session->prev_tstate = NULL; - session->init_tstate = NULL; -} -#ifndef NDEBUG -static int -_session_is_active(_PyXI_session *session) -{ - return (session->init_tstate != NULL); + assert(session->error.info == NULL); + assert(session->error.override == _PyXI_ERR_NO_ERROR); + + *session = (_PyXI_session){0}; } -#endif static void -_propagate_not_shareable_error(_PyXI_session *session) +_propagate_not_shareable_error(_PyXI_errcode *p_errcode) { - if (session == NULL) { - return; - } + assert(p_errcode != NULL); PyThreadState *tstate = PyThreadState_Get(); PyObject *exctype = get_notshareableerror_type(tstate); if (exctype == NULL) { @@ -2261,23 +2428,218 @@ _propagate_not_shareable_error(_PyXI_session *session) } if (PyErr_ExceptionMatches(exctype)) { // We want to propagate the exception directly. - session->_error_override = _PyXI_ERR_NOT_SHAREABLE; - session->error_override = &session->_error_override; + *p_errcode = _PyXI_ERR_NOT_SHAREABLE; + } +} + +int +_PyXI_Enter(_PyXI_session *session, + PyInterpreterState *interp, PyObject *nsupdates, + _PyXI_session_result *result) +{ + // Convert the attrs for cross-interpreter use. + _PyXI_namespace *sharedns = NULL; + if (nsupdates != NULL) { + Py_ssize_t len = PyDict_Size(nsupdates); + if (len < 0) { + if (result != NULL) { + result->errcode = _PyXI_ERR_APPLY_NS_FAILURE; + } + return -1; + } + if (len > 0) { + sharedns = _create_sharedns(nsupdates); + if (sharedns == NULL) { + if (result != NULL) { + result->errcode = _PyXI_ERR_APPLY_NS_FAILURE; + } + return -1; + } + // For now we limit it to shareable objects. + xidata_fallback_t fallback = _PyXIDATA_XIDATA_ONLY; + _PyXI_errcode errcode = _PyXI_ERR_NO_ERROR; + if (_fill_sharedns(sharedns, nsupdates, fallback, &errcode) < 0) { + assert(PyErr_Occurred()); + assert(session->error.info == NULL); + if (errcode == _PyXI_ERR_NO_ERROR) { + errcode = _PyXI_ERR_UNCAUGHT_EXCEPTION; + } + _destroy_sharedns(sharedns); + if (result != NULL) { + result->errcode = errcode; + } + return -1; + } + } + } + + // Switch to the requested interpreter (if necessary). + _enter_session(session, interp); + _PyXI_errcode errcode = _PyXI_ERR_UNCAUGHT_EXCEPTION; + + // Ensure this thread owns __main__. + if (_PyInterpreterState_SetRunningMain(interp) < 0) { + // In the case where we didn't switch interpreters, it would + // be more efficient to leave the exception in place and return + // immediately. However, life is simpler if we don't. + errcode = _PyXI_ERR_ALREADY_RUNNING; + goto error; + } + session->running = 1; + + // Apply the cross-interpreter data. + if (sharedns != NULL) { + if (_ensure_main_ns(session, &errcode) < 0) { + goto error; + } + if (_apply_sharedns(sharedns, session->main_ns, NULL) < 0) { + errcode = _PyXI_ERR_APPLY_NS_FAILURE; + goto error; + } + _destroy_sharedns(sharedns); + } + + errcode = _PyXI_ERR_NO_ERROR; + assert(!PyErr_Occurred()); + return 0; + +error: + // We want to propagate all exceptions here directly (best effort). + assert(errcode != _PyXI_ERR_NO_ERROR); + _session_set_error(session, errcode); + assert(!PyErr_Occurred()); + + // Exit the session. + struct xi_session_error err; + (void)_session_pop_error(session, &err); + _exit_session(session); + + if (sharedns != NULL) { + _destroy_sharedns(sharedns); + } + + // Apply the error from the other interpreter. + PyObject *excinfo = _PyXI_ApplyError(err.info); + _PyXI_excinfo_clear(&err.info->uncaught); + if (excinfo != NULL) { + if (result != NULL) { + result->excinfo = excinfo; + } + else { +#ifdef Py_DEBUG + fprintf(stderr, "_PyXI_Enter(): uncaught exception discarded"); +#endif + } + } + assert(PyErr_Occurred()); + + return -1; +} + +static int _pop_preserved(_PyXI_session *, _PyXI_namespace **, PyObject **, + _PyXI_errcode *); +static int _finish_preserved(_PyXI_namespace *, PyObject **); + +int +_PyXI_Exit(_PyXI_session *session, _PyXI_errcode errcode, + _PyXI_session_result *result) +{ + int res = 0; + + // Capture the raised exception, if any. + assert(session->error.info == NULL); + if (PyErr_Occurred()) { + _session_set_error(session, errcode); + assert(!PyErr_Occurred()); + } + else { + assert(errcode == _PyXI_ERR_NO_ERROR); + assert(session->error.override == NULL); + } + + // Capture the preserved namespace. + _PyXI_namespace *preserved = NULL; + PyObject *preservedobj = NULL; + if (result != NULL) { + errcode = _PyXI_ERR_NO_ERROR; + if (_pop_preserved(session, &preserved, &preservedobj, &errcode) < 0) { + if (session->error.info != NULL) { + // XXX Chain the exception (i.e. set __context__)? + PyErr_FormatUnraisable( + "Exception ignored while capturing preserved objects"); + } + else { + _session_set_error(session, errcode); + } + } + } + + // Exit the session. + struct xi_session_error err; + (void)_session_pop_error(session, &err); + _exit_session(session); + + // Restore the preserved namespace. + assert(preserved == NULL || preservedobj == NULL); + if (_finish_preserved(preserved, &preservedobj) < 0) { + assert(preservedobj == NULL); + if (err.info != NULL) { + // XXX Chain the exception (i.e. set __context__)? + PyErr_FormatUnraisable( + "Exception ignored while capturing preserved objects"); + } + else { + errcode = _PyXI_ERR_PRESERVE_FAILURE; + _propagate_not_shareable_error(&errcode); + } + } + if (result != NULL) { + result->preserved = preservedobj; + result->errcode = errcode; + } + + // Apply the error from the other interpreter, if any. + if (err.info != NULL) { + res = -1; + assert(!PyErr_Occurred()); + PyObject *excinfo = _PyXI_ApplyError(err.info); + _PyXI_excinfo_clear(&err.info->uncaught); + if (excinfo == NULL) { + assert(PyErr_Occurred()); + if (result != NULL) { + _PyXI_ClearResult(result); + *result = (_PyXI_session_result){ + .errcode = _PyXI_ERR_EXC_PROPAGATION_FAILURE, + }; + } + } + else if (result != NULL) { + result->excinfo = excinfo; + } + else { +#ifdef Py_DEBUG + fprintf(stderr, "_PyXI_Exit(): uncaught exception discarded"); +#endif + } } + return res; } + +/* in an active cross-interpreter session */ + static void _capture_current_exception(_PyXI_session *session) { - assert(session->error == NULL); + assert(session->error.info == NULL); if (!PyErr_Occurred()) { - assert(session->error_override == NULL); + assert(session->error.override == NULL); return; } // Handle the exception override. - _PyXI_errcode *override = session->error_override; - session->error_override = NULL; + _PyXI_errcode *override = session->error.override; + session->error.override = NULL; _PyXI_errcode errcode = override != NULL ? *override : _PyXI_ERR_UNCAUGHT_EXCEPTION; @@ -2300,7 +2662,7 @@ _capture_current_exception(_PyXI_session *session) } // Capture the exception. - _PyXI_error *err = &session->_error; + _PyXI_error *err = &session->error._info; *err = (_PyXI_error){ .interp = session->init_tstate->interp, }; @@ -2327,100 +2689,194 @@ _capture_current_exception(_PyXI_session *session) // Finished! assert(!PyErr_Occurred()); - session->error = err; + session->error.info = err; } -PyObject * -_PyXI_ApplyCapturedException(_PyXI_session *session) +static inline void +_session_set_error(_PyXI_session *session, _PyXI_errcode errcode) { - assert(!PyErr_Occurred()); - assert(session->error != NULL); - PyObject *res = _PyXI_ApplyError(session->error); - assert((res == NULL) != (PyErr_Occurred() == NULL)); - session->error = NULL; - return res; + assert(_session_is_active(session)); + assert(PyErr_Occurred()); + if (errcode == _PyXI_ERR_NO_ERROR) { + // We're a bit forgiving here. + errcode = _PyXI_ERR_UNCAUGHT_EXCEPTION; + } + if (errcode != _PyXI_ERR_UNCAUGHT_EXCEPTION) { + session->error._override = errcode; + session->error.override = &session->error._override; + } + _capture_current_exception(session); } -int -_PyXI_HasCapturedException(_PyXI_session *session) +static int +_ensure_main_ns(_PyXI_session *session, _PyXI_errcode *p_errcode) { - return session->error != NULL; + assert(_session_is_active(session)); + if (session->main_ns != NULL) { + return 0; + } + // Cache __main__.__dict__. + PyObject *main_mod = _Py_GetMainModule(session->init_tstate); + if (_Py_CheckMainModule(main_mod) < 0) { + if (p_errcode != NULL) { + *p_errcode = _PyXI_ERR_MAIN_NS_FAILURE; + } + return -1; + } + PyObject *ns = PyModule_GetDict(main_mod); // borrowed + Py_DECREF(main_mod); + if (ns == NULL) { + if (p_errcode != NULL) { + *p_errcode = _PyXI_ERR_MAIN_NS_FAILURE; + } + return -1; + } + session->main_ns = Py_NewRef(ns); + return 0; } -int -_PyXI_Enter(_PyXI_session *session, - PyInterpreterState *interp, PyObject *nsupdates) +PyObject * +_PyXI_GetMainNamespace(_PyXI_session *session, _PyXI_errcode *p_errcode) { - // Convert the attrs for cross-interpreter use. - _PyXI_namespace *sharedns = NULL; - if (nsupdates != NULL) { - sharedns = _PyXI_NamespaceFromDict(nsupdates, NULL); - if (sharedns == NULL && PyErr_Occurred()) { - assert(session->error == NULL); - return -1; - } + if (!_session_is_active(session)) { + PyErr_SetString(PyExc_RuntimeError, "session not active"); + return NULL; + } + if (_ensure_main_ns(session, p_errcode) < 0) { + return NULL; } + return session->main_ns; +} - // Switch to the requested interpreter (if necessary). - _enter_session(session, interp); - PyThreadState *session_tstate = session->init_tstate; - _PyXI_errcode errcode = _PyXI_ERR_UNCAUGHT_EXCEPTION; - // Ensure this thread owns __main__. - if (_PyInterpreterState_SetRunningMain(interp) < 0) { - // In the case where we didn't switch interpreters, it would - // be more efficient to leave the exception in place and return - // immediately. However, life is simpler if we don't. - errcode = _PyXI_ERR_ALREADY_RUNNING; - goto error; +static int +_pop_preserved(_PyXI_session *session, + _PyXI_namespace **p_xidata, PyObject **p_obj, + _PyXI_errcode *p_errcode) +{ + assert(_PyThreadState_GET() == session->init_tstate); // active session + if (session->_preserved == NULL) { + *p_xidata = NULL; + *p_obj = NULL; + return 0; } - session->running = 1; + if (session->init_tstate == session->prev_tstate) { + // We did not switch interpreters. + *p_xidata = NULL; + *p_obj = session->_preserved; + session->_preserved = NULL; + return 0; + } + *p_obj = NULL; - // Cache __main__.__dict__. - PyObject *main_mod = _Py_GetMainModule(session_tstate); - if (_Py_CheckMainModule(main_mod) < 0) { - errcode = _PyXI_ERR_MAIN_NS_FAILURE; - goto error; + // We did switch interpreters. + Py_ssize_t len = PyDict_Size(session->_preserved); + if (len < 0) { + if (p_errcode != NULL) { + *p_errcode = _PyXI_ERR_PRESERVE_FAILURE; + } + return -1; } - PyObject *ns = PyModule_GetDict(main_mod); // borrowed - Py_DECREF(main_mod); - if (ns == NULL) { - errcode = _PyXI_ERR_MAIN_NS_FAILURE; - goto error; + else if (len == 0) { + *p_xidata = NULL; } - session->main_ns = Py_NewRef(ns); + else { + _PyXI_namespace *xidata = _create_sharedns(session->_preserved); + if (xidata == NULL) { + if (p_errcode != NULL) { + *p_errcode = _PyXI_ERR_PRESERVE_FAILURE; + } + return -1; + } + _PyXI_errcode errcode = _PyXI_ERR_NO_ERROR; + if (_fill_sharedns(xidata, session->_preserved, + _PyXIDATA_FULL_FALLBACK, &errcode) < 0) + { + assert(session->error.info == NULL); + if (errcode != _PyXI_ERR_NOT_SHAREABLE) { + errcode = _PyXI_ERR_PRESERVE_FAILURE; + } + if (p_errcode != NULL) { + *p_errcode = errcode; + } + _destroy_sharedns(xidata); + return -1; + } + *p_xidata = xidata; + } + Py_CLEAR(session->_preserved); + return 0; +} - // Apply the cross-interpreter data. - if (sharedns != NULL) { - if (_PyXI_ApplyNamespace(sharedns, ns, NULL) < 0) { - errcode = _PyXI_ERR_APPLY_NS_FAILURE; - goto error; +static int +_finish_preserved(_PyXI_namespace *xidata, PyObject **p_preserved) +{ + if (xidata == NULL) { + return 0; + } + int res = -1; + if (p_preserved != NULL) { + PyObject *ns = PyDict_New(); + if (ns == NULL) { + goto finally; + } + if (_apply_sharedns(xidata, ns, NULL) < 0) { + Py_CLEAR(ns); + goto finally; } - _PyXI_FreeNamespace(sharedns); + *p_preserved = ns; } + res = 0; - errcode = _PyXI_ERR_NO_ERROR; - assert(!PyErr_Occurred()); +finally: + _destroy_sharedns(xidata); + return res; +} + +int +_PyXI_Preserve(_PyXI_session *session, const char *name, PyObject *value, + _PyXI_errcode *p_errcode) +{ + if (!_session_is_active(session)) { + PyErr_SetString(PyExc_RuntimeError, "session not active"); + return -1; + } + if (session->_preserved == NULL) { + session->_preserved = PyDict_New(); + if (session->_preserved == NULL) { + set_exc_with_cause(PyExc_RuntimeError, + "failed to initialize preserved objects"); + if (p_errcode != NULL) { + *p_errcode = _PyXI_ERR_PRESERVE_FAILURE; + } + return -1; + } + } + if (PyDict_SetItemString(session->_preserved, name, value) < 0) { + set_exc_with_cause(PyExc_RuntimeError, "failed to preserve object"); + if (p_errcode != NULL) { + *p_errcode = _PyXI_ERR_PRESERVE_FAILURE; + } + return -1; + } return 0; +} -error: - assert(PyErr_Occurred()); - // We want to propagate all exceptions here directly (best effort). - assert(errcode != _PyXI_ERR_UNCAUGHT_EXCEPTION); - session->error_override = &errcode; - _capture_current_exception(session); - _exit_session(session); - if (sharedns != NULL) { - _PyXI_FreeNamespace(sharedns); +PyObject * +_PyXI_GetPreserved(_PyXI_session_result *result, const char *name) +{ + PyObject *value = NULL; + if (result->preserved != NULL) { + (void)PyDict_GetItemStringRef(result->preserved, name, &value); } - return -1; + return value; } void -_PyXI_Exit(_PyXI_session *session) +_PyXI_ClearResult(_PyXI_session_result *result) { - _capture_current_exception(session); - _exit_session(session); + Py_CLEAR(result->preserved); + Py_CLEAR(result->excinfo); } |