Add new event loop api for watching signals

This will provide us with a nice, safe mechanism
for getting notification of VT changes.

diff --git a/event-loop.c b/event-loop.c
index e83573c..f6252a8 100644 (file)
--- a/event-loop.c
+++ b/event-loop.c
@@ -23,11 +23,13 @@
 #include <stddef.h>
 #include <stdio.h>
 #include <errno.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <sys/epoll.h>
+#include <sys/signalfd.h>
 #include <sys/timerfd.h>
 #include <unistd.h>
 #include <assert.h>
@@ -238,6 +240,87 @@ wl_event_source_timer_update(struct wl_event_source *source, int ms_delay)
        return 0;
 }
 
+struct wl_event_source_signal {
+       struct wl_event_source base;
+       int fd;
+       int signal_number;
+       wl_event_loop_signal_func_t func;
+       void *data;
+};
+
+static void
+wl_event_source_signal_dispatch(struct wl_event_source *source,
+                              struct epoll_event *ep)
+{
+       struct wl_event_source_signal *signal_source =
+               (struct wl_event_source_signal *) source;
+       struct signalfd_siginfo signal_info;
+
+       read(signal_source->fd, &signal_info, sizeof signal_info);
+
+       signal_source->func(signal_source->signal_number, signal_source->data);
+}
+
+static int
+wl_event_source_signal_remove(struct wl_event_source *source)
+{
+       struct wl_event_source_signal *signal_source =
+               (struct wl_event_source_signal *) source;
+       struct wl_event_loop *loop = source->loop;
+       int fd;
+
+       fd = signal_source->fd;
+       free(source);
+
+       return epoll_ctl(loop->epoll_fd, EPOLL_CTL_DEL, fd, NULL);
+}
+
+struct wl_event_source_interface signal_source_interface = {
+       wl_event_source_signal_dispatch,
+       wl_event_source_signal_remove
+};
+
+WL_EXPORT struct wl_event_source *
+wl_event_loop_add_signal(struct wl_event_loop *loop,
+                       int signal_number,
+                       wl_event_loop_signal_func_t func,
+                       void *data)
+{
+       struct wl_event_source_signal *source;
+       struct epoll_event ep;
+       sigset_t mask;
+
+       source = malloc(sizeof *source);
+       if (source == NULL)
+               return NULL;
+
+       source->base.interface = &signal_source_interface;
+       source->base.loop = loop;
+
+       sigemptyset(&mask);
+       sigaddset(&mask, signal_number);
+       source->fd = signalfd(-1, &mask, 0);
+       if (source->fd < 0) {
+               fprintf(stderr, "could not create fd to watch signal\n: %m");
+               free(source);
+               return NULL;
+       }
+       sigprocmask(SIG_BLOCK, &mask, NULL);
+
+       source->func = func;
+       source->data = data;
+
+       ep.events = EPOLLIN;
+       ep.data.ptr = source;
+
+       if (epoll_ctl(loop->epoll_fd, EPOLL_CTL_ADD, source->fd, &ep) < 0) {
+               free(source);
+               return NULL;
+       }
+
+       return &source->base;
+}
+
 struct wl_event_source_idle {
        struct wl_event_source base;
        struct wl_list link;

diff --git a/wayland.h b/wayland.h
index bac9c5b..ecf0c7e 100644 (file)
--- a/wayland.h
+++ b/wayland.h
@@ -35,6 +35,7 @@ struct wl_event_loop;
 struct wl_event_source;
 typedef void (*wl_event_loop_fd_func_t)(int fd, uint32_t mask, void *data);
 typedef void (*wl_event_loop_timer_func_t)(void *data);
+typedef void (*wl_event_loop_signal_func_t)(int signal_number, void *data);
 typedef void (*wl_event_loop_idle_func_t)(void *data);
 
 struct wl_event_loop *wl_event_loop_create(void);
@@ -47,6 +48,12 @@ int wl_event_source_fd_update(struct wl_event_source *source, uint32_t mask);
 struct wl_event_source *wl_event_loop_add_timer(struct wl_event_loop *loop,
                                                wl_event_loop_timer_func_t func,
                                                void *data);
+struct wl_event_source *
+wl_event_loop_add_signal(struct wl_event_loop *loop,
+                       int signal_number,
+                       wl_event_loop_signal_func_t func,
+                       void *data);
+
 int wl_event_source_timer_update(struct wl_event_source *source,
                                 int ms_delay);
 int wl_event_source_remove(struct wl_event_source *source);