PHP 는 프로세스가 실행후 죽으므로 각각의 프로세스는 독립되어있음

동시환경이란 swoole 이랑 프랑켄 php 같은 프로세스가 죽지않는 환경임

뮤텍스락이 걸려있는데 이를 해결함으로서 20~40% 가까이 향상되었다는

https://github.com/php/php-src/pull/13974

[wip] Remove zend_strtod mutex by arnaud-lb · Pull Request #13974 · php/php-src

zend_strtod.c uses a global state (mostly an allocation freelist) protected by a mutex in ZTS builds. This state is used by zend_dtoa(). This creates a lot of contention in concurrent loads. zend_d...

github.com

The impact on non-concurrent environments is null or negligible, but there is a considerable speed up on concurrent environments, especially on Alpine/Musl. When comparing master to this branch, the frankenphp-demo is sped up 10% under Apache/musl, 20% under FrankenPHP/glibc, and 40% under FrankenPHP/musl. Some synthetic benchmark is 80% faster.

# Event 'cpu_atom/cycles/P'
#
# Baseline  Delta Abs  Shared Object        Symbol                                                                 
# ........  .........  ...................  .......................................................................
#
    30.24%    -30.23%  [kernel.kallsyms]    [k] native_queued_spin_lock_slowpath
     7.80%     +9.31%  libphp.so            [.] execute_ex
     2.39%     +4.45%  libphp.so            [.] zend_gc_collect_cycles
     4.62%     +4.21%  libz.so.1.3.1        [.] 0x0000000000003da8
     3.74%     -3.74%  ld-musl-x86_64.so.1  [.] pthread_mutex_timedlock
     2.90%     -2.89%  ld-musl-x86_64.so.1  [.] pthread_mutex_lock
     0.98%     +2.19%  libphp.so            [.] gc_scan
     1.89%     -1.88%  ld-musl-x86_64.so.1  [.] pthread_mutex_unlock
     1.06%     +1.43%  libphp.so            [.] zend_hash_find
     1.30%     +1.38%  frankenphp           [.] 0x0000000000009f06
     1.76%     +1.34%  ld-musl-x86_64.so.1  [.] memcpy
     1.22%     -1.21%  [kernel.kallsyms]    [k] futex_wake
     1.21%     -1.19%  [kernel.kallsyms]    [k] try_to_wake_up