[core] tighter OS event poll loops (better asm)

slightly reorganize some code for better asm

src/fdevent_freebsd_kqueue.c

@@ -72,17 +72,16 @@ static int fdevent_freebsd_kqueue_event_set(fdevents *ev, fdnode *fdn, int event
 
 static int fdevent_freebsd_kqueue_poll(fdevents * const ev, int timeout_ms) {
     struct timespec ts;
-    int n;
-
     ts.tv_sec  = timeout_ms / 1000;
     ts.tv_nsec = (timeout_ms % 1000) * 1000000;
 
-    n = kevent(ev->kq_fd, NULL, 0, ev->kq_results, ev->maxfds, &ts);
+    struct kevent * const restrict kq_results = ev->kq_results;
+    const int n = kevent(ev->kq_fd, NULL, 0, kq_results, ev->maxfds, &ts);
 
     for (int i = 0; i < n; ++i) {
-        fdnode * const fdn = (fdnode *)ev->kq_results[i].udata;
-        int filt = ev->kq_results[i].filter;
-        int e = ev->kq_results[i].flags;
+        fdnode * const fdn = (fdnode *)kq_results[i].udata;
+        int filt = kq_results[i].filter;
+        int e = kq_results[i].flags;
         if ((fdevent_handler)NULL != fdn->handler) {
             int revents = (filt == EVFILT_READ) ? FDEVENT_IN : FDEVENT_OUT;
             if (e & EV_EOF)

src/fdevent_linux_sysepoll.c

@@ -35,10 +35,11 @@ static int fdevent_linux_sysepoll_event_set(fdevents *ev, fdnode *fdn, int event
 }
 
 static int fdevent_linux_sysepoll_poll(fdevents * const ev, int timeout_ms) {
-    int n = epoll_wait(ev->epoll_fd, ev->epoll_events, ev->maxfds, timeout_ms);
+    struct epoll_event * const restrict epoll_events = ev->epoll_events;
+    int n = epoll_wait(ev->epoll_fd, epoll_events, ev->maxfds, timeout_ms);
     for (int i = 0; i < n; ++i) {
-        fdnode * const fdn = (fdnode *)ev->epoll_events[i].data.ptr;
-        int revents = ev->epoll_events[i].events;
+        fdnode * const fdn = (fdnode *)epoll_events[i].data.ptr;
+        int revents = epoll_events[i].events;
         if ((fdevent_handler)NULL != fdn->handler) {
             (*fdn->handler)(fdn->ctx, revents);
         }

src/fdevent_poll.c

@@ -77,22 +77,16 @@ static int fdevent_poll_event_set(fdevents *ev, fdnode *fdn, int events) {
 	return 0;
 }
 
-__attribute_pure__
-static int fdevent_poll_next_ndx(const fdevents *ev, int ndx) {
-	for (uint32_t i = (uint32_t)(ndx+1); i < ev->used; ++i) {
-		if (ev->pollfds[i].revents) return i;
-	}
-	return -1;
-}
-
 static int fdevent_poll_poll(fdevents *ev, int timeout_ms) {
-    const int n = poll(ev->pollfds, ev->used, timeout_ms);
-    for (int ndx=-1,i=0; i<n && -1!=(ndx=fdevent_poll_next_ndx(ev,ndx)); ++i){
-        fdnode *fdn = ev->fdarray[ev->pollfds[ndx].fd];
-        int revents = ev->pollfds[ndx].revents;
-        if (0 == ((uintptr_t)fdn & 0x3)) {
-            (*fdn->handler)(fdn->ctx, revents);
-        }
+    struct pollfd * const restrict pfds = ev->pollfds;
+    fdnode ** const fdarray = ev->fdarray;
+    const int n = poll(pfds, ev->used, timeout_ms);
+    for (int i = 0, m = 0; m < n; ++i) {
+        if (0 == pfds[i].revents) continue;
+        fdnode *fdn = fdarray[pfds[i].fd];
+        if (0 == ((uintptr_t)fdn & 0x3))
+            (*fdn->handler)(fdn->ctx, pfds[i].revents);
+        ++m;
     }
     return n;
 }

src/fdevent_solaris_devpoll.c

@@ -42,18 +42,19 @@ static int fdevent_solaris_devpoll_event_set(fdevents *ev, fdnode *fdn, int even
 }
 
 static int fdevent_solaris_devpoll_poll(fdevents *ev, int timeout_ms) {
-    int n;
+    fdnode ** const fdarray = ev->fdarray;
+    struct pollfd * const devpollfds = ev->devpollfds;
     struct dvpoll dopoll;
 
     dopoll.dp_timeout = timeout_ms;
     dopoll.dp_nfds = ev->maxfds - 1;
-    dopoll.dp_fds = ev->devpollfds;
+    dopoll.dp_fds = devpollfds;
 
-    n = ioctl(ev->devpoll_fd, DP_POLL, &dopoll);
+    const int n = ioctl(ev->devpoll_fd, DP_POLL, &dopoll);
 
     for (int i = 0; i < n; ++i) {
-        fdnode * const fdn = ev->fdarray[ev->devpollfds[i].fd];
-        int revents = ev->devpollfds[i].revents;
+        fdnode * const fdn = fdarray[devpollfds[i].fd];
+        int revents = devpollfds[i].revents;
         if (0 == ((uintptr_t)fdn & 0x3)) {
             (*fdn->handler)(fdn->ctx, revents);
         }