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RE: [cdt-dev] GDB hangs after a series of commands?

And, if I'd had more sleep, I would have seen that this is a deadlock.  I'll
try putting my Runnable on a separate thread.
	-- Steve G.


-----Original Message-----
From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On
Behalf Of Steve Goodrich
Sent: Thursday, April 22, 2010 12:09 PM
To: 'CDT General developers list.'
Subject: [cdt-dev] GDB hangs after a series of commands?

It is, indeed, a console problem.  

BUG: If the console is enabled ("Verbose console mode" checkbox on the
Debugger tab) and you have a thread which sends around 80 K of text to the
console before the console can be displayed, the system will hang.

Here's what I believe to be happening:
With console enabled, I have a thread (a BusyIndicator Runnable) which is
activated via a button press (SelectionEvent) in my View.  Within this
thread I send dozens of commands to GDB (e.g. "show print").  During
execution of this thread the GDB console window (Console View) does not
update, and therefore the GDB output gets queued up in that OutputStream.
At some point during output, the OutputStream reaches a point of being full
and can accept no more data.  The RXThread keeps trying to add the GDB
output to that stream and gets blocked because the stream is waiting to be
emptied.  Unfortunately, the stream will not get emptied because [I'm
guessing here] the Thread managing the Console View is not executing and
therefore is not pulling data out of that OutputStream.  Thus, a hang.

With the console disabled, the OutputStream is not gating RXThread and
therefore there is no hang.

Is this worthy of being filed as a bug?
	-- Steve G.

 
-----Original Message-----
From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On
Behalf Of Mikhail Khodjaiants
Sent: Tuesday, April 20, 2010 3:07 PM
To: cdt-dev@xxxxxxxxxxx
Subject: Re: [cdt-dev] GDB hangs after a series of commands?

It could be a console problem. I remember seeing bug reports about large 
output blocking the console.

On 20/04/2010 1:02 PM, James Blackburn wrote:
> It looks like your're using CDI. One thing that can make it hang is if
> GDB itself is blocked trying to write to one of its output streams
> (stdout and stderr).  Before CDT 7 we never read from stderr, so if
> there's periodic output here, GDB eventually locks up.
>
> It's worth finding out what the other end is doing -- attach another
> to the gdb eclipse is talking to to find out...
>
> Cheers,
> James
>
> On 20 April 2010 17:45, Steve Goodrich<steve.goodrich@xxxxxxxxxx>  wrote:
>    
>> I'm working on a custom View in the context of CDI.  I have a valid
>> MISession, and I'm hammering it with commands:
>>
>>         CLICommand cli = new CLICommand("test");
>>         MIOOBRecord oobRecord[] = null;
>>         for (int i = 0; i<  2000; i++) {
>>                 System.out.println(String.format("%4d - sending", i));
>>                 try {
>>                         miSession.postCommand(cli, MISession.FOREVER);
>>                         System.out.println(String.format("%4d - waiting",
>> i));
>>                         oobRecord =
>> cli.getMIInfo().getMIOutput().getMIOOBRecords();
>>                         System.out.println(String.format("%4d -
completed",
>> i));
>>                 } catch (Exception e) {
>>                         System.out.println(String.format("%4d -
exception:
>> ", i) + e.getMessage());
>>                 }
>>         }
>>         System.out.println("DONE!");
>>
>>
>> I'm able to go through this loop about 900 times, and then my debug
session
>> will hang.  The last debug output I have is this (the exception is
expected
>> since "test" is not a valid GDB command):
>>
>>          890 - sending
>>          890 - waiting
>>          890 - exception: Undefined command: "test".  Try "help".
>>          891 - sending
>>
>>
>> And now Eclipse is hung.  The call stack looks like this:
>>
>>         Thread [main] (Suspended)
>>                 Object.wait(long) line: not available [native method]
>>                 PipedInputStream.awaitSpace() line: not available
>>                 PipedInputStream.receive(byte[], int, int) line: not
>> available
>>                 PipedOutputStream.write(byte[], int, int) line: not
>> available
>>                 PipedOutputStream(OutputStream).write(byte[]) line: not
>> available
>>                 MISession.writeToConsole(String) line: 831
>>                 MISession.postCommand0(Command, long) line: 591
>>                 MISession.postCommand(Command, long) line: 573
>>                 MyView.testloop(boolean) line: 602
>>                 (etc.)
>>
>>
>> I don't have the PipedOutputStream or PipedInputStream sources, so the
>> lowest level at which I have visibility is here:
>>
>>         protected void writeToConsole(String text) {
>>                 OutputStream console = getConsolePipe();
>>                 if (console != null) {
>>                         try {
>>                                 console.write(text.getBytes());
//<<<<<<<<
>> hangs somewhere in here
>>                                 console.flush();
>>                         }
>>                         catch(IOException e) {
>>                         }
>>                 }
>>         }
>>
>>
>> Does this make sense to anyone?  Aside from "don't do that to GDB", is
there
>> something obvious I'm doing wrong?  Is there some pacing I need to follow
>> when dealing with MISession?  Is there some way to get more information
on
>> this so I can figure out what's happening?
>>
>> Thanks!
>>         -- Steve G.
>>
>>
>> _______________________________________________
>> cdt-dev mailing list
>> cdt-dev@xxxxxxxxxxx
>> https://dev.eclipse.org/mailman/listinfo/cdt-dev
>>
>>      
> _______________________________________________
> cdt-dev mailing list
> cdt-dev@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/cdt-dev
>    
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