Hello Daine,
a) i didn't contradict myself - you obviously didn't really follow
what i wrote
b) you can force calling the destructor by using unset() or = null;
but only if reference count is 1.
c) exceptions are 'thrown' not called, maybe you didn't use throw new
exception here or you were just writing a bit weired?
d) as said already several times (not only to you) exceptions *can*
be thrown in destructors
e) this doesn't belong in internals@
regards
marcus
Tuesday, December 20, 2005, 6:22:31 PM, you wrote:
> I agree completely...
> I think the GC should be better documented.
> I also would like someone to tell me why exceptions cannot be called in the
> destructor? Since they can't, this means the reliability of a destructor is
> uncontrolled and nothing can be done to see if this completes successfully.
> This in some way or another, renders them completely useless if you require
> them to complete an operation and at least have the peace of mind that you
> will be able to deal with errors rather than the application throwing a fatal
> error.
> On Tue, 20 Dec 2005 11:38:34 -0500, Alan Pinstein wrote
>> > Your last post also indicates, that because the destructors are
>> > only called
>> > after script termination, the scope of an object is global, always.
>> > Is this true?
>>
>> This isn't true, at least empirically. Destructors are called when
>> the GC frees the object.
>>
>> For many objects, this is at script termination. But if you null out
>> the ref to an object, it will occur immediately.
>>
>> $a = new A();
>> $a = null; // destructor called just after this line
>>
>> I am not certain that this should be considered *predictable*
>> behavior, as the behavior of the GC is not well/publicly documented
>> to my knowledge, and thus this is a reasonable question for the
>> internals list.
>>
>> Personally I would like to see more documentation of how GC works so
>> that we as developers can depend on it a little better for OO
>> cleanup activities. I have another thread going that still remains
>> unanswered about how to prevent circular references to objects that
>> deadlock the GC.
>>
>> Alan
>>
>> > Also, I've called fwrite in a destructor before, so clearly not all
>> > IO is
>> > terminated before the destructor is called.
>> > When you refer to output facility, what are you talking about?
>> >
>> > Many thanks
>> > Daine Mamacos.
>> >
>> >
>> > On Mon, 19 Dec 2005 20:16:07 +0100, Marcus Boerger wrote
>> >> Hello Daine,
>> >>
>> >> you still don't get it. Your problem is the way php works. You
>> >> cannot put any output functionality in destructors because they are
>> >> called *after* your scipt is being terminted (to be precise after
>> >> the output facility has been shutdown on script termination).
>> >>
>> >> This is btw a question the general php list.
>> >>
>> >> marcus
>> >>
>> >> Monday, December 19, 2005, 11:07:53 AM, you wrote:
>> >>
>> >>> While you're example works, mine doesn't, it has to do with the
>> >>> class
>> >>> assignment. If you actually bother to do anything with the class, it
>> > doesn't work.
>> >>
>> >>> $ php -r 'class blah { function __destruct() { throw new Exception
>> >>> ("exception
>> >>> thrown"); } } $blah = new blah();'
>> >>
>> >>> give that a try and see what happens
>> >>> (;
>> >>> also http://bugs.php.net/bug.php?id=33598 clearly states that
>> >>> they cannoy be
>> >>> thrown in the destructor.
>> >>> Errrr... *shrug*
>> >>
>> >>> On Fri, 16 Dec 2005 20:38:20 +0100, Marcus Boerger wrote
>> >>>> Hello Daine,
>> >>>>
>> >>>> [EMAIL PROTECTED] /usr/src/PHP_5_1 $ php -r 'class A{function
>> >>>> __destruct(){throw new Exception("A");}} new A;' make:
>> >>>> `sapi/cli/php' is up to date.
>> >>>>
>> >>>> Fatal error: Uncaught exception 'Exception' with message 'A' in
>> >>>> Command line code:1 Stack trace:
>> >>>> #0 Command line code(1): A::__destruct()
>> >>>> #1 {main}
>> >>>> thrown in Command line code on line 1
>> >>>>
>> >>>> As the code above clearly show, exceptions can be thrown.
>> >>>>
>> >>>> marcus
>> >>>>
>> >>>> Friday, December 16, 2005, 3:17:54 PM, you wrote:
>> >>>>
>> >>>>> Is there any reason why one is not allowed to throw an
>> >>>>> exception in the
>> >>>>> destructor of a class?
>> >>>>> I mean, it makes sense, considering this is not always the
>> >>>>> final step
>> > of code,
>> >>>>> and it is usually used for finalising things, and it would be a
>> >>>>> good
>> > idea to
>> >>>>> know if anything goes wrong at that stage.
>> >>>>> Otherwise is there any compromise one can use to "emulate" this
>> >>>>> feature?
>> >>>>
>> >>>>> Daine Mamacos.
>> >>>>
>> >>>>> --
>> >>>>> random signature
>> >>>>
>> >>>> Best regards,
>> >>>> Marcus
>> >>>>
>> >>>> --
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>> >>
>> >>> --
>> >>> random signature
>> >>
>> >> --
>> >> Best regards,
>> >> Marcus mailto:[EMAIL PROTECTED]
>> >
>> >
>> > --
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Best regards,
Marcus
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