The real solution is to have a two-phased shutdown sequence in PHP 6
because we're constantly "Fixing" the shutdown due to chicken&egg problem.
At 11:19 AM 9/6/2005, steve wrote:

I agree. Having no access MySQL(i) during shutdown has already broken
scripts I've used. Thankfully, Jani mentioned the change so I no
longer felt like I was going crazy, and I was able to work around it
by creating a "shutdown object" that contained references to all the
objects it might need, and then used it's destroy call. Same issue in
5.1.

If the behavior is to change from what we expect, I'd propose that we
add something to the manual. That said, I only found this problem
because of strange Fatal Error in Unknown on line 0 errors in the
error log. It took me a while to link that to the change in shutdown
behavior, and I don't think too many will be able to make the link
between the two.

My $0.02.

-steve--

Zeev Suraski wrote:

If there are no (ultra last) objections, I'll roll 5.0.5 tomorrow
morning (.il/Europe time) and post it in the evening.

Zeev

I'm still objecting to a patch by Jani made in April to move destructor
before shutdown functions. It was in response to the following report,
http://bugs.php.net/bug.php?id=30578

The problem being other than the fact that it's broken some BC is that
when it comes around to using the shutdown function any objects you
might actually have wished to use have since had their destructor called
closing connections and finalising data.

All I am proposing is that the shutdown function is run prior to
destruct functions being called as I don't expect to still be able to
access objects after the destructor is called which is still the case.
Changing the order doesn't effect bug 30578 which it was fixing.

The attached code demonstrates the problem, I'd expect to get the
following output

__construct
execution
execution
__destruct

the shutdown function checking the last step run, unfortunately I get

__construct
execution
__destruct
__destruct

Even though the destructor has been called I can still access the object
and fetch the value of the step variable.

Scott

<?php

error_reporting(E_ALL);

class example
{
var $step;
function __construct()
{
echo "__construct\n";
$this->step = '__construct';
}
function execution()
{
echo "execution\n";
$this->step = 'execution';
}
function __destruct()
{
echo "__destruct\n";
$this->step = '__destruct';
}
}
echo "<pre>";
$obj = new example();
$obj->execution();

function shutdown()
{
global $obj;
echo $obj->step . "\n";
}
register_shutdown_function('shutdown');
?>

Index: main/main.c

RCS file: /repository/php-src/main/main.c,v
retrieving revision 1.648
diff -u -r1.648 main.c
--- main/main.c 2 Sep 2005 14:08:09 -0000 1.648
+++ main/main.c 6 Sep 2005 13:12:22 -0000
@@ -1319,16 +1319,16 @@
EG(opline_ptr) = NULL;
EG(active_op_array) = NULL;

•   /* 1. Call all possible __destruct() functions */
  

•   /* 1. Call all possible shutdown functions registered 
  

with register_shutdown_function() */

•   if (PG(modules_activated)) zend_try {
  

•           php_call_shutdown_functions(TSRMLS_C);
  

•   } zend_end_try();
  

•   /* 2. Call all possible __destruct() functions */
    zend_try {
            zend_call_destructors(TSRMLS_C);
    } zend_end_try();
  

•   /* 2. Call all possible shutdown functions registered 
  

with register_shutdown_function() */

•   if (PG(modules_activated)) zend_try {
  

•           php_call_shutdown_functions(TSRMLS_C);
  

•   } zend_end_try();
  

•   /* 3. Flush all output buffers */
    zend_try {
  

php_end_ob_buffers((zend_bool)(SG(request_info).headers_only?0:1) TSRMLS_CC);

Index: main/main.c

RCS file: /repository/php-src/main/main.c,v
retrieving revision 1.604.2.22
diff -u -r1.604.2.22 main.c
--- main/main.c 16 Aug 2005 18:11:34 -0000 1.604.2.22
+++ main/main.c 6 Sep 2005 13:34:15 -0000
@@ -1194,14 +1194,14 @@
sapi_send_headers(TSRMLS_C);
} zend_end_try();

•   if (PG(modules_activated)) zend_try {
  

•           php_call_shutdown_functions(TSRMLS_C);
  

•   } zend_end_try();
  

•   zend_try {
            zend_call_destructors(TSRMLS_C);
    } zend_end_try();
  

•   if (PG(modules_activated)) zend_try {
  

•           php_call_shutdown_functions(TSRMLS_C);
  

•   } zend_end_try();
  

•   if (PG(modules_activated)) {
            zend_deactivate_modules(TSRMLS_C);
            php_free_shutdown_functions(TSRMLS_C);
  

Index: main/main.c

RCS file: /repository/php-src/main/main.c,v
retrieving revision 1.640.2.4
diff -u -r1.640.2.4 main.c
--- main/main.c 2 Sep 2005 14:05:45 -0000 1.640.2.4
+++ main/main.c 6 Sep 2005 13:17:14 -0000
@@ -1200,16 +1200,16 @@
EG(opline_ptr) = NULL;
EG(active_op_array) = NULL;

•   /* 1. Call all possible __destruct() functions */
  

•   /* 1. Call all possible shutdown functions registered 
  

with register_shutdown_function() */

•   if (PG(modules_activated)) zend_try {
  

•           php_call_shutdown_functions(TSRMLS_C);
  

•   } zend_end_try();
  

•   /* 2. Call all possible __destruct() functions */
    zend_try {
            zend_call_destructors(TSRMLS_C);
    } zend_end_try();
  

•   /* 2. Call all possible shutdown functions registered 
  

with register_shutdown_function() */

•   if (PG(modules_activated)) zend_try {
  

•           php_call_shutdown_functions(TSRMLS_C);
  

•   } zend_end_try();
  

•   /* 3. Flush all output buffers */
    zend_try {
  

php_end_ob_buffers((zend_bool)(SG(request_info).headers_only?0:1) TSRMLS_CC);