Bug 654041 - Add buttons that trigger GC and CC from about:memory. r=vlad,jruderman.

const Cc = Components.classes;

const Ci = Components.interfaces;

const Cu = Components.utils;

// Must use .href here instead of .search because "about:memory" is a

// non-standard URL.

  return document.getElementById(n);

}

function doGlobalGC()

{

  Cu.forceGC();

  update();

}

function doGlobalGCandCC()

{

  window.QueryInterface(Ci.nsIInterfaceRequestor)

        .getInterface(Ci.nsIDOMWindowUtils)

        .garbageCollect();

  update();

}

// For maximum effect, this returns to the event loop between each

// notification.  See bug 610166 comment 12 for an explanation.

// Ideally a single notification would be enough.

function sendHeapMinNotifications()

{

  function runSoon(f)

  {

    var tm = Cc["@mozilla.org/thread-manager;1"]

              .getService(Ci.nsIThreadManager);

    tm.mainThread.dispatch({ run: f }, Ci.nsIThread.DISPATCH_NORMAL);

  }

  function sendHeapMinNotificationsInner()

  {

    var os = Cc["@mozilla.org/observer-service;1"]

             .getService(Ci.nsIObserverService);

    os.notifyObservers(null, "memory-pressure", "heap-minimize");

    if (++j < 3)

      runSoon(sendHeapMinNotificationsInner);

    else

      runSoon(update);

  }

  var j = 0;

  sendHeapMinNotificationsInner();

}

/**

 * Top-level function that does the work of generating the page.

 */

    }

  }

  // Memory-related actions.

  const GCDesc = "Do a global garbage collection.";

  // XXX: once bug 625302 is fixed, should change this button to just do a CC.

  const CCDesc = "Do a global garbage collection followed by a cycle " +

                 "collection. (It currently is not possible to do a cycle " +

                 "collection on its own, see bug 625302.)";

  const MPDesc = "Send three \"heap-minimize\" notifications in a row.  Each " +

                 "notification triggers a global garbage collection followed " +

                 "by a cycle collection, and causes the process to reduce " +

                 "memory usage in other ways, e.g. by flushing various caches.";

  text += "<div>" +

    "<button title='" + GCDesc + "' onclick='doGlobalGC()'>GC</button>" +

    "<button title='" + CCDesc + "' onclick='doGlobalGCandCC()'>GC + CC</button>" +

    "<button title='" + MPDesc + "' onclick='sendHeapMinNotifications()'>" + "Minimize memory usage</button>" +

    "</div>";

  // Generate verbosity option link at the bottom.

  text += gVerbose

        ? "<span class='option'><a href='about:memory'>Less verbose</a></span>"