As documentation says IEnumerator methods are executed like thread, but I'm confused why
AssetBundleCreateRequest assetBundleCreateRequest = AssetBundle.CreateFromMemory(ByteArray);
yield return assetBundleCreateRequest;
freezes my game for 2 seconds. Can anybody explain?
Well it freezes for 2 seconds because that is what you are actually requesting with your yield return assetBundleCreateRequest
Asynchronous operation coroutine.
You can yield until asynchronous operation continues, or manually check whether it's done (isDone) or progress (progress). AsyncOperation
So right now you are requesting your coroutine to wait till your assetbundlecreaterequest is done.
For manually checking wheter the function is done, without having to freeze your application would be using the isdone or progress command instead
If you need further clarification feel free to comment.
Edit
Sample of using isdone
AssetBundleCreateRequest acr = AssetBundle.CreateFromMemory(decryptedData);
while (!acr.isDone)
{
yield;
}
AssetBundle bundle = acr.assetBundle;
Related
I'm trying to create a function that after some time you go back to the menu. I'm using coroutines to do it but it isn't working
I used:
StartCoroutine(BackToMenu(3));
To invoke the following function:
IEnumerator BackToMenu(float time)
{
Debug.Log($"you are going back to the menu in {time} seconds");
yield return new WaitForSeconds(time);
Debug.Log("back to menu");
SceneManager.LoadScene("Glitch Main Menu");
}
The console is only logging the first Log, after the return it just doesn't do anything. It's my first time using coroutines so I don't know what the problem could be.
I'm running a simple Parse FindAsync method as show below (on Unity3d):
Task queryTask = query.FindAsync();
Debug.Log("Start");
Thread.Sleep(5000);
Debug.Log("Middle");
while (!queryTask.IsCompleted) {
Debug.Log("Waiting");
Thread.Sleep(1);
}
Debug.Log("Finished");
I'm running this method on a separate thread and I put a load circle on UI. My load freezes (+- 1 second) somewhere in the middle of the Thread.sleep method. It's look like when findAsync finishes the process it freezes the UI until it complete their job. Is there anything I could do?
Ps: This works perfectly on editor, the problem is on Android devices.
Ps2: I'm running parse 1.4.1
Ps3: I already tried the continueWith method, but the same problem happens.
IEnumerator RunSomeLongLastingTask () {
Task queryTask = query.FindAsync();
Debug.Log("Start");
//Thread.Sleep(5000); //Replace with below call
yield WaitForSeconds(5); //Try this
Debug.Log("Middle");
while (!queryTask.IsCompleted) {
Debug.Log("Waiting");
//Thread.Sleep(1);
yield WaitForSeconds(0.001f);
}
Debug.Log("Finished");
}
To call this function, use:
StartCoroutine(RunSomeLongLastingTask());
Making the thread sleep might not be a good idea, mainly because the number of threads available is different on each device.
Unity as a built-in scheduler that uses coroutines, so it is better to use it.
IEnumerator RunSomeLongLastingTask()
{
Task queryTask = query.FindAsync();
while (!queryTask.IsCompleted)
{
Debug.Log("Waiting"); // consider removing this log because it also impact performance
yield return null; // wait until next frame
}
}
Now, one possible issue is if your task take too much CPU, then the UI will still not be responsive. If possible, try to give a lower priority to this task.
We have a HTTP end-point that takes a long time to run and can also be called concurrently by users. As part of this request, we update the model inside a synchronized block so that other (possibly concurrent) requests pick up that change.
E.g.
MyModel m = null;
synchronized (lockObject) {
m = MyModel.findById(id);
if (m.status == PENDING) {
m.status = ACTIVE;
} else {
//render a response back to user that the operation is not allowed
}
m.save(); //Is not expected to be called unless we set m.status = ACTIVE
}
//Long running operation continues here. It can involve further changes to instance "m"
The reason for the synchronized block is to ensure that even concurrent requests get to pick up the latest status. However, the underlying JPA does not commit my changes (m.save()) until the request is complete. Since this is a long-running request, I do not want to wait until the request is complete and still want to ensure that other callers are notified of the change in status. I tried to call "m.em().flush(); JPA.em().getTransaction().commit();" after m.save(), but that makes the transaction unavailable for the subsequent action as part of the same request. Can I just given "JPA.em().getTransaction().begin();" and let Play handle the transaction from then on? If not, what is the best way to handle this use-case?
UPDATE:
Based on the response, I modified my code as follows:
MyModel m = null;
synchronized (lockObject) {
m = MyModel.findById(id);
if (m.status == PENDING) {
m.status = ACTIVE;
} else {
//render a response back to user that the operation is not allowed
}
m.save(); //Is not expected to be called unless we set m.status = ACTIVE
}
new MyModelUpdateJob(m.id).now();
And in my job, I have the following line:
doJob() {
MyModel m = MyModel.findById(id);
print m.status; //This still prints the old status as-if m.save() had no effect...
}
What am I missing?
Put your update code in a job an call
new MyModelUpdateJob(id).now().get();
thus the update will be done in another transaction that is commited at the end of the job
ouch, as soon as you add more play servers, you will be in trouble. You may want to play with optimistic locking in your example or and I advise against it pessimistic locking....ick.
HOWEVER, looking at your code, maybe read the article Building on Quicksand. I am not sure you need a synchronized block in that case at all...try to go after being idempotent.
In your case if
1. user 1 and user 2 both call that method and it is pending, then it goes to active(Idempotent)
If user 1 or user 2 wins, well that would be like you had the synchronization block anyways.
I am sure however you have a more complex scenario not shown here, BUT READ that article Building on Quicksand as it really changes the traditional way of thinking and is how google and amazon and very large scale systems operate.
Another option for distributed transactions across play servers is zookeeper which the big large nosql guys use BUT only as a last resort ;) ;)
later,
Dean
That sinking feeling when you realize you have no idea what's going on...
I've been using this code in my network code for almost two years without problems.
if (!CFReadStreamOpen(myReadStream)) {
CFStreamError myErr = CFReadStreamGetError(myReadStream);
if (myErr.error != 0) {
// An error has occurred.
if (myErr.domain == kCFStreamErrorDomainPOSIX) {
// Interpret myErr.error as a UNIX errno.
strerror(myErr.error);
} else if (myErr.domain == kCFStreamErrorDomainMacOSStatus) {
OSStatus macError = (OSStatus)myErr.error;
}
// Check other domains.
}
}
I believe it was originally based on the code samples given here:
http://developer.apple.com/library/mac/#documentation/Networking/Conceptual/CFNetwork/CFStreamTasks/CFStreamTasks.html
I recently noticed, however, that some connections are failing, because CFReadStreamOpen returns false but the error code is 0. After staring at the above link some more, I noticed the CFRunLoopRun() statement, and added it:
if (!CFReadStreamOpen(myReadStream)) {
CFStreamError myErr = CFReadStreamGetError(myReadStream);
if (myErr.error != 0) {
// An error has occurred.
if (myErr.domain == kCFStreamErrorDomainPOSIX) {
// Interpret myErr.error as a UNIX errno.
strerror(myErr.error);
} else if (myErr.domain == kCFStreamErrorDomainMacOSStatus) {
OSStatus macError = (OSStatus)myErr.error;
}
// Check other domains.
} else
// start the run loop
CFRunLoopRun();
}
This fixed the connection problem. However, my app started showing random problems - interface sometimes not responsive, or not drawing, text fields not editable, that kind of stuff.
I've read up on CFReadStreamOpen and on run loops (specifically, that the main run loop runs by itself and I shouldn't run a run loop unless I'm setting it up myself in a secondary thread - which I'm not, as far as I know). But I'm still confused about what's actually happening above. Specifically:
1) Why does CFReadStreamOpen sometimes return FALSE and error code 0? What does that actually mean?
2) What does the CFRunLoopRun call actually do in the above code? Why does the sample code make that call - if this code is running in the main thread I shouldn't have to run the run loop?
I guess I'll answer my own question, as much as I can.
1) In my code, at least, CFReadStreamOpen always seems to return false. The documentation is a bit confusing, but I read it to mean the stream wasn't opened yet, but will be open later in the run loop.
2) Most of the calls I was making were happening in the main thread, where the run loop was already running, so calling CFRunLoopRun was unnecessary. The call that was giving me problems was happening inside a block, which apparently spawned a new thread. This new thread didn't start a new run loop - so the stream would never open unless I explicitly ran the new thread's run loop.
I'm still not 100% clear on what happens if I call CFRunLoopRun() on a thread with an already running run loop, but it's obviously not good.
I ended up ditching my home-brewed networking code and switching to ASIHTTPRequest, which I was considering to do anyway.
I am Using WaitforComplete() in watiN but it doesnt seems to work well. As it executes the next statement even if you have given longer time to wait. I am using thread.sleep() to stop my application until it gets the desired page or element. But the thing is pages are so much dynamic that sometimes it takes much longer time as specified.
Any better solution. Any thing that will catch the page return dynamically and dont go to execute next statments in application.
Sample of Code
'Show Details page
Assert.AreEqual("Confirmation", _internetExplorer.Title)
If (_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Exists) Then
_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Click()
Else
Assert.Fail("Could not Find Finish Booking Button on Confirmation Page")
End If
System.Threading.Thread.Sleep(100000)
'Show Booking Summary page
Assert.AreEqual("Display Booking", _internetExplorer.Title)
I want something that detect the return of page dynamically. instead of giving some constant value.
WaitForComplete only works well if there is a postback after some action. Otherwise you have to find something else to wait for. Following an example on how to wait for the specified title:
_internetExplorer.Element("title", "Confirmation").WaitUntilExists();
I would always prefer to use one of the WaitXXX methods instead of Thread.Sleep cause the WaitXXX methods do only wait until the contraint is met. Where as Sleep waits for the time you specified. If its to long, time is waisted. If its to short, problems arise.
HTH,
Jeroen
The WaitForComplete method esentially moves on once the browser has set it's readystate to comllete and the busy state to false.
What I typically do is to try and access what you need to, then perform a thread.sleep for say half a second, then try again. I also have a global timeout that quits after say 10 seconds.
int timeout = 20;
bool controlFound = false;
for (int i = 0; i < timeout; i++)
{
if (_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Exists)
{
_internetExplorer.Button(Find.ById(New Regex("btnFinish"))).Click();
controlFound = true;
break;
}
else
{
System.Threading.Thread.Sleep(500);
}
}
if (!controlFound)
{
Assert.Fail("Control not found");
}
If it is executing the next statement, it should be finding the corresponding element. I suggest posting a sample of the code you are trying.