On Sun, Feb 5, 2017 at 3:03 PM, Andrey E Baranov <and...@andb.name> wrote:
> Hi all,
>
> I have problem, debug is not yet finished, and for now do not can
> reproduce, problem occurs only in production (after migrate to PHP7).
> perhaps someone else can help :)
> PHP 7.0.13 (Ubuntu 16.04 package repository), php-fpm
>
> For simplify:
> ```
> ...
> Log::debug('1:' . print_r($video, true));
> Log::debug('2:' . json_encode($video) . ' json_last_error: ' .
> json_last_error() . ' json_last_error_msg: ' . json_last_error_msg());
>
> $video['delivery'] = [2]; // after this line: serialize and json_encode do
> not work as expected
>
> Log::debug('3:' . print_r($video, true));
> Log::debug('4:' . serialize($video));
> Log::debug('5:' . json_encode($video) . ' json_last_error: ' .
> json_last_error() . ' json_last_error_msg: ' . json_last_error_msg());
> ...
> ```
>
> log with bug:
> ```
> DEBUG: 1:Array
> (
> [mimes] => Array
> (
> [0] => video/mp4
> )
>
> [linearity] => 1
> [minduration] => 5
> [maxduration] => 60
> [protocols] => Array
> (
> [0] => 2
> [1] => 3
> )
>
> [w] => 818
> [h] => 460
> [minbitrate] => 100
> [maxbitrate] => 1200
> )
> DEBUG: 2: {"mimes":["video/mp4"],"linearity":1,"minduration":5,"maxdur
> ation":60,"protocols":[2,3],"w":818,"h":460,"minbitrate":
> 100,"maxbitrate":1200}
> DEBUG: 3:Array
> (
> [mimes] => Array
> (
> [0] => video/mp4
> )
>
> [linearity] => 1
> [minduration] => 5
> [maxduration] => 60
> [protocols] => Array
> (
> [0] => 2
> [1] => 3
> )
>
> [w] => 818
> [h] => 460
> [minbitrate] => 100
> [maxbitrate] => 1200
> [delivery] => Array
> (
> [0] => 2
> )
>
> )
> DEBUG: 4:a:10:{s:5:"mimes";a:1:{i:0;s:9:"video/mp4";}s:9:"linearity
> ";i:1;s:11:"minduration";i:5;s:11:"maxduration";i:60;s:9:"p
> rotocols";a:2:{i:0;i:2;i:1;i:3;}s:1:"w";i:818;s:1:"h";i:460;
> s:10:"minbitrate";i:100;s:10:"maxbitrate";i:1200;s:8:"delivery";N;}
> DEBUG: 5: json_last_error: 6 json_last_error_msg: Recursion detected
> ```
>
> - 4: `serialize($video)` - `"delivery";N;` - it is mean that `delivery` is
> Null - that is not true
> - 5: `json_encode($video)` - Recursion detected
>
> Problem occurs in random period after start fpm process (after 10..30
> min), and remains constant until restart fpm
>
> Same problem as I see in http://stackoverflow.com/quest
> ions/37456845/what-does-json-error-recursion-mean-from-json-encode
>
> After deep analyze:
>
> php_json_encode_array:
> ```
> ```
> if (myht && ZEND_HASH_GET_APPLY_COUNT(myht) > 1) {
> JSON_G(error_code) = PHP_JSON_ERROR_RECURSION;
> smart_str_appendl(buf, "null", 4);
> return;
> }
> ```
>
> serialize:
> ```
> if (... || (Z_TYPE_P(data) == IS_ARRAY && Z_ARRVAL_P(data)->u.v.nApplyCount
> > 1)
> ) {
> smart_str_appendl(buf, "N;", 2);
> ...
> ```
>
> so looks like problem in `HashTable.v.nApplyCount`
>
>
> Also I am find commit - https://github.com/php/php-src
> /commit/d26ca894020bc28eb55b153fac5548374d5ce16d
>
> In this commit added
> ```
> target->u.flags = (source->u.flags & ~(...|ZEND_HASH_APPLY_COUNT_MASK))...
> ```
> But not added to case if `if (GC_FLAGS(source) & IS_ARRAY_IMMUTABLE)` -
> maybe need fix in this place? :) I guess that the problem in immutable
> arrays.
>
The apply count on immutable arrays is always zero, so this shouldn't be a
problem. However, it may be that some other code is incrementing the apply
count on an immutable array. Can you please check whether running with
opcache.protect_memory=1 gives you any segmentation faults or bus errors?
Nikita
