venv

1 files changed, 667 insertions, 0 deletions

diff --git a/venv/lib/python3.11/site-packages/greenlet/TUserGreenlet.cpp b/venv/lib/python3.11/site-packages/greenlet/TUserGreenlet.cpp
new file mode 100644
index 0000000..495a794
--- /dev/null
+++ b/venv/lib/python3.11/site-packages/greenlet/TUserGreenlet.cpp
@@ -0,0 +1,667 @@
+/* -*- indent-tabs-mode: nil; tab-width: 4; -*- */
+/**
+ * Implementation of greenlet::UserGreenlet.
+ *
+ * Format with:
+ *  clang-format -i --style=file src/greenlet/greenlet.c
+ *
+ *
+ * Fix missing braces with:
+ *   clang-tidy src/greenlet/greenlet.c -fix -checks="readability-braces-around-statements"
+*/
+
+#include "greenlet_internal.hpp"
+#include "greenlet_greenlet.hpp"
+#include "greenlet_thread_state.hpp"
+#include "TThreadStateDestroy.cpp"
+
+
+namespace greenlet {
+using greenlet::refs::BorrowedMainGreenlet;
+greenlet::PythonAllocator<UserGreenlet> UserGreenlet::allocator;
+
+void* UserGreenlet::operator new(size_t UNUSED(count))
+{
+    return allocator.allocate(1);
+}
+
+
+void UserGreenlet::operator delete(void* ptr)
+{
+    return allocator.deallocate(static_cast<UserGreenlet*>(ptr),
+                                1);
+}
+
+
+UserGreenlet::UserGreenlet(PyGreenlet* p, BorrowedGreenlet the_parent)
+    : Greenlet(p), _parent(the_parent)
+{
+    this->_self = p;
+}
+
+UserGreenlet::~UserGreenlet()
+{
+    // Python 3.11: If we don't clear out the raw frame datastack
+    // when deleting an unfinished greenlet,
+    // TestLeaks.test_untracked_memory_doesnt_increase_unfinished_thread_dealloc_in_main fails.
+    this->python_state.did_finish(nullptr);
+    this->tp_clear();
+}
+
+BorrowedGreenlet
+UserGreenlet::self() const noexcept
+{
+    return this->_self;
+}
+
+
+
+const BorrowedMainGreenlet
+UserGreenlet::main_greenlet() const
+{
+    return this->_main_greenlet;
+}
+
+
+BorrowedMainGreenlet
+UserGreenlet::find_main_greenlet_in_lineage() const
+{
+    if (this->started()) {
+        assert(this->_main_greenlet);
+        return BorrowedMainGreenlet(this->_main_greenlet);
+    }
+
+    if (!this->_parent) {
+        /* garbage collected greenlet in chain */
+        // XXX: WHAT?
+        return BorrowedMainGreenlet(nullptr);
+    }
+
+    return this->_parent->find_main_greenlet_in_lineage();
+}
+
+
+/**
+ * CAUTION: This will allocate memory and may trigger garbage
+ * collection and arbitrary Python code.
+ */
+OwnedObject
+UserGreenlet::throw_GreenletExit_during_dealloc(const ThreadState& current_thread_state)
+{
+    /* The dying greenlet cannot be a parent of ts_current
+       because the 'parent' field chain would hold a
+       reference */
+    UserGreenlet::ParentIsCurrentGuard with_current_parent(this, current_thread_state);
+
+    // We don't care about the return value, only whether an
+    // exception happened. Whether or not an exception happens,
+    // we need to restore the parent in case the greenlet gets
+    // resurrected.
+    return Greenlet::throw_GreenletExit_during_dealloc(current_thread_state);
+}
+
+ThreadState*
+UserGreenlet::thread_state() const noexcept
+{
+    // TODO: maybe make this throw, if the thread state isn't there?
+    // if (!this->main_greenlet) {
+    //     throw std::runtime_error("No thread state"); // TODO: Better exception
+    // }
+    if (!this->_main_greenlet) {
+        return nullptr;
+    }
+    return this->_main_greenlet->thread_state();
+}
+
+
+bool
+UserGreenlet::was_running_in_dead_thread() const noexcept
+{
+    return this->_main_greenlet && !this->thread_state();
+}
+
+OwnedObject
+UserGreenlet::g_switch()
+{
+    assert(this->args() || PyErr_Occurred());
+
+    try {
+        this->check_switch_allowed();
+    }
+    catch (const PyErrOccurred&) {
+        this->release_args();
+        throw;
+    }
+
+    // Switching greenlets used to attempt to clean out ones that need
+    // deleted *if* we detected a thread switch. Should it still do
+    // that?
+    // An issue is that if we delete a greenlet from another thread,
+    // it gets queued to this thread, and ``kill_greenlet()`` switches
+    // back into the greenlet
+
+    /* find the real target by ignoring dead greenlets,
+       and if necessary starting a greenlet. */
+    switchstack_result_t err;
+    Greenlet* target = this;
+    // TODO: probably cleaner to handle the case where we do
+    // switch to ourself separately from the other cases.
+    // This can probably even further be simplified if we keep
+    // track of the switching_state we're going for and just call
+    // into g_switch() if it's not ourself. The main problem with that
+    // is that we would be using more stack space.
+    bool target_was_me = true;
+    bool was_initial_stub = false;
+    while (target) {
+        if (target->active()) {
+            if (!target_was_me) {
+                target->args() <<= this->args();
+                assert(!this->args());
+            }
+            err = target->g_switchstack();
+            break;
+        }
+        if (!target->started()) {
+            // We never encounter a main greenlet that's not started.
+            assert(!target->main());
+            UserGreenlet* real_target = static_cast<UserGreenlet*>(target);
+            assert(real_target);
+            void* dummymarker;
+            was_initial_stub = true;
+            if (!target_was_me) {
+                target->args() <<= this->args();
+                assert(!this->args());
+            }
+            try {
+                // This can only throw back to us while we're
+                // still in this greenlet. Once the new greenlet
+                // is bootstrapped, it has its own exception state.
+                err = real_target->g_initialstub(&dummymarker);
+            }
+            catch (const PyErrOccurred&) {
+                this->release_args();
+                throw;
+            }
+            catch (const GreenletStartedWhileInPython&) {
+                // The greenlet was started sometime before this
+                // greenlet actually switched to it, i.e.,
+                // "concurrent" calls to switch() or throw().
+                // We need to retry the switch.
+                // Note that the current greenlet has been reset
+                // to this one (or we wouldn't be running!)
+                continue;
+            }
+            break;
+        }
+
+        target = target->parent();
+        target_was_me = false;
+    }
+    // The ``this`` pointer and all other stack or register based
+    // variables are invalid now, at least where things succeed
+    // above.
+    // But this one, probably not so much? It's not clear if it's
+    // safe to throw an exception at this point.
+
+    if (err.status < 0) {
+        // If we get here, either g_initialstub()
+        // failed, or g_switchstack() failed. Either one of those
+        // cases SHOULD leave us in the original greenlet with a valid
+        // stack.
+        return this->on_switchstack_or_initialstub_failure(target, err, target_was_me, was_initial_stub);
+    }
+
+    // err.the_new_current_greenlet would be the same as ``target``,
+    // if target wasn't probably corrupt.
+    return err.the_new_current_greenlet->g_switch_finish(err);
+}
+
+
+
+Greenlet::switchstack_result_t
+UserGreenlet::g_initialstub(void* mark)
+{
+    OwnedObject run;
+
+    // We need to grab a reference to the current switch arguments
+    // in case we're entered concurrently during the call to
+    // GetAttr() and have to try again.
+    // We'll restore them when we return in that case.
+    // Scope them tightly to avoid ref leaks.
+    {
+        SwitchingArgs args(this->args());
+
+        /* save exception in case getattr clears it */
+        PyErrPieces saved;
+
+        /*
+          self.run is the object to call in the new greenlet.
+          This could run arbitrary python code and switch greenlets!
+        */
+        run = this->_self.PyRequireAttr(mod_globs->str_run);
+        /* restore saved exception */
+        saved.PyErrRestore();
+
+
+        /* recheck that it's safe to switch in case greenlet reparented anywhere above */
+        this->check_switch_allowed();
+
+        /* by the time we got here another start could happen elsewhere,
+         * that means it should now be a regular switch.
+         * This can happen if the Python code is a subclass that implements
+         * __getattribute__ or __getattr__, or makes ``run`` a descriptor;
+         * all of those can run arbitrary code that switches back into
+         * this greenlet.
+         */
+        if (this->stack_state.started()) {
+            // the successful switch cleared these out, we need to
+            // restore our version. They will be copied on up to the
+            // next target.
+            assert(!this->args());
+            this->args() <<= args;
+            throw GreenletStartedWhileInPython();
+        }
+    }
+
+    // Sweet, if we got here, we have the go-ahead and will switch
+    // greenlets.
+    // Nothing we do from here on out should allow for a thread or
+    // greenlet switch: No arbitrary calls to Python, including
+    // decref'ing
+
+#if GREENLET_USE_CFRAME
+    /* OK, we need it, we're about to switch greenlets, save the state. */
+    /*
+      See green_new(). This is a stack-allocated variable used
+      while *self* is in PyObject_Call().
+      We want to defer copying the state info until we're sure
+      we need it and are in a stable place to do so.
+    */
+    _PyCFrame trace_info;
+
+    this->python_state.set_new_cframe(trace_info);
+#endif
+    /* start the greenlet */
+    ThreadState& thread_state = GET_THREAD_STATE().state();
+    this->stack_state = StackState(mark,
+                                   thread_state.borrow_current()->stack_state);
+    this->python_state.set_initial_state(PyThreadState_GET());
+    this->exception_state.clear();
+    this->_main_greenlet = thread_state.get_main_greenlet();
+
+    /* perform the initial switch */
+    switchstack_result_t err = this->g_switchstack();
+    /* returns twice!
+       The 1st time with ``err == 1``: we are in the new greenlet.
+       This one owns a greenlet that used to be current.
+       The 2nd time with ``err <= 0``: back in the caller's
+       greenlet; this happens if the child finishes or switches
+       explicitly to us. Either way, the ``err`` variable is
+       created twice at the same memory location, but possibly
+       having different ``origin`` values. Note that it's not
+       constructed for the second time until the switch actually happens.
+    */
+    if (err.status == 1) {
+        // In the new greenlet.
+
+        // This never returns! Calling inner_bootstrap steals
+        // the contents of our run object within this stack frame, so
+        // it is not valid to do anything with it.
+        try {
+            this->inner_bootstrap(err.origin_greenlet.relinquish_ownership(),
+                                  run.relinquish_ownership());
+        }
+        // Getting a C++ exception here isn't good. It's probably a
+        // bug in the underlying greenlet, meaning it's probably a
+        // C++ extension. We're going to abort anyway, but try to
+        // display some nice information *if* possible. Some obscure
+        // platforms don't properly support this (old 32-bit Arm, see see
+        // https://github.com/python-greenlet/greenlet/issues/385); that's not
+        // great, but should usually be OK because, as mentioned above, we're
+        // terminating anyway.
+        //
+        // The catching is tested by
+        // ``test_cpp.CPPTests.test_unhandled_exception_in_greenlet_aborts``.
+        //
+        // PyErrOccurred can theoretically be thrown by
+        // inner_bootstrap() -> g_switch_finish(), but that should
+        // never make it back to here. It is a std::exception and
+        // would be caught if it is.
+        catch (const std::exception& e) {
+            std::string base = "greenlet: Unhandled C++ exception: ";
+            base += e.what();
+            Py_FatalError(base.c_str());
+        }
+        catch (...) {
+            // Some compilers/runtimes use exceptions internally.
+            // It appears that GCC on Linux with libstdc++ throws an
+            // exception internally at process shutdown time to unwind
+            // stacks and clean up resources. Depending on exactly
+            // where we are when the process exits, that could result
+            // in an unknown exception getting here. If we
+            // Py_FatalError() or abort() here, we interfere with
+            // orderly process shutdown. Throwing the exception on up
+            // is the right thing to do.
+            //
+            // gevent's ``examples/dns_mass_resolve.py`` demonstrates this.
+#ifndef NDEBUG
+            fprintf(stderr,
+                    "greenlet: inner_bootstrap threw unknown exception; "
+                    "is the process terminating?\n");
+#endif
+            throw;
+        }
+        Py_FatalError("greenlet: inner_bootstrap returned with no exception.\n");
+    }
+
+
+    // In contrast, notice that we're keeping the origin greenlet
+    // around as an owned reference; we need it to call the trace
+    // function for the switch back into the parent. It was only
+    // captured at the time the switch actually happened, though,
+    // so we haven't been keeping an extra reference around this
+    // whole time.
+
+    /* back in the parent */
+    if (err.status < 0) {
+        /* start failed badly, restore greenlet state */
+        this->stack_state = StackState();
+        this->_main_greenlet.CLEAR();
+        // CAUTION: This may run arbitrary Python code.
+        run.CLEAR(); // inner_bootstrap didn't run, we own the reference.
+    }
+
+    // In the success case, the spawned code (inner_bootstrap) will
+    // take care of decrefing this, so we relinquish ownership so as
+    // to not double-decref.
+
+    run.relinquish_ownership();
+
+    return err;
+}
+
+
+void
+UserGreenlet::inner_bootstrap(PyGreenlet* origin_greenlet, PyObject* run)
+{
+    // The arguments here would be another great place for move.
+    // As it is, we take them as a reference so that when we clear
+    // them we clear what's on the stack above us. Do that NOW, and
+    // without using a C++ RAII object,
+    // so there's no way that exiting the parent frame can clear it,
+    // or we clear it unexpectedly. This arises in the context of the
+    // interpreter shutting down. See https://github.com/python-greenlet/greenlet/issues/325
+    //PyObject* run = _run.relinquish_ownership();
+
+    /* in the new greenlet */
+    assert(this->thread_state()->borrow_current() == this->_self);
+    // C++ exceptions cannot propagate to the parent greenlet from
+    // here. (TODO: Do we need a catch(...) clause, perhaps on the
+    // function itself? ALl we could do is terminate the program.)
+    // NOTE: On 32-bit Windows, the call chain is extremely
+    // important here in ways that are subtle, having to do with
+    // the depth of the SEH list. The call to restore it MUST NOT
+    // add a new SEH handler to the list, or we'll restore it to
+    // the wrong thing.
+    this->thread_state()->restore_exception_state();
+    /* stack variables from above are no good and also will not unwind! */
+    // EXCEPT: That can't be true, we access run, among others, here.
+
+    this->stack_state.set_active(); /* running */
+
+    // We're about to possibly run Python code again, which
+    // could switch back/away to/from us, so we need to grab the
+    // arguments locally.
+    SwitchingArgs args;
+    args <<= this->args();
+    assert(!this->args());
+
+    // XXX: We could clear this much earlier, right?
+    // Or would that introduce the possibility of running Python
+    // code when we don't want to?
+    // CAUTION: This may run arbitrary Python code.
+    this->_run_callable.CLEAR();
+
+
+    // The first switch we need to manually call the trace
+    // function here instead of in g_switch_finish, because we
+    // never return there.
+    if (OwnedObject tracefunc = this->thread_state()->get_tracefunc()) {
+        OwnedGreenlet trace_origin;
+        trace_origin = origin_greenlet;
+        try {
+            g_calltrace(tracefunc,
+                        args ? mod_globs->event_switch : mod_globs->event_throw,
+                        trace_origin,
+                        this->_self);
+        }
+        catch (const PyErrOccurred&) {
+            /* Turn trace errors into switch throws */
+            args.CLEAR();
+        }
+    }
+
+    // We no longer need the origin, it was only here for
+    // tracing.
+    // We may never actually exit this stack frame so we need
+    // to explicitly clear it.
+    // This could run Python code and switch.
+    Py_CLEAR(origin_greenlet);
+
+    OwnedObject result;
+    if (!args) {
+        /* pending exception */
+        result = NULL;
+    }
+    else {
+        /* call g.run(*args, **kwargs) */
+        // This could result in further switches
+        try {
+            //result = run.PyCall(args.args(), args.kwargs());
+            // CAUTION: Just invoking this, before the function even
+            // runs, may cause memory allocations, which may trigger
+            // GC, which may run arbitrary Python code.
+            result = OwnedObject::consuming(PyObject_Call(run, args.args().borrow(), args.kwargs().borrow()));
+        }
+        catch (...) {
+            // Unhandled C++ exception!
+
+            // If we declare ourselves as noexcept, if we don't catch
+            // this here, most platforms will just abort() the
+            // process. But on 64-bit Windows with older versions of
+            // the C runtime, this can actually corrupt memory and
+            // just return. We see this when compiling with the
+            // Windows 7.0 SDK targeting Windows Server 2008, but not
+            // when using the Appveyor Visual Studio 2019 image. So
+            // this currently only affects Python 2.7 on Windows 64.
+            // That is, the tests pass and the runtime aborts
+            // everywhere else.
+            //
+            // However, if we catch it and try to continue with a
+            // Python error, then all Windows 64 bit platforms corrupt
+            // memory. So all we can do is manually abort, hopefully
+            // with a good error message. (Note that the above was
+            // tested WITHOUT the `/EHr` switch being used at compile
+            // time, so MSVC may have "optimized" out important
+            // checking. Using that switch, we may be in a better
+            // place in terms of memory corruption.) But sometimes it
+            // can't be caught here at all, which is confusing but not
+            // terribly surprising; so again, the G_NOEXCEPT_WIN32
+            // plus "/EHr".
+            //
+            // Hopefully the basic C stdlib is still functional enough
+            // for us to at least print an error.
+            //
+            // It gets more complicated than that, though, on some
+            // platforms, specifically at least Linux/gcc/libstdc++. They use
+            // an exception to unwind the stack when a background
+            // thread exits. (See comments about noexcept.) So this
+            // may not actually represent anything untoward. On those
+            // platforms we allow throws of this to propagate, or
+            // attempt to anyway.
+# if defined(WIN32) || defined(_WIN32)
+            Py_FatalError(
+                "greenlet: Unhandled C++ exception from a greenlet run function. "
+                "Because memory is likely corrupted, terminating process.");
+            std::abort();
+#else
+            throw;
+#endif
+        }
+    }
+    // These lines may run arbitrary code
+    args.CLEAR();
+    Py_CLEAR(run);
+
+    if (!result
+        && mod_globs->PyExc_GreenletExit.PyExceptionMatches()
+        && (this->args())) {
+        // This can happen, for example, if our only reference
+        // goes away after we switch back to the parent.
+        // See test_dealloc_switch_args_not_lost
+        PyErrPieces clear_error;
+        result <<= this->args();
+        result = single_result(result);
+    }
+    this->release_args();
+    this->python_state.did_finish(PyThreadState_GET());
+
+    result = g_handle_exit(result);
+    assert(this->thread_state()->borrow_current() == this->_self);
+
+    /* jump back to parent */
+    this->stack_state.set_inactive(); /* dead */
+
+
+    // TODO: Can we decref some things here? Release our main greenlet
+    // and maybe parent?
+    for (Greenlet* parent = this->_parent;
+         parent;
+         parent = parent->parent()) {
+        // We need to somewhere consume a reference to
+        // the result; in most cases we'll never have control
+        // back in this stack frame again. Calling
+        // green_switch actually adds another reference!
+        // This would probably be clearer with a specific API
+        // to hand results to the parent.
+        parent->args() <<= result;
+        assert(!result);
+        // The parent greenlet now owns the result; in the
+        // typical case we'll never get back here to assign to
+        // result and thus release the reference.
+        try {
+            result = parent->g_switch();
+        }
+        catch (const PyErrOccurred&) {
+            // Ignore, keep passing the error on up.
+        }
+
+        /* Return here means switch to parent failed,
+         * in which case we throw *current* exception
+         * to the next parent in chain.
+         */
+        assert(!result);
+    }
+    /* We ran out of parents, cannot continue */
+    PyErr_WriteUnraisable(this->self().borrow_o());
+    Py_FatalError("greenlet: ran out of parent greenlets while propagating exception; "
+                  "cannot continue");
+    std::abort();
+}
+
+void
+UserGreenlet::run(const BorrowedObject nrun)
+{
+    if (this->started()) {
+        throw AttributeError(
+                        "run cannot be set "
+                        "after the start of the greenlet");
+    }
+    this->_run_callable = nrun;
+}
+
+const OwnedGreenlet
+UserGreenlet::parent() const
+{
+    return this->_parent;
+}
+
+void
+UserGreenlet::parent(const BorrowedObject raw_new_parent)
+{
+    if (!raw_new_parent) {
+        throw AttributeError("can't delete attribute");
+    }
+
+    BorrowedMainGreenlet main_greenlet_of_new_parent;
+    BorrowedGreenlet new_parent(raw_new_parent.borrow()); // could
+                                                          // throw
+                                                          // TypeError!
+    for (BorrowedGreenlet p = new_parent; p; p = p->parent()) {
+        if (p == this->_self) {
+            throw ValueError("cyclic parent chain");
+        }
+        main_greenlet_of_new_parent = p->main_greenlet();
+    }
+
+    if (!main_greenlet_of_new_parent) {
+        throw ValueError("parent must not be garbage collected");
+    }
+
+    if (this->started()
+        && this->_main_greenlet != main_greenlet_of_new_parent) {
+        throw ValueError("parent cannot be on a different thread");
+    }
+
+    this->_parent = new_parent;
+}
+
+void
+UserGreenlet::murder_in_place()
+{
+    this->_main_greenlet.CLEAR();
+    Greenlet::murder_in_place();
+}
+
+bool
+UserGreenlet::belongs_to_thread(const ThreadState* thread_state) const
+{
+    return Greenlet::belongs_to_thread(thread_state) && this->_main_greenlet == thread_state->borrow_main_greenlet();
+}
+
+
+int
+UserGreenlet::tp_traverse(visitproc visit, void* arg)
+{
+    Py_VISIT(this->_parent.borrow_o());
+    Py_VISIT(this->_main_greenlet.borrow_o());
+    Py_VISIT(this->_run_callable.borrow_o());
+
+    return Greenlet::tp_traverse(visit, arg);
+}
+
+int
+UserGreenlet::tp_clear()
+{
+    Greenlet::tp_clear();
+    this->_parent.CLEAR();
+    this->_main_greenlet.CLEAR();
+    this->_run_callable.CLEAR();
+    return 0;
+}
+
+UserGreenlet::ParentIsCurrentGuard::ParentIsCurrentGuard(UserGreenlet* p,
+                                                     const ThreadState& thread_state)
+    : oldparent(p->_parent),
+      greenlet(p)
+{
+    p->_parent = thread_state.get_current();
+}
+
+UserGreenlet::ParentIsCurrentGuard::~ParentIsCurrentGuard()
+{
+    this->greenlet->_parent = oldparent;
+    oldparent.CLEAR();
+}
+
+}; //namespace greenlet