uloop: add back support for overriding signal handlers when signalfd is in use
[project/libubox.git] / uloop.c
diff --git a/uloop.c b/uloop.c
index 9a77ce4..af84737 100644 (file)
--- a/uloop.c
+++ b/uloop.c
@@ -1,7 +1,7 @@
 /*
  * uloop - event loop implementation
  *
- * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2010-2016 Felix Fietkau <nbd@openwrt.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -56,6 +56,7 @@ static struct uloop_fd_stack *fd_stack = NULL;
 static struct list_head timeouts = LIST_HEAD_INIT(timeouts);
 static struct list_head processes = LIST_HEAD_INIT(processes);
 
+static int signal_fd = -1;
 static int poll_fd = -1;
 bool uloop_cancelled = false;
 static bool do_sigchld = false;
@@ -63,235 +64,14 @@ static bool do_sigchld = false;
 static struct uloop_fd_event cur_fds[ULOOP_MAX_EVENTS];
 static int cur_fd, cur_nfds;
 
-#ifdef USE_KQUEUE
-
-int uloop_init(void)
-{
-       struct timespec timeout = { 0, 0 };
-       struct kevent ev = {};
-
-       if (poll_fd >= 0)
-               return 0;
-
-       poll_fd = kqueue();
-       if (poll_fd < 0)
-               return -1;
-
-       EV_SET(&ev, SIGCHLD, EVFILT_SIGNAL, EV_ADD, 0, 0, 0);
-       kevent(poll_fd, &ev, 1, NULL, 0, &timeout);
-
-       return 0;
-}
-
-
-static uint16_t get_flags(unsigned int flags, unsigned int mask)
-{
-       uint16_t kflags = 0;
-
-       if (!(flags & mask))
-               return EV_DELETE;
-
-       kflags = EV_ADD;
-       if (flags & ULOOP_EDGE_TRIGGER)
-               kflags |= EV_CLEAR;
-
-       return kflags;
-}
-
-static struct kevent events[ULOOP_MAX_EVENTS];
-
-static int register_kevent(struct uloop_fd *fd, unsigned int flags)
-{
-       struct timespec timeout = { 0, 0 };
-       struct kevent ev[2];
-       int nev = 0;
-       unsigned int fl = 0;
-       unsigned int changed;
-       uint16_t kflags;
-
-       if (flags & ULOOP_EDGE_DEFER)
-               flags &= ~ULOOP_EDGE_TRIGGER;
-
-       changed = flags ^ fd->flags;
-       if (changed & ULOOP_EDGE_TRIGGER)
-               changed |= flags;
-
-       if (changed & ULOOP_READ) {
-               kflags = get_flags(flags, ULOOP_READ);
-               EV_SET(&ev[nev++], fd->fd, EVFILT_READ, kflags, 0, 0, fd);
-       }
-
-       if (changed & ULOOP_WRITE) {
-               kflags = get_flags(flags, ULOOP_WRITE);
-               EV_SET(&ev[nev++], fd->fd, EVFILT_WRITE, kflags, 0, 0, fd);
-       }
-
-       if (!flags)
-               fl |= EV_DELETE;
-
-       fd->flags = flags;
-       if (kevent(poll_fd, ev, nev, NULL, fl, &timeout) == -1)
-               return -1;
-
-       return 0;
-}
-
-static int register_poll(struct uloop_fd *fd, unsigned int flags)
-{
-       if (flags & ULOOP_EDGE_TRIGGER)
-               flags |= ULOOP_EDGE_DEFER;
-       else
-               flags &= ~ULOOP_EDGE_DEFER;
-
-       return register_kevent(fd, flags);
-}
-
-static int __uloop_fd_delete(struct uloop_fd *fd)
-{
-       return register_poll(fd, 0);
-}
-
-static int uloop_fetch_events(int timeout)
-{
-       struct timespec ts;
-       int nfds, n;
-
-       if (timeout >= 0) {
-               ts.tv_sec = timeout / 1000;
-               ts.tv_nsec = (timeout % 1000) * 1000000;
-       }
-
-       nfds = kevent(poll_fd, NULL, 0, events, ARRAY_SIZE(events), timeout >= 0 ? &ts : NULL);
-       for (n = 0; n < nfds; n++) {
-               struct uloop_fd_event *cur = &cur_fds[n];
-               struct uloop_fd *u = events[n].udata;
-               unsigned int ev = 0;
-
-               cur->fd = u;
-               if (!u)
-                       continue;
-
-               if (events[n].flags & EV_ERROR) {
-                       u->error = true;
-                       if (!(u->flags & ULOOP_ERROR_CB))
-                               uloop_fd_delete(u);
-               }
-
-               if(events[n].filter == EVFILT_READ)
-                       ev |= ULOOP_READ;
-               else if (events[n].filter == EVFILT_WRITE)
-                       ev |= ULOOP_WRITE;
-
-               if (events[n].flags & EV_EOF)
-                       u->eof = true;
-               else if (!ev)
-                       cur->fd = NULL;
-
-               cur->events = ev;
-               if (u->flags & ULOOP_EDGE_DEFER) {
-                       u->flags &= ~ULOOP_EDGE_DEFER;
-                       u->flags |= ULOOP_EDGE_TRIGGER;
-                       register_kevent(u, u->flags);
-               }
-       }
-       return nfds;
-}
+static void uloop_handle_signal(int signo);
 
+#ifdef USE_KQUEUE
+#include "uloop-kqueue.c"
 #endif
 
 #ifdef USE_EPOLL
-
-/**
- * FIXME: uClibc < 0.9.30.3 does not define EPOLLRDHUP for Linux >= 2.6.17
- */
-#ifndef EPOLLRDHUP
-#define EPOLLRDHUP 0x2000
-#endif
-
-int uloop_init(void)
-{
-       if (poll_fd >= 0)
-               return 0;
-
-       poll_fd = epoll_create(32);
-       if (poll_fd < 0)
-               return -1;
-
-       fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
-       return 0;
-}
-
-static int register_poll(struct uloop_fd *fd, unsigned int flags)
-{
-       struct epoll_event ev;
-       int op = fd->registered ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
-
-       memset(&ev, 0, sizeof(struct epoll_event));
-
-       if (flags & ULOOP_READ)
-               ev.events |= EPOLLIN | EPOLLRDHUP;
-
-       if (flags & ULOOP_WRITE)
-               ev.events |= EPOLLOUT;
-
-       if (flags & ULOOP_EDGE_TRIGGER)
-               ev.events |= EPOLLET;
-
-       ev.data.fd = fd->fd;
-       ev.data.ptr = fd;
-       fd->flags = flags;
-
-       return epoll_ctl(poll_fd, op, fd->fd, &ev);
-}
-
-static struct epoll_event events[ULOOP_MAX_EVENTS];
-
-static int __uloop_fd_delete(struct uloop_fd *sock)
-{
-       sock->flags = 0;
-       return epoll_ctl(poll_fd, EPOLL_CTL_DEL, sock->fd, 0);
-}
-
-static int uloop_fetch_events(int timeout)
-{
-       int n, nfds;
-
-       nfds = epoll_wait(poll_fd, events, ARRAY_SIZE(events), timeout);
-       for (n = 0; n < nfds; ++n) {
-               struct uloop_fd_event *cur = &cur_fds[n];
-               struct uloop_fd *u = events[n].data.ptr;
-               unsigned int ev = 0;
-
-               cur->fd = u;
-               if (!u)
-                       continue;
-
-               if (events[n].events & (EPOLLERR|EPOLLHUP)) {
-                       u->error = true;
-                       if (!(u->flags & ULOOP_ERROR_CB))
-                               uloop_fd_delete(u);
-               }
-
-               if(!(events[n].events & (EPOLLRDHUP|EPOLLIN|EPOLLOUT|EPOLLERR|EPOLLHUP))) {
-                       cur->fd = NULL;
-                       continue;
-               }
-
-               if(events[n].events & EPOLLRDHUP)
-                       u->eof = true;
-
-               if(events[n].events & EPOLLIN)
-                       ev |= ULOOP_READ;
-
-               if(events[n].events & EPOLLOUT)
-                       ev |= ULOOP_WRITE;
-
-               cur->events = ev;
-       }
-
-       return nfds;
-}
-
+#include "uloop-epoll.c"
 #endif
 
 static bool uloop_fd_stack_event(struct uloop_fd *fd, int events)
@@ -453,14 +233,14 @@ int uloop_timeout_set(struct uloop_timeout *timeout, int msecs)
        if (timeout->pending)
                uloop_timeout_cancel(timeout);
 
-       uloop_gettime(&timeout->time);
+       uloop_gettime(time);
 
        time->tv_sec += msecs / 1000;
        time->tv_usec += (msecs % 1000) * 1000;
 
        if (time->tv_usec > 1000000) {
                time->tv_sec++;
-               time->tv_usec %= 1000000;
+               time->tv_usec -= 1000000;
        }
 
        return uloop_timeout_add(timeout);
@@ -531,6 +311,9 @@ static void uloop_handle_processes(void)
 
        while (1) {
                pid = waitpid(-1, &ret, WNOHANG);
+               if (pid < 0 && errno == EINTR)
+                       continue;
+
                if (pid <= 0)
                        return;
 
@@ -548,14 +331,17 @@ static void uloop_handle_processes(void)
 
 }
 
-static void uloop_handle_sigint(int signo)
-{
-       uloop_cancelled = true;
-}
-
-static void uloop_sigchld(int signo)
+static void uloop_handle_signal(int signo)
 {
-       do_sigchld = true;
+       switch (signo) {
+       case SIGINT:
+       case SIGQUIT:
+       case SIGTERM:
+               uloop_cancelled = true;
+               break;
+       case SIGCHLD:
+               do_sigchld = true;
+       }
 }
 
 static void uloop_install_handler(int signum, void (*handler)(int), struct sigaction* old, bool add)
@@ -582,13 +368,40 @@ static void uloop_install_handler(int signum, void (*handler)(int), struct sigac
                sigaction(signum, act, NULL);
 }
 
+static void uloop_ignore_signal(int signum, bool ignore)
+{
+       struct sigaction s;
+       void *new_handler = NULL;
+
+       sigaction(signum, NULL, &s);
+
+       if (ignore) {
+               if (s.sa_handler == SIG_DFL) /* Ignore only if there isn't any custom handler */
+                       new_handler = SIG_IGN;
+       } else {
+               if (s.sa_handler == SIG_IGN) /* Restore only if noone modified our SIG_IGN */
+                       new_handler = SIG_DFL;
+       }
+
+       if (new_handler) {
+               s.sa_handler = new_handler;
+               s.sa_flags = 0;
+               sigaction(signum, &s, NULL);
+       }
+}
+
 static void uloop_setup_signals(bool add)
 {
-       static struct sigaction old_sigint, old_sigchld, old_sigterm;
+       static struct sigaction old_sigint, old_sigchld, old_sigterm, old_sigquit;
+
+       uloop_setup_signalfd(add);
 
-       uloop_install_handler(SIGINT, uloop_handle_sigint, &old_sigint, add);
-       uloop_install_handler(SIGTERM, uloop_handle_sigint, &old_sigterm, add);
-       uloop_install_handler(SIGCHLD, uloop_sigchld, &old_sigchld, add);
+       uloop_install_handler(SIGINT, uloop_handle_signal, &old_sigint, add);
+       uloop_install_handler(SIGTERM, uloop_handle_signal, &old_sigterm, add);
+       uloop_install_handler(SIGQUIT, uloop_handle_signal, &old_sigquit, add);
+       uloop_install_handler(SIGCHLD, uloop_handle_signal, &old_sigchld, add);
+
+       uloop_ignore_signal(SIGPIPE, add);
 }
 
 static int uloop_get_next_timeout(struct timeval *tv)
@@ -656,11 +469,13 @@ void uloop_run(void)
        {
                uloop_gettime(&tv);
                uloop_process_timeouts(&tv);
-               if (uloop_cancelled)
-                       break;
 
                if (do_sigchld)
                        uloop_handle_processes();
+
+               if (uloop_cancelled)
+                       break;
+
                uloop_gettime(&tv);
                uloop_run_events(uloop_get_next_timeout(&tv));
        }
@@ -671,6 +486,11 @@ void uloop_run(void)
 
 void uloop_done(void)
 {
+       if (signal_fd >= 0) {
+               close(signal_fd);
+               signal_fd = -1;
+       }
+
        if (poll_fd < 0)
                return;