uloop: fix event delete races on mac os x
authorFelix Fietkau <nbd@openwrt.org>
Sun, 21 Oct 2012 01:40:35 +0000 (03:40 +0200)
committerFelix Fietkau <nbd@openwrt.org>
Sun, 21 Oct 2012 01:40:35 +0000 (03:40 +0200)
uloop.c

diff --git a/uloop.c b/uloop.c
index 4de26d4..acf46db 100644 (file)
--- a/uloop.c
+++ b/uloop.c
@@ -54,6 +54,7 @@ static int poll_fd = -1;
 bool uloop_cancelled = false;
 bool uloop_handle_sigchld = true;
 static bool do_sigchld = false;
+static int cur_fd, cur_nfds;
 
 #ifdef USE_KQUEUE
 
@@ -84,12 +85,15 @@ static uint16_t get_flags(unsigned int flags, unsigned int mask)
        return kflags;
 }
 
+static struct kevent events[ULOOP_MAX_EVENTS];
+
 static int register_poll(struct uloop_fd *fd, unsigned int flags)
 {
        struct timespec timeout = { 0, 0 };
        struct kevent ev[2];
        unsigned int changed;
        int nev = 0;
+       unsigned int fl = 0;
 
        changed = fd->kqflags ^ flags;
        if (changed & ULOOP_EDGE_TRIGGER)
@@ -105,7 +109,10 @@ static int register_poll(struct uloop_fd *fd, unsigned int flags)
                EV_SET(&ev[nev++], fd->fd, EVFILT_WRITE, kflags, 0, 0, fd);
        }
 
-       if (nev && (kevent(poll_fd, ev, nev, NULL, 0, &timeout) == -1))
+       if (!flags)
+               fl |= EV_DELETE;
+
+       if (nev && (kevent(poll_fd, ev, nev, NULL, fl, &timeout) == -1))
                return -1;
 
        fd->kqflags = flags;
@@ -114,13 +121,21 @@ static int register_poll(struct uloop_fd *fd, unsigned int flags)
 
 int uloop_fd_delete(struct uloop_fd *sock)
 {
+       int i;
+
+       for (i = cur_fd + 1; i < cur_nfds; i++) {
+               if (events[i].udata != sock)
+                       continue;
+
+               events[i].udata = NULL;
+       }
+
        sock->registered = false;
        return register_poll(sock, 0);
 }
 
 static void uloop_run_events(int timeout)
 {
-       struct kevent events[ULOOP_MAX_EVENTS];
        struct timespec ts;
        int nfds, n;
 
@@ -135,7 +150,10 @@ static void uloop_run_events(int timeout)
                struct uloop_fd *u = events[n].udata;
                unsigned int ev = 0;
 
-               if(events[n].flags & EV_ERROR) {
+               if (!u)
+                       continue;
+
+               if (events[n].flags & EV_ERROR) {
                        u->error = true;
                        uloop_fd_delete(u);
                }
@@ -145,14 +163,18 @@ static void uloop_run_events(int timeout)
                else if (events[n].filter == EVFILT_WRITE)
                        ev |= ULOOP_WRITE;
 
-               if(events[n].flags & EV_EOF)
+               if (events[n].flags & EV_EOF)
                        u->eof = true;
                else if (!ev)
                        continue;
 
-               if(u->cb)
+               if (u->cb) {
+                       cur_fd = n;
+                       cur_nfds = nfds;
                        u->cb(u, ev);
+               }
        }
+       cur_nfds = 0;
 }
 
 #endif
@@ -201,7 +223,6 @@ static int register_poll(struct uloop_fd *fd, unsigned int flags)
        return epoll_ctl(poll_fd, op, fd->fd, &ev);
 }
 
-static int cur_fd, cur_nfds;
 static struct epoll_event events[ULOOP_MAX_EVENTS];
 
 int uloop_fd_delete(struct uloop_fd *sock)