[fpc-pascal] dynamic array and new/dispose

[Amit Bueno]

Seems that I found a workaround.

When calling the NewSubChunk in the following syntax:

SubChunks[NewSubChunk]^.read(fl);  /// raise an exception.

 

While

MyIndex := NewSubChunk;

SubChunks[MyIndex]^.read(fl);  /// raise an exception.

 

Doesn't raise any excetion…. 

Maybe the experts could say why, I don't know why…

Amit

From: fpc-pascal-bounces at lists.freepascal.org [mailto:fpc-pascal-bounces at lists.freepascal.org] On Behalf Of ik
Sent: Wednesday, February 02, 2011 5:48 PM
To: FPC-Pascal users discussions
Subject: Re: [fpc-pascal] dynamic array and new/dispose

 

I have created a proof of concept from your code:

----------------------------
{$mode delphi}
program test;

type
  PChunk = ^Chunk;
  Chunk = Object
       SubChunks : array of PChunk;
       data : Pointer;
       Function NewSubchunk: integer;
  end;

function Chunk.NewSubchunk :integer;
var
 x : integer;
begin
  x := High(SubChunks)+2;
  setlength(SubChunks, x); 
  New(subchunks[x]);
  SubChunks[x]^.Data := Self.Data;
  Result := x;
end;

var
 ac : Chunk; 

begin
 ac.data := PChar('Hello world');
 writeln(ac.NewSubchunk);
end.

-----------------------

Does it work for you (I do not have any apple to test it on, but it works on my Linux) ?

And yes it leaks memory :)

Ido


LINESIP - Opening the source for communication
http://www.linesip.com
http://www.linesip.co.il





On Wed, Feb 2, 2011 at 17:29, Amit Bueno <amitbueno at gmail.com> wrote:

Of course it does -- otherwise it won't have worked on delphi under windows.

The X = High(SubChunks);

---

Amit

On Wed, Feb 2, 2011 at 5:27 PM, ik <idokan at gmail.com> wrote:

On Wed, Feb 2, 2011 at 17:18, Amit Bueno <amitbueno at gmail.com> wrote:

The SubChunks are -- 'var subchunks array of pchunk;' contained in chunk

before allocating the subchunks a setlength(subchunks, High(subchunks)+2) is called.


But does the X variable point to existed index in the array ? if not, then it explains the "access violation".
 

---

Amit

On Wed, Feb 2, 2011 at 5:15 PM, ik <idokan at gmail.com> wrote:





On Wed, Feb 2, 2011 at 16:57, Amit Bueno <amitbueno at gmail.com> wrote:

Seems that the ios doesn't allocated properly my objects,. after allocation when trying to run a function from the object it fails.

I tried replacing the New(subchunks[X]) to SubChunks[X] := AllocMem(sizeof(Chunk));

Again this works on the windows, it doesn't on the ios.

 

Have you got any ideas?


Does "X" actually exists as an index (I mean the value of it) ?

 

---

Amit

On Wed, Feb 2, 2011 at 3:34 PM, Amit Bueno <amitbueno at gmail.com> wrote:

Attached is the shrinked prof.rar file (481kb).
You can download it as well from:
http://bueno.co.il/files/prof.rar 

 


---
Amit

-----Original Message-----
From: fpc-pascal-bounces at lists.freepascal.org
[mailto:fpc-pascal-bounces at lists.freepascal.org] On Behalf Of Jonas Maebe

Sent: Wednesday, February 02, 2011 3:28 PM
To: FPC-Pascal users discussions
Subject: Re: [fpc-pascal] dynamic array and new/dispose



On 02 Feb 2011, at 14:10, Amit Bueno wrote:

> Have you got the prof.rar?

No. I've just looked at the posts held for moderation and your mail is over
5MB. That is way too large to send to a mailing list. First of all, make
sure to only include source code, not compiled units, programs or resources.
Secondly, if it's that big, put it online on a website and only send the
link to the mailing list.



Jonas
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Ido


LINESIP - Opening the source for communication
http://www.linesip.com <http://www.linesip.com/> 
http://www.linesip.co.il <http://www.linesip.co.il/> 

 


_______________________________________________
fpc-pascal maillist  -  fpc-pascal at lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal

 


_______________________________________________
fpc-pascal maillist  -  fpc-pascal at lists.freepascal.org
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Ido
LINESIP - Opening the source for communication
http://www.linesip.com <http://www.linesip.com/> 
http://www.linesip.co.il <http://www.linesip.co.il/> 


_______________________________________________
fpc-pascal maillist  -  fpc-pascal at lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal

 


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