I use cefsharp(version:92.260) in my application. the application may crash when loading url, but not always.
below is my code:
Task.Factory.StartNew(() =>
{
var spinWait = new SpinWait();
while(!_Browser.IsBrowserInitialized)
{
spinWait.SpinOnce();
}
_Browser.Load(url);
});
I'd suggest you upgrade to a supported version, 103 at time of writing.
Improvements have been made, no longer is it nessicary to wait for IsBrowserInitialized to be equal to true before you can call Load(url).
You can just call Load without the IsBrowserInitialized check.
Related
I have this formatter in my .NET Core 3.1 project (which I recently upgraded from 2.1):
public class JilOutputFormatter : TextOutputFormatter {
public JilOutputFormatter() =>
JilFormatterConfig.AddSupportedHeaders(SupportedMediaTypes, SupportedEncodings);
public override Task WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding) {
using (var writer = new StreamWriter(context.HttpContext.Response.Body)) {
JSON.Serialize(context.Object, writer, MyOptions);
writer.Flush();
}
return Task.FromResult(true);
}
}
And I'm adding it to pipeline with this snippet:
services.AddMvcCore(o => {
o.OutputFormatters.Insert(0, new JilOutputFormatter());
}).AddOthersBlahBlah();
It was working like a charm when the application was on 2.1. But now on 3.1 I'm getting this error:
An unhandled exception occurred while processing the request.
InvalidOperationException: Synchronous operations are disallowed. Call
WriteAsync or set AllowSynchronousIO to true instead.
I tried to async the write operation, but can't find the method on Jil. Do you have any idea please?
NOTE: I know there are some answers - like this one - that are saying how to AllowSynchronousIO. But I'm interested on how to async write in Jil.
You'll have to use the 3.0 alpha versions. Jil doesn't even include the word Task in the source code in the latest stable version, 2.17 (or Github search is having some issues).
Version 3.0 uses Pipelines directly. You can use the SerializeAsync(T, PipeWriter , Encoding, Options, CancellationToken). Maybe you can work with HttpContext.Response.BodyWriter. I haven't tested this though.
Eg :
public override async Task WriteResponseBodyAsync(OutputFormatterWriteContext context,
Encoding selectedEncoding)
{
var data=context.Object;
var writer=contest.Response.BodyWriter;
await JSON.SerializeAsync(data,writer,selectedEncoding);
}
Errors can revolve around ReadAsync, WriteAsync, and FlushAsync with outputs similar to what is listed below.
Synchronous operations are disallowed. Call ReadAsync or set AllowSynchronousIO to true instead.
Synchronous operations are disallowed. Call WriteAsync or set AllowSynchronousIO to true instead.
Synchronous operations are disallowed. Call FlushAsync or set AllowSynchronousIO to true instead.
As a temporary workaround, you can set the value of AllowSynchronousIO in your ConfigureServices method found in your Startup class.
public void ConfigureServices(IServiceCollection services)
{
services.Configure<KestrelServerOptions>(options =>
{
options.AllowSynchronousIO = true;
});
// If using IIS:
services.Configure<IISServerOptions>(options =>
{
options.AllowSynchronousIO = true;
});
// other services
}
It isn’t a great workaround, but it will keep you moving forward. The better solution is to upgrade your libraries and perform all your actions asynchronously.
See the detailed post .NET Core 3.0 AllowSynchronousIO Workaround by Khalid Abuhakmeh
TLDR: As of Dotnet Core 5.0, the default web-server (Kestral) is designed to perform only Async Level work to be the most performant. Enable Sync within Kestral.
Rational: Due to to the majority of software being more IO Dependent than CPU Dependent, Async Programming allows for the system to perform other work, while waiting for the IO to complete (IE; Writing to Disk, Reading something from the network).
Place this within Startup.cs within the ConfigurationService function.
services.Configure<KestrelServerOptions>(options =>
{
options.AllowSynchronousIO = true;
});
I apologize in advance for what I write through a translator, I am very bad at English.
I was faced with the following problem: I need to perform validation css files. To this end, I decided to use the NPM package w3c-css, first it worked, but then start giving "connected etimedout", in the course of research, I noticed that through the browser and the validator stops working.
Sniffer log at start of my script: link (<10 rep :( )
My code:
gulp.task('css', function() {
gulp.src('dev/sass/*.scss')
.pipe(through2.obj(function(file, enc, cb){
w3c_css.validate({text: file.contents.toString('utf8')}, function(err, data) {
if(err) {
// an error happened
console.error(err);
} else {
// validation errors
console.log('validation errors', data.errors);
// validation warnings
console.log('validation warnings', data.warnings);
}
});
cb(null, file);
}))
.pipe(gulp.dest('build/'));
});
What is the reason? It must be some mistake, or I block due to too frequent requests and it does not change? Maybe there is some other way to check the css files?
Thx!
From the "About" page of the CSS validation service of the W3C:
Can I build an application upon this validator? Is there an API?
Yes, and yes. The CSS Validator has a (RESTful) SOAP interface which should make it reasonably easy to build applications (Web or otherwise) upon it. Good manners and respectful usage of shared resources are of course customary: make sure your applications sleep() between calls to the validator, or install and run your own instance of the validator.
So yes, it seems you have been banned.
I don't know how to make a gulp task to be called from time to time. You may mount a local version of the CSS Validator webservice and editing the w3c-css package to point to your own server.
Make sure that your script will sleep for at least 1 second between requests.
From the manual:
Note: If you wish to call the validator programmatically for a batch
of documents, please make sure that your script will sleep for at
least 1 second between requests. The CSS Validation service is a free,
public service for all, your respect is appreciated. thanks.
To validate multiple links, use async + setTimeout or any related way to pause between the requests:
'use strict';
var async = require('async');
var validator = require('w3c-css');
var hrefs = [
'http://google.com',
'https://developer.mozilla.org',
'http://www.microsoft.com/'];
async.eachSeries(hrefs, function(href, next) {
validator.validate(href, function(err, data) {
// { process err, data.errors & data.warnings }
// sleep for 1.5 seconds between the requests
setTimeout(function() { next(err); }, 1500);
});
}, function(err) {
if(err) {
console.log('Failed to process an url', err);
} else {
console.log('All urls have been processed successfully');
}
});
EDIT:
To mitigate this issue:
Added some comments and an example.
Placed setTimeout right into the gulp-w3c-css plugin.
My application is not spiderable both on local and production.
When I go to http://localhost:3000/?_escaped_fragment_=, I can see the following error appears (phantom is killed after 15 seconds):
spiderable: phantomjs failed: { [Error: Command failed: ] killed: true, code: null, signal: 'SIGTERM' }
It seems that many other people got this problem:
https://github.com/gadicc/meteor-phantomjs/issues/1
https://groups.google.com/forum/#!msg/meteor-talk/Lnm9HFs4MgM/YKDMR80fVecJ
https://groups.google.com/forum/#!topic/meteor-talk/7ZbidddRGo4
The thing is I am not using observatory or select2 and all my publications return a cursor. According to me, the problem comes from the minification. I just read in this thread that someone succeed to display "SyntaxError: Parse error". How can I know more about what is going wrong with Phantom and which file is causing the problem?
This happens when spiderable is waiting for subscriptions that fail to return any data and end up timing out, as mentioned in some of the threads you linked.
Make sure that all of your publish functions are either returning a cursor, a (possibly empty) list of cursors, or sending this.ready().
Meteor APM may be useful in determining which publications aren't returning.
If you want to know more about what is wrong with phatomjs, you might try this code (1):
// Put your URL below, no "?_escaped_fragment_=" necessary
var url = "http://your-url.com/";
var page = require('webpage').create();
page.open(url);
setInterval(function() {
var ready = page.evaluate(function () {
if (typeof Meteor !== 'undefined'
&& typeof(Meteor.status) !== 'undefined'
&& Meteor.status().connected) {
Deps.flush();
return DDP._allSubscriptionsReady();
}
return false;
});
if (ready) {
var out = page.content;
out = out.replace(/<script[^>]+>(.|\n|\r)*?<\/script\s*>/ig, '');
out = out.replace('<meta name=\"fragment\" content=\"!\">', '');
console.log(out);
phantom.exit();
}
}, 100);
For use in local, install phantomjs. Then outside your app, create a file phantomtest.js with the code above. And run phantomjs phantomtest.js
Another thing that maybe you can try is to use UglifyJS to catch some errors in the minified JS file as Payner35 did.
My problem was coming from SSL. You can have a complete overview of what I did here.
Edit the spiderable source and add --ignore-ssl-errors=yes to the phantomjs command line, it will work.
i'm working on a simple app based on meteor and MeteorStreams.
The aim is simple :
one user will click on a button to create a room
other users will join the room
those users can emit streams with simple message
the creator will listen to that message and then display them
In fact : message from other users are sent (log in server script), but the creator doesn't receive them.
If i reload the page of the creator, then it will get messages sent from other user.
I don't really understand why it doesn't work the first time.
I use meteor-router for my routing system.
Code can be seen here
https://github.com/Rebolon/MeetingTimeCost/tree/feature/pokerVoteProtection
for the client side code is availabel in client/views/poker/* and client/helpers
for the server stream's code is in server/pokerStreams.js
Application can be tested here : http://meetingtimecost.meteor.com
The creator must be logged.
If you have any idea, any help is welcome.
Thanks
Ok, Ok,
after doing some debugging, i now understand what is wrong in my code :
it's easy in fact. The problem comes from the fact that i forgot to bind the Stream.on event to Deps.autorun.
The result is that this part of code was not managed by reactivity so it was never re-run automatically when the Session changed.
The solution is so easy with Meteor : just wrap this part of code inside the Deps.autorun
Meteor.startup(function () {
Deps.autorun(function funcReloadStreamListeningOnNewRoom () {
PokerStream.on(Session.get('currentRoom') + ':currentRoom:vote', function (vote) {
var voteFound = 0;
// update is now allowed
if (Session.get('pokerVoteStatus') === 'voting') {
voteFound = Vote.find({subscriptionId: this.subscriptionId});
if (!voteFound.count()) {
Vote.insert({value: vote, userId: this.userId, subscriptionId: this.subscriptionId});
} else {
Vote.update({_id: voteFound._id}, {$set: {value: vote}});
}
}
});
});
});
So it was not a Meteor Streams problem, but only my fault.
Hope it will help people to understand that outside Template and Collection, you need to wrap your code inside Deps if you want reactivity.
I am just starting to build a new Meteor app. The only thing I have done so far is add one Collection. It will start, run fine for about 5 minutes, and then give me the error message "Failed to receive keepalive! Exiting."
What is failing to receive keepalive from what? I assume this has something to do with Mongo since that is the only thing I have added. Googling the error message turns up nothing except Meteor sites that are just showing this error message instead of the their app.
My MongoDB collection already had data in it that was not created by Meteor and it is over 4GB if that makes any difference.
This is the complete app.
pitches_sum = new Meteor.Collection( 'pitches_sum' );
if (Meteor.is_client) {
Template.hello.greeting = function () {
return "Welcome to my site.";
};
Template.hello.events = {
'click input' : function () {
// template data, if any, is available in 'this'
if (typeof console !== 'undefined')
console.log("You pressed the button");
}
};
}
if (Meteor.is_server) {
Meteor.startup(function () {
console.log( '**asdf**' );
});
}
If I comment out the pitches_sum = new Meteor.Collection( 'pitches_sum' ); line, then I don't think I will get the error message any more.
This was being caused by my large data set and autopublish. Since autopublish was on, Meteor was trying to send the whole 4GB collection down to the client. Trying to process all the data prevented the client from responding to the server's keep alive pings. Or something to that effect.
Removing autopublish with meteor remove autopublish and then writing my own publish and subscribe functions fixed the problem.