From 4058fe910a6a621f2e1071dde06df4c9b6c8aa3a Mon Sep 17 00:00:00 2001
From: Aman Gupta <aman@tmm1.net>
Date: Mon, 16 Mar 2009 19:41:54 -0700
Subject: [PATCH] Inotify fixes: file_delete only fires after fds have been
 closed, use syscall hackery for older linux distributions (*cough* debian)

---
 ext/em.cpp               |  2 +-
 ext/extconf.rb           |  3 ++-
 ext/project.h            | 21 +++++++++++++++++----
 lib/em/filewatcher.rb    |  3 +++
 tests/test_file_watch.rb |  2 +-
 5 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/ext/em.cpp b/ext/em.cpp
index a27898226..324fe2d57 100644
--- a/ext/em.cpp
+++ b/ext/em.cpp
@@ -2054,7 +2054,7 @@ void EventMachine_t::_ReadInotifyEvents()
 			msg = "";
 
 		if (EventCallback && strlen(msg) > 0)
-			(*EventCallback)(Watches [event->wd]->GetBinding().c_str(), EM_CONNECTION_READ, msg, strlen(msg));
+			(*EventCallback)(Watches [event.wd]->GetBinding().c_str(), EM_CONNECTION_READ, msg, strlen(msg));
 	}
 	#endif
 }
diff --git a/ext/extconf.rb b/ext/extconf.rb
index b72f3b21e..3f94f6f95 100644
--- a/ext/extconf.rb
+++ b/ext/extconf.rb
@@ -15,7 +15,8 @@ def add_define(name)
 add_define 'BUILD_FOR_RUBY'
 add_define 'HAVE_RBTRAP' if have_var('rb_trap_immediate', ['ruby.h', 'rubysig.h'])
 add_define "HAVE_TBR" if have_func('rb_thread_blocking_region')# and have_macro('RUBY_UBF_IO', 'ruby.h')
-add_define "HAVE_INOTIFY" if have_func('inotify_init', ['sys/inotify.h'])
+add_define "HAVE_INOTIFY" if inotify = have_func('inotify_init', 'sys/inotify.h')
+add_define "HAVE_OLD_INOTIFY" if !inotify && have_macro('__NR_inotify_init', 'sys/syscall.h')
 
 # Minor platform details between *nix and Windows:
 
diff --git a/ext/project.h b/ext/project.h
index 890d6c8bf..eff510591 100644
--- a/ext/project.h
+++ b/ext/project.h
@@ -55,10 +55,6 @@ See the file COPYING for complete licensing information.
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
 #include <pwd.h>
-#ifdef HAVE_INOTIFY
-#include <sys/inotify.h>
-#define INOTIFY_EVENT_SIZE  (sizeof(struct inotify_event))
-#endif
 typedef int SOCKET;
 #define closesocket close
 #define INVALID_SOCKET -1
@@ -106,6 +102,23 @@ using namespace std;
 #include <sys/queue.h>
 #endif
 
+#ifdef HAVE_INOTIFY
+#include <sys/inotify.h>
+#endif
+
+#ifdef HAVE_OLD_INOTIFY
+#include <sys/syscall.h>
+#include <linux/inotify.h>
+static inline int inotify_init (void) { return syscall (__NR_inotify_init); }
+static inline int inotify_add_watch (int fd, const char *name, __u32 mask) { return syscall (__NR_inotify_add_watch, fd, name, mask); }
+static inline int inotify_rm_watch (int fd, __u32 wd) { return syscall (__NR_inotify_rm_watch, fd, wd); }
+#define HAVE_INOTIFY 1
+#endif
+
+#ifdef HAVE_INOTIFY
+#define INOTIFY_EVENT_SIZE  (sizeof(struct inotify_event))
+#endif
+
 #include "binder.h"
 #include "em.h"
 #include "epoll.h"
diff --git a/lib/em/filewatcher.rb b/lib/em/filewatcher.rb
index eb2b89823..e9299c275 100644
--- a/lib/em/filewatcher.rb
+++ b/lib/em/filewatcher.rb
@@ -29,6 +29,9 @@ def file_modified
     # Should be redefined with the user's custom callback that will be fired when the file is deleted.
     # When the file is deleted, stop_watching will be called after this to make sure everything is
     # cleaned up correctly.
+    #
+    # Note that on linux (with inotify), file_deleted will not be called until all open file descriptors to
+    # the file have been closed.
     def file_deleted
     end
 
diff --git a/tests/test_file_watch.rb b/tests/test_file_watch.rb
index 26c10411c..f0087d116 100644
--- a/tests/test_file_watch.rb
+++ b/tests/test_file_watch.rb
@@ -38,7 +38,7 @@ def test_events
       File.open(file.path, 'w'){ |f| f.puts 'hi' }
 
       # delete it
-      EM.add_timer(0.25){ file.delete }
+      EM.add_timer(0.25){ file.close; file.delete }
     }
 
     assert_equal($path, $tmp_path)