From daacb81d3ab8008d0aa3437216df32394e46186e Mon Sep 17 00:00:00 2001
From: Ryan Dahl <ry@tinyclouds.org>
Date: Sat, 20 Feb 2010 18:23:21 -0800
Subject: [PATCH] Experimental idle garbage compact

---
 src/node.cc | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/src/node.cc b/src/node.cc
index c24ecd31dc4..408bd865883 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -68,6 +68,34 @@ static ev_async eio_want_poll_notifier;
 static ev_async eio_done_poll_notifier;
 static ev_idle  eio_poller;
 
+static ev_idle  gc_idle_watcher;
+static ev_timer  gc_timer;
+#define GC_INTERVAL 1.0
+
+
+// Node calls this every GC_INTERVAL seconds in order to try
+// and turn on the gc_idle_watcher, which will eventually (when the process
+// isn't busy) call the GC
+static void GCTimeout(EV_P_ ev_timer *watcher, int revents) {
+  assert(watcher == &gc_timer);
+  assert(revents == EV_TIMER);
+
+  if (ev_pending_count() == 0 && !ev_is_active(&gc_idle_watcher)) {
+    ev_idle_start(EV_DEFAULT_UC_ &gc_idle_watcher);
+    ev_unref(EV_DEFAULT_UC);
+  }
+}
+
+
+static void DoGC(EV_P_ ev_idle *watcher, int revents) {
+  assert(watcher == &gc_idle_watcher);
+  assert(revents == EV_IDLE);
+  if (V8::IdleNotification()) {
+    ev_ref(EV_DEFAULT_UC);
+    ev_idle_stop(EV_DEFAULT_UC_ watcher);
+  }
+}
+
 
 static void DoPoll(EV_P_ ev_idle *watcher, int revents) {
   assert(watcher == &eio_poller);
@@ -1125,6 +1153,17 @@ int main(int argc, char *argv[]) {
   // Initialize the default ev loop.
   ev_default_loop(EVFLAG_AUTO);
 
+
+  // The idle watcher which will call GC
+  ev_idle_init(&node::gc_idle_watcher, node::DoGC);
+  ev_set_priority(&node::gc_idle_watcher, EV_MINPRI);
+  // The check for pending events (will start the idle watcher)
+  ev_timer_init(&node::gc_timer, node::GCTimeout, GC_INTERVAL, GC_INTERVAL);
+  ev_set_priority(&node::gc_timer, EV_MINPRI);
+  ev_timer_start(EV_DEFAULT_UC_ &node::gc_timer);
+  ev_unref(EV_DEFAULT_UC);
+
+
   // Setup the EIO thread pool
   { // It requires 3, yes 3, watchers.
     ev_idle_init(&node::eio_poller, node::DoPoll);