[core] use kqueue() instead of FAM/gamin on *BSD

Note: there have always been limitations with lighttpd stat_cache.[ch]
using FAM/gamin on *BSD via kqueue() as lighttpd stat_cache.[ch] only
monitors directories.  This kqueue() implementation also only monitors
directories and has limitations.

lighttpd stat_cache.[ch] is notified about additions and removals of
files within a monitored directory but might not be notified of changes
such as timestamps (touch), ownership, or even changes in contents
(e.g. if a file is edited through a hard link)

server.stat-cache-engine = "disable" should be used when files should
not be cached.  Full stop.  Similarly, "disable" is recommended if files
change frequently.  If using server.stat-cache-engine with any engine,
there are caching effects and tradeoffs.

On *BSD and using kqueue() on directories, any change detected clears
the stat_cache of all entries in that directory, since monitoring only
the directory does not indicate which file was added or removed.  This
is not efficient for directories containing frequently changed files.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/stat_cache.h b/src/stat_cache.h
index 3c496bd1..06c1142e 100644
--- a/src/stat_cache.h
+++ b/src/stat_cache.h
@@ -17,7 +17,7 @@ typedef struct stat_cache_entry {
     time_t stat_ts;
     int fd;
     int refcnt;
-  #if defined(HAVE_FAM_H) || defined(HAVE_SYS_INOTIFY_H)
+  #if defined(HAVE_FAM_H) || defined(HAVE_SYS_INOTIFY_H) || defined(HAVE_SYS_EVENT_H)
     void *fam_dir;
   #endif
     buffer etag;