/* -*- indent-tabs-mode: nil; tab-width: 4; -*- */ /* 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" */ #define GREENLET_MODULE #include "greenlet.h" #include "structmember.h" #ifdef __clang__ # pragma clang diagnostic push # pragma clang diagnostic ignored "-Wunused-parameter" # pragma clang diagnostic ignored "-Wmissing-field-initializers" #endif /*********************************************************** A PyGreenlet is a range of C stack addresses that must be saved and restored in such a way that the full range of the stack contains valid data when we switch to it. Stack layout for a greenlet: | ^^^ | | older data | | | stack_stop . |_______________| . | | . | greenlet data | . | in stack | . * |_______________| . . _____________ stack_copy + stack_saved . | | | | . | data | |greenlet data| . | unrelated | | saved | . | to | | in heap | stack_start . | this | . . |_____________| stack_copy | greenlet | | | | newer data | | vvv | Note that a greenlet's stack data is typically partly at its correct place in the stack, and partly saved away in the heap, but always in the above configuration: two blocks, the more recent one in the heap and the older one still in the stack (either block may be empty). Greenlets are chained: each points to the previous greenlet, which is the one that owns the data currently in the C stack above my stack_stop. The currently running greenlet is the first element of this chain. The main (initial) greenlet is the last one. Greenlets whose stack is entirely in the heap can be skipped from the chain. The chain is not related to execution order, but only to the order in which bits of C stack happen to belong to greenlets at a particular point in time. The main greenlet doesn't have a stack_stop: it is responsible for the complete rest of the C stack, and we don't know where it begins. We use (char*) -1, the largest possible address. States: stack_stop == NULL && stack_start == NULL: did not start yet stack_stop != NULL && stack_start == NULL: already finished stack_stop != NULL && stack_start != NULL: active The running greenlet's stack_start is undefined but not NULL. ***********************************************************/ /*** global state ***/ /* In the presence of multithreading, this is a bit tricky: - ts_current always store a reference to a greenlet, but it is not really the current greenlet after a thread switch occurred. - each *running* greenlet uses its run_info field to know which thread it is attached to. A greenlet can only run in the thread where it was created. This run_info is a ref to tstate->dict. - the thread state dict is used to save and restore ts_current, using the dictionary key 'ts_curkey'. */ extern PyTypeObject PyGreenlet_Type; #if PY_VERSION_HEX >= 0x030700A3 # define GREENLET_PY37 1 #else # define GREENLET_PY37 0 #endif #if PY_VERSION_HEX >= 0x30A00B1 /* Python 3.10 beta 1 changed tstate->use_tracing to a nested cframe member. See https://github.com/python/cpython/pull/25276 We have to save and restore this as well. */ #define TSTATE_USE_TRACING(tstate) (tstate->cframe->use_tracing) #define GREENLET_USE_CFRAME 1 #else #define TSTATE_USE_TRACING(tstate) (tstate->use_tracing) #define GREENLET_USE_CFRAME 0 #endif #ifndef Py_SET_REFCNT /* Py_REFCNT and Py_SIZE macros are converted to functions https://bugs.python.org/issue39573 */ # define Py_SET_REFCNT(obj, refcnt) Py_REFCNT(obj) = (refcnt) #endif #ifndef _Py_DEC_REFTOTAL /* _Py_DEC_REFTOTAL macro has been removed from Python 3.9 by: https://github.com/python/cpython/commit/49932fec62c616ec88da52642339d83ae719e924 */ # ifdef Py_REF_DEBUG # define _Py_DEC_REFTOTAL _Py_RefTotal-- # else # define _Py_DEC_REFTOTAL # endif #endif /* Weak reference to the switching-to greenlet during the slp switch */ static PyGreenlet* volatile ts_target = NULL; /* Strong reference to the switching from greenlet after the switch */ static PyGreenlet* volatile ts_origin = NULL; /* Strong reference to the current greenlet in this thread state */ static PyGreenlet* volatile ts_current = NULL; /* NULL if error, otherwise args tuple to pass around during slp switch */ static PyObject* volatile ts_passaround_args = NULL; static PyObject* volatile ts_passaround_kwargs = NULL; /* Used internally in ``g_switchstack()`` */ #if GREENLET_USE_CFRAME static int volatile ts__g_switchstack_use_tracing = 0; #endif /***********************************************************/ /* Thread-aware routines, switching global variables when needed */ #define STATE_OK \ (ts_current->run_info == PyThreadState_GET()->dict || \ !green_updatecurrent()) static PyObject* ts_curkey; static PyObject* ts_delkey; static PyObject* ts_tracekey; static PyObject* ts_event_switch; static PyObject* ts_event_throw; static PyObject* PyExc_GreenletError; static PyObject* PyExc_GreenletExit; static PyObject* ts_empty_tuple; static PyObject* ts_empty_dict; #define GREENLET_GC_FLAGS Py_TPFLAGS_HAVE_GC #define GREENLET_tp_alloc PyType_GenericAlloc #define GREENLET_tp_free PyObject_GC_Del #define GREENLET_tp_traverse green_traverse #define GREENLET_tp_clear green_clear #define GREENLET_tp_is_gc green_is_gc static void green_clear_exc(PyGreenlet* g) { #if GREENLET_PY37 g->exc_info = NULL; g->exc_state.exc_type = NULL; g->exc_state.exc_value = NULL; g->exc_state.exc_traceback = NULL; g->exc_state.previous_item = NULL; #else g->exc_type = NULL; g->exc_value = NULL; g->exc_traceback = NULL; #endif } static PyGreenlet* green_create_main(void) { PyGreenlet* gmain; PyObject* dict = PyThreadState_GetDict(); if (dict == NULL) { if (!PyErr_Occurred()) { PyErr_NoMemory(); } return NULL; } /* create the main greenlet for this thread */ gmain = (PyGreenlet*)PyType_GenericAlloc(&PyGreenlet_Type, 0); if (gmain == NULL) { return NULL; } gmain->stack_start = (char*)1; gmain->stack_stop = (char*)-1; /* GetDict() returns a borrowed reference. Make it strong. */ gmain->run_info = dict; Py_INCREF(dict); return gmain; } static int green_updatecurrent(void) { PyObject *exc, *val, *tb; PyThreadState* tstate; PyGreenlet* current; PyGreenlet* previous; PyObject* deleteme; green_updatecurrent_restart: /* save current exception */ PyErr_Fetch(&exc, &val, &tb); /* get ts_current from the active tstate */ tstate = PyThreadState_GET(); if (tstate->dict && (current = (PyGreenlet*)PyDict_GetItem(tstate->dict, ts_curkey))) { /* found -- remove it, to avoid keeping a ref */ Py_INCREF(current); PyDict_DelItem(tstate->dict, ts_curkey); } else { /* first time we see this tstate */ current = green_create_main(); if (current == NULL) { Py_XDECREF(exc); Py_XDECREF(val); Py_XDECREF(tb); return -1; } } assert(current->run_info == tstate->dict); green_updatecurrent_retry: /* update ts_current as soon as possible, in case of nested switches */ Py_INCREF(current); previous = ts_current; ts_current = current; /* save ts_current as the current greenlet of its own thread */ if (PyDict_SetItem(previous->run_info, ts_curkey, (PyObject*)previous)) { Py_DECREF(previous); Py_DECREF(current); Py_XDECREF(exc); Py_XDECREF(val); Py_XDECREF(tb); return -1; } Py_DECREF(previous); /* green_dealloc() cannot delete greenlets from other threads, so it stores them in the thread dict; delete them now. */ deleteme = PyDict_GetItem(tstate->dict, ts_delkey); if (deleteme != NULL) { /* The only reference to these greenlets should be in this list, so clearing the list should let them be deleted again, triggering calls to green_dealloc() in the correct thread. This may run arbitrary Python code? */ PyList_SetSlice(deleteme, 0, INT_MAX, NULL); } if (ts_current != current) { /* some Python code executed above and there was a thread switch, * so ts_current points to some other thread again. We need to * delete ts_curkey (it's likely there) and retry. */ PyDict_DelItem(tstate->dict, ts_curkey); goto green_updatecurrent_retry; } /* release an extra reference */ Py_DECREF(current); /* restore current exception */ PyErr_Restore(exc, val, tb); /* thread switch could happen during PyErr_Restore, in that case there's nothing to do except restart from scratch. */ if (ts_current->run_info != tstate->dict) { goto green_updatecurrent_restart; } return 0; } static PyObject* green_statedict(PyGreenlet* g) { while (!PyGreenlet_STARTED(g)) { g = g->parent; if (g == NULL) { /* garbage collected greenlet in chain */ return NULL; } } return g->run_info; } /***********************************************************/ /* Some functions must not be inlined: * slp_restore_state, when inlined into slp_switch might cause it to restore stack over its own local variables * slp_save_state, when inlined would add its own local variables to the saved stack, wasting space * slp_switch, cannot be inlined for obvious reasons * g_initialstub, when inlined would receive a pointer into its own stack frame, leading to incomplete stack save/restore */ #if defined(__GNUC__) && \ (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) # define GREENLET_NOINLINE_SUPPORTED # define GREENLET_NOINLINE(name) __attribute__((noinline)) name #elif defined(_MSC_VER) && (_MSC_VER >= 1300) # define GREENLET_NOINLINE_SUPPORTED # define GREENLET_NOINLINE(name) __declspec(noinline) name #endif #ifdef GREENLET_NOINLINE_SUPPORTED /* add forward declarations */ static void GREENLET_NOINLINE(slp_restore_state)(void); static int GREENLET_NOINLINE(slp_save_state)(char*); # if !(defined(MS_WIN64) && defined(_M_X64)) static int GREENLET_NOINLINE(slp_switch)(void); # endif static int GREENLET_NOINLINE(g_initialstub)(void*); # define GREENLET_NOINLINE_INIT() \ do { \ } while (0) #else /* force compiler to call functions via pointers */ static void (*slp_restore_state)(void); static int (*slp_save_state)(char*); static int (*slp_switch)(void); static int (*g_initialstub)(void*); # define GREENLET_NOINLINE(name) cannot_inline_##name # define GREENLET_NOINLINE_INIT() \ do { \ slp_restore_state = GREENLET_NOINLINE(slp_restore_state); \ slp_save_state = GREENLET_NOINLINE(slp_save_state); \ slp_switch = GREENLET_NOINLINE(slp_switch); \ g_initialstub = GREENLET_NOINLINE(g_initialstub); \ } while (0) #endif /* * the following macros are spliced into the OS/compiler * specific code, in order to simplify maintenance. */ #define SLP_SAVE_STATE(stackref, stsizediff) \ stackref += STACK_MAGIC; \ if (slp_save_state((char*)stackref)) \ return -1; \ if (!PyGreenlet_ACTIVE(ts_target)) \ return 1; \ stsizediff = ts_target->stack_start - (char*)stackref #define SLP_RESTORE_STATE() slp_restore_state() #define SLP_EVAL #define slp_switch GREENLET_NOINLINE(slp_switch) #include "slp_platformselect.h" #undef slp_switch #ifndef STACK_MAGIC # error \ "greenlet needs to be ported to this platform, or taught how to detect your compiler properly." #endif /* !STACK_MAGIC */ #ifdef EXTERNAL_ASM /* CCP addition: Make these functions, to be called from assembler. * The token include file for the given platform should enable the * EXTERNAL_ASM define so that this is included. */ intptr_t slp_save_state_asm(intptr_t* ref) { intptr_t diff; SLP_SAVE_STATE(ref, diff); return diff; } void slp_restore_state_asm(void) { SLP_RESTORE_STATE(); } extern int slp_switch(void); #endif /***********************************************************/ static int g_save(PyGreenlet* g, char* stop) { /* Save more of g's stack into the heap -- at least up to 'stop' g->stack_stop |________| | | | __ stop . . . . . | | ==> . . |________| _______ | | | | | | | | g->stack_start | | |_______| g->stack_copy */ intptr_t sz1 = g->stack_saved; intptr_t sz2 = stop - g->stack_start; assert(g->stack_start != NULL); if (sz2 > sz1) { char* c = (char*)PyMem_Realloc(g->stack_copy, sz2); if (!c) { PyErr_NoMemory(); return -1; } memcpy(c + sz1, g->stack_start + sz1, sz2 - sz1); g->stack_copy = c; g->stack_saved = sz2; } return 0; } static void GREENLET_NOINLINE(slp_restore_state)(void) { PyGreenlet* g = ts_target; PyGreenlet* owner = ts_current; #ifdef SLP_BEFORE_RESTORE_STATE SLP_BEFORE_RESTORE_STATE(); #endif /* Restore the heap copy back into the C stack */ if (g->stack_saved != 0) { memcpy(g->stack_start, g->stack_copy, g->stack_saved); PyMem_Free(g->stack_copy); g->stack_copy = NULL; g->stack_saved = 0; } if (owner->stack_start == NULL) { owner = owner->stack_prev; /* greenlet is dying, skip it */ } while (owner && owner->stack_stop <= g->stack_stop) { owner = owner->stack_prev; /* find greenlet with more stack */ } g->stack_prev = owner; } static int GREENLET_NOINLINE(slp_save_state)(char* stackref) { /* must free all the C stack up to target_stop */ char* target_stop = ts_target->stack_stop; PyGreenlet* owner = ts_current; assert(owner->stack_saved == 0); if (owner->stack_start == NULL) { owner = owner->stack_prev; /* not saved if dying */ } else { owner->stack_start = stackref; } #ifdef SLP_BEFORE_SAVE_STATE SLP_BEFORE_SAVE_STATE(); #endif while (owner->stack_stop < target_stop) { /* ts_current is entierely within the area to free */ if (g_save(owner, owner->stack_stop)) { return -1; /* XXX */ } owner = owner->stack_prev; } if (owner != ts_target) { if (g_save(owner, target_stop)) { return -1; /* XXX */ } } return 0; } /** Perform a stack switch according to some global variables that must be set before calling this function. Those variables are: - ts_current: current greenlet (holds a reference) - ts_target: greenlet to switch to (weak reference) - ts_passaround_args: NULL if PyErr_Occurred(), else a tuple of args sent to ts_target (holds a reference) - ts_passaround_kwargs: switch kwargs (holds a reference) Because the stack switch happens in this function, this function can't use its own stack (local) variables, set before the switch, and then accessed after the switch. Global variables beginning with ``ts__g_switchstack`` are used internally instead. On return results are passed via global variables as well: - ts_origin: originating greenlet (holds a reference) - ts_current: current greenlet (holds a reference) - ts_passaround_args: NULL if PyErr_Occurred(), else a tuple of args sent to ts_current (holds a reference) - ts_passaround_kwargs: switch kwargs (holds a reference) It is very important that stack switch is 'atomic', i.e. no calls into other Python code allowed (except very few that are safe), because global variables are very fragile. */ static int g_switchstack(void) { int err; { /* save state */ PyGreenlet* current = ts_current; PyThreadState* tstate = PyThreadState_GET(); current->recursion_depth = tstate->recursion_depth; current->top_frame = tstate->frame; #if GREENLET_PY37 current->context = tstate->context; #endif #if GREENLET_PY37 current->exc_info = tstate->exc_info; current->exc_state = tstate->exc_state; #else current->exc_type = tstate->exc_type; current->exc_value = tstate->exc_value; current->exc_traceback = tstate->exc_traceback; #endif #if GREENLET_USE_CFRAME /* IMPORTANT: ``cframe`` is a pointer into the STACK. Thus, because the call to ``slp_switch()`` changes the contents of the stack, you cannot read from ``ts_current->cframe`` after that call and necessarily get the same values you get from reading it here. Anything you need to restore from now to then must be saved in a global variable (because we can't use stack variables here either). */ current->cframe = tstate->cframe; ts__g_switchstack_use_tracing = tstate->cframe->use_tracing; #endif } err = slp_switch(); if (err < 0) { /* error */ PyGreenlet* current = ts_current; current->top_frame = NULL; #if GREENLET_PY37 green_clear_exc(current); #else current->exc_type = NULL; current->exc_value = NULL; current->exc_traceback = NULL; #endif assert(ts_origin == NULL); ts_target = NULL; } else { PyGreenlet* target = ts_target; PyGreenlet* origin = ts_current; PyThreadState* tstate = PyThreadState_GET(); tstate->recursion_depth = target->recursion_depth; tstate->frame = target->top_frame; target->top_frame = NULL; #if GREENLET_PY37 tstate->context = target->context; target->context = NULL; /* Incrementing this value invalidates the contextvars cache, which would otherwise remain valid across switches */ tstate->context_ver++; #endif #if GREENLET_PY37 tstate->exc_state = target->exc_state; tstate->exc_info = target->exc_info ? target->exc_info : &tstate->exc_state; #else tstate->exc_type = target->exc_type; tstate->exc_value = target->exc_value; tstate->exc_traceback = target->exc_traceback; #endif green_clear_exc(target); #if GREENLET_USE_CFRAME tstate->cframe = target->cframe; /* If we were tracing, we need to keep tracing. There should never be the possibility of hitting the root_cframe here. See note above about why we can't just copy this from ``origin->cframe->use_tracing``. */ tstate->cframe->use_tracing = ts__g_switchstack_use_tracing; #endif assert(ts_origin == NULL); Py_INCREF(target); ts_current = target; ts_origin = origin; ts_target = NULL; } return err; } static int g_calltrace(PyObject* tracefunc, PyObject* event, PyGreenlet* origin, PyGreenlet* target) { PyObject* retval; PyObject *exc_type, *exc_val, *exc_tb; PyThreadState* tstate; PyErr_Fetch(&exc_type, &exc_val, &exc_tb); tstate = PyThreadState_GET(); tstate->tracing++; TSTATE_USE_TRACING(tstate) = 0; retval = PyObject_CallFunction(tracefunc, "O(OO)", event, origin, target); tstate->tracing--; TSTATE_USE_TRACING(tstate) = (tstate->tracing <= 0 && ((tstate->c_tracefunc != NULL) || (tstate->c_profilefunc != NULL))); if (retval == NULL) { /* In case of exceptions trace function is removed */ if (PyDict_GetItem(tstate->dict, ts_tracekey)) { PyDict_DelItem(tstate->dict, ts_tracekey); } Py_XDECREF(exc_type); Py_XDECREF(exc_val); Py_XDECREF(exc_tb); return -1; } else { Py_DECREF(retval); } PyErr_Restore(exc_type, exc_val, exc_tb); return 0; } static PyObject* g_switch(PyGreenlet* target, PyObject* args, PyObject* kwargs) { /* _consumes_ a reference to the args tuple and kwargs dict, and return a new tuple reference */ int err = 0; PyObject* run_info; /* check ts_current */ if (!STATE_OK) { Py_XDECREF(args); Py_XDECREF(kwargs); return NULL; } run_info = green_statedict(target); if (run_info == NULL || run_info != ts_current->run_info) { Py_XDECREF(args); Py_XDECREF(kwargs); PyErr_SetString(PyExc_GreenletError, run_info ? "cannot switch to a different thread" : "cannot switch to a garbage collected greenlet"); return NULL; } ts_passaround_args = args; ts_passaround_kwargs = kwargs; /* find the real target by ignoring dead greenlets, and if necessary starting a greenlet. */ while (target) { if (PyGreenlet_ACTIVE(target)) { ts_target = target; err = g_switchstack(); break; } if (!PyGreenlet_STARTED(target)) { void* dummymarker; ts_target = target; err = g_initialstub(&dummymarker); if (err == 1) { continue; /* retry the switch */ } break; } target = target->parent; } /* For a very short time, immediately after the 'atomic' g_switchstack() call, global variables are in a known state. We need to save everything we need, before it is destroyed by calls into arbitrary Python code. */ args = ts_passaround_args; ts_passaround_args = NULL; kwargs = ts_passaround_kwargs; ts_passaround_kwargs = NULL; if (err < 0) { /* Turn switch errors into switch throws */ assert(ts_origin == NULL); Py_CLEAR(kwargs); Py_CLEAR(args); } else { PyGreenlet* origin; PyGreenlet* current; PyObject* tracefunc; origin = ts_origin; ts_origin = NULL; current = ts_current; if ((tracefunc = PyDict_GetItem(current->run_info, ts_tracekey)) != NULL) { Py_INCREF(tracefunc); if (g_calltrace(tracefunc, args ? ts_event_switch : ts_event_throw, origin, current) < 0) { /* Turn trace errors into switch throws */ Py_CLEAR(kwargs); Py_CLEAR(args); } Py_DECREF(tracefunc); } Py_DECREF(origin); } /* We need to figure out what values to pass to the target greenlet based on the arguments that have been passed to greenlet.switch(). If switch() was just passed an arg tuple, then we'll just return that. If only keyword arguments were passed, then we'll pass the keyword argument dict. Otherwise, we'll create a tuple of (args, kwargs) and return both. */ if (kwargs == NULL) { return args; } else if (PyDict_Size(kwargs) == 0) { Py_DECREF(kwargs); return args; } else if (PySequence_Length(args) == 0) { Py_DECREF(args); return kwargs; } else { PyObject* tuple = PyTuple_New(2); if (tuple == NULL) { Py_DECREF(args); Py_DECREF(kwargs); return NULL; } PyTuple_SET_ITEM(tuple, 0, args); PyTuple_SET_ITEM(tuple, 1, kwargs); return tuple; } } static PyObject* g_handle_exit(PyObject* result) { if (result == NULL && PyErr_ExceptionMatches(PyExc_GreenletExit)) { /* catch and ignore GreenletExit */ PyObject *exc, *val, *tb; PyErr_Fetch(&exc, &val, &tb); if (val == NULL) { Py_INCREF(Py_None); val = Py_None; } result = val; Py_DECREF(exc); Py_XDECREF(tb); } if (result != NULL) { /* package the result into a 1-tuple */ PyObject* r = result; result = PyTuple_New(1); if (result) { PyTuple_SET_ITEM(result, 0, r); } else { Py_DECREF(r); } } return result; } static int GREENLET_NOINLINE(g_initialstub)(void* mark) { int err; PyObject *o, *run; PyObject *exc, *val, *tb; PyObject* run_info; PyGreenlet* self = ts_target; PyObject* args = ts_passaround_args; PyObject* kwargs = ts_passaround_kwargs; #if GREENLET_USE_CFRAME /* 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. */ CFrame trace_info; #endif /* save exception in case getattr clears it */ PyErr_Fetch(&exc, &val, &tb); /* self.run is the object to call in the new greenlet */ run = PyObject_GetAttrString((PyObject*)self, "run"); if (run == NULL) { Py_XDECREF(exc); Py_XDECREF(val); Py_XDECREF(tb); return -1; } /* restore saved exception */ PyErr_Restore(exc, val, tb); /* recheck the state in case getattr caused thread switches */ if (!STATE_OK) { Py_DECREF(run); return -1; } /* recheck run_info in case greenlet reparented anywhere above */ run_info = green_statedict(self); if (run_info == NULL || run_info != ts_current->run_info) { Py_DECREF(run); PyErr_SetString(PyExc_GreenletError, run_info ? "cannot switch to a different thread" : "cannot switch to a garbage collected greenlet"); return -1; } /* by the time we got here another start could happen elsewhere, * that means it should now be a regular switch */ if (PyGreenlet_STARTED(self)) { Py_DECREF(run); ts_passaround_args = args; ts_passaround_kwargs = kwargs; return 1; } #if GREENLET_USE_CFRAME /* OK, we need it, we're about to switch greenlets, save the state. */ trace_info = *PyThreadState_GET()->cframe; /* Make the target greenlet refer to the stack value. */ self->cframe = &trace_info; /* And restore the link to the previous frame so this one gets unliked appropriately. */ self->cframe->previous = &PyThreadState_GET()->root_cframe; #endif /* start the greenlet */ self->stack_start = NULL; self->stack_stop = (char*)mark; if (ts_current->stack_start == NULL) { /* ts_current is dying */ self->stack_prev = ts_current->stack_prev; } else { self->stack_prev = ts_current; } self->top_frame = NULL; green_clear_exc(self); self->recursion_depth = PyThreadState_GET()->recursion_depth; /* restore arguments in case they are clobbered */ ts_target = self; ts_passaround_args = args; ts_passaround_kwargs = kwargs; /* perform the initial switch */ err = g_switchstack(); /* returns twice! The 1st time with ``err == 1``: we are in the new greenlet The 2nd time with ``err <= 0``: back in the caller's greenlet */ if (err == 1) { /* in the new greenlet */ PyGreenlet* origin; PyObject* tracefunc; PyObject* result; PyGreenlet* parent; self->stack_start = (char*)1; /* running */ /* grab origin while we still can */ origin = ts_origin; ts_origin = NULL; /* now use run_info to store the statedict */ o = self->run_info; self->run_info = green_statedict(self->parent); Py_INCREF(self->run_info); Py_XDECREF(o); if ((tracefunc = PyDict_GetItem(self->run_info, ts_tracekey)) != NULL) { Py_INCREF(tracefunc); if (g_calltrace(tracefunc, args ? ts_event_switch : ts_event_throw, origin, self) < 0) { /* Turn trace errors into switch throws */ Py_CLEAR(kwargs); Py_CLEAR(args); } Py_DECREF(tracefunc); } Py_DECREF(origin); if (args == NULL) { /* pending exception */ result = NULL; } else { /* call g.run(*args, **kwargs) */ result = PyObject_Call(run, args, kwargs); Py_DECREF(args); Py_XDECREF(kwargs); } Py_DECREF(run); result = g_handle_exit(result); /* jump back to parent */ self->stack_start = NULL; /* dead */ for (parent = self->parent; parent != NULL; parent = parent->parent) { result = g_switch(parent, result, NULL); /* Return here means switch to parent failed, * in which case we throw *current* exception * to the next parent in chain. */ assert(result == NULL); } /* We ran out of parents, cannot continue */ PyErr_WriteUnraisable((PyObject*)self); Py_FatalError("greenlets cannot continue"); } /* back in the parent */ if (err < 0) { /* start failed badly, restore greenlet state */ self->stack_start = NULL; self->stack_stop = NULL; self->stack_prev = NULL; } return err; } /***********************************************************/ static PyObject* green_new(PyTypeObject* type, PyObject* args, PyObject* kwds) { PyObject* o = PyBaseObject_Type.tp_new(type, ts_empty_tuple, ts_empty_dict); if (o != NULL) { if (!STATE_OK) { Py_DECREF(o); return NULL; } Py_INCREF(ts_current); ((PyGreenlet*)o)->parent = ts_current; #if GREENLET_USE_CFRAME /* The PyThreadState->cframe pointer usually points to memory on the stack, alloceted in a call into PyEval_EvalFrameDefault. Initially, before any evaluation begins, it points to the initial PyThreadState object's ``root_cframe`` object, which is statically allocated for the lifetime of the thread. A greenlet can last for longer than a call to PyEval_EvalFrameDefault, so we can't set its ``cframe`` pointer to be the current ``PyThreadState->cframe``; nor could we use one from the greenlet parent for the same reason. Yet a further no: we can't allocate one scoped to the greenlet and then destroy it when the greenlet is deallocated, because inside the interpreter the CFrame objects form a linked list, and that too can result in accessing memory beyond its dynamic lifetime (if the greenlet doesn't actually finish before it dies, its entry could still be in the list). Using the ``root_cframe`` is problematic, though, because its members are never modified by the interpreter and are set to 0, meaning that its ``use_tracing`` flag is never updated. We don't want to modify that value in the ``root_cframe`` ourself: it *shouldn't* matter much because we should probably never get back to the point where that's the only cframe on the stack; even if it did matter, the major consequence of an incorrect value for ``use_tracing`` is that if its true the interpreter does some extra work --- however, it's just good code hygiene. Our solution: before a greenlet runs, after its initial creation, it uses the ``root_cframe`` just to have something to put there. However, once the greenlet is actually switched to for the first time, ``g_initialstub`` (which doesn't actually "return" while the greenlet is running) stores a new CFrame on its local stack, and copies the appropriate values from the currently running CFrame; this is then made the CFrame for the newly-minted greenlet. ``g_initialstub`` then proceeds to call ``glet.run()``, which results in ``PyEval_...`` adding the CFrame to the list. Switches continue as normal. Finally, when the greenlet finishes, the call to ``glet.run()`` returns and the CFrame is taken out of the linked list and the stack value is now unused and free to expire. */ ((PyGreenlet*)o)->cframe = &PyThreadState_GET()->root_cframe; #endif } return o; } static int green_setrun(PyGreenlet* self, PyObject* nrun, void* c); static int green_setparent(PyGreenlet* self, PyObject* nparent, void* c); static int green_init(PyGreenlet* self, PyObject* args, PyObject* kwargs) { PyObject* run = NULL; PyObject* nparent = NULL; static char* kwlist[] = {"run", "parent", 0}; if (!PyArg_ParseTupleAndKeywords( args, kwargs, "|OO:green", kwlist, &run, &nparent)) { return -1; } if (run != NULL) { if (green_setrun(self, run, NULL)) { return -1; } } if (nparent != NULL && nparent != Py_None) { return green_setparent(self, nparent, NULL); } return 0; } static int kill_greenlet(PyGreenlet* self) { /* Cannot raise an exception to kill the greenlet if it is not running in the same thread! */ if (self->run_info == PyThreadState_GET()->dict) { /* The dying greenlet cannot be a parent of ts_current because the 'parent' field chain would hold a reference */ PyObject* result; PyGreenlet* oldparent; PyGreenlet* tmp; if (!STATE_OK) { return -1; } oldparent = self->parent; self->parent = ts_current; Py_INCREF(self->parent); /* Send the greenlet a GreenletExit exception. */ PyErr_SetNone(PyExc_GreenletExit); result = g_switch(self, NULL, NULL); tmp = self->parent; self->parent = oldparent; Py_XDECREF(tmp); if (result == NULL) { return -1; } Py_DECREF(result); return 0; } else { /* Not the same thread! Temporarily save the greenlet into its thread's ts_delkey list. */ PyObject* lst; lst = PyDict_GetItem(self->run_info, ts_delkey); if (lst == NULL) { lst = PyList_New(0); if (lst == NULL || PyDict_SetItem(self->run_info, ts_delkey, lst) < 0) { return -1; } /* PyDict_SetItem now holds a strong reference. PyList_New also returned a fresh reference. We need to DECREF it now and let the dictionary keep sole ownership. Frow now on, we're working with a borrowed reference that will go away when the thread dies. */ Py_DECREF(lst); } if (PyList_Append(lst, (PyObject*)self) < 0) { return -1; } if (!STATE_OK) { /* to force ts_delkey to be reconsidered */ return -1; } 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: alive greenlets are not garbage collected anyway */ Py_VISIT((PyObject*)self->parent); Py_VISIT(self->run_info); #if GREENLET_PY37 Py_VISIT(self->context); #endif #if GREENLET_PY37 Py_VISIT(self->exc_state.exc_type); Py_VISIT(self->exc_state.exc_value); Py_VISIT(self->exc_state.exc_traceback); #else Py_VISIT(self->exc_type); Py_VISIT(self->exc_value); Py_VISIT(self->exc_traceback); #endif Py_VISIT(self->dict); return 0; } static int green_is_gc(PyGreenlet* self) { /* Main greenlet can be garbage collected since it can only become unreachable if the underlying thread exited. Active greenlet cannot be garbage collected, however. */ if (PyGreenlet_MAIN(self) || !PyGreenlet_ACTIVE(self)) { return 1; } return 0; } 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. */ Py_CLEAR(self->parent); Py_CLEAR(self->run_info); #if GREENLET_PY37 Py_CLEAR(self->context); #endif #if GREENLET_PY37 Py_CLEAR(self->exc_state.exc_type); Py_CLEAR(self->exc_state.exc_value); Py_CLEAR(self->exc_state.exc_traceback); #else Py_CLEAR(self->exc_type); Py_CLEAR(self->exc_value); Py_CLEAR(self->exc_traceback); #endif Py_CLEAR(self->dict); return 0; } static void green_dealloc(PyGreenlet* self) { PyObject *error_type, *error_value, *error_traceback; Py_ssize_t refcnt; PyObject_GC_UnTrack(self); if (PyGreenlet_ACTIVE(self) && self->run_info != NULL && !PyGreenlet_MAIN(self)) { /* Hacks hacks hacks copied from instance_dealloc() */ /* Temporarily resurrect the greenlet. */ assert(Py_REFCNT(self) == 0); Py_SET_REFCNT(self, 1); /* Save the current exception, if any. */ PyErr_Fetch(&error_type, &error_value, &error_traceback); if (kill_greenlet(self) < 0) { PyErr_WriteUnraisable((PyObject*)self); /* 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 (Py_REFCNT(self) == 1 && PyGreenlet_ACTIVE(self)) { /* Not resurrected, but still not dead! XXX what else should we do? we complain. */ PyObject* f = PySys_GetObject("stderr"); Py_INCREF(self); /* leak! */ if (f != NULL) { PyFile_WriteString("GreenletExit did not kill ", f); PyFile_WriteObject((PyObject*)self, f, 0); PyFile_WriteString("\n", f); } } /* Restore the saved exception. */ PyErr_Restore(error_type, error_value, error_traceback); /* Undo the temporary resurrection; can't use DECREF here, * it would cause a recursive call. */ assert(Py_REFCNT(self) > 0); refcnt = Py_REFCNT(self) - 1; Py_SET_REFCNT(self, refcnt); if (refcnt != 0) { /* Resurrected! */ _Py_NewReference((PyObject*)self); Py_SET_REFCNT(self, 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(Py_TYPE(self), Py_TPFLAGS_HEAPTYPE)) { Py_INCREF(Py_TYPE(self)); } 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; } } if (self->weakreflist != NULL) { PyObject_ClearWeakRefs((PyObject*)self); } Py_CLEAR(self->parent); Py_CLEAR(self->run_info); #if GREENLET_PY37 Py_CLEAR(self->context); #endif #if GREENLET_PY37 Py_CLEAR(self->exc_state.exc_type); Py_CLEAR(self->exc_state.exc_value); Py_CLEAR(self->exc_state.exc_traceback); #else Py_CLEAR(self->exc_type); Py_CLEAR(self->exc_value); Py_CLEAR(self->exc_traceback); #endif Py_CLEAR(self->dict); Py_TYPE(self)->tp_free((PyObject*)self); } static PyObject* single_result(PyObject* results) { if (results != NULL && PyTuple_Check(results) && PyTuple_GET_SIZE(results) == 1) { PyObject* result = PyTuple_GET_ITEM(results, 0); Py_INCREF(result); Py_DECREF(results); return result; } else { return results; } } static PyObject* throw_greenlet(PyGreenlet* self, PyObject* typ, PyObject* val, PyObject* tb) { /* Note: _consumes_ a reference to typ, val, tb */ PyObject* result = NULL; PyErr_Restore(typ, val, tb); if (PyGreenlet_STARTED(self) && !PyGreenlet_ACTIVE(self)) { /* dead greenlet: turn GreenletExit into a regular return */ result = g_handle_exit(result); } return single_result(g_switch(self, result, NULL)); } 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) { Py_INCREF(args); Py_XINCREF(kwargs); return single_result(g_switch(self, args, kwargs)); } 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) { PyObject* typ = PyExc_GreenletExit; PyObject* val = NULL; PyObject* tb = NULL; if (!PyArg_ParseTuple(args, "|OOO:throw", &typ, &val, &tb)) { return NULL; } /* First, check the traceback argument, replacing None, with NULL */ if (tb == Py_None) { tb = NULL; } else if (tb != NULL && !PyTraceBack_Check(tb)) { PyErr_SetString(PyExc_TypeError, "throw() third argument must be a traceback object"); return NULL; } Py_INCREF(typ); Py_XINCREF(val); Py_XINCREF(tb); if (PyExceptionClass_Check(typ)) { PyErr_NormalizeException(&typ, &val, &tb); } else if (PyExceptionInstance_Check(typ)) { /* Raising an instance. The value should be a dummy. */ if (val && val != Py_None) { PyErr_SetString( PyExc_TypeError, "instance exception may not have a separate value"); goto failed_throw; } else { /* Normalize to raise , */ Py_XDECREF(val); val = typ; typ = PyExceptionInstance_Class(typ); Py_INCREF(typ); } } else { /* Not something you can raise. throw() fails. */ PyErr_Format(PyExc_TypeError, "exceptions must be classes, or instances, not %s", Py_TYPE(typ)->tp_name); goto failed_throw; } return throw_greenlet(self, typ, val, tb); failed_throw: /* Didn't use our arguments, so restore their original refcounts */ Py_DECREF(typ); Py_XDECREF(val); Py_XDECREF(tb); return NULL; } static int green_bool(PyGreenlet* self) { return PyGreenlet_ACTIVE(self); } static PyObject* green_getdict(PyGreenlet* self, void* c) { 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* c) { 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 int _green_not_dead(PyGreenlet* self) { return PyGreenlet_ACTIVE(self) || !PyGreenlet_STARTED(self); } static PyObject* green_getdead(PyGreenlet* self, void* c) { if (_green_not_dead(self)) { Py_RETURN_FALSE; } else { Py_RETURN_TRUE; } } static PyObject* green_get_stack_saved(PyGreenlet* self, void* c) { return PyLong_FromSsize_t(self->stack_saved); } static PyObject* green_getrun(PyGreenlet* self, void* c) { if (PyGreenlet_STARTED(self) || self->run_info == NULL) { PyErr_SetString(PyExc_AttributeError, "run"); return NULL; } Py_INCREF(self->run_info); return self->run_info; } static int green_setrun(PyGreenlet* self, PyObject* nrun, void* c) { PyObject* o; if (PyGreenlet_STARTED(self)) { PyErr_SetString(PyExc_AttributeError, "run cannot be set " "after the start of the greenlet"); return -1; } o = self->run_info; self->run_info = nrun; Py_XINCREF(nrun); Py_XDECREF(o); return 0; } static PyObject* green_getparent(PyGreenlet* self, void* c) { PyObject* result = self->parent ? (PyObject*)self->parent : Py_None; Py_INCREF(result); return result; } static int green_setparent(PyGreenlet* self, PyObject* nparent, void* c) { PyGreenlet* p; PyObject* run_info = NULL; if (nparent == NULL) { PyErr_SetString(PyExc_AttributeError, "can't delete attribute"); return -1; } if (!PyGreenlet_Check(nparent)) { PyErr_SetString(PyExc_TypeError, "parent must be a greenlet"); return -1; } for (p = (PyGreenlet*)nparent; p; p = p->parent) { if (p == self) { PyErr_SetString(PyExc_ValueError, "cyclic parent chain"); return -1; } run_info = PyGreenlet_ACTIVE(p) ? p->run_info : NULL; } if (run_info == NULL) { PyErr_SetString(PyExc_ValueError, "parent must not be garbage collected"); return -1; } if (PyGreenlet_STARTED(self) && self->run_info != run_info) { PyErr_SetString(PyExc_ValueError, "parent cannot be on a different thread"); return -1; } p = self->parent; self->parent = (PyGreenlet*)nparent; Py_INCREF(nparent); Py_XDECREF(p); return 0; } #ifdef Py_CONTEXT_H # define GREENLET_NO_CONTEXTVARS_REASON "This build of greenlet" #else # define GREENLET_NO_CONTEXTVARS_REASON "This Python interpreter" #endif static PyObject* green_getcontext(PyGreenlet* self, void* c) { #if GREENLET_PY37 PyThreadState* tstate = PyThreadState_GET(); PyObject* result; if (!STATE_OK) { return NULL; } if (PyGreenlet_ACTIVE(self) && self->top_frame == NULL) { /* Currently running greenlet: context is stored in the thread state, not the greenlet object. */ if (self == ts_current) { result = tstate->context; } else { PyErr_SetString(PyExc_ValueError, "cannot get context of a " "greenlet that is running in a different thread"); return NULL; } } else { /* Greenlet is not running: just return context. */ result = self->context; } if (result == NULL) { result = Py_None; } Py_INCREF(result); return result; #else PyErr_SetString(PyExc_AttributeError, GREENLET_NO_CONTEXTVARS_REASON " does not support context variables"); return NULL; #endif } static int green_setcontext(PyGreenlet* self, PyObject* nctx, void* c) { #if GREENLET_PY37 PyThreadState* tstate; PyObject* octx = NULL; if (!STATE_OK) { return -1; } if (nctx == NULL) { PyErr_SetString(PyExc_AttributeError, "can't delete attribute"); return -1; } if (nctx == Py_None) { /* "Empty context" is stored as NULL, not None. */ nctx = NULL; } else if (!PyContext_CheckExact(nctx)) { PyErr_SetString(PyExc_TypeError, "greenlet context must be a " "contextvars.Context or None"); return -1; } tstate = PyThreadState_GET(); if (PyGreenlet_ACTIVE(self) && self->top_frame == NULL) { /* Currently running greenlet: context is stored in the thread state, not the greenlet object. */ if (self == ts_current) { octx = tstate->context; tstate->context = nctx; tstate->context_ver++; Py_XINCREF(nctx); } else { PyErr_SetString(PyExc_ValueError, "cannot set context of a " "greenlet that is running in a different thread"); return -1; } } else { /* Greenlet is not running: just set context. */ octx = self->context; self->context = nctx; Py_XINCREF(nctx); } Py_XDECREF(octx); return 0; #else PyErr_SetString(PyExc_AttributeError, GREENLET_NO_CONTEXTVARS_REASON " does not support context variables"); return -1; #endif } #undef GREENLET_NO_CONTEXTVARS_REASON static PyObject* green_getframe(PyGreenlet* self, void* c) { PyObject* result = self->top_frame ? (PyObject*)self->top_frame : Py_None; Py_INCREF(result); return result; } static PyObject* green_getstate(PyGreenlet* self) { PyErr_Format(PyExc_TypeError, "cannot serialize '%s' object", Py_TYPE(self)->tp_name); return NULL; } static PyObject* green_repr(PyGreenlet* self) { /* Return a string like 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 = !PyGreenlet_STARTED(self) && !PyGreenlet_ACTIVE(self); if (!STATE_OK) { return NULL; } #if PY_MAJOR_VERSION >= 3 # define GNative_FromFormat PyUnicode_FromFormat #else # define GNative_FromFormat PyString_FromFormat #endif if (_green_not_dead(self)) { /* XXX: The otid= is almost useless becasue 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. */ result = GNative_FromFormat( "<%s object at %p (otid=%p)%s%s%s%s>", Py_TYPE(self)->tp_name, self, self->run_info, ts_current == self ? " current" : (PyGreenlet_STARTED(self) ? " suspended" : ""), PyGreenlet_ACTIVE(self) ? " active" : "", never_started ? " pending" : " started", PyGreenlet_MAIN(self) ? " main" : "" ); } else { /* main greenlets never really appear dead. */ result = GNative_FromFormat( "<%s object at %p (otid=%p) dead>", Py_TYPE(self)->tp_name, self, self->run_info ); } #undef GNative_FromFormat return result; } /***************************************************************************** * C interface * * These are exported using the CObject API */ static PyGreenlet* PyGreenlet_GetCurrent(void) { if (!STATE_OK) { return NULL; } Py_INCREF(ts_current); return ts_current; } static int PyGreenlet_SetParent(PyGreenlet* g, PyGreenlet* nparent) { if (!PyGreenlet_Check(g)) { PyErr_SetString(PyExc_TypeError, "parent must be a greenlet"); return -1; } return green_setparent((PyGreenlet*)g, (PyObject*)nparent, NULL); } static PyGreenlet* PyGreenlet_New(PyObject* run, PyGreenlet* parent) { /* XXX: Why doesn't this call green_new()? There's some duplicate code. */ PyGreenlet* g = NULL; g = (PyGreenlet*)PyType_GenericAlloc(&PyGreenlet_Type, 0); if (g == NULL) { return NULL; } if (run != NULL) { Py_INCREF(run); g->run_info = run; } if (parent != NULL) { if (PyGreenlet_SetParent(g, parent)) { Py_DECREF(g); return NULL; } } else { if ((g->parent = PyGreenlet_GetCurrent()) == NULL) { Py_DECREF(g); return NULL; } } #if GREENLET_USE_CFRAME g->cframe = &PyThreadState_GET()->root_cframe; #endif return g; } static PyObject* PyGreenlet_Switch(PyGreenlet* g, PyObject* args, PyObject* kwargs) { PyGreenlet* self = (PyGreenlet*)g; if (!PyGreenlet_Check(self)) { PyErr_BadArgument(); return NULL; } if (args == NULL) { args = Py_BuildValue("()"); } else { Py_INCREF(args); } if (kwargs != NULL && PyDict_Check(kwargs)) { Py_INCREF(kwargs); } else { kwargs = NULL; } return single_result(g_switch(self, args, kwargs)); } static PyObject* PyGreenlet_Throw(PyGreenlet* self, PyObject* typ, PyObject* val, PyObject* tb) { if (!PyGreenlet_Check(self)) { PyErr_BadArgument(); return NULL; } Py_INCREF(typ); Py_XINCREF(val); Py_XINCREF(tb); return throw_greenlet(self, typ, val, tb); } /** End C API ****************************************************************/ static PyMethodDef green_methods[] = { {"switch", (PyCFunction)green_switch, METH_VARARGS | METH_KEYWORDS, green_switch_doc}, {"throw", (PyCFunction)green_throw, METH_VARARGS, green_throw_doc}, {"__getstate__", (PyCFunction)green_getstate, METH_NOARGS, NULL}, {NULL, NULL} /* sentinel */ }; static PyGetSetDef green_getsets[] = { {"__dict__", (getter)green_getdict, (setter)green_setdict, /*XXX*/ NULL}, {"run", (getter)green_getrun, (setter)green_setrun, /*XXX*/ NULL}, {"parent", (getter)green_getparent, (setter)green_setparent, /*XXX*/ NULL}, {"gr_frame", (getter)green_getframe, NULL, /*XXX*/ NULL}, {"gr_context", (getter)green_getcontext, (setter)green_setcontext, /*XXX*/ NULL}, {"dead", (getter)green_getdead, NULL, /*XXX*/ NULL}, {"_stack_saved", (getter)green_get_stack_saved, NULL, /*XXX*/ NULL}, {NULL}}; static PyNumberMethods green_as_number = { NULL, /* nb_add */ NULL, /* nb_subtract */ NULL, /* nb_multiply */ #if PY_MAJOR_VERSION < 3 NULL, /* nb_divide */ #endif NULL, /* nb_remainder */ NULL, /* nb_divmod */ NULL, /* nb_power */ NULL, /* nb_negative */ NULL, /* nb_positive */ NULL, /* nb_absolute */ (inquiry)green_bool, /* nb_bool */ }; PyTypeObject PyGreenlet_Type = { PyVarObject_HEAD_INIT(NULL, 0) "greenlet.greenlet", /* tp_name */ sizeof(PyGreenlet), /* tp_basicsize */ 0, /* tp_itemsize */ /* methods */ (destructor)green_dealloc, /* tp_dealloc */ 0, /* tp_print */ 0, /* tp_getattr */ 0, /* tp_setattr */ 0, /* tp_compare */ (reprfunc)green_repr, /* tp_repr */ &green_as_number, /* tp_as _number*/ 0, /* tp_as _sequence*/ 0, /* tp_as _mapping*/ 0, /* tp_hash */ 0, /* tp_call */ 0, /* tp_str */ 0, /* tp_getattro */ 0, /* tp_setattro */ 0, /* tp_as_buffer*/ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | GREENLET_GC_FLAGS, /* tp_flags */ "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 */ (traverseproc)GREENLET_tp_traverse, /* tp_traverse */ (inquiry)GREENLET_tp_clear, /* tp_clear */ 0, /* tp_richcompare */ offsetof(PyGreenlet, weakreflist), /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ green_methods, /* tp_methods */ 0, /* tp_members */ green_getsets, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ offsetof(PyGreenlet, dict), /* tp_dictoffset */ (initproc)green_init, /* tp_init */ GREENLET_tp_alloc, /* tp_alloc */ green_new, /* tp_new */ GREENLET_tp_free, /* tp_free */ (inquiry)GREENLET_tp_is_gc, /* tp_is_gc */ }; PyDoc_STRVAR(mod_getcurrent_doc, "getcurrent() -> greenlet\n" "\n" "Returns the current greenlet (i.e. the one which called this " "function).\n"); static PyObject* mod_getcurrent(PyObject* self) { if (!STATE_OK) { return NULL; } Py_INCREF(ts_current); return (PyObject*)ts_current; } PyDoc_STRVAR(mod_settrace_doc, "settrace(callback) -> object\n" "\n" "Sets a new tracing function and returns the previous one.\n"); static PyObject* mod_settrace(PyObject* self, PyObject* args) { int err; PyObject* previous; PyObject* tracefunc; PyGreenlet* current; if (!PyArg_ParseTuple(args, "O", &tracefunc)) { return NULL; } if (!STATE_OK) { return NULL; } current = ts_current; previous = PyDict_GetItem(current->run_info, ts_tracekey); if (previous == NULL) { previous = Py_None; } Py_INCREF(previous); if (tracefunc == Py_None) { err = previous != Py_None ? PyDict_DelItem(current->run_info, ts_tracekey) : 0; } else { err = PyDict_SetItem(current->run_info, ts_tracekey, tracefunc); } if (err < 0) { Py_CLEAR(previous); } return previous; } PyDoc_STRVAR(mod_gettrace_doc, "gettrace() -> object\n" "\n" "Returns the currently set tracing function, or None.\n"); static PyObject* mod_gettrace(PyObject* self) { PyObject* tracefunc; if (!STATE_OK) { return NULL; } tracefunc = PyDict_GetItem(ts_current->run_info, ts_tracekey); if (tracefunc == NULL) { tracefunc = Py_None; } Py_INCREF(tracefunc); return tracefunc; } static PyMethodDef GreenMethods[] = { {"getcurrent", (PyCFunction)mod_getcurrent, METH_NOARGS, mod_getcurrent_doc}, {"settrace", (PyCFunction)mod_settrace, METH_VARARGS, mod_settrace_doc}, {"gettrace", (PyCFunction)mod_gettrace, METH_NOARGS, mod_gettrace_doc}, {NULL, NULL} /* Sentinel */ }; static char* copy_on_greentype[] = { "getcurrent", "error", "GreenletExit", "settrace", "gettrace", NULL}; #if PY_MAJOR_VERSION >= 3 # define INITERROR return NULL static struct PyModuleDef greenlet_module_def = { PyModuleDef_HEAD_INIT, "greenlet._greenlet", NULL, -1, GreenMethods, }; PyMODINIT_FUNC PyInit__greenlet(void) #else # define INITERROR return PyMODINIT_FUNC init_greenlet(void) #endif { PyObject* m = NULL; char** p = NULL; PyObject* c_api_object; static void* _PyGreenlet_API[PyGreenlet_API_pointers]; GREENLET_NOINLINE_INIT(); #if PY_MAJOR_VERSION >= 3 m = PyModule_Create(&greenlet_module_def); #else m = Py_InitModule("greenlet._greenlet", GreenMethods); #endif if (m == NULL) { INITERROR; } #if PY_MAJOR_VERSION >= 3 # define Greenlet_Intern PyUnicode_InternFromString #else # define Greenlet_Intern PyString_InternFromString #endif ts_curkey = Greenlet_Intern("__greenlet_ts_curkey"); ts_delkey = Greenlet_Intern("__greenlet_ts_delkey"); ts_tracekey = Greenlet_Intern("__greenlet_ts_tracekey"); ts_event_switch = Greenlet_Intern("switch"); ts_event_throw = Greenlet_Intern("throw"); #undef Greenlet_Intern if (ts_curkey == NULL || ts_delkey == NULL) { INITERROR; } if (PyType_Ready(&PyGreenlet_Type) < 0) { INITERROR; } PyExc_GreenletError = PyErr_NewException("greenlet.error", NULL, NULL); if (PyExc_GreenletError == NULL) { INITERROR; } PyExc_GreenletExit = PyErr_NewException("greenlet.GreenletExit", PyExc_BaseException, NULL); if (PyExc_GreenletExit == NULL) { INITERROR; } ts_empty_tuple = PyTuple_New(0); if (ts_empty_tuple == NULL) { INITERROR; } ts_empty_dict = PyDict_New(); if (ts_empty_dict == NULL) { INITERROR; } ts_current = green_create_main(); if (ts_current == NULL) { INITERROR; } Py_INCREF(&PyGreenlet_Type); PyModule_AddObject(m, "greenlet", (PyObject*)&PyGreenlet_Type); Py_INCREF(PyExc_GreenletError); PyModule_AddObject(m, "error", PyExc_GreenletError); Py_INCREF(PyExc_GreenletExit); PyModule_AddObject(m, "GreenletExit", PyExc_GreenletExit); PyModule_AddObject(m, "GREENLET_USE_GC", PyBool_FromLong(1)); PyModule_AddObject(m, "GREENLET_USE_TRACING", PyBool_FromLong(1)); PyModule_AddObject( m, "GREENLET_USE_CONTEXT_VARS", PyBool_FromLong(GREENLET_PY37)); /* also publish module-level data as attributes of the greentype. */ /* XXX: Why? */ for (p = copy_on_greentype; *p; p++) { PyObject* o = PyObject_GetAttrString(m, *p); if (!o) { continue; } PyDict_SetItemString(PyGreenlet_Type.tp_dict, *p, o); Py_DECREF(o); } /* * Expose C API */ /* types */ _PyGreenlet_API[PyGreenlet_Type_NUM] = (void*)&PyGreenlet_Type; /* exceptions */ _PyGreenlet_API[PyExc_GreenletError_NUM] = (void*)PyExc_GreenletError; _PyGreenlet_API[PyExc_GreenletExit_NUM] = (void*)PyExc_GreenletExit; /* methods */ _PyGreenlet_API[PyGreenlet_New_NUM] = (void*)PyGreenlet_New; _PyGreenlet_API[PyGreenlet_GetCurrent_NUM] = (void*)PyGreenlet_GetCurrent; _PyGreenlet_API[PyGreenlet_Throw_NUM] = (void*)PyGreenlet_Throw; _PyGreenlet_API[PyGreenlet_Switch_NUM] = (void*)PyGreenlet_Switch; _PyGreenlet_API[PyGreenlet_SetParent_NUM] = (void*)PyGreenlet_SetParent; /* XXX: Note that our module name is ``greenlet._greenlet``, but for backwards compatibility with existing C code, we need the _C_API to be directly in greenlet. */ c_api_object = PyCapsule_New((void*)_PyGreenlet_API, "greenlet._C_API", NULL); if (c_api_object != NULL) { PyModule_AddObject(m, "_C_API", c_api_object); } #if PY_MAJOR_VERSION >= 3 return m; #endif } #ifdef __clang__ # pragma clang diagnostic pop #endif