gecko/mobile/android/chrome/content/MemoryObserver.js

66 lines
2.4 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
var MemoryObserver = {
observe: function mo_observe(aSubject, aTopic, aData) {
if (aTopic == "memory-pressure") {
if (aData != "heap-minimize") {
this.handleLowMemory();
}
// The JS engine would normally GC on this notification, but since we
// disabled that in favor of this method (bug 669346), we should gc here.
// See bug 784040 for when this code was ported from XUL to native Fennec.
this.gc();
} else if (aTopic == "Memory:Dump") {
this.dumpMemoryStats(aData);
}
},
handleLowMemory: function() {
// do things to reduce memory usage here
let tabs = BrowserApp.tabs;
let selected = BrowserApp.selectedTab;
for (let i = 0; i < tabs.length; i++) {
if (tabs[i] != selected) {
this.zombify(tabs[i]);
Telemetry.addData("FENNEC_TAB_ZOMBIFIED", (Date.now() - tabs[i].lastTouchedAt) / 1000);
}
}
Telemetry.addData("FENNEC_LOWMEM_TAB_COUNT", tabs.length);
},
zombify: function(tab) {
let browser = tab.browser;
let data = browser.__SS_data;
let extra = browser.__SS_extdata;
// We need this data to correctly create and position the new browser
// If this browser is already a zombie, fallback to the session data
let currentURL = browser.__SS_restore ? data.entries[0].url : browser.currentURI.spec;
let sibling = browser.nextSibling;
let isPrivate = PrivateBrowsingUtils.isWindowPrivate(browser.contentWindow);
tab.destroy();
tab.create(currentURL, { sibling: sibling, zombifying: true, delayLoad: true, isPrivate: isPrivate });
// Reattach session store data and flag this browser so it is restored on select
browser = tab.browser;
browser.__SS_data = data;
browser.__SS_extdata = extra;
browser.__SS_restore = true;
browser.setAttribute("pending", "true");
},
gc: function() {
window.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils).garbageCollect();
Cu.forceGC();
},
dumpMemoryStats: function(aLabel) {
let memDumper = Cc["@mozilla.org/memory-info-dumper;1"].getService(Ci.nsIMemoryInfoDumper);
memDumper.dumpMemoryInfoToTempDir(aLabel, false, true);
},
};