event loop for darwin

1 month ago · 9a00a29af6
parent 45284910cc
commit 9a00a29af6
7 changed files with 217 additions and 25 deletions
--- a/include/container_of.h
+++ b/include/container_of.h
@ -0,0 +1,10 @@
+#pragma once
+
+#include <stddef.h>
+
+#include "typecheck.h"
+
+#define CONTAINER_OF(PTR, TYPE, MEMBER) ({                \
+  CHECK_TYPE(__typeof__(((TYPE *)NULL)->MEMBER), *(PTR)); \
+  (TYPE *)((char *)(PTR) - offsetof(TYPE, MEMBER));       \
+})
--- a/include/eventloop.h
+++ b/include/eventloop.h
@ -1,6 +1,47 @@
 #pragma once

-struct eventloop;
+#include <stdint.h>
+#include <stdbool.h>
+#include <time.h>

-struct eventloop *eventloop_new(void);
-void eventloop_free(struct eventloop *el);
+#include "list.h"
+
+#define OWD_EVENT_READABLE (1 << 0)
+#define OWD_EVENT_WRITABLE (1 << 1)
+
+enum owd_event_source {
+  OWD_EVENT_SOURCE_FD,
+  OWD_EVENT_SOURCE_TIMER,
+};
+
+typedef struct {
+  uintptr_t obj;
+  enum owd_event_source source;
+} owd_event_id_t;
+
+struct owd_event {
+  owd_event_id_t id;
+  struct intrusive_list list;
+  
+  uintptr_t kqueue_ident;
+  short kqueue_filter;
+};
+
+struct owd_eventloop {
+  struct intrusive_list event_list;
+
+  uintptr_t kqueue_timer_next;
+  int kqueue_fd;
+};
+
+static inline bool owd_event_id_eq(owd_event_id_t eid1, owd_event_id_t eid2) {
+  return (eid1.obj == eid2.obj) && (eid1.source == eid2.source);
+}
+
+int owd_eventloop_init(struct owd_eventloop *el);
+void owd_eventloop_cleanup(struct owd_eventloop *el);
+
+int owd_eventloop_wait(struct owd_eventloop *el, owd_event_id_t *id_out, const struct timespec *timeout);
+int owd_eventloop_clear(struct owd_eventloop *el, struct owd_event *e);
+void owd_eventloop_remove(struct owd_eventloop *el, struct owd_event *e);
+int owd_eventloop_add_timer(struct owd_eventloop *el, struct owd_event *e, uint64_t millis, bool oneshot);
--- a/include/list.h
+++ b/include/list.h
@ -0,0 +1,46 @@
+#pragma once
+
+#include "typecheck.h"
+
+struct intrusive_list {
+  struct intrusive_list *next;
+  struct intrusive_list *prev;
+};
+
+static inline void intrusive_list_init_empty(struct intrusive_list *head) {
+  head->next = head;
+  head->prev = head;
+}
+
+static inline void intrusive_list_del(struct intrusive_list *node) {
+  struct intrusive_list old_node;
+
+  old_node = *node;
+  node->prev->next = old_node.next;
+  node->next->prev = old_node.prev;
+}
+
+static inline void intrusive_list_add(
+  struct intrusive_list *add_after,
+  struct intrusive_list *new_node)
+{
+  new_node->prev = add_after;
+  new_node->next = add_after->next;
+  new_node->prev->next = new_node;
+  new_node->next->prev = new_node;
+}
+
+#define INTRUSIVE_LIST_FOR_EACH(ITER, NEXT, HEAD) \
+  for (                                           \
+    CHECK_TYPE(struct intrusive_list *, HEAD),    \
+      (ITER) = (HEAD)->next,                      \
+      (NEXT) = (ITER)->next;                      \
+    (ITER) != (HEAD);                             \
+    (ITER) = (NEXT), (NEXT) = (ITER)->next)
+
+#define INTRUSIVE_LIST_FOR_EACH_NO_REMOVE(ITER, HEAD) \
+  for (                                               \
+    CHECK_TYPE(struct intrusive_list *, HEAD),        \
+      (ITER) = (HEAD)->next;                          \
+    (ITER) != (HEAD);                                 \
+    (ITER) = (ITER)->next)
--- a/include/mem.h
+++ b/include/mem.h
@ -3,6 +3,7 @@
 #include <stdlib.h>

 #include "scoped.h"
+#include "typecheck.h"

 DEF_SCOPED_TYPE(mem, void *, NULL, free)

--- a/include/scoped.h
+++ b/include/scoped.h
@ -1,13 +1,5 @@
 #pragma once

-#define CHECK_TYPE(TYPE, VAL) ({                                              \
-  typedef void (*_check_type_dummy_fn_t)(TYPE);                               \
-  _check_type_dummy_fn_t _check_type_dummy_fn = (_check_type_dummy_fn_t)NULL; \
-  if (0)                                                                      \
-    _check_type_dummy_fn(VAL);                                                \
-  1;                                                                          \
-})
-
 #define DEF_SCOPED_TYPE(NAME, TYPE, UNOCCUPIED, CLEANUP_FN)     \
  static inline TYPE _scoped_##NAME##_unoccupied(void) {        \
    return (UNOCCUPIED);                                        \
--- a/include/typecheck.h
+++ b/include/typecheck.h
@ -0,0 +1,9 @@
+#pragma once
+
+#define CHECK_TYPE(TYPE, VAL) ({                                              \
+  typedef void (*_check_type_dummy_fn_t)(TYPE);                               \
+  _check_type_dummy_fn_t _check_type_dummy_fn = (_check_type_dummy_fn_t)NULL; \
+  if (0)                                                                      \
+    _check_type_dummy_fn(VAL);                                                \
+  1;                                                                          \
+})
--- a/src/eventloop.c
+++ b/src/eventloop.c
@ -1,28 +1,121 @@
-#include <stdlib.h>
 #include <unistd.h>
+#include <string.h>
 #include <errno.h>
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/time.h>

 #include "eventloop.h"
-#include "mem.h"
+#include "container_of.h"
+#include "list.h"

-struct eventloop {
-  int kqueue_fd;
-};
+int owd_eventloop_init(struct owd_eventloop *el) {
+  intrusive_list_init_empty(&el->event_list);

-struct eventloop *eventloop_new(void) {
-  MEM_SCOPED(struct eventloop, el);
+  if ((el->kqueue_fd = kqueue()) < 0)
+    return -1;
+  el->kqueue_timer_next = 0;

-  if (!(el = malloc(sizeof(struct eventloop)))) {
-    errno = ENOMEM;
-    return NULL;
+  return 0;
 }

-  return MEM_RELEASE(struct eventloop, &el);
+static void event_cleanup(struct owd_eventloop *el, struct owd_event *e) {
+  if (!e)
+    return;
+
+  // TODO: any platform-specific cleanup
 }

-void eventloop_free(struct eventloop *el) {
+void owd_eventloop_cleanup(struct owd_eventloop *el) {
+  struct intrusive_list *li;
+  struct owd_event *e;
+  
  if (!el)
    return;
+
+  INTRUSIVE_LIST_FOR_EACH_NO_REMOVE(li, &el->event_list) {
+    e = CONTAINER_OF(li, struct owd_event, list);
+    event_cleanup(el, e);
+  }
+
  close(el->kqueue_fd);
-  free(el);
+}
+
+int owd_eventloop_wait(
+  struct owd_eventloop *el,
+  owd_event_id_t *id_out,
+  const struct timespec *timeout)
+{
+  struct kevent kev;
+  int res;
+
+  do {
+    res = kevent(el->kqueue_fd, NULL, 0, &kev, 1, timeout);
+  } while ((res < 0) && (errno == EINTR));
+
+  if (res <= 0) {
+    if (!res)
+      errno = ETIMEDOUT;
+    return -1;
+  }
+
+  id_out->obj = kev.ident;
+
+  if (kev.filter & EVFILT_TIMER)
+    id_out->source = OWD_EVENT_SOURCE_TIMER;
+  else
+    id_out->source = OWD_EVENT_SOURCE_FD;
+
+  return 0;
+}
+
+int owd_eventloop_clear(struct owd_eventloop *el, struct owd_event *e) {
+  // TODO: read timerfd on linux
+  return 0;
+}
+
+void owd_eventloop_remove(struct owd_eventloop *el, struct owd_event *e) {
+  struct kevent kev;
+
+  memset(&kev, 0, sizeof(kev));
+  kev.ident = e->kqueue_ident;
+  kev.filter = e->kqueue_filter;
+  kev.flags = EV_DELETE;
+  kevent(el->kqueue_fd, &kev, 1, NULL, 0, NULL);
+
+  event_cleanup(el, e);
+}
+
+int owd_eventloop_add_timer(
+  struct owd_eventloop *el,
+  struct owd_event *e,
+  uint64_t millis,
+  bool oneshot)
+{
+  struct kevent kev;
+  uintptr_t ident;
+  unsigned short kev_flags;
+
+  ident = el->kqueue_timer_next;
+
+  kev_flags = 0;
+  if (oneshot)
+    kev_flags |= EV_ONESHOT;
+
+  memset(&kev, 0, sizeof(kev));
+  kev.ident = ident;
+  kev.filter = EVFILT_TIMER;
+  kev.flags =  EV_ADD | kev_flags;
+  kev.data = (int64_t)millis;
+
+  if (kevent(el->kqueue_fd, &kev, 1, NULL, 0, NULL))
+    return -1;
+
+  e->id.obj = ident;
+  e->id.source = OWD_EVENT_SOURCE_TIMER;
+  e->kqueue_ident = kev.ident;
+  e->kqueue_filter = kev.filter;
+  
+  el->kqueue_timer_next++;
+  return 0;
 }