opcache.file_cache_only seems to disable opcache

[homersimpsons]

Description

The following code:

❯ mkdir -p /tmp/.opcache && php -d opcache.enable_cli=1  -d opcache.file_cache=/tmp/.opcache -d opcache.file_cache_only=1 -r "var_dump(opcache_get_status());"

Resulted in this output:

array(3) {
  ["opcache_enabled"]=>
  bool(false)
  ["file_cache"]=>
  string(13) "/tmp/.opcache"
  // ...
}

But I expected this output instead:

array(10) {
  ["opcache_enabled"]=>
  bool(true)
  ["file_cache"]=>
  string(13) "/tmp/.opcache"
  // ...
}

Note that without opcache.file_cache_only the output is correct:

❯ mkdir -p /tmp/.opcache && php -d opcache.enable_cli=1  -d opcache.file_cache=/tmp/.opcache  -r "var_dump(opcache_get_status());"
array(10) {
  ["opcache_enabled"]=>
  bool(true)
  ["file_cache"]=>
  string(13) "/tmp/.opcache"
  // ...
}

Context

Overall context: I have a short-living container that runs a script (that is doing computations) and I wanted to experiment warming up opcache before so I could speed up the script execution.

I tried the following setup:

<?php
// opcache_compile.php
// This is assuming composer install --classmap-authoritative

declare(strict_types=1);

use Composer\Autoload\ClassLoader;

$loader = include 'vendor/autoload.php';
assert($loader instanceof ClassLoader);

foreach ($loader->getClassMap() as $file) {
    opcache_compile_file($file);
}

# Dockerfile
FROM php:8.4-cli-alpine

COPY --from=builder /opt/app /opt/app
RUN docker-php-ext-install opcache \
    && mkdir /opt/app/.opcache \
    && /usr/local/bin/php -d opcache.enable_cli=1 -d opcache.file_cache=/opt/app/.opcache -d opcache.file_cache_only=1 /opt/app/opcache_compile.php

ENTRYPOINT ["/opt/app/bin/run.sh"]

With the expectation of running it with

docker run --rm app /usr/local/bin/php -d opcache.enable_cli=1 -d opcache.file_cache=/opt/app/.opcache -d opcache.file_cache_only=1 /opt/app/app.php

PHP Version

PHP 8.3.6 (cli) (built: Mar 19 2025 10:08:38) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.3.6, Copyright (c) Zend Technologies
    with Zend OPcache v8.3.6, Copyright (c), by Zend Technologies

Operating System

Ubuntu 24.04

[SakiTakamachi]

This appears to be intentional behavior, originating from a patch that was applied in the past to work around a bug.

https://bugs.php.net/bug.php?id=78106

96a1257

cc: @dstogov

[dstogov]

opcache_enabled string in the output of opcache_get_status() actually means shm_cache.
May be it make sense to change the string or/and add a note in the documentation.