ID: 9477
Updated by: andre
Reported By: [EMAIL PROTECTED]
Old-Status: Open
Status: Bogus
Bug Type: Scripting Engine problem
Assigned To:
Comments:
this all makes sense and generally you do NOT need to use
"=& new" your case included, this is due to PHPs nature and
this all has been discussed
search the archives (marc.theaimsgroup.com) for
"reference counting" and "this+constructor" or maybe "=&" to
understand when it required to use "=&" with new
there are some resources on reference counting in the manual
or at zend.com IRC
Previous Comments:
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[2001-03-09 00:32:08] [EMAIL PROTECTED]
I retract this bug. I think the issue is that I was looking for pointer semantics in a
language that does not support it but at the same time is not strongly typed so that
what appears to be correct, does not in fact reset the reference but actually
overwrites the original object by assignment.
Thank you all for your help. I now have a proper reference implementation of the
subscriber/publisher pattern for PHP.
Hopefully, I'll be able to keep this all straight for any other patterns I conver to
PHP.
Just out of curiosity, has ANYONE questioned the whole =& new construct's necessity in
terms of why the semantics allows for = new as well??? When would you want to assign
the a copy of the object you just created?
Any help would be appreciated.
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[2001-03-08 20:55:49] [EMAIL PROTECTED]
bogusifying
apparently you do not know what you are doing here exactly,
please read "references explained" from the manual again...
/* your version - you do not destroy the reference, you
simply overwritte all referenced variables (remember they
are all ONE variable know) with "" */
function junk($name){$this->array[$name]="";}
/* corrected version - this one does what it is written in
your description */
function junk($name){unset($this->array[$name]);}
the corrected one works for me.
/* to clear things up a bit - the following code does the
following: remove the reference by replacing it with another
(to $t), I could imagine you thought it does something
different */
function nojunk($name){$t="";$this->array[$name]=&$t;}
please note I still did not read your comments, your code
reduced code was enough to understand the situation completely
note: please do not use pass-by-ref in call time
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[2001-03-08 20:07:23] [EMAIL PROTECTED]
I'm really getting tired of this. I guess what I REALLY needed to do is strip out the
do nothing functions in the skeletons I had on that page because even though they were
base classes, everyone was missing the point.
Here is the simplest case that generates an error. Anyone want to take a stab at why
it happens?
<?php
class obj {
var $array;
// Assigns object reference to the associative array
function test($name,$obj){$this->array[$name]=&$obj;}
// Removes the reference from the associative, supposedly
// but what it does decrease the actual object to nothing
function junk($name){$this->array[$name]="";}
// If I do it this way it works. The object isn't nuked.
// What gives? Do I *HAVE* to use =&$ when assigning refs?
// Is there an array function that can be used to simply
// remove the array element out, w/o expensive copying?
function nojunk($name){$t="";$this->array[$name]=&$t;}
};
// Our do nothing class.
class me{
function test(){echo "Hello, I'm still validn";}
};
// Please don't tell me not to send the reference to the
// object because I need to have only one copy of the object
// and not a million of them especially since these objects
// might be opening files and sockets.
$m=& new me();
$o=& new obj();
// This section works
$o->test("test",&$m);
$m->test();
$o->nojunk("test");
$m->test();
// This section fails....
$o->test("test",&$m);
$m->test();
$o->junk("test");
// Right here
$m->test();
?>
So? What's the deal? Once you assign a reference to a variable, you're done? You can't
ever reassign the reference? Does what I'm proposing make sense syntactically
speaking? I want the array to contain the reference to the object, but then I want to
be able to unassign the reference from the array so that that particular object
doesn't get used. An unregistration as it were.
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[2001-03-08 17:24:46] [EMAIL PROTECTED]
> Did I miss anything in helping debug this issue or did I
> just do too much?
you did the wrong thing!
the following passage is the only one I have read, I have
not visited your site, nor anything else (we simply do not
have the time to do this kind of things, it's exactly the
same in any bigger OS project I know of (eg. bugzilla,
provide minimized testcases or your bug will never be fixed)
<quote>
Bottom line: global object passed as a reference to a method
and then assigned to an array
which is a member of another object. The second object is
then requested to delete the
reference to global object. At the moment the reference in
the array is deleted, the global
object goes kaboom too.
</quote>
what I have done then, is creating PHP source reading the
words above:
function foo (&$foo) {
$zoo->array['foo']=&$foo;
unset($zoo->array['foo']); // simplified
}
$foo->test=TRUE;
foo($foo);
var_dump($foo);
***
This is works for me and this is how we expect code
snipplets, feel free to modify it to match exactly your
problem...
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[2001-03-08 16:55:04] [EMAIL PROTECTED]
a) The comment I got in my eyes said there was nothing that was looked at.
b) I do open source work too.
c) I have tried over and over in the past to get things included in php that were
overlooked for almost 3 years until they finally got put in. Specifically detecting
the different datatypes that some of the databases generate as field types.
d) The URL I gave has a total of 4 files. 2 source files. And to active scripts that
when run, generate the results.
e) The one marked Normal, which completes with no errors, is obviously correct.
f) The other one fails.
g) There is only one line difference in the entire code.
i) I have a global object passed by reference that is then assigned to an array.
j) When this object reference in the array is set to nothing, the global object is
destroyed.
k) If on the other hand I use a separate array to identify what array elements are
defunt, the object still exists.
l) If you ran the non-normal script by clicking on it, it would report the line where
the error occurred.
m) In my scripts, which unfortunately are part of another open source project, I have
VERY CLEARLY marked the section of the code that is different in each instance.
o) If someone is wading through 313 lines of code to find my bug, then they really
didn't think to click on the script, and I guess THAT is truly my REAL error as I did
not specify that I had set up two identical scripts with one line that is different
such that one completes and the other fails using the same algorithm, with one minor
difference.
p) I'm just wondering whether anyone tried clicking on the scripts and saw what I
indicated or looked at the script in detail long enough to look at the offending line
and the demarcated difference in each case.
q) If my comments were interpreted as abusive, I apologize, but understand that when I
have taken all the steps outlined and someone still tells me they cannot reproduce the
behavior, or they cannot understand it, it tells me they didn't look at the problem.
Had someone simply said, I don't understand what's different, I wouldn't have felt
like no one gave a damn to even look at my bug report and had dropped it.
r) In the past my bug reports have been accompanied by no less than a full source code
solution to the error discovered and you'll have to pardon my disillusionment in
providing a solution where my answers are obviously ignored regardless of whether they
are correct or not.
Bottom line: global object passed as a reference to a method and then assigned to an
array which is a member of another object. The second object is then requested to
delete the reference to global object. At the moment the reference in the array is
deleted, the global object goes kaboom too.
You can see this in the scripts at that URL because I have each object serialized as
output prior to the error line as well as each object reporting it's operation so you
can see where things are running.
Did I miss anything in helping debug this issue or did I just do too much?
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