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 int kill_greenlet(greenlet* self)
{
/* Cannot raise an exception to kill the greenlet if
it is not running in the same thread! */
/* The dying greenlet cannot be a parent of ts_current
because the 'parent' field chain would hold a
reference */
gr_param result;
greenlet* oldparent;
if (!STATE_OK)
{
return -1;
}
oldparent = self->parent;
self->parent = ts_current;
/* Send the greenlet a GreenletExit exception. */
//PyErr_SetNone(PyExc_GreenletExit);
result = g_switch(self, 0);
if (result == 0)
return -1;
free(self);
return 0;
}
static PyObject* green_switch(
PyGreenlet* self,
PyObject* args,
PyObject* kwargs)
{
Py_INCREF(args);
Py_XINCREF(kwargs);
return single_result(g_switch(self, args, kwargs));
}
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));
}
gr_param greenlet_switch(greenlet* self, gr_param data)
{
if (self->stack_stop && !self->stack_start)
{
assert(!"finished");
return 0;
}
if (!STATE_OK)
return 0;
return g_switch(self, data);
}
static void GREENLET_NOINLINE(g_initialstub)(void* mark)
{
int err;
gr_param ret;
/* now use run_info to store the statedict */
/* start the greenlet */
ts_target->stack_start = NULL;
ts_target->stack_stop = (char*) mark;
if (ts_current->stack_start == NULL)
{
/* ts_current is dying */
ts_target->stack_prev = ts_current->stack_prev;
}
else
{
ts_target->stack_prev = ts_current;
}
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 */
greenlet* ts_self = ts_current;
ts_self->stack_start = (char*) 1;
ret = ts_self->callback(ts_self->data);
//result = g_handle_exit(result);
/* jump back to parent */
ts_self->stack_start = NULL; /* dead */
g_switch(ts_self->parent, ret);
assert(0);
/* must not return from here! */
//PyErr_WriteUnraisable((PyObject *) ts_self);
//Py_FatalError("greenlets cannot continue");
}
/* back in the parent */
}
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;
}
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 GREENLET_NOINLINE(g_initialstub)(void* mark)
{
int err;
PyObject *o, *run;
PyObject *exc, *val, *tb;
PyGreenlet* self = ts_target;
PyObject* args = ts_passaround_args;
PyObject* kwargs = ts_passaround_kwargs;
/* 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;
}
/* 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;
}
/* restore arguments in case they are clobbered */
ts_target = self;
ts_passaround_args = args;
ts_passaround_kwargs = kwargs;
/* 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);
/* 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;
self->exc_type = NULL;
self->exc_value = NULL;
self->exc_traceback = NULL;
self->recursion_depth = PyThreadState_GET()->recursion_depth;
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 */
PyObject* result;
PyGreenlet* parent;
self->stack_start = (char*) 1; /* running */
if (args == NULL) {
/* pending exception */
result = NULL;
} else {
/* call g.run(*args, **kwargs) */
result = PyEval_CallObjectWithKeywords(
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.
*/
}
/* We ran out of parents, cannot continue */
PyErr_WriteUnraisable((PyObject *) self);
Py_FatalError("greenlets cannot continue");
}
/* back in the parent */
return err;
}
void SwitchStatement (void)
/* Handle a switch statement for chars with a cmp cascade for the selector */
{
ExprDesc SwitchExpr; /* Switch statement expression */
CodeMark CaseCodeStart; /* Start of code marker */
CodeMark SwitchCodeStart;/* Start of switch code */
CodeMark SwitchCodeEnd; /* End of switch code */
unsigned ExitLabel; /* Exit label */
unsigned SwitchCodeLabel;/* Label for the switch code */
int HaveBreak = 0; /* True if the last statement had a break */
int RCurlyBrace; /* True if last token is right curly brace */
SwitchCtrl* OldSwitch; /* Pointer to old switch control data */
SwitchCtrl SwitchData; /* New switch data */
/* Eat the "switch" token */
NextToken ();
/* Read the switch expression and load it into the primary. It must have
* integer type.
*/
ConsumeLParen ();
Expression0 (&SwitchExpr);
if (!IsClassInt (SwitchExpr.Type)) {
Error ("Switch quantity is not an integer");
/* To avoid any compiler errors, make the expression a valid int */
ED_MakeConstAbsInt (&SwitchExpr, 1);
}
ConsumeRParen ();
/* Add a jump to the switch code. This jump is usually unnecessary,
* because the switch code will moved up just behind the switch
* expression. However, in rare cases, there's a label at the end of
* the switch expression. This label will not get moved, so the code
* jumps around the switch code, and after moving the switch code,
* things look really weird. If we add a jump here, we will never have
* a label attached to the current code position, and the jump itself
* will get removed by the optimizer if it is unnecessary.
*/
SwitchCodeLabel = GetLocalLabel ();
g_jump (SwitchCodeLabel);
/* Remember the current code position. We will move the switch code
* to this position later.
*/
GetCodePos (&CaseCodeStart);
/* Setup the control structure, save the old and activate the new one */
SwitchData.Nodes = NewCollection ();
SwitchData.ExprType = UnqualifiedType (SwitchExpr.Type[0].C);
SwitchData.Depth = SizeOf (SwitchExpr.Type);
SwitchData.DefaultLabel = 0;
OldSwitch = Switch;
Switch = &SwitchData;
/* Get the exit label for the switch statement */
ExitLabel = GetLocalLabel ();
/* Create a loop so we may use break. */
AddLoop (ExitLabel, 0);
/* Make sure a curly brace follows */
if (CurTok.Tok != TOK_LCURLY) {
Error ("`{' expected");
}
/* Parse the following statement, which will actually be a compound
* statement because of the curly brace at the current input position
*/
HaveBreak = Statement (&RCurlyBrace);
/* Check if we had any labels */
if (CollCount (SwitchData.Nodes) == 0 && SwitchData.DefaultLabel == 0) {
Warning ("No case labels");
}
/* If the last statement did not have a break, we may have an open
* label (maybe from an if or similar). Emitting code and then moving
* this code to the top will also move the label to the top which is
* wrong. So if the last statement did not have a break (which would
* carry the label), add a jump to the exit. If it is useless, the
* optimizer will remove it later.
*/
if (!HaveBreak) {
g_jump (ExitLabel);
}
/* Remember the current position */
GetCodePos (&SwitchCodeStart);
/* Output the switch code label */
g_defcodelabel (SwitchCodeLabel);
/* Generate code */
if (SwitchData.DefaultLabel == 0) {
/* No default label, use switch exit */
SwitchData.DefaultLabel = ExitLabel;
}
g_switch (SwitchData.Nodes, SwitchData.DefaultLabel, SwitchData.Depth);
/* Move the code to the front */
GetCodePos (&SwitchCodeEnd);
MoveCode (&SwitchCodeStart, &SwitchCodeEnd, &CaseCodeStart);
/* Define the exit label */
g_defcodelabel (ExitLabel);
/* Exit the loop */
DelLoop ();
/* Switch back to the enclosing switch statement if any */
Switch = OldSwitch;
/* Free the case value tree */
FreeCaseNodeColl (SwitchData.Nodes);
/* If the case statement was (correctly) terminated by a closing curly
* brace, skip it now.
*/
if (RCurlyBrace) {
NextToken ();
}
}
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;
/* 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;
}
/* 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;
self->exc_type = NULL;
self->exc_value = NULL;
self->exc_traceback = NULL;
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;
#if GREENLET_USE_TRACING
PyObject* tracefunc;
#endif
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 GREENLET_USE_TRACING
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);
}
#endif
Py_DECREF(origin);
if (args == NULL) {
/* pending exception */
result = NULL;
} else {
/* call g.run(*args, **kwargs) */
result = PyEval_CallObjectWithKeywords(
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;
}
