unix: revert recent FSEvent changes

This commit reverts the following commits:

    983fa68 darwin: fix 10.6 build error in fsevents.c
    684e212 fsevents: use shared FSEventStream
    ea4cb77 fsevents: FSEvents is most likely not thread-safe
    9bae606 darwin: create fsevents thread on demand

Several people have reported stability issues on OS X 10.8 and bus
errors on the 10.9 developer preview.

See also nodejs/node-v0.x-archive#6296 and nodejs/node-v0.x-archive#6251.

include/uv-private/uv-darwin.h

@@ -36,8 +36,8 @@
 
 #define UV_PLATFORM_LOOP_FIELDS                                               \
   uv_thread_t cf_thread;                                                      \
-  void* _cf_reserved;                                                         \
-  void* cf_state;                                                             \
+  void* cf_cb;                                                                \
+  void* cf_loop;                                                              \
   uv_mutex_t cf_mutex;                                                        \
   uv_sem_t cf_sem;                                                            \
   ngx_queue_t cf_signals;                                                     \
@@ -47,10 +47,10 @@
   char* realpath;                                                             \
   int realpath_len;                                                           \
   int cf_flags;                                                               \
-  void* cf_event;                                                             \
+  void* cf_eventstream;                                                       \
   uv_async_t* cf_cb;                                                          \
-  ngx_queue_t cf_member;                                                      \
-  uv_sem_t _cf_reserved;                                                      \
+  ngx_queue_t cf_events;                                                      \
+  uv_sem_t cf_sem;                                                            \
   uv_mutex_t cf_mutex;                                                        \
 
 #define UV_STREAM_PRIVATE_PLATFORM_FIELDS                                     \

src/unix/darwin.c

@@ -28,26 +28,153 @@
 #include <ifaddrs.h>
 #include <net/if.h>
 
+#include <CoreFoundation/CFRunLoop.h>
+
 #include <mach/mach.h>
 #include <mach/mach_time.h>
 #include <mach-o/dyld.h> /* _NSGetExecutablePath */
 #include <sys/resource.h>
 #include <sys/sysctl.h>
 #include <unistd.h>  /* sysconf */
 
+/* Forward declarations */
+static void uv__cf_loop_runner(void* arg);
+static void uv__cf_loop_cb(void* arg);
+
+typedef struct uv__cf_loop_signal_s uv__cf_loop_signal_t;
+struct uv__cf_loop_signal_s {
+  void* arg;
+  cf_loop_signal_cb cb;
+  ngx_queue_t member;
+};
+
 
 int uv__platform_loop_init(uv_loop_t* loop, int default_loop) {
-  loop->cf_state = NULL;
+  CFRunLoopSourceContext ctx;
+  int r;
 
   if (uv__kqueue_init(loop))
     return -1;
 
+  loop->cf_loop = NULL;
+  if ((r = uv_mutex_init(&loop->cf_mutex)))
+    return r;
+  if ((r = uv_sem_init(&loop->cf_sem, 0)))
+    return r;
+  ngx_queue_init(&loop->cf_signals);
+
+  memset(&ctx, 0, sizeof(ctx));
+  ctx.info = loop;
+  ctx.perform = uv__cf_loop_cb;
+  loop->cf_cb = CFRunLoopSourceCreate(NULL, 0, &ctx);
+
+  if ((r = uv_thread_create(&loop->cf_thread, uv__cf_loop_runner, loop)))
+    return r;
+
+  /* Synchronize threads */
+  uv_sem_wait(&loop->cf_sem);
+  assert(ACCESS_ONCE(CFRunLoopRef, loop->cf_loop) != NULL);
+
   return 0;
 }
 
 
 void uv__platform_loop_delete(uv_loop_t* loop) {
-  uv__fsevents_loop_delete(loop);
+  ngx_queue_t* item;
+  uv__cf_loop_signal_t* s;
+
+  assert(loop->cf_loop != NULL);
+  uv__cf_loop_signal(loop, NULL, NULL);
+  uv_thread_join(&loop->cf_thread);
+
+  uv_sem_destroy(&loop->cf_sem);
+  uv_mutex_destroy(&loop->cf_mutex);
+
+  /* Free any remaining data */
+  while (!ngx_queue_empty(&loop->cf_signals)) {
+    item = ngx_queue_head(&loop->cf_signals);
+
+    s = ngx_queue_data(item, uv__cf_loop_signal_t, member);
+
+    ngx_queue_remove(item);
+    free(s);
+  }
+}
+
+
+static void uv__cf_loop_runner(void* arg) {
+  uv_loop_t* loop;
+
+  loop = arg;
+
+  /* Get thread's loop */
+  ACCESS_ONCE(CFRunLoopRef, loop->cf_loop) = CFRunLoopGetCurrent();
+
+  CFRunLoopAddSource(loop->cf_loop,
+                     loop->cf_cb,
+                     kCFRunLoopDefaultMode);
+
+  uv_sem_post(&loop->cf_sem);
+
+  CFRunLoopRun();
+
+  CFRunLoopRemoveSource(loop->cf_loop,
+                        loop->cf_cb,
+                        kCFRunLoopDefaultMode);
+}
+
+
+static void uv__cf_loop_cb(void* arg) {
+  uv_loop_t* loop;
+  ngx_queue_t* item;
+  ngx_queue_t split_head;
+  uv__cf_loop_signal_t* s;
+
+  loop = arg;
+
+  uv_mutex_lock(&loop->cf_mutex);
+  ngx_queue_init(&split_head);
+  if (!ngx_queue_empty(&loop->cf_signals)) {
+    ngx_queue_t* split_pos = ngx_queue_next(&loop->cf_signals);
+    ngx_queue_split(&loop->cf_signals, split_pos, &split_head);
+  }
+  uv_mutex_unlock(&loop->cf_mutex);
+
+  while (!ngx_queue_empty(&split_head)) {
+    item = ngx_queue_head(&split_head);
+
+    s = ngx_queue_data(item, uv__cf_loop_signal_t, member);
+
+    /* This was a termination signal */
+    if (s->cb == NULL)
+      CFRunLoopStop(loop->cf_loop);
+    else
+      s->cb(s->arg);
+
+    ngx_queue_remove(item);
+    free(s);
+  }
+}
+
+
+void uv__cf_loop_signal(uv_loop_t* loop, cf_loop_signal_cb cb, void* arg) {
+  uv__cf_loop_signal_t* item;
+
+  item = malloc(sizeof(*item));
+  /* XXX: Fail */
+  if (item == NULL)
+    abort();
+
+  item->arg = arg;
+  item->cb = cb;
+
+  uv_mutex_lock(&loop->cf_mutex);
+  ngx_queue_insert_tail(&loop->cf_signals, &item->member);
+  uv_mutex_unlock(&loop->cf_mutex);
+
+  assert(loop->cf_loop != NULL);
+  CFRunLoopSourceSignal(loop->cf_cb);
+  CFRunLoopWakeUp(loop->cf_loop);
 }