I added a startUp-Method to one of my classes that immediatelly quits my image. Is there a way to prevent Pharo from executing that method so that I can fix it?
No, this is an issue of ongoing discussion. See this post on the Pharo mailing list.
Your only way to recover the image is to hack the VM, which I describe here. If you go that route, use the stack VM instead of the JIT (the same thread explains why further down).
Related
I using freertos on my project. My code is stuck in hardfault handler, I want know last executed function address or last executed line address for debugging.How to debug code when PC is pointing Hardfault handler.
That information is 100% dependent on which microcontroller you are using, and also which tool chain you are using as some IDEs will do this for you. You failed to provide either piece of information, so are asking people to guess on your behalf. A good question is one that cannot only possibly be answered by another question.
I am going to guess you are using a Cortex-M microcontroller, in which case information on debugging a hard fault can be found on lots of links found by Google, including the following: http://www.freertos.org/Debugging-Hard-Faults-On-Cortex-M-Microcontrollers.html
I am using gocraft/web in a project and am trying to debug some high memory usage. gocraft/web uses reflection to call handlers. I've set up the net/http/pprof profiler which works very well, but the largest block of memory, and the one that I am iterested in, only shows reflect.Value.call as the function. That's not very helpful.
How can I get around the fact that gocraft/web is using reflection and dig deeper into the memory profile?
Here's an example of the profile output I am seeing:
Thanks to #thwd for filing http://golang.org/issue/11786 about this. This is a display issue in pprof. All the data is there, just being hidden. You can get the data you need by invoking pprof with the -runtime flag. It will also show data you don't need, but it should serve as a decent workaround until Go 1.6 is out.
The short answer is that you can't directly. reflect.Value.call calls reflect.call which forwards to runtime.reflectcall which is an assembly routine implemented in the runtime, for example for amd64, here. This circumvents what the profiler can see.
Your best bet is to invoke your handlers without reflection and test them like that individually.
Also, enabling the profiler to follow reflective calls would arguably be an acceptable change to propose for the next Go iteration. You should follow the change proposal process for this.
Edit: issue created.
Here is a simple question.
suppose that I have a very long loop to execute, It would be nice to keep the user informed about the progressing right? I would print for example the number of loops that have been executed so far and how many are remaining.
The problem that I have is those output wouldn't be visualized until the the loop is finished, and thus there will be no point for them to be displayed.
I'm sure that there is some method in dart that can some sort of a handler to the browser to execute tasks and events whenever I want to and keep running the loop.
I'm new to dart, I hope that someone could answer this question.
Thank you.
PS: If you don't know how to, you can give me any ideas of keywords that I can use to look for this particular feature in dart documentation, it will be very helpful.
You can dig into Isolates, which allow background work on supported browsers.
https://api.dartlang.org/docs/channels/stable/latest/dart_isolate.html
Nothing as simple as DoEvents(), but all of the pieces are there.
I think too that Isolates are the best approach but wasn't successful using them on the browser a while ago, but there was a bigger refactoring going on lately in Isolates.
Does anyone know of a current client side Isolates example?
The API doc referenced by #kevmoo contains a link to an Isolates article that doesn't exist anymore (maybe must be rewritten due to the mentioned refactoring).
Another approach would be a method that returns after a chunk of work and gets recalled repeated in a loop until it returns for example true for done (false for not yet).
When you call this method using scheduleMicrotask(doChunk) or new Timer(() => doChunk()) other tasks get some air (import 'dart:async';) each time before the method gets actually called.
I recently met a problem using blocks with Facebook's app switching. I needed to call a block after the Facebook login.
First my block was destroyed when the app switched back ('cause it was on the stack), so I decided to retain it. But that didn't work, and I messed with that problem :/. I found a solution on that blog and also here.
My question is simply : why copy works and retain does not ?
Because when you create a block there is nothing to retain, since it doesn't exist in the heap until you copy it there with Block_copy. This is covered in the WWDC lectures about blocks.
More info: http://www.friday.com/bbum/2009/08/29/blocks-tips-tricks/
See my recent answer to another similar question:
By default blocks are created on the stack. Meaning they only exist in the scope they have been created in.
[...]
Read Stack and Heap Objects in Objective-C by Mike Ash for more info on stack vs. heap.
I've got a program that's having some trouble during shutdown, raising exceptions that I can't trace back to their source. It appears to be timing-related and non-deterministic. This is occurring after all shared resources have been released, and since it's shutdown, memory leaks are not an issue, so that makes me wonder if there's any way to just tell the program to terminate immediately and silently after releasing the shared resources, instead of continuing with the shutdown sequence and giving an exception message box.
Does anyone know how to do that?
After looking at the Delphi Run Time Library source code, and at the Microsoft documentation; I can corroborate Mason and Paul-Jan comments.
The hierarchy of shutdown is as follows
Application.Terminate()
performs some unidentified housekeeping of application
calls Halt()
Halt()
calls ExitProc if set
alerts the user in case of runtime error
get rid of PackageLoad call contexts that might be pending
finalize all units
clear all exception handlers
call ExitprocessProc if set
and finally, call ExitProcess() from 'kernel32.dll'
ExitProcess()
unloads all DLLs
uses TerminateProcess() to kill the process
ExitProcess(0) ?
Halt(0) used to be the good old fashioned way of telling the program to end with immediate effect. There's probably a more Delphi-friendly way of doing that now, but I'm 95% sure halt(0) still works. :-)
In case HeartWare's suggestion of using ExitProcess() fails, it might be you are using some DLL's that do not respond well to the DLL_PROCESS_DETACH. In that case, try using a TerminateProcess( getCurrentProcess, 0 );
Once you resort to such measures, one might wonder if the "cleanly" part of the topic title still holds up to scrutiny.
The last time I had to hunt a problem like this was the shutdown was a causing an event (resize? It's been a while.) to fire on the dying window causing an attempt to redraw something that needed stuff that had already been disposed of.