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WordPress

wp_is_maintenance_mode(): bool

Since
5.5.0
Source
wp-includes/load.php:437
Checks if maintenance mode is enabled.

Description

Checks for a file in the WordPress root directory named ".maintenance".
This file will contain the variable $upgrading, set to the time the file was created. If the file was created less than 10 minutes ago, WordPress is in maintenance mode.

Compatibility

WordPress
since 5.5.0
PHP
7.4–8.6-dev
  • 6.7.7
  • 6.8.8
  • 6.9.7
  • 7.0.4
  • 7.1.0

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Return value

bool
True if maintenance mode is enabled, false otherwise.

Performance profile

How much work a call to wp_is_maintenance_mode() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class
Heavy

Reads or writes the filesystem via file_exists().

Scaling
Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions
8–55

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 59.

Plugin surface
1 hook

Third-party callbacks on 'enable_maintenance_mode' run inside this call, and their cost is not bounded by anything here.

Called by
2

2 places in core call this, so the cost is paid more often than your own code shows.

What it touches

  • hookthird-party callbacksapply_filters()called directly
  • filesystemfilesystem accessfile_exists()called directly

What one call costs · 6 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_is_maintenance_mode() can have, taken from its control-flow graph on PHP 8.5.

WhenInstructionsCalls it makes
!file_exists()8file_exists()
file_exists() && wp_installing()11file_exists(), wp_installing()
file_exists() && !wp_installing()21file_exists(), wp_installing(), time()
file_exists() && !wp_installing()29–35file_exists(), wp_installing(), time(), apply_filters()
file_exists() && !wp_installing() && is_int($upgrading) && isset($value) && $key === false && $upgrading === false49file_exists(), wp_installing(), time(), stripslashes(), stripslashes(), md5()
file_exists() && !wp_installing() && is_int($upgrading) && isset($value)52–55file_exists(), wp_installing(), time(), stripslashes(), stripslashes(), md5(), apply_filters()

Across PHP versions

Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 59 instructions, 8–55 executed per call, 9 branches. The work does not change between versions.

An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.

Hooks and filters fired · 1

One hook fires while wp_is_maintenance_mode() runs, in this order:

  1. apply_filters( enable_maintenance_mode )filterline 474 (+37 into the body)

    Filters whether to enable maintenance mode.

Uses · 2

  • wp_installing()Checks or sets whether WordPress is in "installation" mode.
  • apply_filters()Calls the callback functions that have been added to a filter hook.

Used by · 2

Source code

function wp_is_maintenance_mode() {	global $upgrading; 	if ( ! file_exists( ABSPATH . '.maintenance' ) || wp_installing() ) {		return false;	} 	require ABSPATH . '.maintenance'; 	// If the $upgrading timestamp is older than 10 minutes, consider maintenance over.	if ( ( time() - $upgrading ) >= 10 * MINUTE_IN_SECONDS ) {		return false;	} 	// Don't enable maintenance mode while scraping for fatal errors.	if ( is_int( $upgrading ) && isset( $_REQUEST['wp_scrape_key'], $_REQUEST['wp_scrape_nonce'] ) ) {		$key   = stripslashes( $_REQUEST['wp_scrape_key'] );		$nonce = stripslashes( $_REQUEST['wp_scrape_nonce'] ); 		if ( md5( $upgrading ) === $key && (int) $nonce === $upgrading ) {			return false;		}	} 	/**	 * Filters whether to enable maintenance mode.	 *	 * This filter runs before it can be used by plugins. It is designed for	 * non-web runtimes. If this filter returns true, maintenance mode will be	 * active and the request will end. If false, the request will be allowed to	 * continue processing even if maintenance mode should be active.	 *	 * @since 4.6.0	 *	 * @param bool $enable_checks Whether to enable maintenance mode. Default true.	 * @param int  $upgrading     The timestamp set in the .maintenance file.	 */	if ( ! apply_filters( 'enable_maintenance_mode', true, $upgrading ) ) {		return false;	} 	return true;}

Changelog

Introduced in 5.5.0. Unchanged from 6.7.7 through 7.1.0.

  1. 6.7.7
  2. 6.8.8
  3. 6.9.7
  4. 7.0.4
  5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

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Generated from the wordpress-develop 7.0.4 tag, from src/wp-includes/load.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.
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