在包含包含它的文件后，PHP不会实例化该类

Here is my problem. I have one file (say, func.inc.php) with autoloader function, registered by spl_autoload_register():

function autoloaderFnc($class) {
    global $__CONFIG;

    $original = $class_name;
    $class_name = mb_strtolower ( $class_name );

    foreach ( $__CONFIG ['include_dirs'] as $path ) {
        if(file_exists ( $__CONFIG ['root'] . $path . $class_name . '.inc.php' )) {
            require ($__CONFIG ['root'] . $path . $class_name . '.inc.php');

            $classFound = TRUE;
            $foundAt = $__CONFIG ['root'] . $path . $class_name . '.inc.php';
            break;
        }
    }

    if( $classFound ) {
        if ( class_exists( $original ) ) {
            return true;
        } else {
            $backtrace = debug_backtrace();
            $error = "PHP User error: Cannot load class <b>$original</b> included at " . $backtrace[1]['file'] . ":" . $backtrace[1]['line'] . " (searching for <i>$class_name.inc.php</i>), but following file was included: $foundAt";
            error_log( $error );

            return false;
        }
    } else {
        $backtrace = debug_backtrace();
        $error = "PHP User error: Cannot find file with class <b>$original</b> included at " . $backtrace[1]['file'] . ":" . $backtrace[1]['line'] . " (searching for <i>$class_name.model.php</i> and <i>$class_name.inc.php</i>) in none of the following include dirs:<br />" . join ( '<br />', $__CONFIG ['include_dirs'] );
        error_log( $error );
    }

}

spl_autoload_register('autoloaderFnc');

Then I have a second file (show_me_poi.php), calling some class:

POI::doSmth();

Everything seems OK, but sometimes (and only sometimes!) I receive a following error in log:

[error] PHP User error: Cannot load class POI included at /path_to_dir/php/generators/export.generator.php:156 (searching for poi.inc.php), but following file was included: /path_to_dir/php/scripts/php/incs/poi.inc.php

This is weird, because class POI is defined in properly included file! And I repeat, this situation happens only sometime (10 out of 100 I think). What can cause such behaviour? And how can I fix it?

Thanks in advance!

The problem seems to arise only with APC op-cache turned on. I think that __autoload function can't work properly with caches in some cases. AFAIS only some PHP and APC versions are not compatible with each other.

I've run into this problem as well and I found a solution for my case.

In my situation I had a custom session handler as well which wrote data to the database when closing the session.

When an error occurred the error handler would fire and the error would be handled normally. But then the session close handler would run and it would encounter and error when trying to write to the database which caused catch statement to fire which, depending on the type of SQL error would throw an Exception of a certain type, but those classes had to be autoloaded. At that point (in a session close handler) you can no longer autoload classes apparently.

Check when this is happening. During normal PHP execution, or in some 'special' PHP mode such as a session handler or a while doing error handling?

The solution in my case was to add class_exists("MyClass", true) before trying to use it. I could throw a normal Exception instead. The Exception will still 'Fatal' as there is nothing left to catch it, but at least it will show the real Exception and not the autoload error.