php.ini中max_execution_time的最大允许值是多少

Question

I tried increasing the value of max_execution_time in php using

ini_set('max_execution_time', 108000);

which equals to 30 hours. I was just playing with this value to crawl websites with large amount of data in it. But, I go this fatal error that said the maximum execution time cannot exceed 30 seconds. When I changed 108000 value to 300, my script executed for 5 minutes. I wonder what is the maximum allowed value for this thing in php?

Answer 1

Correct answer in reference to Mjh's comment.

Signature for parsing integer ini values:

ZEND_API long zend_ini_long(char *name, uint name_length, int orig);

Therefore the maximum value that can be entered into that field is: 2147483647

Old answer.

The only clue I could find was here: https://github.com/php/php-src/blob/master/main/php_ini.h

#define php_ini_long    zend_ini_long

Which eventually leads back to: https://github.com/php/php-src/blob/master/Zend/zend_long.h

typedef int64_t zend_long;

That is a 64 bit integer, or:

−9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

EDIT: Correction.

// PHP x64
typedef int64_t zend_long;

// PHP x86
typedef int32_t zend_long;

So the max value is PHP_INT_MAX .

If you are getting errors saying it cannot exceed 30 seconds, this is because your server configuration has forbidden changing that value to anything above 30 seconds.

Answer 2

Quoting the manual set_time_limit

seconds The maximum execution time, in seconds. If set to zero, no time limit is imposed.

It maybe unlimited so perhaps for php the limit is just the maximum int value.

But there could be external factors, if I remember correctly suhosin patch have its own maximum execution time if executed from a web server maybe the server itself have some limit, looking at php sources I've the impression also network timeouts may be a factor.