This app provides monitoring and information features for the common freifunk user and the technical stuff of a freifunk community.
Code base is taken from a TUM Practical Course project and added here to see if Freifunk Altdorf can use it.
https://www.freifunk-altdorf.de
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
89 lines
2.7 KiB
89 lines
2.7 KiB
/** |
|
* Copyright (c) 2015-present, Facebook, Inc. |
|
* |
|
* This source code is licensed under the MIT license found in the |
|
* LICENSE file in the root directory of this source tree. |
|
* |
|
* @providesModule JSEventLoopWatchdog |
|
* @flow |
|
*/ |
|
'use strict'; |
|
|
|
const infoLog = require('infoLog'); |
|
/* $FlowFixMe(>=0.54.0 site=react_native_oss) This comment suppresses an error |
|
* found when Flow v0.54 was deployed. To see the error delete this comment and |
|
* run Flow. */ |
|
const performanceNow = require('fbjs/lib/performanceNow'); |
|
|
|
type Handler = { |
|
onIterate?: () => void, |
|
onStall: (params: {lastInterval: number, busyTime: number}) => ?string, |
|
}; |
|
|
|
/** |
|
* A utility for tracking stalls in the JS event loop that prevent timers and |
|
* other events from being processed in a timely manner. |
|
* |
|
* The "stall" time is defined as the amount of time in access of the acceptable |
|
* threshold, which is typically around 100-200ms. So if the treshold is set to |
|
* 100 and a timer fires 150 ms later than it was scheduled because the event |
|
* loop was tied up, that would be considered a 50ms stall. |
|
* |
|
* By default, logs stall events to the console when installed. Can also be |
|
* queried with `getStats`. |
|
*/ |
|
const JSEventLoopWatchdog = { |
|
getStats: function(): Object { |
|
return {stallCount, totalStallTime, longestStall, acceptableBusyTime}; |
|
}, |
|
reset: function() { |
|
infoLog('JSEventLoopWatchdog: reset'); |
|
totalStallTime = 0; |
|
stallCount = 0; |
|
longestStall = 0; |
|
lastInterval = performanceNow(); |
|
}, |
|
addHandler: function(handler: Handler) { |
|
handlers.push(handler); |
|
}, |
|
install: function({thresholdMS}: {thresholdMS: number}) { |
|
acceptableBusyTime = thresholdMS; |
|
if (installed) { |
|
return; |
|
} |
|
installed = true; |
|
lastInterval = performanceNow(); |
|
function iteration() { |
|
const now = performanceNow(); |
|
const busyTime = now - lastInterval; |
|
if (busyTime >= thresholdMS) { |
|
const stallTime = busyTime - thresholdMS; |
|
stallCount++; |
|
totalStallTime += stallTime; |
|
longestStall = Math.max(longestStall, stallTime); |
|
let msg = `JSEventLoopWatchdog: JS thread busy for ${busyTime}ms. ` + |
|
`${totalStallTime}ms in ${stallCount} stalls so far. `; |
|
handlers.forEach((handler) => { |
|
msg += handler.onStall({lastInterval, busyTime}) || ''; |
|
}); |
|
infoLog(msg); |
|
} |
|
handlers.forEach((handler) => { |
|
handler.onIterate && handler.onIterate(); |
|
}); |
|
lastInterval = now; |
|
setTimeout(iteration, thresholdMS / 5); |
|
} |
|
iteration(); |
|
}, |
|
}; |
|
|
|
let acceptableBusyTime = 0; |
|
let installed = false; |
|
let totalStallTime = 0; |
|
let stallCount = 0; |
|
let longestStall = 0; |
|
let lastInterval = 0; |
|
const handlers: Array<Handler> = []; |
|
|
|
module.exports = JSEventLoopWatchdog;
|
|
|