Skip to content

gh-128002: use internal llist implementation for asyncio tasks #128256

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Dec 25, 2024
Merged

gh-128002: use internal llist implementation for asyncio tasks #128256

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
257bbd9
reuse llist impl
kumaraditya303 Dec 25, 2024
ff6894e
sort import
kumaraditya303 Dec 25, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
70 changes: 20 additions & 50 deletions Modules/_asynciomodule.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,9 +6,9 @@
#include "pycore_critical_section.h" // Py_BEGIN_CRITICAL_SECTION_MUT()
#include "pycore_dict.h" // _PyDict_GetItem_KnownHash()
#include "pycore_freelist.h" // _Py_FREELIST_POP()
#include "pycore_llist.h" // struct llist_node
#include "pycore_modsupport.h" // _PyArg_CheckPositional()
#include "pycore_moduleobject.h" // _PyModule_GetState()
#include "pycore_object.h" // _Py_SetImmortalUntracked()
#include "pycore_pyerrors.h" // _PyErr_ClearExcState()
#include "pycore_pylifecycle.h" // _Py_IsInterpreterFinalizing()
#include "pycore_pystate.h" // _PyThreadState_GET()
Expand Down Expand Up @@ -60,8 +60,7 @@ typedef struct TaskObj {
PyObject *task_coro;
PyObject *task_name;
PyObject *task_context;
struct TaskObj *next;
struct TaskObj *prev;
struct llist_node task_node;
} TaskObj;

typedef struct {
Expand Down Expand Up @@ -136,21 +135,11 @@ typedef struct {
/* Counter for autogenerated Task names */
uint64_t task_name_counter;

/* Circular linked-list of all tasks which are instances of asyncio.Task or subclasses
of it. Third party tasks implementations which don't inherit from
asyncio.Task are tracked separately using the 'non_asyncio_tasks' WeakSet.
`first` is used as a sentinel to mark the end of the linked-list. It avoids one
branch in checking for empty list when adding a new task, the list is
initialized with `head`, `head->next` and `head->prev` pointing to `first`
to mark an empty list.

/* Head of circular linked-list of all tasks which are instances of `asyncio.Task`
or subclasses of it. Third party tasks implementations which don't inherit from
`asyncio.Task` are tracked separately using the `non_asyncio_tasks` WeakSet.
*/

struct {
TaskObj first;
TaskObj *head;
} asyncio_tasks;

struct llist_node asyncio_tasks_head;
} asyncio_state;

static inline asyncio_state *
Expand Down Expand Up @@ -1896,19 +1885,12 @@ register_task(asyncio_state *state, TaskObj *task)
{
ASYNCIO_STATE_LOCK(state);
assert(Task_Check(state, task));
assert(task != &state->asyncio_tasks.first);
if (task->next != NULL) {
if (task->task_node.next != NULL) {
// already registered
assert(task->task_node.prev != NULL);
goto exit;
}
assert(task->prev == NULL);
assert(state->asyncio_tasks.head != NULL);

task->next = state->asyncio_tasks.head;
task->prev = state->asyncio_tasks.head->prev;
state->asyncio_tasks.head->prev->next = task;
state->asyncio_tasks.head->prev = task;

llist_insert_tail(&state->asyncio_tasks_head, &task->task_node);
exit:
ASYNCIO_STATE_UNLOCK(state);
}
Expand All @@ -1924,18 +1906,12 @@ unregister_task(asyncio_state *state, TaskObj *task)
{
ASYNCIO_STATE_LOCK(state);
assert(Task_Check(state, task));
assert(task != &state->asyncio_tasks.first);
if (task->next == NULL) {
if (task->task_node.next == NULL) {
// not registered
assert(task->prev == NULL);
assert(state->asyncio_tasks.head != task);
assert(task->task_node.prev == NULL);
goto exit;
}
task->next->prev = task->prev;
task->prev->next = task->next;
task->next = NULL;
task->prev = NULL;
assert(state->asyncio_tasks.head != task);
llist_remove(&task->task_node);
exit:
ASYNCIO_STATE_UNLOCK(state);
}
Expand Down Expand Up @@ -3625,20 +3601,18 @@ _asyncio_all_tasks_impl(PyObject *module, PyObject *loop)
Py_DECREF(eager_iter);
int err = 0;
ASYNCIO_STATE_LOCK(state);
TaskObj *first = &state->asyncio_tasks.first;
TaskObj *head = state->asyncio_tasks.head->next;
Py_INCREF(head);
while (head != first)
{
if (add_one_task(state, tasks, (PyObject *)head, loop) < 0) {
struct llist_node *node;
llist_for_each_safe(node, &state->asyncio_tasks_head) {
TaskObj *task = llist_data(node, TaskObj, task_node);
Py_INCREF(task);
if (add_one_task(state, tasks, (PyObject *)task, loop) < 0) {
Py_DECREF(task);
Py_DECREF(tasks);
Py_DECREF(loop);
Py_DECREF(head);
err = 1;
break;
}
Py_INCREF(head->next);
Py_SETREF(head, head->next);
Py_DECREF(task);
}
ASYNCIO_STATE_UNLOCK(state);
if (err) {
Expand Down Expand Up @@ -3847,11 +3821,7 @@ module_exec(PyObject *mod)
{
asyncio_state *state = get_asyncio_state(mod);

Py_SET_TYPE(&state->asyncio_tasks.first, state->TaskType);
_Py_SetImmortalUntracked((PyObject *)&state->asyncio_tasks.first);
state->asyncio_tasks.head = &state->asyncio_tasks.first;
state->asyncio_tasks.head->next = &state->asyncio_tasks.first;
state->asyncio_tasks.head->prev = &state->asyncio_tasks.first;
llist_init(&state->asyncio_tasks_head);

#define CREATE_TYPE(m, tp, spec, base) \
do { \
Expand Down
Loading