diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/greenlet/PyGreenlet.cpp')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/greenlet/PyGreenlet.cpp | 738 |
1 files changed, 738 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/greenlet/PyGreenlet.cpp b/.venv/lib/python3.12/site-packages/greenlet/PyGreenlet.cpp new file mode 100644 index 00000000..29c0bba0 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/greenlet/PyGreenlet.cpp @@ -0,0 +1,738 @@ +/* -*- indent-tabs-mode: nil; tab-width: 4; -*- */ +#ifndef PYGREENLET_CPP +#define PYGREENLET_CPP +/***************** +The Python slot functions for TGreenlet. + */ + + +#define PY_SSIZE_T_CLEAN +#include <Python.h> +#include "structmember.h" // PyMemberDef + +#include "greenlet_internal.hpp" +#include "TThreadStateDestroy.cpp" +#include "TGreenlet.hpp" +// #include "TUserGreenlet.cpp" +// #include "TMainGreenlet.cpp" +// #include "TBrokenGreenlet.cpp" + + +#include "greenlet_refs.hpp" +#include "greenlet_slp_switch.hpp" + +#include "greenlet_thread_support.hpp" +#include "TGreenlet.hpp" + +#include "TGreenletGlobals.cpp" +#include "TThreadStateDestroy.cpp" +#include "PyGreenlet.hpp" +// #include "TGreenlet.cpp" + +// #include "TExceptionState.cpp" +// #include "TPythonState.cpp" +// #include "TStackState.cpp" + +using greenlet::LockGuard; +using greenlet::LockInitError; +using greenlet::PyErrOccurred; +using greenlet::Require; + +using greenlet::g_handle_exit; +using greenlet::single_result; + +using greenlet::Greenlet; +using greenlet::UserGreenlet; +using greenlet::MainGreenlet; +using greenlet::BrokenGreenlet; +using greenlet::ThreadState; +using greenlet::PythonState; + + + +static PyGreenlet* +green_new(PyTypeObject* type, PyObject* UNUSED(args), PyObject* UNUSED(kwds)) +{ + PyGreenlet* o = + (PyGreenlet*)PyBaseObject_Type.tp_new(type, mod_globs->empty_tuple, mod_globs->empty_dict); + if (o) { + new UserGreenlet(o, GET_THREAD_STATE().state().borrow_current()); + assert(Py_REFCNT(o) == 1); + } + return o; +} + + +// green_init is used in the tp_init slot. So it's important that +// it can be called directly from CPython. Thus, we don't use +// BorrowedGreenlet and BorrowedObject --- although in theory +// these should be binary layout compatible, that may not be +// guaranteed to be the case (32-bit linux ppc possibly). +static int +green_init(PyGreenlet* self, PyObject* args, PyObject* kwargs) +{ + PyArgParseParam run; + PyArgParseParam nparent; + static const char* kwlist[] = { + "run", + "parent", + NULL + }; + + // recall: The O specifier does NOT increase the reference count. + if (!PyArg_ParseTupleAndKeywords( + args, kwargs, "|OO:green", (char**)kwlist, &run, &nparent)) { + return -1; + } + + if (run) { + if (green_setrun(self, run, NULL)) { + return -1; + } + } + if (nparent && !nparent.is_None()) { + return green_setparent(self, nparent, NULL); + } + return 0; +} + + + +static int +green_traverse(PyGreenlet* self, visitproc visit, void* arg) +{ + // We must only visit referenced objects, i.e. only objects + // Py_INCREF'ed by this greenlet (directly or indirectly): + // + // - stack_prev is not visited: holds previous stack pointer, but it's not + // referenced + // - frames are not visited as we don't strongly reference them; + // alive greenlets are not garbage collected + // anyway. This can be a problem, however, if this greenlet is + // never allowed to finish, and is referenced from the frame: we + // have an uncollectible cycle in that case. Note that the + // frame object itself is also frequently not even tracked by the GC + // starting with Python 3.7 (frames are allocated by the + // interpreter untracked, and only become tracked when their + // evaluation is finished if they have a refcount > 1). All of + // this is to say that we should probably strongly reference + // the frame object. Doing so, while always allowing GC on a + // greenlet, solves several leaks for us. + + Py_VISIT(self->dict); + if (!self->pimpl) { + // Hmm. I have seen this at interpreter shutdown time, + // I think. That's very odd because this doesn't go away until + // we're ``green_dealloc()``, at which point we shouldn't be + // traversed anymore. + return 0; + } + + return self->pimpl->tp_traverse(visit, arg); +} + +static int +green_is_gc(PyObject* _self) +{ + BorrowedGreenlet self(_self); + int result = 0; + /* Main greenlet can be garbage collected since it can only + become unreachable if the underlying thread exited. + Active greenlets --- including those that are suspended --- + cannot be garbage collected, however. + */ + if (self->main() || !self->active()) { + result = 1; + } + // The main greenlet pointer will eventually go away after the thread dies. + if (self->was_running_in_dead_thread()) { + // Our thread is dead! We can never run again. Might as well + // GC us. Note that if a tuple containing only us and other + // immutable objects had been scanned before this, when we + // would have returned 0, the tuple will take itself out of GC + // tracking and never be investigated again. So that could + // result in both us and the tuple leaking due to an + // unreachable/uncollectible reference. The same goes for + // dictionaries. + // + // It's not a great idea to be changing our GC state on the + // fly. + result = 1; + } + return result; +} + + +static int +green_clear(PyGreenlet* self) +{ + /* Greenlet is only cleared if it is about to be collected. + Since active greenlets are not garbage collectable, we can + be sure that, even if they are deallocated during clear, + nothing they reference is in unreachable or finalizers, + so even if it switches we are relatively safe. */ + // XXX: Are we responsible for clearing weakrefs here? + Py_CLEAR(self->dict); + return self->pimpl->tp_clear(); +} + +/** + * Returns 0 on failure (the object was resurrected) or 1 on success. + **/ +static int +_green_dealloc_kill_started_non_main_greenlet(BorrowedGreenlet self) +{ + /* Hacks hacks hacks copied from instance_dealloc() */ + /* Temporarily resurrect the greenlet. */ + assert(self.REFCNT() == 0); + Py_SET_REFCNT(self.borrow(), 1); + /* Save the current exception, if any. */ + PyErrPieces saved_err; + try { + // BY THE TIME WE GET HERE, the state may actually be going + // away + // if we're shutting down the interpreter and freeing thread + // entries, + // this could result in freeing greenlets that were leaked. So + // we can't try to read the state. + self->deallocing_greenlet_in_thread( + self->thread_state() + ? static_cast<ThreadState*>(GET_THREAD_STATE()) + : nullptr); + } + catch (const PyErrOccurred&) { + PyErr_WriteUnraisable(self.borrow_o()); + /* XXX what else should we do? */ + } + /* Check for no resurrection must be done while we keep + * our internal reference, otherwise PyFile_WriteObject + * causes recursion if using Py_INCREF/Py_DECREF + */ + if (self.REFCNT() == 1 && self->active()) { + /* Not resurrected, but still not dead! + XXX what else should we do? we complain. */ + PyObject* f = PySys_GetObject("stderr"); + Py_INCREF(self.borrow_o()); /* leak! */ + if (f != NULL) { + PyFile_WriteString("GreenletExit did not kill ", f); + PyFile_WriteObject(self.borrow_o(), f, 0); + PyFile_WriteString("\n", f); + } + } + /* Restore the saved exception. */ + saved_err.PyErrRestore(); + /* Undo the temporary resurrection; can't use DECREF here, + * it would cause a recursive call. + */ + assert(self.REFCNT() > 0); + + Py_ssize_t refcnt = self.REFCNT() - 1; + Py_SET_REFCNT(self.borrow_o(), refcnt); + if (refcnt != 0) { + /* Resurrected! */ + _Py_NewReference(self.borrow_o()); + Py_SET_REFCNT(self.borrow_o(), refcnt); + /* Better to use tp_finalizer slot (PEP 442) + * and call ``PyObject_CallFinalizerFromDealloc``, + * but that's only supported in Python 3.4+; see + * Modules/_io/iobase.c for an example. + * + * The following approach is copied from iobase.c in CPython 2.7. + * (along with much of this function in general). Here's their + * comment: + * + * When called from a heap type's dealloc, the type will be + * decref'ed on return (see e.g. subtype_dealloc in typeobject.c). */ + if (PyType_HasFeature(self.TYPE(), Py_TPFLAGS_HEAPTYPE)) { + Py_INCREF(self.TYPE()); + } + + PyObject_GC_Track((PyObject*)self); + + _Py_DEC_REFTOTAL; +#ifdef COUNT_ALLOCS + --Py_TYPE(self)->tp_frees; + --Py_TYPE(self)->tp_allocs; +#endif /* COUNT_ALLOCS */ + return 0; + } + return 1; +} + + +static void +green_dealloc(PyGreenlet* self) +{ + PyObject_GC_UnTrack(self); + BorrowedGreenlet me(self); + if (me->active() + && me->started() + && !me->main()) { + if (!_green_dealloc_kill_started_non_main_greenlet(me)) { + return; + } + } + + if (self->weakreflist != NULL) { + PyObject_ClearWeakRefs((PyObject*)self); + } + Py_CLEAR(self->dict); + + if (self->pimpl) { + // In case deleting this, which frees some memory, + // somehow winds up calling back into us. That's usually a + //bug in our code. + Greenlet* p = self->pimpl; + self->pimpl = nullptr; + delete p; + } + // and finally we're done. self is now invalid. + Py_TYPE(self)->tp_free((PyObject*)self); +} + + + +static OwnedObject +internal_green_throw(BorrowedGreenlet self, PyErrPieces& err_pieces) +{ + PyObject* result = nullptr; + err_pieces.PyErrRestore(); + assert(PyErr_Occurred()); + if (self->started() && !self->active()) { + /* dead greenlet: turn GreenletExit into a regular return */ + result = g_handle_exit(OwnedObject()).relinquish_ownership(); + } + self->args() <<= result; + + return single_result(self->g_switch()); +} + + + +PyDoc_STRVAR( + green_switch_doc, + "switch(*args, **kwargs)\n" + "\n" + "Switch execution to this greenlet.\n" + "\n" + "If this greenlet has never been run, then this greenlet\n" + "will be switched to using the body of ``self.run(*args, **kwargs)``.\n" + "\n" + "If the greenlet is active (has been run, but was switch()'ed\n" + "out before leaving its run function), then this greenlet will\n" + "be resumed and the return value to its switch call will be\n" + "None if no arguments are given, the given argument if one\n" + "argument is given, or the args tuple and keyword args dict if\n" + "multiple arguments are given.\n" + "\n" + "If the greenlet is dead, or is the current greenlet then this\n" + "function will simply return the arguments using the same rules as\n" + "above.\n"); + +static PyObject* +green_switch(PyGreenlet* self, PyObject* args, PyObject* kwargs) +{ + using greenlet::SwitchingArgs; + SwitchingArgs switch_args(OwnedObject::owning(args), OwnedObject::owning(kwargs)); + self->pimpl->may_switch_away(); + self->pimpl->args() <<= switch_args; + + // If we're switching out of a greenlet, and that switch is the + // last thing the greenlet does, the greenlet ought to be able to + // go ahead and die at that point. Currently, someone else must + // manually switch back to the greenlet so that we "fall off the + // end" and can perform cleanup. You'd think we'd be able to + // figure out that this is happening using the frame's ``f_lasti`` + // member, which is supposed to be an index into + // ``frame->f_code->co_code``, the bytecode string. However, in + // recent interpreters, ``f_lasti`` tends not to be updated thanks + // to things like the PREDICT() macros in ceval.c. So it doesn't + // really work to do that in many cases. For example, the Python + // code: + // def run(): + // greenlet.getcurrent().parent.switch() + // produces bytecode of len 16, with the actual call to switch() + // being at index 10 (in Python 3.10). However, the reported + // ``f_lasti`` we actually see is...5! (Which happens to be the + // second byte of the CALL_METHOD op for ``getcurrent()``). + + try { + //OwnedObject result = single_result(self->pimpl->g_switch()); + OwnedObject result(single_result(self->pimpl->g_switch())); +#ifndef NDEBUG + // Note that the current greenlet isn't necessarily self. If self + // finished, we went to one of its parents. + assert(!self->pimpl->args()); + + const BorrowedGreenlet& current = GET_THREAD_STATE().state().borrow_current(); + // It's possible it's never been switched to. + assert(!current->args()); +#endif + PyObject* p = result.relinquish_ownership(); + + if (!p && !PyErr_Occurred()) { + // This shouldn't be happening anymore, so the asserts + // are there for debug builds. Non-debug builds + // crash "gracefully" in this case, although there is an + // argument to be made for killing the process in all + // cases --- for this to be the case, our switches + // probably nested in an incorrect way, so the state is + // suspicious. Nothing should be corrupt though, just + // confused at the Python level. Letting this propagate is + // probably good enough. + assert(p || PyErr_Occurred()); + throw PyErrOccurred( + mod_globs->PyExc_GreenletError, + "Greenlet.switch() returned NULL without an exception set." + ); + } + return p; + } + catch(const PyErrOccurred&) { + return nullptr; + } +} + +PyDoc_STRVAR( + green_throw_doc, + "Switches execution to this greenlet, but immediately raises the\n" + "given exception in this greenlet. If no argument is provided, the " + "exception\n" + "defaults to `greenlet.GreenletExit`. The normal exception\n" + "propagation rules apply, as described for `switch`. Note that calling " + "this\n" + "method is almost equivalent to the following::\n" + "\n" + " def raiser():\n" + " raise typ, val, tb\n" + " g_raiser = greenlet(raiser, parent=g)\n" + " g_raiser.switch()\n" + "\n" + "except that this trick does not work for the\n" + "`greenlet.GreenletExit` exception, which would not propagate\n" + "from ``g_raiser`` to ``g``.\n"); + +static PyObject* +green_throw(PyGreenlet* self, PyObject* args) +{ + PyArgParseParam typ(mod_globs->PyExc_GreenletExit); + PyArgParseParam val; + PyArgParseParam tb; + + if (!PyArg_ParseTuple(args, "|OOO:throw", &typ, &val, &tb)) { + return nullptr; + } + + assert(typ.borrow() || val.borrow()); + + self->pimpl->may_switch_away(); + try { + // Both normalizing the error and the actual throw_greenlet + // could throw PyErrOccurred. + PyErrPieces err_pieces(typ.borrow(), val.borrow(), tb.borrow()); + + return internal_green_throw(self, err_pieces).relinquish_ownership(); + } + catch (const PyErrOccurred&) { + return nullptr; + } +} + +static int +green_bool(PyGreenlet* self) +{ + return self->pimpl->active(); +} + +/** + * CAUTION: Allocates memory, may run GC and arbitrary Python code. + */ +static PyObject* +green_getdict(PyGreenlet* self, void* UNUSED(context)) +{ + if (self->dict == NULL) { + self->dict = PyDict_New(); + if (self->dict == NULL) { + return NULL; + } + } + Py_INCREF(self->dict); + return self->dict; +} + +static int +green_setdict(PyGreenlet* self, PyObject* val, void* UNUSED(context)) +{ + PyObject* tmp; + + if (val == NULL) { + PyErr_SetString(PyExc_TypeError, "__dict__ may not be deleted"); + return -1; + } + if (!PyDict_Check(val)) { + PyErr_SetString(PyExc_TypeError, "__dict__ must be a dictionary"); + return -1; + } + tmp = self->dict; + Py_INCREF(val); + self->dict = val; + Py_XDECREF(tmp); + return 0; +} + +static bool +_green_not_dead(BorrowedGreenlet self) +{ + // XXX: Where else should we do this? + // Probably on entry to most Python-facing functions? + if (self->was_running_in_dead_thread()) { + self->deactivate_and_free(); + return false; + } + return self->active() || !self->started(); +} + + +static PyObject* +green_getdead(PyGreenlet* self, void* UNUSED(context)) +{ + if (_green_not_dead(self)) { + Py_RETURN_FALSE; + } + else { + Py_RETURN_TRUE; + } +} + +static PyObject* +green_get_stack_saved(PyGreenlet* self, void* UNUSED(context)) +{ + return PyLong_FromSsize_t(self->pimpl->stack_saved()); +} + + +static PyObject* +green_getrun(PyGreenlet* self, void* UNUSED(context)) +{ + try { + OwnedObject result(BorrowedGreenlet(self)->run()); + return result.relinquish_ownership(); + } + catch(const PyErrOccurred&) { + return nullptr; + } +} + + +static int +green_setrun(PyGreenlet* self, PyObject* nrun, void* UNUSED(context)) +{ + try { + BorrowedGreenlet(self)->run(nrun); + return 0; + } + catch(const PyErrOccurred&) { + return -1; + } +} + +static PyObject* +green_getparent(PyGreenlet* self, void* UNUSED(context)) +{ + return BorrowedGreenlet(self)->parent().acquire_or_None(); +} + + +static int +green_setparent(PyGreenlet* self, PyObject* nparent, void* UNUSED(context)) +{ + try { + BorrowedGreenlet(self)->parent(nparent); + } + catch(const PyErrOccurred&) { + return -1; + } + return 0; +} + + +static PyObject* +green_getcontext(const PyGreenlet* self, void* UNUSED(context)) +{ + const Greenlet *const g = self->pimpl; + try { + OwnedObject result(g->context()); + return result.relinquish_ownership(); + } + catch(const PyErrOccurred&) { + return nullptr; + } +} + +static int +green_setcontext(PyGreenlet* self, PyObject* nctx, void* UNUSED(context)) +{ + try { + BorrowedGreenlet(self)->context(nctx); + return 0; + } + catch(const PyErrOccurred&) { + return -1; + } +} + + +static PyObject* +green_getframe(PyGreenlet* self, void* UNUSED(context)) +{ + const PythonState::OwnedFrame& top_frame = BorrowedGreenlet(self)->top_frame(); + return top_frame.acquire_or_None(); +} + + +static PyObject* +green_getstate(PyGreenlet* self) +{ + PyErr_Format(PyExc_TypeError, + "cannot serialize '%s' object", + Py_TYPE(self)->tp_name); + return nullptr; +} + +static PyObject* +green_repr(PyGreenlet* _self) +{ + BorrowedGreenlet self(_self); + /* + Return a string like + <greenlet.greenlet at 0xdeadbeef [current][active started]|dead main> + + The handling of greenlets across threads is not super good. + We mostly use the internal definitions of these terms, but they + generally should make sense to users as well. + */ + PyObject* result; + int never_started = !self->started() && !self->active(); + + const char* const tp_name = Py_TYPE(self)->tp_name; + + if (_green_not_dead(self)) { + /* XXX: The otid= is almost useless because you can't correlate it to + any thread identifier exposed to Python. We could use + PyThreadState_GET()->thread_id, but we'd need to save that in the + greenlet, or save the whole PyThreadState object itself. + + As it stands, its only useful for identifying greenlets from the same thread. + */ + const char* state_in_thread; + if (self->was_running_in_dead_thread()) { + // The thread it was running in is dead! + // This can happen, especially at interpreter shut down. + // It complicates debugging output because it may be + // impossible to access the current thread state at that + // time. Thus, don't access the current thread state. + state_in_thread = " (thread exited)"; + } + else { + state_in_thread = GET_THREAD_STATE().state().is_current(self) + ? " current" + : (self->started() ? " suspended" : ""); + } + result = PyUnicode_FromFormat( + "<%s object at %p (otid=%p)%s%s%s%s>", + tp_name, + self.borrow_o(), + self->thread_state(), + state_in_thread, + self->active() ? " active" : "", + never_started ? " pending" : " started", + self->main() ? " main" : "" + ); + } + else { + result = PyUnicode_FromFormat( + "<%s object at %p (otid=%p) %sdead>", + tp_name, + self.borrow_o(), + self->thread_state(), + self->was_running_in_dead_thread() + ? "(thread exited) " + : "" + ); + } + + return result; +} + + +static PyMethodDef green_methods[] = { + { + .ml_name="switch", + .ml_meth=reinterpret_cast<PyCFunction>(green_switch), + .ml_flags=METH_VARARGS | METH_KEYWORDS, + .ml_doc=green_switch_doc + }, + {.ml_name="throw", .ml_meth=(PyCFunction)green_throw, .ml_flags=METH_VARARGS, .ml_doc=green_throw_doc}, + {.ml_name="__getstate__", .ml_meth=(PyCFunction)green_getstate, .ml_flags=METH_NOARGS, .ml_doc=NULL}, + {.ml_name=NULL, .ml_meth=NULL} /* sentinel */ +}; + +static PyGetSetDef green_getsets[] = { + /* name, getter, setter, doc, context pointer */ + {.name="__dict__", .get=(getter)green_getdict, .set=(setter)green_setdict}, + {.name="run", .get=(getter)green_getrun, .set=(setter)green_setrun}, + {.name="parent", .get=(getter)green_getparent, .set=(setter)green_setparent}, + {.name="gr_frame", .get=(getter)green_getframe }, + { + .name="gr_context", + .get=(getter)green_getcontext, + .set=(setter)green_setcontext + }, + {.name="dead", .get=(getter)green_getdead}, + {.name="_stack_saved", .get=(getter)green_get_stack_saved}, + {.name=NULL} +}; + +static PyMemberDef green_members[] = { + {.name=NULL} +}; + +static PyNumberMethods green_as_number = { + .nb_bool=(inquiry)green_bool, +}; + + +PyTypeObject PyGreenlet_Type = { + .ob_base=PyVarObject_HEAD_INIT(NULL, 0) + .tp_name="greenlet.greenlet", /* tp_name */ + .tp_basicsize=sizeof(PyGreenlet), /* tp_basicsize */ + /* methods */ + .tp_dealloc=(destructor)green_dealloc, /* tp_dealloc */ + .tp_repr=(reprfunc)green_repr, /* tp_repr */ + .tp_as_number=&green_as_number, /* tp_as _number*/ + .tp_flags=G_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */ + .tp_doc="greenlet(run=None, parent=None) -> greenlet\n\n" + "Creates a new greenlet object (without running it).\n\n" + " - *run* -- The callable to invoke.\n" + " - *parent* -- The parent greenlet. The default is the current " + "greenlet.", /* tp_doc */ + .tp_traverse=(traverseproc)green_traverse, /* tp_traverse */ + .tp_clear=(inquiry)green_clear, /* tp_clear */ + .tp_weaklistoffset=offsetof(PyGreenlet, weakreflist), /* tp_weaklistoffset */ + + .tp_methods=green_methods, /* tp_methods */ + .tp_members=green_members, /* tp_members */ + .tp_getset=green_getsets, /* tp_getset */ + .tp_dictoffset=offsetof(PyGreenlet, dict), /* tp_dictoffset */ + .tp_init=(initproc)green_init, /* tp_init */ + .tp_alloc=PyType_GenericAlloc, /* tp_alloc */ + .tp_new=(newfunc)green_new, /* tp_new */ + .tp_free=PyObject_GC_Del, /* tp_free */ + .tp_is_gc=(inquiry)green_is_gc, /* tp_is_gc */ +}; + +#endif + +// Local Variables: +// flycheck-clang-include-path: ("/opt/local/Library/Frameworks/Python.framework/Versions/3.8/include/python3.8") +// End: |