Use one-shot epoll

packages/bun-usockets/src/eventing/epoll_kqueue.c

@@ -299,8 +299,8 @@ void us_loop_run_bun_tick(struct us_loop_t *loop, const struct timespec* timeout
             // > Multiple events which trigger the filter do not result in multiple kevents being placed on the kqueue
             // > Instead, the filter will aggregate the events into a single kevent struct
             int events = 0
-                | ((filter & EVFILT_READ) ? LIBUS_SOCKET_READABLE : 0)
-                | ((filter & EVFILT_WRITE) ? LIBUS_SOCKET_WRITABLE : 0);
+                | ((filter == EVFILT_READ) ? LIBUS_SOCKET_READABLE : 0)
+                | ((filter == EVFILT_WRITE) ? LIBUS_SOCKET_WRITABLE : 0);
 
             // Note: EV_ERROR only sets the error in data as part of changelist. Not in this call!
             const int error = (flags & (EV_ERROR)) ? ((int)fflags || 1) : 0;
@@ -360,11 +360,11 @@ int kqueue_change(int kqfd, int fd, int old_events, int new_events, void *user_d
     if(!is_readable && !is_writable) {
         if(!(old_events & LIBUS_SOCKET_WRITABLE)) {
             // if we are not reading or writing, we need to add writable to receive FIN
-            EV_SET64(&change_list[change_length++], fd, EVFILT_WRITE, EV_ADD, 0, 0, (uint64_t)(void*)user_data, 0, 0);
+            EV_SET64(&change_list[change_length++], fd, EVFILT_WRITE, EV_ADD | EV_ONESHOT, 0, 0, (uint64_t)(void*)user_data, 0, 0);
         }
     } else if ((new_events & LIBUS_SOCKET_WRITABLE) != (old_events & LIBUS_SOCKET_WRITABLE)) {
         /* Do they differ in writable? */
-        EV_SET64(&change_list[change_length++], fd, EVFILT_WRITE, (new_events & LIBUS_SOCKET_WRITABLE) ? EV_ADD : EV_DELETE, 0, 0, (uint64_t)(void*)user_data, 0, 0);
+        EV_SET64(&change_list[change_length++], fd, EVFILT_WRITE, (new_events & LIBUS_SOCKET_WRITABLE) ? (EV_ADD | EV_ONESHOT) : EV_DELETE, 0, 0, (uint64_t)(void*)user_data, 0, 0);
     }
     int ret;
     do {
@@ -406,6 +406,13 @@ int us_poll_start_rc(struct us_poll_t *p, struct us_loop_t *loop, int events) {
         // if we are disabling readable, we need to add the other events to detect EOF/HUP/ERR
         events |= EPOLLRDHUP | EPOLLHUP | EPOLLERR;
     }
+    // Make writable events one-shot, but keep readable events level-triggered
+    if (events & LIBUS_SOCKET_WRITABLE) {
+        events |= EPOLLONESHOT;
+    } else if (events & LIBUS_SOCKET_READABLE) {
+        // Ensure readable is level-triggered by explicitly removing EPOLLONESHOT
+        events &= ~EPOLLONESHOT;
+    }
     event.events = events;
     event.data.ptr = p;
     int ret;
@@ -433,6 +440,13 @@ void us_poll_change(struct us_poll_t *p, struct us_loop_t *loop, int events) {
         if(!(events & LIBUS_SOCKET_READABLE) && !(events & LIBUS_SOCKET_WRITABLE)) {
              // if we are disabling readable, we need to add the other events to detect EOF/HUP/ERR
             events |= EPOLLRDHUP | EPOLLHUP | EPOLLERR;
+        } 
+        // Make writable events one-shot, but keep readable events level-triggered
+        if (events & LIBUS_SOCKET_WRITABLE) {
+            events |= EPOLLONESHOT;
+        } else if (events & LIBUS_SOCKET_READABLE) {
+            // Ensure readable is level-triggered by explicitly removing EPOLLONESHOT
+            events &= ~EPOLLONESHOT;
         }
         event.events = events;
         event.data.ptr = p;