mozilla-central/browser/base/content/test/performance/browser_preferences_usage.js (file symbol)

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Test Info: Warnings

/* Any copyright is dedicated to the Public Domain.
if (SpecialPowers.useRemoteSubframes) {
requestLongerTimeout(2);
}
const DEFAULT_PROCESS_COUNT = Services.prefs
.getDefaultBranch(null)
.getIntPref("dom.ipc.processCount");
/**
* A test that checks whether any preference getter from the given list
* of stats was called more often than the max parameter.
*
* @param {Array} stats - an array of [prefName, accessCount] tuples
* @param {Number} max - the maximum number of times any of the prefs should
* have been called.
* @param {Object} knownProblematicPrefs (optional) - an object that defines
* prefs that should be exempt from checking the
* maximum access. It looks like the following:
*
* pref_name: {
* min: [Number] the minimum amount of times this should have
* been called (to avoid keeping around dead items)
* max: [Number] the maximum amount of times this should have
* been called (to avoid this creeping up further)
* }
*/
function checkPrefGetters(stats, max, knownProblematicPrefs = {}) {
let getterStats = Object.entries(stats).sort(
([, val1], [, val2]) => val2 - val1
);
// Clone the list to be able to delete entries to check if we
// forgot any later on.
knownProblematicPrefs = Object.assign({}, knownProblematicPrefs);
for (let [pref, count] of getterStats) {
let prefLimits = knownProblematicPrefs[pref];
if (!prefLimits) {
Assert.lessOrEqual(
count,
max,
`${pref} should not be accessed more than ${max} times.`
);
} else {
// Still record how much this pref was accessed even if we don't do any real assertions.
if (!prefLimits.min && !prefLimits.max) {
info(
`${pref} should not be accessed more than ${max} times and was accessed ${count} times.`
);
}
if (prefLimits.min) {
Assert.lessOrEqual(
prefLimits.min,
count,
`${pref} should be accessed at least ${prefLimits.min} times.`
);
}
if (prefLimits.max) {
Assert.lessOrEqual(
count,
prefLimits.max,
`${pref} should be accessed at most ${prefLimits.max} times.`
);
}
delete knownProblematicPrefs[pref];
}
}
let unusedPrefs = Object.keys(knownProblematicPrefs);
is(
unusedPrefs.length,
0,
`Should have accessed all known problematic prefs. Remaining: ${unusedPrefs}`
);
}
/**
* A helper function to read preference access data
* using the Services.prefs.readStats() function.
*/
function getPreferenceStats() {
let stats = {};
Services.prefs.readStats((key, value) => (stats[key] = value));
return stats;
}
add_task(async function debug_only() {
ok(AppConstants.DEBUG, "You need to run this test on a debug build.");
});
// Just checks how many prefs were accessed during startup.
add_task(async function startup() {
let max = 40;
let knownProblematicPrefs = {
"network.loadinfo.skip_type_assertion": {
// This is accessed in debug only.
},
};
let startupRecorder =
Cc["@mozilla.org/test/startuprecorder;1"].getService().wrappedJSObject;
await startupRecorder.done;
ok(startupRecorder.data.prefStats, "startupRecorder has prefStats");
checkPrefGetters(startupRecorder.data.prefStats, max, knownProblematicPrefs);
});
// This opens 10 tabs and checks pref getters.
add_task(async function open_10_tabs() {
// This is somewhat arbitrary. When we had a default of 4 content processes
// the value was 15. We need to scale it as we increase the number of
// content processes so we approximate with 4 * process_count.
const max = 4 * DEFAULT_PROCESS_COUNT;
let knownProblematicPrefs = {
"browser.tabs.remote.logSwitchTiming": {
max: 35,
},
"network.loadinfo.skip_type_assertion": {
// This is accessed in debug only.
},
};
Services.prefs.resetStats();
let tabs = [];
while (tabs.length < 10) {
tabs.push(
await BrowserTestUtils.openNewForegroundTab(
gBrowser,
// eslint-disable-next-line @microsoft/sdl/no-insecure-url
true,
true
)
);
}
for (let tab of tabs) {
await BrowserTestUtils.removeTab(tab);
}
checkPrefGetters(getPreferenceStats(), max, knownProblematicPrefs);
});
// This navigates to 50 sites and checks pref getters.
add_task(async function navigate_around() {
await SpecialPowers.pushPrefEnv({
set: [
// Disable bfcache so that we can measure more accurately the number of
// pref accesses in the child processes.
// If bfcache is enabled on Fission
// security.sandbox.content.force-namespace is accessed only a couple of
// times.
["browser.sessionhistory.max_total_viewers", 0],
],
});
let max = 40;
let knownProblematicPrefs = {
"network.loadinfo.skip_type_assertion": {
// This is accessed in debug only.
},
};
if (SpecialPowers.useRemoteSubframes) {
// We access this when considering starting a new content process.
// Because there is no complete list of content process types,
// caching this is not trivial. Opening 50 different content
// processes and throwing them away immediately is a bit artificial;
// we're more likely to keep some around so this shouldn't be quite
// this bad in practice. Fixing this is
knownProblematicPrefs["dom.ipc.processCount.webIsolated"] = {
min: 50,
max: 51,
};
if (AppConstants.platform == "linux") {
// The following sandbox pref is covered by
knownProblematicPrefs["security.sandbox.content.force-namespace"] = {
min: 45,
max: 55,
};
} else if (AppConstants.platform == "win") {
// The following 2 graphics prefs are covered by
knownProblematicPrefs["gfx.canvas.azure.backends"] = {
min: 90,
max: 110,
};
knownProblematicPrefs["gfx.content.azure.backends"] = {
min: 90,
max: 110,
};
// The following 2 sandbox prefs are covered by
knownProblematicPrefs["security.sandbox.content.read_path_whitelist"] = {
min: 47,
max: 55,
};
knownProblematicPrefs["security.sandbox.logging.enabled"] = {
min: 47,
max: 55,
};
}
}
Services.prefs.resetStats();
let tab = await BrowserTestUtils.openNewForegroundTab(
gBrowser,
// eslint-disable-next-line @microsoft/sdl/no-insecure-url
true,
true
);
let urls = [
// eslint-disable-next-line @microsoft/sdl/no-insecure-url
// eslint-disable-next-line @microsoft/sdl/no-insecure-url
];
for (let i = 0; i < 50; i++) {
let url = urls[i % urls.length];
info(`Navigating to ${url}...`);
BrowserTestUtils.startLoadingURIString(tab.linkedBrowser, url);
await BrowserTestUtils.browserLoaded(tab.linkedBrowser, false, url);
info(`Loaded ${url}.`);
}
await BrowserTestUtils.removeTab(tab);
checkPrefGetters(getPreferenceStats(), max, knownProblematicPrefs);
});