void test_simple_switch(void)
{
status = 0;
stacklet_handle h = stacklet_new(thrd, switchbackonce_callback, (void *)123);
assert(h != EMPTY_STACKLET_HANDLE);
assert(status == 1);
status = 2;
h = stacklet_switch(thrd, h);
assert(status == 3);
assert(h == EMPTY_STACKLET_HANDLE);
}
static PyObject *
do_switch(Fiber *self, PyObject *value)
{
PyThreadState *tstate;
stacklet_handle stacklet_h;
Fiber *current;
PyObject *result;
/* save state */
current = _global_state.current;
tstate = PyThreadState_Get();
current->ts.recursion_depth = tstate->recursion_depth;
current->ts.frame = tstate->frame;
current->ts.exc_type = tstate->exc_type;
current->ts.exc_value = tstate->exc_value;
current->ts.exc_traceback = tstate->exc_traceback;
_global_state.origin = current;
_global_state.destination = self;
_global_state.value = value;
if (self->stacklet_h == NULL) {
stacklet_h = stacklet_new(self->thread_h, stacklet__callback, NULL);
} else {
stacklet_h = stacklet_switch(self->stacklet_h);
}
result = stacklet__post_switch(stacklet_h);
/* restore state */
tstate = PyThreadState_Get();
tstate->recursion_depth = current->ts.recursion_depth;
tstate->frame = current->ts.frame;
tstate->exc_type = current->ts.exc_type;
tstate->exc_value = current->ts.exc_value;
tstate->exc_traceback = current->ts.exc_traceback;
current->ts.frame = NULL;
current->ts.exc_type = NULL;
current->ts.exc_value = NULL;
current->ts.exc_traceback = NULL;
return result;
}
static PyObject *
do_switch(Fiber *self, PyObject *value)
{
PyThreadState *tstate;
stacklet_handle stacklet_h;
Fiber *origin, *current;
PyObject *result;
/* save state */
current = get_current();
ASSERT(current != NULL);
tstate = PyThreadState_Get();
ASSERT(tstate != NULL);
ASSERT(tstate->dict != NULL);
current->ts.recursion_depth = tstate->recursion_depth;
current->ts.frame = tstate->frame;
current->ts.exc_type = tstate->exc_type;
current->ts.exc_value = tstate->exc_value;
current->ts.exc_traceback = tstate->exc_traceback;
ASSERT(current->stacklet_h == NULL);
/* _global_state is to pass values across a switch. Its contents are only
* valid immediately before and after a switch. For any other purpose, the
* current fiber is identified by current_fiber_key in the thread state
* dictionary. */
_global_state.origin = current;
_global_state.value = value;
/* make the target fiber the new current one. */
if (PyDict_SetItem(tstate->dict, current_fiber_key, (PyObject *) self) < 0) {
return NULL;
}
/* switch to existing, or create new fiber */
if (self->stacklet_h == NULL) {
stacklet_h = stacklet_new(self->thread_h, stacklet__callback, NULL);
} else {
stacklet_h = stacklet_switch(self->stacklet_h);
}
/* need to store the handle of the stacklet that switched to us, so that
* later it can be resumed again. (stacklet_h can also be
* EMPTY_STACKLET_HANDLE in which case the stacklet exited) */
ASSERT(stacklet_h != NULL);
origin = _global_state.origin;
origin->stacklet_h = stacklet_h;
current->stacklet_h = NULL; /* handle is valid only once */
result = _global_state.value;
/* back to the fiber that did the switch. this may drop the refcount on
* origin to zero. */
if (PyDict_SetItem(tstate->dict, current_fiber_key, (PyObject *) current) < 0) {
return NULL;
}
/* restore state */
tstate->recursion_depth = current->ts.recursion_depth;
tstate->frame = current->ts.frame;
tstate->exc_type = current->ts.exc_type;
tstate->exc_value = current->ts.exc_value;
tstate->exc_traceback = current->ts.exc_traceback;
current->ts.frame = NULL;
current->ts.exc_type = NULL;
current->ts.exc_value = NULL;
current->ts.exc_traceback = NULL;
return result;
}
void test_new(void)
{
stacklet_handle h = stacklet_new(thrd, empty_callback, (void *)123);
assert(h == EMPTY_STACKLET_HANDLE);
}
int withdepth(int self, float d)
{
int res = 0;
if (d > 0.0)
{
foo_t *foo = malloc(sizeof(foo_t));
foo_t *foo2 = malloc(sizeof(foo_t));
foo->self = self;
foo->d = d;
foo->next = foo2;
foo2->self = self + 100;
foo2->d = d;
foo2->next = NULL;
res = withdepth(self, d - 1.1);
assert(foo->self == self);
assert(foo->d == d);
assert(foo->next == foo2);
assert(foo2->self == self + 100);
assert(foo2->d == d);
assert(foo2->next == NULL);
free(foo2);
free(foo);
}
else
{
stacklet_handle h;
int n = rand() % 10;
if (n == self || (status >= statusmax && handles[n] == NULL))
return 1;
//printf("status == %d, self = %d\n", status, self);
assert(handles[self] == NULL);
assert(nextstep == -1);
nextstep = ++status;
comefrom = self;
gointo = n;
if (handles[n] == NULL)
{
/* start a new stacklet */
//printf("new %d\n", n);
h = stacklet_new(thrd, variousdepths_callback, (void *)(ptrdiff_t)n);
}
else
{
/* switch to this stacklet */
//printf("switch to %d\n", n);
h = handles[n];
handles[n] = NULL;
h = stacklet_switch(thrd, h);
}
//printf("back in self = %d, coming from %d\n", self, comefrom);
assert(nextstep == status);
nextstep = -1;
assert(gointo == self);
assert(comefrom != self);
assert(handles[self] == NULL);
if (comefrom != -42)
{
assert(0 <= comefrom && comefrom < 10);
assert(handles[comefrom] == NULL);
handles[comefrom] = h;
}
else
assert(h == EMPTY_STACKLET_HANDLE);
comefrom = -1;
gointo = -1;
}
assert((res & (res-1)) == 0); /* to prevent a tail-call to withdepth() */
return res;
}
