Move the GSource attach out to the generic watch code, and avoid blocking reads

GLib seems to call the read function sometimes even tho the PollFD's revents
field is empty.  So don't read from the fd if this happens.

diff --git a/obt/watch.c b/obt/watch.c
index 6e1971ac44339a9fb841cf081365322b80fcf322..487655cd792c8ee4a64376052c999ace8be2a88d 100644 (file)
--- a/obt/watch.c
+++ b/obt/watch.c
@@ -88,6 +88,8 @@ ObtWatch* obt_watch_new()
         w->targets_by_path = g_hash_table_new_full(
             g_str_hash, g_str_equal, NULL, (GDestroyNotify)target_free);
         w->source = source;
+
+        g_source_attach(source, NULL);
     }
     return w;
 }

diff --git a/obt/watch_inotify.c b/obt/watch_inotify.c
index f9a5649afa7a350ebd11bc4c0576ea11fe8c36b9..2aff0e394e8e89e2ee92783a85e515ba38fc0010 100644 (file)
--- a/obt/watch_inotify.c
+++ b/obt/watch_inotify.c
@@ -121,7 +121,6 @@ GSource* watch_sys_create_source(ObtWatchNotifyFunc notify)
             g_str_hash, g_str_equal, NULL, (GDestroyNotify)target_free);
         ino_source->pfd = (GPollFD){ fd, G_IO_IN, G_IO_IN };
         g_source_add_poll(source, &ino_source->pfd);
-        g_source_attach(source, NULL);
     }
     return source;
 }
@@ -158,7 +157,9 @@ static gboolean source_read(GSource *source, GSourceFunc cb, gpointer data)
     state = READING_EVENT;
     len = event_len = name_len = 0;
 
-    while (TRUE) {
+    /* sometimes we can end up here even tho no events have been reported by
+       the kernel.  blame glib?  but we'll block if we read in that case. */
+    while (ino_source->pfd.revents) {
         if (pos == len || !len || event_len) {
             /* refill the buffer */
 
@@ -169,10 +170,16 @@ static gboolean source_read(GSource *source, GSourceFunc cb, gpointer data)
 
             len = read(ino_source->pfd.fd, &buffer[pos], BUF_LEN-pos);
 
-            if (len < 0 && errno != EINTR) {
-                gchar *s = strerror(errno);
-                g_warning("Failed to read from inotify: %s", s);
-                return FALSE; /* won't read any more */
+            if (len < 0) {
+                if (errno != EINTR) {
+                    gchar *s = strerror(errno);
+                    g_warning("Failed to read from inotify: %s", s);
+                    return FALSE; /* won't read any more */
+                }
+                else {
+                    g_warning("Interrupted reading from inotify");
+                    return TRUE;
+                }
             }
             if (len == 0) {
                 g_debug("Done reading from inotify");